Opioids are among most effective drugs for managing acute postoperative pain. This article discusses the potential effects of perioperative opioids on endocrine and immune function. Surgery is associated with a massive inflammatory and stress response. Untreated postoperative pain results in immunosuppression, increases the risk of thromboembolic events, and delays recovery.Chronic opioid therapy results in major endocrine changes such as opioid-induced androgen deficiency and bone demineralization. The clinical relevance of these phenomena with short-term opioid use for postoperative pain is unclear.In the surgical setting, high-dose opioids may contribute to inhibition of immune responses and curbing of stress response , but the clinical consequences of these observations are still unclear.Multimodal postoperative approaches, especially those combining regional anesthesia with local anesthetics, help improve pain scores and reduce postoperative opioid requirements; however, contradictory data exist on their effect in reducing immune-mediated complications such as infections or tumor dissemination.22“The pathetically grim and perspiring patient, fearful of moving or breathing, has become a constant fixture on postsurgical wards. His suffering was anticipated by his physician and is accepted in the knowledge that it will disappear in time.”Acute postoperative pain is considered an unavoidable consequence of a surgery, and is somewhat anticipated, given the  massive tissue injury, inflammation, and stress response as a result of a surgical procedure. However, it is well documented that the “perspiring patient, who is fearful of moving or breathing,” ie, the patient who suffers from severe postoperative pain, is more prone to adverse outcomes. Patients, in whom severe pain impairs breathing, coughing, physical therapy, and early mobilization, are more likely to develop complications such as respiratory infections and thromboembolic events. The pain is also a significant stressor both from the psychological and physiological points of view.42The responses of the central nervous system and the hypothalamus-pituitary-adrenal (HPA) axis to a perceived stress involve a complex network of signaling molecules, including endorphins, catecholamines, and cortisol. The stress response to surgery is characterized by activation of HPA axis, as reflected by increased secretion of hypothalamic corticotropin-releasing hormone (CRH), and subsequently increased levels of adrenocorticotropic hormone (ACTH) and cortisol. In addition, surgical stress enhances the secretion of other catabolically active hormones, mainly catecholamines and glucagon, but also prolactin, growth hormone, and β-endorphin.33 supporting the notion that the relief of pain should be beneficial in preventing, eg, postoperative infections.33 In the setting of cancer surgery, the immune function may have even further implications, as animal studies have shown that surgery-induced stress is associated with impaired natural killer (NK) lymphocyte activity, impairing the body's ability to clear tumor cells.33The enhanced postsurgical stress response, which leads to high cortisol levels, can result in immunosuppression,36Although the description of a grim, perspiring, and suffering patient as a constant fixture may not have been surprising in the 1950s, one would expect that the development of novel drugs and multimodal analgesia approaches in the past few decades would dramatically improve the quality of postoperative pain management, and reduce the undesired hormonal and inflammatory consequences associated with the surgical stress. However, current data from inpatient and outpatient surgical settings indicate that between 30% and 50% of postoperative patients consistently experience moderate to severe pain.Opioids are the most commonly used drugs for the management of acute postoperative pain. Depending on the setting and type of surgery, opioids are delivered systemically either through scheduled or pro re nata (as needed) dosing, or through a patient-controlled analgesia device. Alternatively, the postoperative opioid regimen may include neuraxial delivery through an epidural catheter, as a part of patient-controlled epidural analgesia (PCEA) technique. Mostly, opioids that are used for acute postoperative pain relief, include the short-acting morphine, hydromorphone, oxycodone , and occasionally fentanyl or tramadol (which is a weak opioid agonist and a serotonin–norepinephrine reuptake inhibitor).2 (through chemosensors in carotid and aortic bodies) and CO2 (through chemosensors in the brainstem). Opioids, through μ-opioid receptor-mediated depression of excitability of brainstem chemosensory neurons, depress the ventilatory response to increased CO2, thus depressing respiration.31Opioids are very effective in treating acute postoperative pain; however, not without important side effects. Among their most commonly observed and reported adverse effects in this setting are nausea, vomiting, sedation, pruritus, and constipation. The more severe undesired outcome is respiratory depression, which is potentially life-threatening, and is the most feared side effect of opioid medications. The brainstem control of respiratory rate and tidal volume is driven by afferent input of partial pressure of arterial OThis update will focus on a different subset of effects associated with the use of opioid analgesics in the acute postoperative setting; these are endocrine changes and immunosuppression. This clinical update will discuss the evidence behind the role of opioids in contributing to each of these phenomena in the postoperative setting, discuss their clinical relevance, and summarize the recent data on approaches that could be considered when treating pain in patients after surgery.To provide systematicity to literature retrieval, PubMed search was performed in September 2017 with the following keywords: “opioids” (All Fields) AND “surgery” (All Fields) AND “pain” (All Fields) AND (“immune suppression” [All Fields] OR endocrine” [All Fields]). The search resulted in 125 articles, which were screened for relevant information, including articles identified from their reference lists.To obtain a comprehensive evaluation of opioid effects in the perioperative setting, information on both postoperative opioids for pain relief and data on intraoperative opioids for analgesia/anesthesia purposes were considered. As rapid recovery from anesthesia is becoming an increasingly important outcome, opioids with faster offset such as remifentanil and sufentanil are used more commonly, but  may be associated with certain adverse effects.(1) Opioids affect the hypothalamic-pituitary-gonadal (HPG) axis.(2) Opioids affect the HPA axis.The current evidence suggests that opioids cause endocrine changes by 2 major mechanisms:29The impact on the HPG axis is a well-described dose-dependent effect of opioids, particularly related to treatment with daily doses above 100 to 200 mg of oral morphine equivalents for more than a few weeks. The HPG cascade is initiated by the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus, which stimulates the anterior pituitary to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which stimulate the gonads to produce testosterone and estrogen. Opioids bind to μ-opioid receptors in the hypothalamus, inhibiting the release of GnRH, thus decreasing LH and FSH secretion from the pituitary. Subsequently, this leads to decrease in testosterone levels and hypogonadism, a condition typically referred to as opioid-induced androgen deficiency (OPIAD).29 The long-term symptoms of OPIAD in this setting include decreased attention, decreased libido, fatigue, erectile dysfunction, and osteoporosis. In women receiving chronic opioids, LH and FSH levels are markedly reduced and are associated with amenorrhea and impaired adrenal androgen production.13Opioid-induced androgen deficiency is a significant observation in the setting of chronic opioid therapy, affecting 53% to 90% of male patients on chronic opioid therapy.10 but the duration of this effect is reported to last between 24 hours to up to 8 weeks after treatment.11Some studies have questioned the suggestion that OPIAD is associated only with chronic opioid therapy. Several animal studies have shown that even acute opioid administration , especially at high doses, results in reduced levels of testosterone,41A significant drop in total testosterone level in humans is also observed with a single ≥30 mg dose of methadone, or within 24 hours of perioperative morphine administration.30 Therefore, more careful studies are warranted to dissect the magnitude and the importance of OPIAD in the perioperative setting.Unfortunately, well-designed studies aimed at understanding the mechanisms of testosterone suppression, and the clinical relevance of short-term hypogonadism in the setting of acute opioid administration are lacking. Moreover, surgical stress may also contribute to these phenomena, and patients receiving ketamine (and not morphine) analgesia still display reduced testosterone plasma levels.The impact of the opioids on the HPA axis is less well described. The HPA cascade is initiated by CRH release from the hypothalamus, which stimulates the pituitary to release ACTH to the systemic circulation, stimulating, in turn, the adrenal glands to produce 2 hormones—dehydroepiandrosterone (DHEA) and cortisol. Opioids seem to inhibit the functioning of the entire HPA axis. On one hand, they reduce the production/release of CRH, and on the other, they decrease the responsiveness of the anterior pituitary to CRH. Both processes lead to reduced ACTH secretion. Independently, opioids may also directly interfere with the adrenal gland production of cortisol and DHEA. Cortisol is important for mounting stress responses, and DHEA is an important precursor for testosterone (in men) and estradiol (in women).2 However, the extrapolation of healthy volunteer data to the surgical setting is not straightforward, as the surgical stress, and the postoperative pain per se, can have a substantial effect on the functionality of the HPA axis. The surgery typically results in an increased stress response, which subsides after about 24 hours. Certain opioids  are reported to acutely suppress plasma cortisol in a dose-dependent manner.1 In the setting of elective C-section, remifentanil administered as a bolus followed by continuous intraoperative infusion (compared with fentanyl administration after delivery) partially obtunded the neuroendocrine response to surgery with a decrease in ACTH rise .14The mechanistic data on opioid-associated changes in HPA axis come primarily from rodent and healthy volunteer experiments. For example, in healthy volunteers, single-dose morphine suppresses ACTH and cortisol levels both at baseline and after CRH stimulation.3 As in the case of reduced testosterone concentrations, the clinical relevance of altered cortisol levels in the setting of perioperative opioid therapy is not clear.The association between opioids and blunting ACTH or cortisol rise seems to be modest at best, and highly dependent on the timeframe of the assessment. In addition, some studies failed to find changes in cortisol levels after intraoperative remifentanil infusion.40 On the contrary, some studies have reported lower inflammatory response (lower C-reactive protein level) with opioid-minimizing analgesia in the setting of colorectal surgery38 or enhanced proinflammatory cytokine release in the spinal cord as a response to opioid challenge. The clinical relevance of these short-term effects of opioids on inflammatory markers remains to be investigated.Opioids do not possess strong anti-inflammatory properties such as nonsteroidal anti-inflammatory drugs or corticosteroid drugs, and their potential effects on inflammatory responses seem to be highly dependent on the setting. For example, in patients undergoing coronary artery bypass graft procedure, administration of continuous remifentanil infusions (vs intermittent fentanyl dosing) resulted in lower levels of proinflammatory cytokines (such as TNF-α and IL-6) at some time points after cardiopulmonary bypass. Eight hours after surgery, however, no differences were observed between the groups.The 2 main areas of research focused on opioid-associated immune effects deal with (1) the effects of opioids on immune response to infections; and (2) opioid effects on tumor-specific immune responses, affecting tumor growth and dissemination.28Major histocompatibility complex, class II (MHC-II) molecules, expressed on antigen-presenting cells, are important regulators of immune cell development and function. Morphine has been shown to alter gene expression of the MHC-II in circulating immunocytes (Beagles 2004), and thus suspected in causing immunosuppression. It is a matter of debate whether these effects are mediated by opioid-induced alteration in cortisol levels , or there is a direct immunosuppressive effect attributable to opioids. Interestingly, morphine withdrawal results in renewed increase in circulating corticosterone levels and a renewed suppression of MHC-II in previously opioid-tolerant animals.21 The findings could be attributable to more substantial immunosuppression with remifentanil , or to opioid withdrawal, which is more likely with the short-acting remifentanil. Additional data support this notion of immunosuppression associated with opioid withdrawal; for example, remifentanil discontinuation increased the risk of intensive care unit–acquired infection,27 and morphine withdrawal in mice (after 96-hour exposure) increased the risk of infection in an experimental model of septic shock. Interestingly, the most commonly detected organisms in tissue of morphine-withdrawn mice were bacteria that are part of the normal gastrointestinal flora.18 There are additional rodent studies suggesting that morphine, by altering gut microbiome, may increased the risk of sepsis by bacterial dissemination.24The risk of surgical site infection was higher after abdominal surgery with remifentanil anesthesia vs fentanyl anesthesia.32 However, these results are not universal and were observed only if laparoscopic vs open surgery  was compared.A review examining whether opioids increase the risk of infections in the perioperative or intensive care setting, suggested that patients receiving higher doses of systemic opioids had an increased risk of developing pneumonia perioperatively.33 whether different opioids have differential effects on immune function still requires detailed investigation.Overall, the data are both inconsistent and insufficient to determine the extent of opioid-associated immune suppression on infectious complications after surgery. Untreated pain itself can increase the risk of infections, eg, because of impaired mobility; pain also enhances the body's stress response, which by enhancing circulating cortisol, can contribute to immunosuppression. It needs to be taken into account that low-dose opioid control groups in some studies  could have better quality of analgesia and improved ability to clear secretions. It is also possible that increased risk of infection is among the immunological sequelae of opioid withdrawal, rather that opioid therapy, per se. The microbiome-related effects of opioids  are another area that requires additional research. Although some studies suggest that buprenorphine  may be devoid of immunosuppressive effects,5 However, rate of recovery of NK cell suppression was longer in the high-dose fentanyl group. Rats, which were treated with 20 mg/kg morphine , developed a decrease in B-lymphocyte blood expression of MHC class II molecules within 2 hours.4 The same group has previously reported that in rats, fentanyl suppresses NK cell cytotoxicity and increases the risk of tumor metastases.34 Although there might be a dose-dependent effect, it is not clear whether different opioids affect the NK function differentially. In this regard, data suggest that endogenous opioids (β-endorphin) inhibit T-cell proliferation to a lesser extent than exogenous morphine.15Opioids can suppress NK cell cytotoxicity. Both high-dose and low-dose fentanyl suppressed NK cytotoxicity for 24 hours.Despite these experimental findings, it is unclear whether there is any long-term immunosuppression associated with similar changes in antigen-presenting cells in humans.12 The researchers categorized “strong immunosuppressive opioids  vs weakly immunosuppressive opioids ,” based on previous literature, but found no difference between the groups.A large retrospective analysis of a national registry data from Denmark  showed no difference of breast cancer recurrence as a function of opioid use.Considering the immunosuppressive effects attributable to pain and the enhanced stress response (and cortisol increase), which opioids may blunt, it is currently unclear whether the clinically relevant “net effect” of postoperative pain management with opioids tips the immune balance towards immune suppression. There is also insufficient evidence to determine that some opioids produce strong immunosuppressive effects, whereas others produce only weak or no such effects.Inflammatory reaction after surgery is a physiological response that helps the healing process. An excessive inflammatory response can lead to complications, but immune suppression could negatively affect the healing process. With potential effects of opioids on inflammation, and potential immunosuppressant activity, the attempt in the recent years has been to use multimodal analgesia approaches that provide adequate analgesia, but avoid excessive opioid use, especially high-dose intraoperative remifentanil.42Patient-controlled epidural analgesia (with bupivacaine and fentanyl) after lower abdominal surgery have resulted in blunted postoperative elevation of cortisol and prolactin, and lower pain scores, compared with other opioid-only systemic analgesia regimens.17In a setting of retropubic prostatectomy, PCEA (with ropivacaine and sufentanil) resulted in lower pain intensity, and reduced the postoperative stress response (plasma cortisol and glucose), but not the acute inflammatory response (TNF-α and IL-6 levels).7 Intraoperative cortisol, noradrenaline, and total catecholamine levels were significantly lower in the intrathecal  anesthesia group (and patients required less systemic fentanyl); ie, spinal anaesthesia produced a more favourable endocrine response than epidural anaesthesia.Another study in 24 women undergoing laparoscopic cholecystectomy assessed the effect of a single-dose intrathecal (bupivacaine with fentanyl) vs epidural (ropivacaine with fentanyl) anesthesia, before general anesthesia in both groups.26In pediatric cardiac surgery, on the other hand, high-dose intraoperative fentanyl has demonstrated better (lower) profile of stress markers such as ACTH, glucose, cortisol, and lactate, compared with low-dose fentanyl. High-dose intraoperative fentanyl also resulted in lower postoperative opioid requirements.The available results demonstrate that neuraxial anesthesia and analgesia , result in either lower pain scores or less systemic opioid requirements, and can blunt the stress response, with minimal effect on acute inflammatory response. This suggests that multimodal anesthesia with neuraxial opioid and local anesthetic delivery, where possible, may provide advantage to systemic  opioid administration. The advantages in the pediatric surgery setting have not been explored sufficiently and merit more thorough investigation.16The literature is divided on the topic of regional anesthesia approaches and their potential effect on cancer-related outcomes. Initial retrospective studies reported that perioperative use of regional  anesthesia is associated with improved outcomes in terms of cancer recurrence and survival after breast and prostate surgery.20 an ad hoc analysis of a prostatectomy study,37 and a retrospective study in lung cancer did not show any benefit of regional anesthesia on cancer-related outcomes.9 A prospective randomized controlled trial25 did not demonstrate prolonged survival in major abdominal surgery, and a recent retrospective study in patients undergoing radical cystectomy for bladder cancer demonstrated more than 50% reduction in perioperative opioid consumption with spinal anesthesia, but this difference was not associated with changes in outcomes such as all-cause mortality, bladder cancer mortality, or cancer recurrence.39However, a later retrospective study in colorectal cancer surgery,8 found that innate immunity  was depressed in lung cancer patients undergoing resection, but postoperative epidural analgesia did not help preserve the immunity.A prospective studyIn addition, a recent systematic review of the literature (15 studies) found inconclusive evidence to support or refute the suggestion that paravertebral blocks in breast cancer can reduce cancer recurrence or improve survival.Currently, there is no conclusive evidence that regional anesthesia, by either reducing opioid doses or by other mechanisms such as sympathetic blockade, can improve long-term cancer-related outcomes in cancer patients undergoing surgery. With that said, there is no major disadvantage in using regional techniques, and the opioid-sparing and stress response–blunting acute effects justify the widespread use of such approaches for postoperative pain relief.23 Are then patients, who are in more pain (and therefore are likely to require higher opioid dose) more likely to develop endocrine adverse effects? What is then the contribution of pain vs opioid (type and dose)? Is it more important to control the pain well, or avoid high-dose opioids, even at the expense of higher pain? These research questions are yet to be answered and need to be address accurately to move the field forward, toward safer and more rational perioperative opioid use.The undesired effects attributable to opioids, which were discussed in this article, are often challenging to address, as some of these effects may be related to surgical stress or postoperative pain, per se. For example, endogenous opioids such as beta-endorphins play an important role in the regulation of gonadotropins through modulation of GnRH pulse amplitude and frequency. Therefore, with the question of OPIAD in mind, it is critical to control for this variable, as some data suggest that testosterone levels are lower in subjects with pain compared with controls, irrespective of opioid use.In a similar scenario, severe pain is associated with enhanced stress response, accompanied by catecholamine and cortisol release. Numerous preclinical and clinical studies have focused on the effect of opioid analgesics on the postoperative stress response. As enhanced stress response may cause immune suppression and lead to postsurgical complications, blunting the stress response has been historically considered as a desirable perioperative outcome. However, the advantages of blunting the stress response with opioids should be weighed against potential immunosuppression, and more research is needed to achieve an optimal balance that would positively affect patient outcomes.The author has no conflict of interest to declare.


Exosomes are important in intercellular communication. They assure the horizontal transfer of specific functional contents  from donor to recipient cells. Notably, tumor-derived exosomes (TDEs) appear to be an important vehicle of specific signals in cancer, impacting on tumor growth and metastasis. Recent researches point to the characterization of exosomes in Hepatocellular Carcinoma (HCC), the major adult liver malignancy. In this review, we summarize current findings on HCC exosomes, focusing on the identification of noncoding RNAs as exosome-enriched functional regulators and new potential biomarkers. The great potential of exosomes in future HCC diagnostic and therapeutic approaches is underlined.  Exosomes are 40–100 nm extracellular vesicles (EV), enriched in endosome-derived components that are secreted both in physiological and pathological conditions by most, if not all, cell types ) is horiStudies on exosomes composition are limited; however, with respect to Hepatocellular Carcinoma- (HCC-) derived EVs, several observations suggest that the exosome cargoes contribute to the metastatic progression as well as to the acquisition of chemoresistance. HCC develops in the context of cirrhosis and chronic inflammation and it is conceivable that exosome-mediated cross-talk between different cell types may contribute to propagation and amplification of oncogenic signals . CoherenIn this review, we firstly summarize the state of the art of exosome research in cancer. Secondly, we focus on exosomes in HCC, specifically providing an overview on the biological role of the up today known noncoding RNA (ncRNA) exosome cargoes. Finally, we highlight that targeting the cell-cell communication mediated by exosomes represents a promising approach in anticancer therapy.Exosome-mediated intercellular communication requires fine regulation that in cancer cells may be overcome; this allows microenvironment alterations and the delivery of specific tumor growth promoting signals.β1 and MAGE3/6 [Characterization studies highlighted that EVs composition profoundly differs between untransformed and tumor cell lines –7. RNA a MAGE3/6 ; (iii) a MAGE3/6 .The mechanisms of selective loading of protein and RNAs in EVs are still poorly understood, but there is evidence that microenvironmental acidic pH  and hypoα), and several metalloproteinases (MMPs) [TDEs may drive different oncogenic signals in autocrine, paracrine, or endocrine manner , 18 and s (MMPs) –23. All s (MMPs) .α6β4 and α6β1 is associated with lung metastasis, while αvβ5 is linked to liver metastasis. These surface proteins are able to guide the exosomes to specific secondary sites, where the fusion of the vesicles with resident cells prepares the premetastatic niche: exosomes from lung-, liver-, and brain-tropic tumor cells preferentially fuse with resident cells at their selected destination, that is, lung fibroblasts and epithelial cells, liver Kupffer cells, and brain endothelial cells [Recent observations also attribute to TDEs the ability to promote the organotropism of metastatic tumors, contributing to premetastatic niche formation: exosomes show “avidity” for specific recipient cells that, in turn, are able to internalize these vesicles –27. In pFurthermore, tumor exosomes may have immunomodulatory properties, influencing T cell function and tumor escape from immune surveillance , 29. ImmIn the liver, exosomes are secreted by hepatocytes, nonparenchymal liver cells  and immune cells  and the cellular interplay mediated by these vesicles holds important functions in liver homeostasis. Exosome content, indeed, impacts on proliferation of hepatocyte after injury , while eHCC is a prevalent worldwide liver cancer and the sixth most lethal malignancy . ApproprRecent studies indicate that exchange of RNAs and proteins via exosomes could not only have a key role in HCC onset and progression but may represent a source of potential real-time, noninvasive biomarkers as well as therapeutic targets.In HCC, cells generally release high levels of exosomes whose involvement in pathogenesis is currently under investigation. Although the identification in HCC of diagnostic and prognostic exosome biomarkers is still at the initial stage, there are encouraging observations that HCC cells produce exosomes that are different from untransformed cells in both RNA and protein content , 39. SpeAfter the discovery of exosome-mediated transfer of mRNA and microRNAs in 2007 , growingSelected miRNAs are enriched in exosomes released from HCC cells in vitro  and in With regard to the functions and potential gene targets of the candidate miRs, it was found that exosomal miR-718 was negatively regulated in aggressive tumors, while HOXB8 gene, potential miR target, was upregulated . FurtherIncreasing evidence also pointed to a role for lncRNAs as signaling molecules in HCC as well as the potential of exosomes as vehicles to transfer them.Mammalian genomes produce thousands of long noncoding transcripts, heterogeneous class of molecules greater than 200 nucleotides in length, that may form complexes with other nucleic acids and proteins inside the cell and that are involved in distinct biological functions . These lβ-dependent HCC cells chemoresistance, whereas knockdown of the same lncRNA enhanced the chemosensitivity [To date, few lncRNAs  have been reported in circulating HCC EVs: (i) exposure of HCC cells to diverse anticancer agents such as sorafenib, camptothecin, and doxorubicin increased the expression of lnc-VLDLR in transformed hepatocytes as well as its recruitment inside EVs released from these cells. These data indicate that this lncRNA could mediate the resistance to chemotherapeutic stress in HCC cells ; (ii) ansitivity ; (iii) tsitivity , 58.Another lncRNA, the lncRNA H19, was specifically enriched in exosomes secreted by CD90+ cells, having a cancer stem cell- (CSC-) like aggressive phenotype; these EVs modulate endothelial cells adhesion and angiogenic phenotype .Several lncRNAs have been recently detected in whole plasma of HCC patients  but furtThe lncRNAs urothelial carcinoma associated-1 (lncRNA-UCA1) and WD repeat containing antisense to TP53 (lnc-WRAP53) were found significantly higher in sera of HCC patients with respect to chronic HCV infected patients or healthy volunteers . NotablyLi et al.  found thOther lncRNAs  have been demonstrated to be sorted in TDEs ; howeverExosome cargo is represented by easily identifiable molecules that reflect the cell of origin as well as the contribution of the immune context and tumor microenvironment. Thus, the characterization of EVs, as a source of biomarkers through bio fluids, can provide an appealing real-time, noninvasive means of monitoring the course of tumor progression, with promising applications ranging from diagnosis to treatment –76.Moreover, exosomes may be efficiently used in antitumor therapies, stimulating the immune response: Zitvogel and colleagues, in a pioneering work, demonstrated that exosome-based cell-free vaccines can represent a valid antitumor approach alternative to dendritic cells (DCs) adoptive therapy. Exosomes, indeed, can prime specific cytotoxic T lymphocytes in vivo and suppress the growth of established murine tumors in a T cell-dependent manner . RecentlOther strategies aim to promote antitumor response by using combination of exosomes and appropriate immune-stimulatory adjuvants, to suppress immune-inhibitory effects . For exaαv integrin-specific iRGD peptide. Intravenous injection of these targeted exosomes delivered DOX specifically to tumor tissues [Exosomes show low immunogenicity and toxicity and are quite stable, in tissues as well as in circulation; thus they appear as better vehicles for delivery of chemotherapeutics in tumor therapeutic approaches with respect to previously used synthetic ones (such as liposomes) (for review ). In an  tissues .To achieve targeted delivery to tumor cells and improve therapeutic applicability, the EVs tropism can be modified by means of the genetic engineering of cells of origin or by modification of EV membrane proteins. Kooijmans et al. recently described the transfection of cells with vectors encoding for anti-epidermal growth factor receptor (EGFR) nanobodies, fused to glycosylphosphatidylinositol (GPI) anchor signal peptides. GPI-linked nanobodies were successfully displayed on the surface of the secreted EVs, altering their targeting .Moreover, with respect to the possible EVs clearance by the monocyte/macrophage and reticuloendothelial system, Watson et al.  recentlyα-Syn, which aggregates are characteristic pathological feature of the Parkinson's disease (PD) brain) [EVs are also attractive candidate for the delivery of different drug types. In particular, small RNAs, such as miRNAs, naturally shuttled by exosomes , may be ) brain) . These eAlternatively, specific stimuli can be used to enhance sorting of specific classes of miRNAs by the cell exploiting, in this case, the preexisting cellular machinery: for instance, blood cells and cultured THP-1 cells actively and selectively package miRNAs into EVs and secrete them in different cell conditions . For insEarly diagnosis of HCC is still very difficult and the development of noninvasive diagnostic tools represents a major challenge. The recent identification of distinct noncoding RNAs  enriched in HCC exosomes strongly encourages the use of these molecules as novel HCC biomarkers . ExosomeExosomes have recently gathered research interest for antitumor therapeutic approaches, representing active drug components (modulating the immune responses and inducing antitumor responses) as well as drug delivery systems. Further efforts are needed in the engineering of exosomes allowing them to convey molecules of interest . These specific signals could be conceivably addressed to achieve targeted therapeutic intervention. The recent discovery of the mechanism of sequence-specific miRNA exosomal loading process opens the way for possible selective modification of the miRNAs exosomal cargo by engineering of the EXO- and hEXO-motifs , 90.


In a Perspective, Mack Su and David Fisher discuss the development of immunotherapies for treatment of melanoma and other cancer types. Innovations in cancer immunotherapy over the past decade have reinvigorated the field, which currently stands poised to transform treatment of certain important cancer types. While recent discoveries in immunotherapy have occurred in an era of intense focus on precision medicine—spurred in large part by advances in sequencing technologies allowing for unprecedented insights into individual and tumor genomes—the field of cancer immunotherapy is rooted in a history that is anything but precise. The idea that the immune system could be used to target cancer has existed for over a century. In the 1890s, William Coley provided a spark by noting a connection between spontaneous tumor regressions and concurrent bacterial infections [Perhaps the most profound impacts of both immunotherapy and precision medicine, in the form of targeted therapy, can be appreciated in the transformation of treatment for metastatic melanoma during the past decade. The discovery of the oncogenic V600E driver mutation in BRAF, which is present in ~50% of melanomas, led to the development of vemurafenib and dabrafenib, which are inhibitors of the mutant BRAF kinase . AlthougThe successes of ipilimumab were quickly followed by trials targeting the immune inhibitory interaction between programmed cell death protein 1 (PD-1), found on T cells, and its ligand, PD-L1, found on tumor cells. In contrast to the central immune inhibitory effects of CTLA-4, inhibition through PD-1 predominantly occurs at the periphery, with tumor cells up-regulating PD-L1 in response to local immune signals such as interferon-γ. In a major head-to-head clinical trial, pembrolizumab, a monoclonal antibody against PD-1, demonstrated improved progression-free and overall survival with fewer high-grade adverse events compared to ipilimumab . ImportaEfforts to uncover the precise mechanisms of immune checkpoint inhibition and identify patients likely to benefit from treatment are well under way. Pathologists have long recognized the prognostic significance of tumor-infiltrating lymphocytes , and, unThe rapid progress in cancer genomics in recent years has enabled a close examination of the genetic makeup of thousands of individual cancers across the entire spectrum of major cancer types. Amidst the search for mutations responsible for driving carcinogenesis, it has become evident that overall mutation rates vary dramatically both within and between cancer types . While tAlthough the importance of neoantigens is now firmly established, substantial overlap in neoantigen burden exists between nonresponders and responders, highlighting the need to more precisely identify the tumor-specific antigens required for a successful immune response. Emerging evidence suggests that clonal neoantigens—that is, neoantigens present in all cancer cells—rather than total neoantigen load are critical for T cell recognition and clinical benefit from checkpoint blockade . The criHowever, selecting and manufacturing the optimal neoantigen vaccines within a clinically meaningful time frame remains challenging, and successful targeting of tumor neoantigens requires antigen-specific T cells, which may not be present. Indeed, the efficacy of CTLA-4 blockade likely stems in part from an expansion of the peripheral T cell receptor (TCR) repertoire , which pc-KIT or epidermal growth factor receptor (EGFR) with specific inhibitors appears to foster antitumor immunity [As the precise mechanisms of immune checkpoint inhibition continue to be unraveled, great interest has emerged in combining checkpoint blockade with current targeted therapies. Substantial research on BRAF mutant melanoma indicates that BRAF inhibition synergizes with immune checkpoint blockade by facilitating T cell recognition of melanoma antigens in a more favorable tumor microenvironment ,26. Althimmunity ,30. In mimmunity . In all Propelled by recent successes, enthusiasm for immunotherapy has surged beyond targeting CTLA-4 and PD-1 pathways. Many additional immune regulators, both stimulatory and inhibitory, are being explored as potential targets for cancer immunotherapy, each with a unique set of advantages and potential risks. Novel insights into neoantigens and combination with immune checkpoint inhibition have breathed new life into cancer vaccines, which had been tested for decades with little success. In addition, cell-based therapies may be required in some patients to elicit a robust antitumor response. Adoptive cell transfer of autologous T cells selected for tumor reactivity  and gene


Excess body weight and heavy alcohol consumption are two of the greatest contributors to global disease. Alcohol use peaks in early adulthood. Alcohol consumption can also exacerbate weight gain. A high body mass index and heavy drinking are independently associated with liver disease but, in combination, they produce an intensified risk of damage, with individuals from lower socio-economic status groups disproportionately affected.We will conduct searches in MEDLINE, Embase, PubMed, PsycINFO, ERIC, ASSIA, Web of Knowledge (WoK), Scopus, CINAHL via EBSCO, LILACS, CENTRAL and ProQuest Dissertations and Theses for studies that assess targeted preventative interventions of any length of time or duration of follow-up that are focused on reducing unhealthy eating behaviour and linked risky alcohol use in 18–25-year-olds. Primary outcomes will be reported changes in: (1) dietary, nutritional or energy intake and (2) alcohol consumption. We will include all randomised controlled trials (RCTs) including cluster RCTs; randomised trials; non-randomised controlled trials; interrupted time series; quasi-experimental; cohort involving concurrent or historical controls and controlled before and after studies. Database searches will be supplemented with searches of Google Scholar, hand searches of key journals and backward and forward citation searches of reference lists of identified papers. Search records will be independently screened by two researchers, with full-text copies of potentially relevant papers retrieved for in-depth review against the inclusion criteria. Methodological quality of RCTs will be evaluated using the Cochrane risk of bias tool. Other study designs will be evaluated using the Cochrane Public Health Review Group’s recommended Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies. Studies will be pooled by meta-analysis and/or narrative synthesis as appropriate for the nature of the data retrieved.It is anticipated that exploration of intervention effectiveness and characteristics  and training of intervention deliverers, including their professional status; and frequency/duration of exposure) will aid subsequent co-design and piloting of a future intervention to help reduce health risk and social inequalities due to excess weight gain and alcohol consumption.CRD42016040128. PROSPERO The online version of this article (doi:10.1186/s13643-017-0434-6) contains supplementary material, which is available to authorized users. Excess body weight and heavy alcohol consumption are two of the greatest contributors to global disease burden , 2. BeinResearch on reducing excess body weight or heavy alcohol consumption typically occurs in isolation or as part of non-specific multiple behaviour change interventions. Recent exceptions have been behavioural modification work with middle-aged obese men who were also alcohol drinkers , 11 and Many eating rituals have become strongly linked to the use of alcohol and vice versa; for instance, salty snacks are often sold in public drinking venues and there is a popular concept of drinking alcohol with dinner or visiting fast food outlets after an evening out at drinking establishments . Indeed,Epidemiological data suggest that energy intake from alcohol, type of beverage and drinking pattern  is associated with excess body weight and weight gain amongst adults , 23. FewRecent qualitative research demonstrates that young adults make trade-offs between food and alcohol consumption and levels of physical activity undertaken . Little Whilst a current Cochrane systematic review examines individual-, family- and school-led interventions for preventing multiple risk behaviours in individuals aged 8 to 25 years , no systThe primary objective of this review is to systematically evaluate the current evidence-base and determine the effectiveness of preventative targeted interventions focused on reducing unhealthy eating behaviour and linked risky alcohol use and their health consequences in adults aged 18–25 years.The review will be carried out following established criteria for the good conduct and reporting of systematic reviews . The proWe will include the following study designs: randomised controlled trials (including cluster RCTs); randomised trials; non-randomised controlled trials ; interrupted time series; quasi-experimental; cohort involving concurrent or historical controls and controlled before and after studies. Unpublished data, abstracts and conference proceedings will not be included. Studies including no primary evaluation data  will also be excluded, as well as studies presenting qualitative data only. For studies using mixed methods, only data relating to the quantitative evaluation will be considered. Studies will be considered where both behaviours are addressed simultaneously (multicomponent interventions) or where one behaviour is the focus of the intervention content but the other is the context of its delivery .This review will focus on interventions targeted at free-living  male and female young adults aged 18–25 years screened for unhealthy eating and risky drinking behaviours in any country, and whose outcomes are assessed for this group. Individuals without dietary risks or who do not currently consume alcohol excessively will be excluded. Studies may subsequently be stratified to account for inter-country differences in overweight/obesity and risky drinking. The review will also include interventions targeted at wider population groups where outcomes have been assessed for this particular subgroup. Studies will be excluded where the study population: (a) requires specialist treatment for alcohol dependency or weight loss and gain (i.e. bariatric surgery) and (b) pregnant or breastfeeding women whose current eating pattern may be time-limited and not reflective of usual diet behaviours.This review will consider studies which evaluate behaviour modification strategies  based on information, advice and counselling targeting unhealthy eating and linked risky alcohol use. These interventions may be delivered in person, by telephone, by internet or a combination of multiple delivery methods. The interventions may be delivered individually, as part of a group or a combination in any setting. Pharmacological and laboratory-based interventions will be excluded. There will be no restrictions in terms of length of intervention or follow-up.Interventions will be compared to control (no intervention or waiting list), screening/assessment only and treatment as usual.Primary outcomes variables will be reported changes in: (1) dietary, nutritional or energy intake and (2) alcohol consumption. Examples of accepted measures will include, but are not restricted to, self-report, researcher observations, relevant validated questionnaires or indicators such as food-frequency, fruit and vegetable intake, delayed first drink, reduction in total volume consumption, Alcohol Use Disorders Identification Test (AUDIT) and Time Line Follow Back (TLFB), photographs of food portions and weighed intake. Secondary outcome variables will be measured of body composition and alcohol-related outcomes which do not focus directly on consumption. Examples of accepted measures will include BMI, waist circumference, waist-hip ratio, % body fat, purchasing behaviour and hospital admissions. We will extract outcomes in all data forms  as reported in the included studies. Guided by existing work on behaviour change techniques , 38, theA three-step search strategy will be undertaken. A scoping search of MEDLINE and CINAHL will be used to identify keywords and phrases in the paper title and abstract and MeSH/thesaurus terms used to index relevant articles. A second search using identified keywords and thesaurus terms will subsequently be undertaken across all included databases. Thesaurus terms will be translated as appropriate across databases. Trial registers  will also be searched for relevant studies that may have resulted in publications not identified using the electronic database search. Finally, database searches will be supplemented with general searches of the internet, searches of Google Scholar for relevant studies based on key names of field experts; grey literature searches; and backward-and-forward hand searches of reference lists of included papers and relevant reviews. We will not exclude papers on the basis of language, country or publication date. The following databases will be searched: MEDLINE, Embase, PubMed, PsycINFO, ERIC, ASSIA, Web of Knowledge, Scopus, CINAHL, LILACS, CENTRAL and ProQuest Dissertations and Theses. A provisional full search strategy (to be confirmed following scoping searches) is presented in Table The title and abstract of all records retrieved will be downloaded to Endnote X7 and independently screened by two researchers , with full-text copies of potentially relevant papers retrieved for in-depth review against the inclusion criteria. Any uncertainties will be resolved by discussion and referral to a third party if necessary (EK). Reasons for exclusion will be noted at the full-text stage. A flow chart of the selection process, following PRISMA guidelines, will be produced. Independent dual data extraction will be carried out using a prepiloted form in an Excel spreadsheet. Study characteristics will include: country of origin; year of study and duration; study design and risk of bias assessment; participants’ characteristics  and intervention characteristics  and training of intervention deliverers, including their professional status; and frequency/duration of exposure). Outcomes will focus on diet, nutritional or energy intake, BMI and other measures of body composition, alcohol use and alcohol-related problems.Where possible, quantitative data will be pooled in statistical meta-analysis using RevMan 5.1. In order to synthesise data across studies, we will compute and report mean differences where identical scales are used to measure the same outcome. Where scales vary, we will compute standardised mean differences (SMDs) (otherwise weighted mean differences) between comparison groups. For dichotomous data, we will report odds ratios (ORs) with 95% confidence intervals (CIs). For continuous data, we will most likely report standardised mean differences and 95% confidence intervals. Statistical analysis of the data will be decided by assessing the quality of included studies and the degree of heterogeneity found.χ2 and I2 values for all outcome variables. Statistical heterogeneity will be considered substantial if I2 values are above 50%. We will also assess the impact of heterogeneity through sensitivity analyses and assume the appropriate random effects or fixed effect model in meta-analyses accordingly [We will assess heterogeneity by calculating ordingly . Thus, iWe anticipate unit of analysis issues such as repeated observations of the same outcome, studies including multiple intervention arms, groups of individuals randomised together to the same intervention  and individuals undergoing more than one intervention . If study authors have not taken into account of these issues, an attempt will be made to investigate subsequent risk of bias.Where possible, authors will be contacted to ask for further information where the reporting of these was insufficient. This includes missing data on the methods used, intervention content or material, outcome or precision measures. If missing data required for analyses cannot be obtained from the study author or extrapolated from other statistics, the study will be excluded. Finally, we will address the potential impact of missing data on the review findings in the ‘If sufficient data are available, a subgroup analysis will be conducted. Proposed subgroups include gender (men versus women), socio-economic status, ethnicity, setting (workplace versus college/university), and mode of intervention delivery.Included studies will be assessed independently by two researchers  for their methodological quality. In order to minimise any selection bias, both reviewers will be blind to the source and the authorship of the paper. If the two reviewers disagree with the rating of any study, a third review author (EK) will be available to consult in order to reach a consensus. The Cochrane risk of bias tool will be used for any RCTs which are included in the analysis to estimate selection bias (differences between groups compared), performance bias (arising from participants being aware of the group they are randomised to), attrition bias  and detection bias (which refers to problems with outcome assessments) . For eacThe review is situated within a broader mixed method research project. The results of this review will be used to inform in-depth qualitative work to explore the links between unhealthy eating behaviour and risky alcohol use in the social, emotional and cultural lives of young adults (aged 18–25), including perceptions of risks, benefits, costs and consequences of these behaviours in early adulthood. It is anticipated that exploration of intervention effectiveness and characteristics  and training of intervention deliverers, including their professional status; and frequency/duration of exposure) will aid subsequent co-design and piloting of a future intervention to help reduce health risk and social inequalities due to excess weight gain and alcohol consumption.


Schizophrenia poses a tremendous health, social, and economic burden upon patients and society, indicating current treatment options remain inadequate. Recent findings from several lines of evidence have pointed to the importance of immune system involvement in not only premorbid neurodevelopmental but also subsequent symptom generation and aging processes of brain change in schizophrenia. In this meta-review, we use the summarized evidence from recent quantitative systematic reviews (SRs) and meta-analyses of several subspecialties to critically evaluate the hypothesis that immune-related processes shape the symptomatic presentation and illness course of schizophrenia, both directly and indirectly through altered neuroplasticity.We performed a data search in PubMed for English language SRs and meta-analyses from 2010 to 2017. The methodological quality of the SRs was assessed with the AMSTAR instrument. In addition, we review in this paper 11 original publications on translocator protein (TSPO) positron emission tomography (PET) imaging in schizophrenia.post-mortem brain tissue analysis and PET neuroimaging studies to evaluate microglial activation have added new perspectives to the available evidence, yet these results are very heterogeneous. Each research domain comes with unique opportunities as well as inherent limitations. A better understanding of the (patho-)physiology of microglial cells and their role in neuroplasticity is key to interpreting the immune-related findings in the context of schizophrenia illness exacerbations and progression.We reviewed 26 SRs and meta-analyses. Evidence from clinical observational studies of inflammatory or immunological markers and randomized controlled drug trials of immunomodulatory compounds as add-on in the treatment of schizophrenia suggests psychotic exacerbations are accompanied by immunological changes different from those seen in non-acute states, and that the symptoms of schizophrenia can be modified by compounds such as non-steroidal anti-inflammatory drug and minocycline. Information derived from post-mortem brain tissue suggests that aberrant immune responses may define schizophrenia illness’ course through altered neuroplasticity representing abnormal aging processes. Most findings are however prone to bias and confounding, and often non-specific to schizophrenia, and a multidisciplinary translational approach is needed to consolidate these findings and link them to other schizophrenia hypotheses.Evidence from clinical studies analyzing patients’ blood and cerebrospinal fluid samples, neuroimaging and  Schizophrenia is a devastating and complex central nervous system (CNS) disorder that affects approximately 1% of the world population. Despite antipsychotic drugs being available for several decades, personal and societal costs remain highly expensive: the World Health Organization estimated that the direct costs of schizophrenia range between 7 and 12% of the gross national product in Western countries –5. AcuteThese problems emphasize the urgent need for novel therapeutic approaches implicating the identification of new pathophysiological substrates. The illness is syndromic, of heterogeneous presentation and course and while there are well-established criteria in place for making the diagnosis of schizophrenia, the causes are still under debate. This is partly due to the complexity of this human disease that cannot be wholly replicated in animal models , as wellIn the late twentieth century, the investigation of astrogliosis as hallmark for an inflammatory reaction in the schizophrenic brain combined with the expansion of neuropsychiatric genetics shape the debate about the etiology of schizophrenia. The absence of neuroinflammation and the presence of heritable candidate genes were thought to indicate a neurodevelopmental origin and a static rather than a neurodegenerative disease course. Although the earliest study reported the presence of low-grade inflammation , subsequin vivo neuroimaging and (2) neuropathological studies of microglial activation; (3) systemic inflammation and its link to psychosis; (4) clinical trials of immunomodulatory drugs as add-on treatment; and (5) neuroplasticity. Other relevant domains such as epidemiological studies, genetic studies, animal studies and clinical studies on changes in related mechanisms such as the kynurenine pathway and oxidative stress markers have their own sub-literature, and will not be dealt with here.The field has now advanced enough for several major meta-analyses and systematic reviews (SRs) to have come out in recent years, each compiling the evidence derived from individual studies and large groups of subjects in a variety of sub-disciplines contributing to this work. This meta-review aims to condense the evidence that immunological factors are critically involved in the schizophrenia illness course—modifying symptomatology and prognosis due to progressive brain changes. We critically appraise the current literature, identifying the opportunities and methodological limitations arising from each of the different lines of evidence. We identify areas where crucial information is still lacking and defend the position that opportunities can emerge by adopting a multidisciplinary translational approach to consolidate current findings and link this field of research to other key hypotheses of schizophrenia research. As the schizophrenia psychoneuroimmunology literature is very large, the scope of this review is necessarily limited. The focus will be on specific topics in the schizophrenia literature on neuroinflammation: (1) in vitro or animal studies; (4) reviews of genome or gene expression studies; (5) reviews of epidemiological risk factors for schizophrenia; or (6) not published in English. We assessed the methodological quality of the SRs using the AMSTAR instrument  meta-analyses and systematic quantitative reviews; (2) investigating immune-related alterations in the blood, cerebrospinal fluid (CSF), or brain (3) of patients meeting DSM-IV or DSM-V criteria for the schizophrenia spectrum. All included studies are summarized in Table strument ; scores schizophrenia[Title/Abstract] AND (*inflamm*[Title/Abstract] OR *immune*[Title/Abstract] OR cytokine*[Title/Abstract] OR chemokine*[Title/Abstract] OR *glia*[Title/Abstract]). 82 articles were retrieved, of which 15 were included. Other studies were excluded because they did not study schizophrenia patients (n = 15); concerned genome or gene expression studies (n = 11); were narrative or qualitative review papers (n = 13); or were outside the scope of this paper (n = 24). Two additional articles were added manually after review of the reference list.Meta-analyses of immunological or inflammatory changes in the blood, CSF and brain of schizophrenia patients were identified using the following search string: schizophrenia[Title/Abstract] AND (RCT*[Title/Abstract] OR randomized[Title/Abstract]) AND (minocycline[Title/Abstract] OR NSAID[Title/Abstract] OR *inflamm*[Title/Abstract]). This generated 11 articles, of which 8 were included. Three studies were excluded for the following reasons: does not concern clinical trials (n = 1); is a narrative review (n = 1); compound is outside the scope of paper (n = 1).To identify meta-analyses pertaining to randomized controlled trials (RCTs) of anti-inflammatory agents in schizophrenia, the following search string was used: (schizophrenia[Title/Abstract] OR psychosis[Title/Abstract]) AND (TSPO*[Title/Abstract] OR Translocator[Title/Abstract] OR *PK11195[Title/Abstract] OR *PBR*[Title/Abstract]).Because no meta-analysis or SR could be identified on positron emission tomography (PET) studies of microglial activation in schizophrenia, we chose to add the eleven original studies to this paper, as this is an important sub-discipline in this research field. These papers were identified using a Pubmed and Medline search executed in August 2017 without limitation of time, language, or publication type. The search string combined following terms: The hallmark of neuroinflammation is the activation of microglia, the resident immune cells in the CNS , which apost-mortem studies as well as a few in vivo PET imaging studies using specific ligands , previously called peripheral benzodiazepine receptor], which is expressed on the outer mitochondrial membrane of microglia in their activated states. Interestingly, although the (patho-)physiological function of the TSPO, which is related to cholesterol transport for steroid production in microglia, is not well understood  in humans that occurs in 30% of the European population. Therefore, genotyping of study subjects at this locus is essential to allow interpretation of TSPO PET studies, by stratifying between genetic groups and exclusion of low-affinity subjects.PET radioligands for microglial activation have recently been developed allowing for the first time functional imaging of neuroinflammation derstood , these t studies . Second-As a meta-analysis is lacking for this specific research domain, the results of the existing studies are summarized in Table One major drawback of this new technology is that it comes with considerable technical requirements. First, the kinetic properties of the TSPO tracers currently require complex dynamic scanning protocols  which are considered a challenging and relatively invasive procedure toward patients. Second, because of the low resolution yielded by PET, co-localization with additional magnetic resonance imaging (MRI) images is essential to assess regional specific uptake. Taken together with the restriction for patients not to use benzodiazepines prior to the scan, these technical requirements arguably compromise the generalizability of PET study samples due to significant non-response bias in patient groups with the highest symptomatic burden and limit the future clinical use of the procedure.VT  the degree of tracer plasma protein binding, which is estimated to introduce up to 30% of variability in primary outcome measure VT , (ii) a VT  . This means the increased uptake observed in a certain region of interest could reflect either increased non-specific tracer binding as well as a true biological signal  as their outcome measure, large effect sizes (Cohen’s d > 1.7) were found  or subject to systematic group differences, for instance caused by elevated acute phase plasma proteins and cytokines in schizophrenia . However, a model which also accounts for endothelial and vascular TSPO binding (2TCM-1K) was recently shown to have improved performance in second-generation TSPO tracers, probably because in these tracers a higher ligand specific TSPO affinity leads to considerable endothelial binding in the blood–brain barrier. Additionally, a less invasive reference tissue model was developed to study TSPO binding using first-generation tracer PK11195 without arterial input function . A seconl signal . Strikinre found . This alre found . The autophrenia .Also remarkably, when one of the pioneering author groups in this field replicated their study in a larger patient sample and using a reference region instead of arterial input function, they no longer found a difference between patients and controls as they did in the original study , 61.in vivo is still not fully understood. The exact cellular source of the upregulated TSPO binding in CNS pathology remains subject to discrepancy, caused by the extrapolation of in vitro data to the in vivo situation and differences in the models used (for instance lesions with or without blood–brain barrier damage) with literature reporting TSPO expression not only on microglial cells but also on astrocytes and some neuronal subtypes, as well as endothelial cells. In non-human primates, endotoxin-induced systemic inflammation caused marked increases in the signal of a second-generation TSPO tracer, confirmed post-mortem to be largely due to microglial binding . The same review reported unchanged expression in 3 out of 3 studies using CD68, a marker of microglial lysosomes indicative of phagocytic microglia and involved in clearance of neuronal debris in neurodegeneration, and 2 out of 2 studies with Iba1 , a protein involved in membrane ruffling  = 0.69**] over all studies, yet again with significant heterogeneity. The authors also reported a significant increase in the overall expression of pro-inflammatory molecular components .More recently, Van Kesteren It is worth noting that these two main meta-analyses included among their results a paper which demonstrated increased microglial staining and increases in IL1β and TNF expression in the frontal cortex, but was retracted afterward .post-mortem research is by definition at the end of life, many clinical confounders related to the life and illness history of both patients and controls may complicate the interpretation of data. Known confounders include gender, age at death, use of medication, etc. The cause of death should also be considered, as the presence of systemic inflammation, hematological malignancies or neurological illness may confound the results, as can suicide, which is common in schizophrenia and has been linked to the presence of elevated pro-inflammatory cytokines regardless of diagnosis , and later also of blood monocytes or lymphocytes, Toxoplasma gondii and auto-antibody titers in patients with schizophrenia or related psychotic disorder and healthy control subjects in a series of meta-analyses. Their analyses included both cross-sectional studies and longitudinal studies in patients with an acute exacerbation of psychosis at baseline and following a period of antipsychotic treatment. All studies included in this paper met strict criteria for defining patients’ clinical status , and the meta-analyses perform quite well on the AMSTAR scale. Yet together, the meta-analyses published by this group of authors make up 6 out of the 12 meta-analyses on blood inflammatory/immunological markers in schizophrenia  linked to acute psychotic exacerbations , as opposed to other “trait” markers that remain elevated throughout the stages of the illness , 77. In rbations . Thus itet al. identified 16 studies of cytokines in CSF, but did not stratify according to patients’ clinical state , body mass index (35%), and smoking (24%) were often not considered  assessed, there was significant heterogeneity in effect size estimates . Indeed nsidered . Furthernsidered .N-acetylcysteine (NAC), and even potent immunosuppressant drugs such as methotrexate. These drugs are being investigated as augmentation to antipsychotics (AP) in patients with a diagnosis of a schizophrenia spectrum disorders, and effects measured as change in symptom severity on the Positive and Negative Syndrome Scale (PANSS) or Brief Psychiatric Rating Scale (BPRS). The results of the most well-studied compounds  are summarized in Table Following the concept that neuroinflammation may play a central role in the symptomatology and prognosis of schizophrenia, novel therapeutic prospects have arisen which aim to modulate immune effects to influence schizophrenia disease course. Non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin and celecoxib have been investigated for therapeutic intervention, as well as other compounds with anti-inflammatory properties which readily cross the blood–brain barrier such as davunetide (derived from activity-dependent neurotrophic protein (ANAP), a growth factor released by glial cells), fatty acids such as eicosapentaenoic acids and docosahexaenoic acids, estrogens, minocycline (a broad-spectrum tetracycline antibiotic with inhibitory effects on microglia), et al. in 2012 and included 5 double-blind, randomized, placebo-controlled trials , reporting on 264 patients. The authors reported a mean effect size of 0.43, which was significant at P = 0.02 in favor of NSAIDs on total symptom severity  and first-episode patients , but not in outpatients and chronic patients , NAC , and estrogens ; while addition of celecoxib, EPA/DHA fatty acids, davunetide, and minocycline did not show efficacy , is not sufficient to identify the phenotype expressed by microglia. Furthermore, if their phenotype is related to a certain clinical state or illness phase, knowledge of the time course of the microglial activation is relevant. Adding to the complexity of microglia, some authors have argued that the microglial activation status is most probably a reflection of the history of life events [defined as innate immune memory  which occurs in older age is amplified in schizophrenia. BDNF is a regulator of microglial-mediated synaptic plasticity , suggestThe evidence from the psychoneuroimmunology research field converges on a progressive illness model of schizophrenia in which primed microglia contribute to altered neuroplasticity, leading to structural and chemical abnormalities that accumulate as patients age. This model integrates both neurodevelopmental and neurodegenerative hypotheses in schizophrenia, as the combination of a pre- or perinatal immunological vulnerability serves as a background for ongoing abnormal peripheral and brain immune responses which throughout life constitute a basis for illness exacerbation and progressive defects. Yet although the psychoneuroimmunology field provides a compelling pathophysiological model, at this moment it has not attained a clinically significant level of relevance to comprehensively explain the etiology, diagnosis or potential treatment of the disorder. In addition, many of the findings appear non-specific to schizophrenia. To enhance the clinical relevance of this field, further links are needed to connect the immune-related hypotheses to other major research fields and hypotheses of schizophrenia psychopathology.in vivo multimodal imaging and analysis of immunological markers and microarchitectural changes in post-mortem brain tissue as translational means. In particular, the underutilized human brain approach has a powerful translational nature in complex neuropsychiatric conditions (Such an interesting new link between immune alterations and neuroplasticity, in which aberrant microglial activation could cause reduced synaptic and neuropil modulation, has recently emerged, but still needs to be comprehensively investigated in the human brain. Furthermore, knowledge on the physiology and functional phenotypes of microglia, as well as their link with systemic inflammation, is crucially insufficient to interpret current findings. We would therefore argue that studies acting as a bridge between the preclinical and clinical studies are crucially missing. We therefore advocate multimodal research studies that explore neuroinflammatory mechanisms both in experimental models and schizophrenia patients; using nditions . OvercomAll authors met ICMJE criteria and all those who fulfilled those criteria were listed as authors. All authors had access to the study data and made the final decision about where to present these data.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


It is widely acknowledged that the human immune system plays a crucial role in preventing the formation and progression of innumerable types of cancer . The mec From the beginning, cancer treatment approaches with chemotherapy and radiation therapy have largely been unable to discriminate between healthy and malignant cells in their killing action. These therapeutics therefore often sacrifice healthy tissue in the effort to treat the cancer, which too often results in temporary, but often harsh side effects, and long-term consequences, including secondary malignancy. In addition, these treatment methods fail to account for cellular heterogeneity between individual patients with the same diagnosis, or even within a single tumor itself. Although still controversial, evidence indicates that in certain cancer types, small portions of cancer cells situated within an individual tumor display “stem-cell” like properties and are resistant to such therapy, such that they continue to proliferate in spite of treatment .Cancer immunotherapy seeks to strengthen and direct the patient’s natural immune mechanisms against malignant cells, with the aim of targeting the disease while minimizing effects to surrounding healthy tissue . Prelimi“Tumor heterogeneity” refers to differences between tumors of the same type in different patients, as well as to differences among cancer cells within the same tumor. Both can lead to diverse responses to therapy and may explain why some tumor cells remain following aggressive treatment . There aThe human immune system is divided into two arms, innate and adaptive, which work cohesively in response to specific internal and external stimuli. The innate immune system is involved in immediate host defense to perceived pathogens and includes neutrophils, monocytes, macrophages, complement, cytokines, and acute phase proteins. Adaptive immunity consists of antigen-specific reactions mediated by T lymphocytes and B lymphocytes.via immunoglobulin receptors leading to antibody-dependent cellular cytotoxicity (ADCC). Second, they bear natural cytotoxicity receptors (NCRs) that detect the altered expression of ligands on the surface of tumor cells, which ultimately triggers NK cell activation. These mechanisms are illustrated in Figures via the generically termed MHC I receptor and ligand —the engraftment of a donor’s immune system into a recipient with the objective of eliminating cancer cells—has provided increased disease-free survival to patients with hematologic malignancies. However, such methods come with the risk of graft versus host disease (GVHD), a life-threatening condition wherein recipient cells are recognized as foreign and attacked by the donor immune cells. One potential alternative to this is to isolate specific donor antitumor cells, most notably NK cells, for use in HCT, which minimizes the risk of GVHD. Such methods have displayed positive clinical outcomes in acute myelogenous leukemia (AML) patients who underwent HLA-haploidentical NK cell-specific HCT , 13.in vitro expansion of NK cells using the cytokine IL-2. However, benefit is limited in vivo due to the high affinity of T-regulatory cells for IL-2, which is responsible for NK cell inhibition to prevent autoimmunity, as well as by the short half-life—approximately 10 min—of IL-2 in serum  or from a donor  and can be derived from multiple sources, including peripheral blood, bone marrow, or umbilical cord blood. Under normal circumstances, few NK cells circulate in human blood, and those that do frequently exhibit limited cytotoxic activity due to immaturity . In addiin serum , 14. Recin serum , 17. IL2in serum . Other dherapies .Besides solitary IL-2, the combination of the cytokines IL-18, IL-15, and IL-12 has shown promise in inducing the proliferation of memory-like NK cells in immunodeficient mice when accompanied by supplemental exogenous IL-2 . Purifiec portion of various IgG antibody isotypes. In addition, NK cell activity is also modulated by various cytokines, toll-like receptor ligands, and T-regulatory cells  therapies such as trastuzumab, rituximab, and elotuzumab due to CD16 interaction with the Fc portion of the mAb that coats the tumor cells, as illustrated in Figure via the inhibition of metalloproteinases (MMP) that cleave them, as shown in Figure Evidence has shown that the antigen-specific NK cell targeting mechanism in vitro treatment of NK cells. NK cells treated with GM6001 displayed preserved CD16 expression despite initial losses stimulated by the presence of tumor cells —which enhance the specificity between NK cell and tumor. This method involves designing bi- and trispecific antibodies that fuse the Fab region of the antibody to the specific tumor cell antigen in combination with another Fab region of the same antibody fused with the CD16 portion of NK cells, which leads to NK cell stimulation and tumor cell lysis. Multiple Fab regions can be utilized to specifically target multiple tumor antigens —molecules artificially engineered and introduced into hematopoietic cells such as NK cells or T lymphocytes to redirect specificity toward a chosen antigen, as shown in Figure As discussed above, mounting evidence indicates that many tumors contain CSCs, rendering them decidedly resistant to established treatments. Recent reports have indicated that CSCs may be preferentially susceptible to NK cell killing, due in part to their decreased expression of MHC class I . FurtherThe theory of NK cell immunotherapy has gained momentum in recent years. This review summarized the most prominent methods by which NK cells are being manipulated for potential therapeutic uses, including population propagation, inhibition of NK cell suppression mechanisms, and enhancement of NK cell target recognition. Numerous studies have shown extensive progress in both managing NK cell proliferation and lifespan, as well as in the direct targeting of tumor cells and tissues. Although much has been discovered, there remains much to learn before such therapies will become widespread. Further cultivation of specific NK cell therapies by both biochemical and clinical studies is necessary before dissemination is possible.In addition, no firm guidelines exist for the application of NK cell-based therapies in practice. While evidence to date seems to support its use as a complementary therapy to existing treatment regimens, the potential for an exclusive NK cell-based polytherapy cannot be ignored.Finally, more research must be completed on the theory of malignancy itself, and on the individual characteristics of specific tumors. Further evaluation of these unique identifiers may help to determine even more precise therapeutic methods, and form the basis for future tumor staging and treatment guidelines.Both authors have made substantive contributions to the review of literature, which included drafting the manuscript and revising it critically for important intellectual content. Both have given final approval of the version to be published.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


An increasing number of studies show how changes in intracellular metabolic pathways alter tumor and immune cell function. However, little information about metabolic changes in other cell types, including synovial fibroblasts, is available. In rheumatoid arthritis (RA), fibroblast-like synoviocytes (FLS) are the most common cell type at the pannus–cartilage junction and contribute to joint destruction through their production of cytokines, chemokines, and matrix-degrading molecules and by migrating and invading joint cartilage. In this review, we show that these cells differ from healthy synovial fibroblasts, not only in their marker expression, proto-oncogene expression, or their epigenetic changes, but also in their intracellular metabolism. These metabolic changes must occur due to the stressful microenvironment of inflamed tissues, where concentrations of crucial nutrients such as glucose, glutamine, and oxygen are spatially and temporally heterogeneous. In addition, these metabolic changes will increase metabolite exchange between fibroblast and other synovial cells, which can potentially be activated. Glucose and phospholipid metabolism as well as bioactive lipids, including sphingosine-1-phosphate and lysophosphatidic acid, among others, are involved in FLS activation. These metabolic changes likely contribute to FLS involvement in aspects of immune response initiation or abnormal immune responses and strongly contribute to joint destruction. Fibroblast-like synoviocytes (FLS), also known as synovial fibroblasts or type B synoviocytes, are the predominant cell type comprising the structure of the synovial intima. They are organized in two to three layers of cells and constitute 75–80% of all synoviocytes in normal human synovium –3, but aIn the inflamed rheumatoid synovium, the healthy two- to three-layer lining structure is converted into a pannus-like structure, a hyperplastic synovial lining containing a higher number of activated FLS and macrophages that extends into the joint space, attaches to the cartilage surface (cartilage–pannus junction), and invades and degrades the cartilage matrix promoting joint destruction Fig. . The subWe would like to further emphasize the unmet need to target FLS in combination with current and future therapies in rheumatoid arthritis (RA). Since Fassbender observed that aggressive resident synovial cells invaded and destroyed cartilage and bone in the joints of patients with RA , publishIn RA patients, the number of FLS together with the number of T cells were immunohistological markers in synovial tissue of early RA patients associated with unfavorable disease outcome, suggesting a pathogenic role for these cells in the process of joint damage . The lacMultiple stimuli activate FLS in the disease initiation, perpetuation, and terminal joint destruction phases Table . In the Most of the stimuli described above that trigger the FLS response activate a specific receptor or channel located on the cell surface or inside the cell which, in turn, activates signaling pathways in FLS –26. Of nAfter activation, cells change the metabolism of all four major classes of macromolecules  and adopt the specific metabolic signatures required for proper effector function. The shuttling of up-regulated metabolites can also serve as a form of intercellular communication , 37. In Recent studies have addressed metabolic changes in the inflamed joints of RA patients and have shown that glucose metabolism is especially increased. Accelerated glucose metabolism is a hallmark of proliferative and activated cells. Elevated glucose metabolism is also required to provide sufficient amounts of metabolic intermediates to support anabolic processes such as nucleic acid, lipid, and protein synthesis. This up-regulation of glycolysis, resulting in increased glucose consumption, can be observed with clinical imaging. Several studies have shown that fluoro-2-deoxyglucose (FDG), which is taken up by glycolytic cells to form FDG-phosphate and can be detected by positron emission tomography (PET), accumulates in swollen joints . MetabolWe have only recently begun to understand activated metabolic pathways in RA FLS. A recent study evaluated the characteristic metabolic profiling of RA FLS compared to OA FLS using GC/TOF-MS . Sugar mMetabolomics studies in inflammatory arthritis, including RA, suggest an alteration of glycolysis metabolism given the increase of lactate in serum . We evalIn the same line, another group showed that hypoxia promoted a switch to glycolysis, supporting abnormal angiogenesis, cellular invasion, and pannus formation . AnotherGlucose and other metabolites such as acetyl coenzyme A (acetyl-CoA) are then metabolized through the mitochondrial tricarboxylic acid (TCA) cycle in highly metabolic tissues, but a shift in metabolism away from oxidative phosphorylation towards aerobic glycolysis has also been described in inflamed tissues . InteresThe choline pathway is highly activated in FLS. An increased level of choline kinase (ChoKα), the enzyme that catalyzes the first step in the CDP-choline pathway and is essential for phosphatidylcholine (PC) expression, has been associated with malignant transformation, invasion, and metastasis in some human cancers –67. ChoKSphingosine kinase (SphK) phosphorylates sphingosine into sphingosine-1-phosphate (S1P). S1P is a well-known bioactive lipid, which has been involved in the pathogenesis of several autoimmune diseases . SphK blAnother study showed that activated inflammatory arthritis SF from humans and animal models expresses significant quantities of autotaxin (ATX), a lysophospholipase D that catalyzes the conversion of lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA). ATX expression from SF was induced by TNF, and LPA induced SF activation and effector functions in synergy with TNF , 76. ConEicosanoids are other potent bioactive lipids that regulate FLS biology. Leukotriene B(4) (LTB(4)) is a potent proinflammatory lipid mediator that initiates and amplifies synovial inflammation in the K/BxN model of arthritis . FLS genOther lipids, such as free fatty acids (FFA) , are notThe response after FLS activation involves changes in the expression of genes and results in the acquisition of new functions, such as the production of cytokines, chemokines, and tissue remodeling enzymes, and the ability to proliferate, migrate, and invade cartilage. There is a growing appreciation of the fact that reaching these activated states requires the input of new metabolites into specific pathways and therefore there is a strong interest in how metabolic pathways are regulated to support these functional changes. Very limited data are available in FLS, although we hypothesize that, similar to other cell types, especially similar to tumor cells, metabolic changes would support and direct the FLS aggressive phenotype. We expect that inflammation, hypoxia, and the need to support high-energy-demanding processes such as migration and invasion will modify FLS metabolism. In addition, fibroblasts are also critical for SF synthesis, which increases, requiring energy-demanding biosynthesis. Fighting oxidative stress would increase flux through the pentose phosphate pathway to produce cytoplasmic NADPH, requiring high mitochondrial membrane potential in the conversion of matrix NADH to NADPH. We also envision that, given the low apoptosis rate, these cells will have intact compensatory mitochondrial mechanisms to respond to increased ATP demands, increased oxidative stress, and other stress signals for continued support of cellular functions and survival.In RA, SF loses its rheological properties. This implies a loss of lubricant properties, which are poor in RA SF, leading to loss of protective properties , 84. ThiHyperplasia of FLS leads to over-proliferation of synovial tissue, resulting in increased oxygen consumption in synovium, thereby forming a hypoxic environment. The main mechanism that promotes the development of new vessel formation is hypoxia , 98. HypRA FLS not only become hyperplastic but also increase their migration and mobility, invading the cartilage and destroying it. Despite a growing understanding of the clinical course of RA, early phases of the disease and the specific sequences of cellular events and interactions leading to progressive destruction of articular structures have not been clarified. In vitro studies suggest that damaged cartilage facilitates the attachment of cells, but there is also evidence that the primary attachment of FLS to matrix components such as collagens and proteoglycans contributes to activation of signaling pathways, triggering their invasive behavior. Thus, a variety of integrins, especially those of the β1 family, have been found to be overexpressed in RA FLS, and blocking these integrins on the surface of RA FLS reduces their attachment and invasive capacity –103.The reciprocal regulation of integrin-dependent functions and cell metabolism is an emerging paradigm . MetabolSeveral molecules and growth factors, such as PDGF, are essential for the formation of ECM-degrading invadosomal structures and cartilage invasion and activate several signaling pathways, including the PI3K/AKT pathway, known to be upstream of glucose metabolism . Also, FThe mechanisms of intimal lining hyperplasia remain controversial. While active proliferation is one explanation, and some proto-oncogenes, such as c-myc, are expressed in FLS, the lack of mitoses and absence of immunohistochemical staining for some nuclear proliferation markers suggest that local cell division might not significantly contribute to the increased number of cells.Resistance to programmed cell death (apoptosis) induced by the apoptotic stimulus signals, which are abundant in the inflamed joint, is a prominent characteristic of RA FLS. Apoptosis is a mechanism by which cells undergo death to control cell proliferation or in response to DNA damage. RA FLS exhibit changes in mitochondrial pathways of apoptosis and are resistant to receptor-mediated apoptosis at multiple levels. Several explanations have been proposed, including deregulation of the Bcl-2 family of proteins critical to intrinsic pathway regulation , 113, deAutophagy is an endogenous process necessary for the turnover of organelles, maintaining cellular homeostasis and directing cell fate. Mitophagy or autophagy of mitochondria is required to eliminate dysfunctional mitochondria and is critical to maintain appropriate metabolic and cell survival signals. Increased mitophagy or autophagy provides survival advantage to the cells in nutrient-deprived or hypoxic conditions. In fact RA FLS showed an increase of genes involved in autophagy, such as beclin-1 and LC3, which inversely correlates with their apoptosis rate . In addiNo cell type explains the pathologic behavior of RA synovial tissue. Rather, it is the interactions between these cells that define the disease. These various cell types can interact in two general ways: first, through secreted mediators and through direct cell–cell contact that is mediated by cell surface receptors and ligands. Metabolic changes will modify metabolite exchange between cells and can potentially help in RA chronic inflammation. As mentioned above, intermediates of glucose metabolism and mitochondrial TCA have extracellular functions, including angiogenesis, invasiveness, and antiapoptosis . Amino aIn arthritic synovium, although no specific co-culture studies have been described, some of the above-mentioned intermediate metabolites that stimulate FLS, including succinate or lactate, are known to be secreted by cells present in the synovium like macrophages and might work through both autocrine and paracrine mechanisms. Further studies are needed to know whether the above or other mechanisms play a role in the crosstalk between FLS and other synovial cell types.Epigenetic changes are changes in gene function that are heritable over generations without altering the DNA sequence. Short-lived chromatin modifications can also substantially alter gene function and indirectly initiate heritable epigenetic changes of the genome. There are three main mechanisms—DNA methylation, histone modification, and expression of microRNAs—with significant cross-regulation . EpigeneConversely, some epigenetic factors have been shown to regulate metabolic genes leading to a shift in energy flow. For instance, emerging evidence now indicates that microRNAs play a significant role in regulating the expression and activity of peroxisome proliferator-activated receptors (PPARs), which control the transcription of genes involved in energy homeostasis . MicroRNMost of the therapies approved for RA do not directly target FLS. Biological therapies that focus on inhibiting immune cell activation or inflammatory cytokines likely improve the inflammation-dependent FLS activation but do not address the chronic inflammatory-independent FLS activation observed in a subset of patients. Reprogramming metabolic changes might be a new modality key to developing joint-protective strategies in RA FLS. In fact, the metabolic rewiring of immune cells has been viewed as a promising source of novel drug targets , 140. ReInhibition of key enzymes that regulate activated pathways, including glycolysis (BrPa or PFKFB3 inhibitor) or phospholipid (ChoK inhibitor) metabolism, would be one way to interfere with these metabolic changes and end products such as lactate, succinate, or bioactive lipids. Other ways to modulate cell and specifically mitochondrial metabolism would be by targeting mitochondria via enhancing mitochondrial biogenesis or by encouraging reliance on oxidative phosphorylation instead of glycolysis. AMPK agonists could improve mitochondria biogenesis if needed. Furthermore, understanding whether there are disease-specific changes in metabolism, or activation of specific changes in metabolic pathways such as mTOR or HIF1a, could lead to identification of key regulatory enzymes or factors as new therapeutic targets. Thus, further characterization of the mechanisms linking cellular metabolism and mitochondrial function is needed to obtain clearer insight into the relationship between mitochondrial homeostasis, metabolic changes, and inflammation in FLS. Whether this truly constitutes an option to increase the drug armamentarium in rheumatic diseases beyond biological and kinase inhibitor therapies remains to be determined.