Lianhua Qingwen Capsules (LHQW) is a traditional Chinese medicine prescription commonly used to treat viral influenza in China. There has been sufficient evidence that LHQW could effectively treat COVID-19. Nevertheless, the potential anti-(mutant) SARS-CoV-2 and anti-inflammation compounds in LHQW are still vague.The compounds of LHQW and targets were collected from TCMSP, TCMID, Shanghai Institute of Organic Chemistry of CAS database, and relevant literature. Autodock Vina was used to carry out molecular docking. The pkCSM platform to predict the relevant parameters of compound absorption in vivo. The protein–protein interaction (PPI) network was constructed by the STRING database. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was carried out by Database for Annotation, Visualization, and Integrated Discovery (DAVID). The anti-(mutant) SARS-CoV-2 and anti-inflammation networks were constructed on the Cytoscape platform.280 compounds, 16 targets related to SARS-CoV-2, and 54 targets related to cytokine storm were obtained by screening. The key pathways Toll-like receptor signaling, NOD-like receptor signal pathway, and Jak-STAT signaling pathway, and the core targets IL6 were obtained by PPI network and KEGG pathway enrichment analysis. The network analysis predicted and discussed the 16 main anti-SARS-CoV-2 active compounds and 12 main anti-inflammation active compounds. Ochnaflavone and Hypericin are potential anti-mutant virus compounds in LHQW.In summary, this study explored the potential anti-(mutant) SARS-CoV-2 and anti-inflammation compounds of LHQW against COVID-19, which can provide new ideas and valuable references for discovering active compounds in the treatment of COVID-19.The online version contains supplementary material available at 10.1186/s13020-022-00637-0. Since the end of 2019, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused an outbreak of Coronavirus Disease (COVID-19) in more than 200 countries/regions around the world. SARS-CoV-2 spreads faster, has a longer incubation time, and has more people infected than Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV). The new coronavirus has become an urgent public health problem in the twenty-first century –5. So, iThe patients infected with SARS-CoV and MERS-CoV have symptoms of acute lung injury (ALI), systemic inflammatory response syndrome (SIRS), and acute respiratory distress syndrome (ARDS), and the patients infected with SARS-CoV-2 also have these symptoms. These clinical features are related to inflammation, which is caused by cytokines. The inflammatory plays an anti-virus effect when the coronavirus infects the host, but the inflammatory storm  caused by the intense stimulation of the virus may cause more harm to the patient . TherefoLHQW is derived from two classics prescriptions: Ma Xing Shi Gan Tang in the Han Dynasty and Yin Qiao San in the Qing Dynasty. LHQW comprises 11 Chinese herbal medicines, Gypsum Fibrosum (Shi Gao-SG) and Menthol (Bo He Nao-BHN). Among them, Chinese herbal medicines include Forsythiae Fructus (Lian Qiao-LQ), Lonicerae Japonicae Flos (Jin Yin Hua-JYH), Ephedrae Herba (Ma Huang-MH), Armeniacae Semen Amarum (Ku Xing Ren-KXR), Isatidis Radix (Ban Lan Gen-BLG), Dryopteridis Crassirhizomatis Rhizoma (Mian Ma Guan Zhong-MMGZ), Houttuyniae Herba (Yu Xing Cao-YXC), Pogostemonis Herba (Guang Huo Xiang-GHX), Rhei Radix et Rhizoma (Da Huang-DH), Rhodiolae Crenulatae Radix et Rhizoma (Hong Jing Tian-HJT) and Glycyrrhizae Radix et Rhizoma (Gan Cao-GC). The combined LHQW and western medicine treatment of COVID-19 can improve the clinical efficacy, significantly relieve the main symptoms and reduce the treatment time –14. In vThe wider recognition of LHQW is limited by its material basis research. Many cutting-edge technologies are valuable for research of material basis of Chinese medicine, such as chemometrics  and netwIn this study, LHQW compounds database was constructed by integrating different databases and related literature. In terms of targets, the collection focused on anti-(mutant) SARS-CoV-2 and anti-inflammation and collected corresponding important targets from the literature. Finally, molecular docking, medicinal properties of compounds, and network pharmacology were adopted to obtain the potential anti-(mutant) SARS-CoV-2 and anti-inflammation compounds of LHQW in the treatment of COVID-19. The flowchart is illustrated in Fig. http://tcmspw.com/tcmsp.php), Traditional Chinese Medicines Integrated Database , Shanghai Institute of Organic Chemistry of CAS (http://www.organchem.csdb.cn/) and related literature [https://pubchem.ncbi.nlm.nih.gov/). The compounds without structural information in Pubchem can be drawn by Chemdraw  and saved as an SDF format file by ChemBio3D , and finally used Open Babel GUI (Version 2.4.1) to batch convert SDF format files into mol2 format files. Subsequently, AutoDock Tools  saved the mol2 format file as a PDBQT coordinate file for molecular docking by Autodock Vina .The compounds of all Chinese herbal medicines were collected through the Traditional Chinese Medicine Systems Pharmacology database , and the 3D structure of targets was downloaded from the PDB database (https://www.rcsb.org/).Seventeen targets related to SARS-CoV-2 were obtained from the literature to analyze potential anti-(mutant) SARS-CoV-2 compounds in LHQW. Specifically, six structural proteins of SARS-CoV-2 were collected, including the original S glycoprotein , five vaAutodock Vina  was usedhttp://biosig.unimelb.edu.au/pkcsm/) [The relevant parameters of compounds absorption in vivo were predicted using pkCSM (/pkcsm/) . The pkChttps://string-db.org/). The Cytoscape 3.7.1 platform was used to visualize and analyze protein interaction networks.With the background of "Homo sapiens", the protein–protein interaction (PPI) network of cytokine storm-related targets was constructed in the STRING database (https://david.ncifcrf.gov/) [The collected gene symbols of 55 cytokine storm-related targets were imported into DAVID 6.8 (rf.gov/) . IdentifAccording to the above results. The anti-(mutant) SARS-CoV-2/anti-inflammation network can be constructed separately by importing the Cytoscape 3.7.1 platform to study the potential anti-SARS-CoV-2 and anti-inflammation effects of LHQW.A total of 3123 compounds of the herbal medicines contained in LHQW were collected from the databases and related literature. There are 612 repetitive compounds, and 2511 compounds were docked with related targets using Autodock Vina. The binding energy of the docking results can be used to evaluate the degree of binding between the ligand and the receptor. The ligand and receptor molecule conformation can be stably combined when affinity is less than 0-the greater the absolute affinity value, the stronger the stability. After docking, 753 chemical compounds can be screened out by the docking threshold setting under '2.3'.After that, the recognized Lipinski's Rule of Five can be used to screen . The rulThe compounds screened by using Lipinski's Rule of Five need to have good pharmacokinetic characteristics to have potential therapeutic effects. Among the ADMET parameters predicted in the pkCSM server, two important in vivo absorption parameters were further selected to screen compounds, that is, Caco2 permeability > 0.9, the compound is considered to have a higher Caco2 permeability; Intestinal absorption (human) > 30%, the compound can be considered to be well absorbed in the human intestine. However, Lipinski's Rule of Five and ADMET parameters are not a panacea. Many compounds violate these rules with clear pharmacological activities . It was After screening, 280 potentially active compounds and 70 targets (16 virus-related targets and 54 cytokine storm-related targets) can be obtained. Each target corresponds to an average of 12.64 compounds, and each compound corresponds to an average of 3.16 targets. It shows that different active compounds can act on the same target, and the same active compound can also act on different targets, reflecting the multi-compounds and multi-targets characteristics of Chinese medicine. The 280 potentially active compounds were classified, as shown in Fig. After molecular docking, 54 cytokine storm-related targets were screened to construct a PPI network, including 53 nodes and 1876 edges  caused by COVID-19 were visualized, as shown in Fig. As shown in Fig. In this section, the compounds and targets screened through molecular docking and medicinal properties were used to construct anti-(mutant) SARS-CoV-2 and anti-inflammation networks, respectively, to explore the potential mechanism of LHQW in the treatment of COVID-19.As shown in Fig. Since the mutation of SARS-CoV-2 greatly enhanced the spread of COVID-19, we also collected five significant variants to predict anti-mutant virus compounds in LHQW. The further anti-mutant virus network was constructed by 30 potentially active compounds and 5 mutant virus targets. In this network, only 2 compounds (−)-Epicatechin-3-O-gallate and Licorice-saponin F3_qt were not present in the 16 compounds screened by the anti-SARS-CoV-2 network in the previous step. Ochnaflavone and Hypericin are associated with the five mutant viruses, indicating that these two compounds are potentially active compounds against the mutant viruses in LHQW. Ochnaflavone and Hypericin are derived from JYH and LQ, respectively, and JYH and LQ are monarch medicines (the most important medicines) in LHQW formula, which further shows that these compounds are worthy of study. The potential binding of Ochnaflavone and Hypericin with the five mutant S glycoproteins is shown in Fig. As shown in Fig. As shown in Fig. The more important active compounds were obtained from the anti-(mutant) SARS-CoV-2 and anti-inflammation network by analyzing the degree value. We chose the degree value of 3 in the anti-SARS-CoV-2 network and the degree value of 9 in the anti-inflammation network as the threshold to obtain and analyze the most critical active compounds, and 24 active compounds were screened. However, this method is largely controversial. There is no standard for threshold setting from the current network analysis, and many methods are adopted, such as selecting the top 3  or top 1This study used molecular docking, medicinal properties of compounds, and network pharmacology to explore the anti-(mutant) SARS-CoV-2 and anti-inflammation compounds from LHQW in treating COVID-19. Firstly, the potential active compounds in LHQW were obtained from molecular docking and medicinal properties of compounds; the PPI network and KEGG pathway were analyzed from the perspective of cytokine storm, and it was found that each target was closely connected, and three key pathways and one core target were obtained. Finally, the key active compounds were obtained from the network analysis. In summary, all works showed that the active compounds in LHQW could inhibit or activate the targets, thereby producing anti-(mutant) SARS-CoV-2 effects or regulating signal pathways to exert anti-inflammation effects. This research can provide some valuable clues for the wider application of LHQW in aginst COVID-19 and the development of new drug strategies to control SARS-CoV-2.Additional file 1: Table S1. List of related targets for cytokine storm. Table S2. List of related targets for SARS-CoV-2. Table S3. Results of docking studies. Table S4. Medicinal properties of LHQW active compounds. Table S5. Results of docking studies-Affinity range of the compounds corresponding to each target. Table S6. Compounds database of LHQW. Table S7. Information about 14 articles related to LHQW Network Pharmacology.


Pemphigus is a rare autoimmune blistering disease, involving potentially life-threatening conditions often requiring immunosuppression. Currently, the COVID-19 pandemic caused by severe acute respiratory disease coronavirus 2 (SARS-CoV-2) infection has become a global public emergency. Vaccines are the most effective defense against COVID-19 infection. However, in clinic, there are cases of new onset or flare of pemphigus following COVID-19 vaccination, where vaccines have manifested significantly desirable risk-benefit profiles for patients. Although Rituximab, as first-line therapy, may impair humoral immunity, pemphigus may not predispose to develop COVID-19 infection compared to a healthy population. Conversely, delay or interruption of immunosuppressants probably results in unfavorable clinical outcomes for disease progression. Overall, clinicians should encourage their patients to undergo the vaccination after a comprehensive assessment. The definite association between COVID-19 vaccination and pemphigus remains to be further elucidated. Herein, we provide an overview of the published studies to date on COVID-19 and pemphigus as well as the exploration of their complicated interplay. In addition, we discuss the management strategies for pemphigus patients in this special period, in an effort to more effectively establish a standard treatment paradigm for this particular patient group. Staphylococcus aureus infection [Pemphigus, a heterogeneous group of IgG-mediated autoimmune bullous disorders, is characterized by acantholysis  that induces fragile blisters and painful erosions on the skin and mucosa ,2. IgG anfection .Systemic glucocorticoids, plus immunosuppressive adjuncts such as azathioprine are conventional treatment regimens for pemphigus . PrelimiThe sudden emergence of the COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which has infected millions of individuals and drew great attention across the globe. SARS-CoV-2 is a single-stranded RNA enveloped virus comprising four crucial structural proteins, including spike (S) glycoprotein, membrane (M), envelope (E), and nucleocapsid (N) protein . Nonethep = 0.023); in contrast, there is no significant difference between patients with pemphigus and their controls  [According to a retrospective cohort study involving 245 pemphigus patients with an average following-up time per person of > 10 years , the ove= 0.789) . Overall= 0.789) . Of note= 0.789) ,22.In response to the global outbreak, the COVID-19 vaccine emerged as a newly approved product in an effort to confer protective efficacy and prevent the public from infection. Generally, it has been indicated comparatively safe and well-tolerated. In an observational cohort study on vaccine safety which enrolled 21,744 subjects, the reported adverse events primarily include pain at the injection site (>80%), headache (>50%), fatigue (>50%); myalgia, malaise (>40%); pyrexia, chills (>30%), arthralgia (>20%), as well as swelling at the injection site (>10%) . SimilarCurrently, the SARS-CoV-2 vaccines are widely administered to prevent deaths due to COVID-19 infection and to end the pandemic. However, it is reported that only 68% of patients with autoimmune bullous diseases would accept the COVID-19 vaccination without hesitancy or denial, while others showed their concerns of whether the vaccine would induce disease exacerbation or relapse . In contThe range that COVID-19 vaccines fight against virus mainly includes: nucleic acid , protein-based , viral vector (replicating and non-replicating), and whole virus (attenuated or inactivated) . Sahin eIn conclusion, molecular mimicry is caused by genetic similarities of SARS-CoV-2 spike protein components to endogenous cross-reactive human antigens, thereby generating autoreactive lymphocytes and cross-reactive antibodies. The hyper-stimulated state of the immune system plausibly triggers the onset of autoimmune dysregulation in genetically predisposed individuals. The RBD of SARS-CoV-2 is highly immunogenic to mediate detectable antibodies; while the protective capacity of such humoral immune responses remains unclear. On the other hand, vaccine-induced immunity likely has both a cell-mediated and humoral response. Different variables including neutralization antibodies and memory cells, as well as the potential emergence of variants, may also impact the responses of patients with immune-mediated inflammatory diseases (IMID) to vaccination ,51. HoweIn recent decades, biologics and new target synthetic agents have tremendously improved the clinical outcomes of autoimmune diseases. However, the COVID-19 pandemic raised concerns that immunosuppressive agents may pose a risk of increased severity and duration of COVID disease since they could lead to the depletion of B-cell lymphocyte counts. Rituximab, is a monoclonal anti-CD20 antibody as first-line therapeutic strategy for pemphigus . ProlongWith vaccines and Rituximab becoming widely available for pemphigus patients, the immune responses to SARS-CoV-2 vaccines in patients are undefined. Studies have found that pemphigus patients following Rituximab develop feeble humoral responses to vaccination, which may not correlate directly with protection from infection . In ApriDermatology is a visual specialty that is particularly suitable for telemedicine, which is conducted on a virtual platform to remotely deliver health information such as diagnoses or consultations and perform internet-based management as well as social care . Given tAll patients with moderate-to-severe pemphigus admitted to the hospital are performed COVID-19 swabs, and immunosuppressive medications would be appropriately administered for disease control. Rituximab has been approved as a first-line treatment for moderate-to-severe pemphigus in updated guidelines . NeverthPatients who receive immunosuppressants such as Rituximab represent a potentially susceptible population requiring the constant monitoring of adverse effects, particularly bacterial, fungal or viral infection. Given that the median incubation period of COVID-19 is around 4 to 5 days and can take up to 1 month, with a peak around day7 to day10 , it is aEmotional management is as important as disease management for patients with pemphigus. The first Chinese dermatologists to face SARS-CoV-2 have shared their experiences about performing telemedicine on 38 AIBD patients during the worst three months of the epidemic in China . It was Management of pemphigus in the COVID-19 epidemic is a challenge for dermatologists. Overall, basic infection-prevention principles should be strictly adhered and drug-induced immunosuppression should be minimized as possible in treating pemphigus patients . As the It was demonstrated that SARS-CoV-2 vaccines do not pose a more prominent danger than virus infection themselves . For tho


The onset of immune checkpoint blockade therapy (ICBT) over the last decade has dramatically revolutionized the treatment paradigm in cancer therapy. Immune checkpoint inhibitors (ICIs), especially monoclonal antibodies designed to block the programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) axis, have scored impressive successes in malignant tumors and continue to show exceptional promise in ongoing clinical trials. However, the widespread utilization of ICIs is greatly hindered by their low response rates, severe adverse effects, innate and acquired drug resistance, etc. Increasing efforts are being made to overcome these issues and improve the clinical efficacy of ICBT. The aim of this Research Topic is to highlight novel and significant discoveries in the field of cancer immunotherapy, extending our understanding of the mechanisms of ICI-induced anti-cancer immunity, thereby improving therapeutic responses of ICBT and reducing the propensity for adverse events.Chen X. et al. regard tyrosine kinase inhibitor Bafetinib as a promising drug targeting PD-L1 that remarkably inhibits PD-L1 protein expression by suppressing the transcription of c-Myc. This study underscores the prospect of c-Myc as a druggable target and provides a new idea for tumor immunotherapy. The ongoing intensive work to mine small molecule inhibitors for clinical immunotherapy holds great promise for maximizing the patient benefit from these innovative therapies.Considering the pitfalls of the existing antibody drugs targeting immune checkpoint molecules, small molecule inhibitors are desirable surrogates owing to their special properties, such as excellent cell permeability, high stability, cost-effectiveness, and low adverse events. Ouyang et al. provide a current landscape of clinical trials of ICIs for patients with hepatocellular carcinoma, including monotherapy or combination therapy. Numerous positive findings from these clinical trials support the rationale of combining ICIs with other therapeutics in cancer therapy. Zheng et al. also present a comprehensive overview of recent advances in combinatorial strategies with PD-1/PD-L1 blockade for breast cancer therapy. As expected, anti-PD-1/PD-L1 therapy combined with chemotherapy, anti-HER2 therapy, and targeted therapy showed synergistic anti-tumor efficacies in the treatment of breast cancer. Nevertheless, several combination options only markedly improved the outcomes of specific subgroups of breast cancer, indicating the importance of patient selection for the optimal benefit of combination therapies.Accumulating evidence indicates that conventional therapeutics could synergize with ICI therapy, by facilitating cancer antigen release and presentation, reshaping the tumor microenvironment, or enhancing effector activity. Therefore, intense interest exists in developing combination therapies to boost the anti-tumor effects of ICIs. Currently, numerous therapeutic strategies that combine ICIs with standard treatment modalities, such as radiotherapy, chemotherapy, targeted therapy, and antiangiogenic therapy, are being evaluated in clinical settings. Zhang et al. found that sodium tanshinone IIA sulfonate (STS), a dual inhibitor of IDO1/TDO2, could decrease kynurenine synthesis, resulting in the lower kynurenine level in the plasma of murine model of colorectal cancer (CRC). Further analysis demonstrated that STS could suppress tumor growth and effectively boost tumor immunotherapy by decreasing the number of FOXP3+ T-cell and increasing the proportion of CD8+ T-cell in tumors. The potential of combined STS and immunotherapy for the synergistic treatment of CRC remains to be investigated. Yan et al., in their case report, found that the patient with ROS1 fusion-positive non-small cell lung cancer achieved a durable response to ICI plus chemotherapy, indicating that immuno-chemotherapy is a feasible option for ROS1-altered lung cancer. Additionally, they emphasized the importance of the sequence of combination treatments and proposed that TKI followed by ICI is a safer option. Yu et al. focus on the immune landscape during MAPK-targeted therapy to explore the mechanism of cross-resistance to ICIs driven by MAPK-targeted therapy. Consistent with previous reports, they found that BRAFi/MEKi acquired resistance was associated with reduced T-cell infiltration, implying that anti-tumor activity was suppressed. Transcriptomic dissection further suggested that deficiency of MHC-I antigen presentation on tumor cells might mediate drug-induced immunosuppression. Besides cross-resistance, aggravated therapeutic toxicity induced by combination therapy is another formidable challenge.Several emerging combination strategies have been proposed to circumvent the pitfalls of immunotherapy and expand the patient population benefiting from immunotherapy. Tryptophan metabolism enzymes indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase 2 (TDO2) are partly responsible for ICIs resistance, thus the combination of IDO1/TDO2 inhibitors with ICI is a promising strategy to activate potent anti-tumor immunity. Chen L. et al. assess the prognostic value of the gastric immune prognostic index (GIPI) in gastric cancer patients receiving anti-PD-1/PD-L1 therapy, which is available for liquid biopsy and reflects systemic inflammatory status. The result showed that high GIPI confers a stronger benefit to patients with gastric cancer.The establishment of predictive and prognostic biomarkers for monotherapy or combination therapy of checkpoint immunotherapy is essential to improve patient selection and avoid therapeutic toxicity. Compared with tissue-based biomarkers, such as PD-1/PD-L1 status, tumor mutational burden, and tumor-infiltrating lymphocytes, numerous blood parameters have increasingly captured the attention of researchers due to their non-invasive, cost-effective, and easy-to-use nature, which are prognostic of outcomes in several cancer types. As mentioned above, ICIs alone or in combination with other cancer therapeutics have exhibited momentous clinical benefits. It is noteworthy that the appropriate timing and sequence of combined treatments are important to attain optimal outcomes of combination therapy. These original research and reviews in this Research Topic help to buttress the potential of immunotherapy and provide important insights for anti-tumor immunity. Several potential effective combination strategies for cancer immunotherapy have been proposed, and further validation in clinical trials is needed. Moreover, molecular mechanisms underlying synergistic or antagonistic effects of combination therapy need further investigation, which will help deepen the understanding of anti-tumor responses and promote the development of promising therapeutic strategies.


Dead-space pattern (D-pattern) was defined as a severe perfusion defect with mild impaired ventilation that results in a regional dead-space in the related lung quasi-consolidated regions (still some ventilation in these regions). In EIT image, high regional Dead-space% should be identified, whereas in ultrasound, absent or dot-like vascularity should be observed in the quasi-consolidated regions. The potential pathophysiologic mechanism could be obstruction or compression of pulmonary capillaries and unobstructed degree of related pulmonary arteries. Respiratory treatment for patients with D-pattern should not only focus on improving regional ventilation but also restoring pulmonary perfusion.The perfusion of lung consolidation regions varies, depending on hypoxic vasoconstriction, obstruction or compression of pulmonary capillaries and unobstructed degree of related pulmonary arteries. The electrical impedance tomography (EIT) could make a rapid assessment of functional ventilation and perfusion in the related lung regions, which was helpful for the broad diagnosis and further treatment . HoweverTo illustrate the typical EIT and ultrasound images, a case with D-pattern was present.2O to 14cmH2O) and drainage of pleural effusion were used. The high PEEP caused a significant improvement of ventilation but less correction of perfusion defect. The range of consolidated region decreased; however, no vascularity was seen within this consolidated lung at the higher PEEP level. The CTPA implied multiple pulmonary artery stenosis of the upper and lower lobe in the right lung. In this case, some shunt% region present in the left lung without pulmonary artery embolism, which indicated redistribution of lung blood perfusion. Moreover, the V/Q match was impaired in the high PEEP that cause leading to heterogeneity in pulmonary perfusion.A 66-year-old man, who had obstructive pneumonia due to central non-small-cell lung cancer in the right lung, was mechanically ventilated. A lower regional ventilation distribution, pleural effusion and consolidation were found in the right lower lobe Fig. A. Color 2.Shunt pattern (S-pattern) was defined as a well or relatively normal perfusion with severe impaired ventilation that result in a regional shunt in the related region of lung consolidation. In EIT image, high regional Shunt% is observed, whereas in ultrasound, pulsatile tree-like, tortuous or homogeneously distributed fragmented vascular structures could be identified through several respiratory cycles in any part of the consolidated tissue . PotentiNot only pulmonary artery embolism but also pulmonary capillaries compression and micro-embolism could cause a perfusion defect in the lung consolidation. COVID-19 also has a high dead-space percentage, which is similar to D-pattern . It mighTo demonstrate the idea, a clinical case of S-pattern was presented. A 55-year-old man, who received the aortic valve replacement due to the severe aortic insufficiency, suffered from refractory hypoxemia on the first postoperative day. The ventilation defect was worse than perfusion defect, which result in intrapulmonary shunt in dependent regions Fig. B. MoreovTo our best knowledge, this is the first clinical report combined ultrasound and electrical impedance tomography for categorizing regional perfusion in lung consolidation. The compute and incorporate the anatomical dead-space and cardiac output could provide EIT map of regional ventilation-perfusion matching . Ultraso


Non-invasive positron emission tomography (PET) imaging of immune cells is a powerful approach for monitoring the dynamics of immune cells in response to immunotherapy. Despite the clinical success of many immunotherapeutic agents, their clinical efficacy is limited to a subgroup of patients. Conventional imaging, as well as analysis of tissue biopsies and blood samples do not reflect the complex interaction between tumour and immune cells. Consequently, PET probes are being developed to capture the dynamics of such interactions, which may improve patient stratification and treatment evaluation. The clinical efficacy of cancer immunotherapy relies on both the infiltration and function of cytotoxic immune cells at the tumour site. Thus, various immune biomarkers have been investigated as potential targets for PET imaging of immune response. Herein, we provide an overview of the most recent developments in PET imaging of immune response, including the radiosynthesis approaches employed in their development. Over the years, various immunotherapy approaches have emerged as powerful treatment options for cancer. These approaches aim to induce an anti-tumour immune response by redirecting or stimulating the patient’s immune system to attack cancer cells. The most common type of cancer immunotherapy is passive immunotherapy, which involves administration effector molecules, including monoclonal antibodies, or the adoptive transfer of lymphocyte-activated killer cells or cytotoxic T lymphocytes that acts to enhance existing anti-tumour immune responses. Another type of cancer immunotherapy is active immunotherapy, which involves administration of agents, such as interferons, interleukins , vaccines, and genetically engineered T cells, to direct the immune system into taking an active role in attacking the cancer cells.The clinical success of immune checkpoint monoclonal antibodies led to the approval of several therapeutic agents by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) ,2. CelluAssessment of immune responses by measuring circulating levels of cytokines, lymphocytes, and immunoglobulins in blood samples or biopsies of tumour tissues is invasive and provides insufficient data on the status of infiltrating immune cells . In compPositron emission tomography (PET) imaging is a powerful imaging technique that possess high sensitivity, quantitative capability, and limitless depth of tissue penetration. Thus, PET imaging is suitable for tracking T cells in clinical settings. Using T cell-specific probes, PET imaging can visualize the homing and accumulation of T cells at the tumour site. To date, few PET radiotracers have been developed for imaging cytotoxic T cells. In this review, we discuss the recent developments in cancer immunotherapy, and the use of PET imaging in predicting and evaluating immune response to cancer immunotherapy. We also discuss radioisotopes and synthesis methods employed in the development of immuno-PET imaging probes.Cancer immunotherapy is an attractive strategy that aims to trigger an immune response against cancer cells, inhibiting their growth. The immune system plays two critical roles; it can suppress and/or promote tumour growth, a process known as immunoediting. During early stages of tumour development, the innate and adaptive immune system eliminates transformed cells that have escaped programmed cell death or repair mechanisms. However, rare subclones of tumour cells may survive this phase and progress into the equilibrium phase, where tumour growth is limited. Persistent activation of the immune system, along with the genetic instability of tumour cells, leads to the selection of tumour subclones with reduced immunogenicity that are capable of evading immune recognition and elimination. These tumour subclones exhibit modifications, such as loss of antigen presentation or increased expression of inhibitory immune checkpoint molecules. Various immunotherapies have been developed to relieve the immunosuppressive tumour microenvironment and subsequently trigger an anti-tumour immune response.Cancer immunotherapy is divided into the following two categories: active and passive immunotherapy. Active immunotherapy aims at the induction of an endogenous, long-lasting tumour antigen-specific immune response. In addition, the anti-tumour response can be further enhanced via non-specific stimulation of the immune system using cytokines. Another strategy to induce in vivo stimulation is through vaccination with tumour antigens ,14. PassImmune checkpoint molecules play a critical role in regulating immune cell activation. Following antigen recognition by a T cell receptor (TCR), a secondary co-stimulatory signal is necessary to trigger T cell activation. This is mediated via the ligation of co-stimulatory molecules, such as CD28, expressed on T cells. Upon T cell activation, co-inhibitory molecules, such as CTLA-4 and PD-1, are recruited to the immunologic synapse to halt T cell activation and maintain physiologic immune responses . To avoiDespite the clinical success of ICI therapy, a large number of cancer patients show no response or resistance to ICI therapy ,21,22. TThe T cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) is an immune receptor that is mostly expressed on T cells and natural killer (NK) cells. Varying levels of TIGIT are detected on different subsets of T cells. Furthermore, TIGIT is an inhibitory immune checkpoint molecule that plays role in modulating tumour-targeted T cell response and, thus, serves as potential target for immune checkpoint inhibition. The main ligand for TIGIT is CD155, which is upregulated on cancer cells and is also expressed on tumour-infiltrating myeloid cells. In pre-clinical studies, anti-TIGIT mAb monotherapy was found to inhibit tumour growth and prevent metastasis. In myeloma mouse models, blocking of TIGIT was found to reduce tumour burden and prolong overall survival . FurtherAnother promising approach in the field of cancer immunotherapy is CAR-T cell therapy, whereby T cells are genetically modified to express synthetic receptors that allow them to recognise tumour-associated antigens (TAAs) presented by human leukocyte antigen  molecules. CAR-T cells consist of an extracellular antigen-binding domain that is linked to an intracellular signalling domain CD3ζ (first generation CARs). In second- and third-generation CARs, CAR-T cell activity is augmented by the addition of one or more co-stimulatory domains. Fourth-generation CARs possess a constitutive or inducible expression of soluble cytokines or co-receptors ,34. To dAlthough CAR-T cell therapy has exhibited promising efficacy, not all patients achieve complete responses. In fact, durable remission is not guaranteed, and 30–60% of patients are reported to relapse following treatment with CD19 CAR-T cells, which may be due to antigen escape . AdditioThe ZUMA-6 trial (phase 1) demonstrated that combining anti-CD19 CAR-T cell therapy with PD-L1 therapy is safe and promising in treating patients with refractory aggressive non-Hodgkin lymphoma . In a smAnother adoptive cell therapy that has gained considerable attention as an attractive candidate for cancer immunotherapy is the use of γδ T cells, which are a minor population of peripheral lymphocytes . Indeed,Cytokines, which are small proteins secreted by different immune cells, play a significant role in cancer immune cycle. This includes antigen presentation on cancer cells, priming and activation of T cells, infiltration of effector cells into tumour tissue, and cancer cell death . FurtherThe promising clinical benefits observed in some patients treated with cancer immunotherapy indicate its feasibility in restoring effective anti-tumour immune surveillance. Cancer vaccines, another type of immunotherapy, have a preventive and therapeutic potential and, thus, may provide long-term immunity against cancer recurrence. To date, three vaccines are approved for treating metastatic melanoma, early-stage bladder cancer, and metastatic castration-resistant prostate cancer ,70,71. CTo date, there are three FDA-approved positive predictive biomarkers, namely PD-L1 expression, tumour mutational burden (TMB), and microsatellite instability (MSI) . The firAnother biomarker, MSI, develops as a result of defects in the DNA mismatch repair pathway that leads to the accumulation of many mutations within microsatellite regions. Tumours with high MSI exhibit increased mutational burden, resulting in the infiltration of T cells in the TME. Furthermore, TMB and the presence of inflamed gene signatures have been reported to positively correlate with response to PD-1/PD-L1 blockade. Patients with high TMB were found to have better overall survival when treated with PD-1/PD-L1 ICIs. In addition, higher TMB associates with a greater probability of displaying neoantigens on HLA molecules on the surface of cancer cells, triggering cytotoxic T cell-dependent immune response . TherefoThe efficacy of cancer therapies is assessed by measuring the tumour volume, analysis of tissue biopsies, and performing peripheral blood assays. However, changes in tumour volume may prove misleading, since the influx of effector immune cells into TME often contributes to increased volume, which is a phenomenon known as pseudoprogression ,78. In aNon-invasive molecular imaging approaches that enable monitoring of systemic and intra-tumoural alterations in immune cell localisation may increase our understanding of the dynamics of various immunotherapeutic strategies. There are multiple techniques for non-invasive cell tracking, such as ex vivo cell labelling and radiolabelled metabolic probes. However, these strategies are associated with potential toxicity to the therapeutic cells, dilution of imaging agents upon cell death, and restricted longitudinal imaging that may limit their clinical translation. In contrast, T cell specific probes made by labelling antibodies or small molecules possess great translation potential. The imaging technologies employed include magnetic resonance imaging (MRI), computer tomography (CT), positron emission tomography (PET), and single photon emission computed tomography (SPECT). Unlike optical cell-tracking methods, PET imaging has high sensitivity and spatial resolution and, thus, may provide insight into immune activity in TME, and subsequently present a tool for evaluating treatment strategies.PET imaging method is a widely used non-invasive clinical diagnostic technique. It tracks the spatial distribution of the PET radiotracer by detecting the 511 keV gamma rays from the positron/electron annihilation events following positron decay of the radionuclide. Owing to the highly distinctive signal, very low levels of radioactivity can be detected. This makes PET imaging a highly sensitive imaging technique . Moreove18F, 68Ga, 89Zr, and 64Cu. Some PET radionuclides have a short half-life (such as 11C t1/2 = 20.4 min) and, therefore, are the reserve of specialist imaging facilities with on-site cyclotrons. Additionally, many other PET radionuclides cannot be easily sourced commercially, such as 44Sc and 124I  by exploiting the high metabolic rate of cancer Zr-DFO-nivolumab demonstrated its safety and ability to quantify PD-1 expression in patients with non-small cell lung carcinoma (NSCLC) [89Zr]Zr-DFO-nivolumab in predicting responses to anti-PD-1 immunotherapy.Different studies have evaluated the potential clinical value of PET imaging of immune checkpoint targets in the assessment of T cell dynamics, cancer diagnosis, and patient stratification prior to initiating immunotherapy. Intact monoclonal antibodies targeting immune checkpoints have been used for PET imaging studies. One example is the radiolabelling of nivolumab with zirconium-89  . Neverth89Zr) is the most widely used radiometal for PET imaging of immune response when mAb is the targeting motif. The long half-life of 78.4 h and the ease of 89Zr-DFO chemistry makes it very attractive for labelling antibodies and smaller antibody fragments, such as minibodies Zr-DFO-antibody is isolated using size exclusion column chromatography at the end of reaction.Zirconium-89  demonstrated a strong correlation between PD-L1 expression and clinical outcome in NSCLC patients [89Zr]Zr-DFO-durvalumab, demonstrated higher tumour uptake in patients with advanced NSCLC who responded to durvalumab. However, uptake of [89Zr]Zr-DFO-durvalumab did not correlate to tumour PD-L1 expression as determined by IHC [89Zr]Zr-DFO-REGN3504 and [89Zr]Zr-DFO-avelumab; however, clinical data are yet to be published Ga-NOTA-(hPD-L1) nanobody for PD-L1 imaging in vivo [68Ga]Ga-NOTA-Nb109, in mapping PD-L1 expression in xenograft tumours [68Ga]Ga-THP-APN09 PET is under clinical evaluation in patients with lung cancer, melanoma, and other solid tumour undergoing anti-PD-L1 therapy Zr-DFO-ipilimumab is another mAb-based PET tracer that was developed to image CTLA-4 expression. Preliminary data from an ongoing clinical study in patients with metastatic melanoma receiving ipilimumab monotherapy reported the feasibility of [89Zr]Zr-DFO-ipilimumab for visualizing and quantifying ipilimumab uptake in tumours [64Cu]Cu-DOTA-ipilimumab in visualising CTLA-4 in NSCLC xenografts Cu–DOTA complex could lead to high liver, kidney, and spleen uptake. Replacing DOTA with a NOTA-like chelator can lead to a more stable complex with 64Cu and can circumvent this issue [64Cu and the resultant [64Cu]Cu–DOTA-antibody could be isolated via size exclusion chromatography.The 12.7 half-life of tibodies ,124. Theis issue ,126. How89Zr]Zr-DFO-ipilimumab is the only PET tracer that is undergoing clinical evaluation for imaging CTLA-4. However, LAG-3 has also been studied as a potential target for PET imaging of immune checkpoints. Furthermore, [89Zr]Zr-DFO-REGN3767, a fully human anti-LAG-3 mAb, was shown to detect LAG-3 expression in mouse tumours [89Zr]Zr-DFO-REGN3767 is under evaluation in a clinical study in patients with diffuse large B cell lymphoma (DLBCL) [68Ga]Ga-NOTA-GP12, a peptide antagonist for TIGIT, was demonstrated to be safe and able to image TIGIT expression in murine models and two patients with advanced NSCLC Zr-DFO-IgG for imaging CD3+ T cells. Evaluation of this PET tracer in murine models demonstrated high uptake by tumours in response to anti-CTLA-4 treatment, which correlated with a subsequent reduction in tumour size [89Zr]Zr-DFO-anti-CD3, imaged the distribution of homeostatic T cells, particularly TILs, in syngeneic mice bearing bladder cancer Ga-NOTA-SNA006a, a nanobody-based tracer targeting CD8, exhibited rapid and persistent uptake in tumour lesions, as well as in CD8-rich tissues in humanised mouse xenografts Zr-DFO-IAB22M2C, a humanised minibody that is biologically inert, is reported to detect CD8+ T cells without affecting T cell proliferation, activation, or function in mouse models [89Zr]Zr-DFO-IAB22M2C was found to accumulate in lymphoid organs and tumour lesions, correlating with infiltration of CD8+ T cells  is expected to be significantly higher than those of small molecules. This, in turn, may potentially limit the clinical application of this imaging probe. Currently, the diagnostic and prognostic potential of [89Zr]Zr-DFO-IAB22M2C in imaging CD8+ T cells in patients treated with immunotherapy is being evaluated in multiple clinical trials; the probe remains one of the most important commercial imaging tools in immuno-oncology . H. H89Zr]Zoncology .+ and CD8+ T cells may capture the dynamics of T cells; however, they do not provide information on the activation and functional state of T cells. The suppressive TME of many malignancies is characterised by the absence of TILs or the presence of exhausted of T cells, which induce immunotolerance. Therefore, characterising the activation and function state of infiltrating immune cells may enable a more accurate prediction of response to cancer immunotherapy. As a result, different PET probes have been developed to image markers that are upregulated on or released by activated cytotoxic immune cells. Such markers are OX40, the IL-2 receptor (IL-2R), granzyme B, and IFN-γ. The PET probes developed for these markers are discussed in this review.The PET probes targeting CD364Cu]Cu-DOTA-AbOX40 that enables imaging of OX40 receptor to monitor activated T cell responses in a clinically relevant in situ cancer vaccine model [89Zr]Zr-DFO-OX40, which has a longer half-life than 64Cu, was developed by the same group to observe the longer kinetics of immune response to a vaccine in a murine glioblastoma model treated with CpG oligodeoxynucleotide [89Zr]Zr-DFO-OX40 in tumour lesions, as well as distant lymph nodes, indicating that the immune response initiated by the vaccine can be analysed in the whole body. Although these studies demonstrate the feasibility of imaging OX40 to detect immune cell activation, smaller constructs that are radiolabelled with short-lived isotopes may be more beneficial, as they are associated with lower radiation exposure.The OX40 marker is a member of TNF receptor superfamily, and its expression is restricted to antigen-specific activated T cells . Alam etne model . Then, fluorobenzoate ([18F]SFB) to affect radiolabelling of the recombinant IL-2 molecule, because of the simplicity of conjugating it with the lysine side chain of a peptide/protein (18F]fluorobenzylidene)amino)oxy)-N-benzyl)acetamide ([18F]FBoxTz). This method allows the whole IL-2 radiolabelling process to be fully automated under GMP compatible conditions with a similar yield to the [18F]SFB method [18F]FB-IL-2 was shown to specifically distinguish between unstimulated and stimulated PBMCs in various murine models [18F]FB-IL-2 was found to be safe in patients with metastatic melanoma receiving ICI therapy, its tumour uptake did not correlate with treatment outcome [18F]FB-IL-2 in four tumour tissue samples. This may be due to competitive binding with endogenous IL-2, as was suggested by the authors of the study; nevertheless, further studies are required to confirm this.Different studies have demonstrated the clinical potential of using radiolabelled IL-2 probes for detecting activated immune cells in chronic autoimmune diseases via SPECT imaging. Gialleonardo et al. have explored PET imaging of activated T cells using AlF have both been used for the labelling of mNOTA-GZP. Indeed, [18F]AlF is an interesting emerging method for the radiolabelling immune molecules. As summarised by Archibald and Allot, its simplicity and efficiency make it a very attractive labelling method [18F]AlF with a suitable chelator, such as 2,2′,2′′-triacetic acid (NOTA). One example of this is the granzyme B imaging agent [18F]AlF-mNOTA-GZP developed by Goggi et al., which was easily synthesized via heating up the fluoride aluminium chloride with a chelator-modified tracer in a suitable buffer at 100 °C for 15 min [68Ga]Ga-mNOTA-GZP and [18F]AlF-mNOTA-GZP exhibit high specificity for granzyme B Cu-DOTA-GRIP B, takes a very different approach for imaging granzyme B Zr-DFO-anti-IFN-γ mAb PET probe was found to detect increased levels of IFN-γ in tumour-bearing BALB/c mice receiving HER2/neu DNA vaccination [89Zr]Zr-DFO-anti-IFN-γ uptake was found to be similar to isotype control, demonstrating a lack of anti-tumour T cell activity. Due to the limitations of mAb as imaging probes, the same group studied the pharmacokinetics and specificity of four 89Zr-labelled anti-IFN-γ diabodies. Only one radiolabelled diabody demonstrated promising in vitro and in vivo properties Zcination . In a mooperties . Neverth18F]F-AraG probe, developed by Namavari et al. for imaging T cell activation and proliferation in cancer, employs comparable radiochemistry to the synthesis of [18F]FDG FDG  (Figure 18F]F-AraG for activated T cells and its feasibility in predicting responses to anti-PD-1 therapy was observed in murine tumour models. A biodistribution study of [18F]F-AraG in six healthy volunteers demonstrated its safety [18F]F-AraG is being evaluated in patients with advanced NSCLC [The specificity of [s safety . Currented NSCLC ,161.+ and CD3+ capture T cell dynamics, they do not provide information on the functional state of cytotoxic T cells. Therefore, tracers targeting IL-2R, granzyme B, OX40, IFN-γ, and AraG may provide more comprehensive information on treatment responses. However, some PET imaging approaches have been associated with unclear results as seen for IL-2R, consequently hindering the clinical application of these tracers. Nevertheless, multiple PET tracers targeting activation/exhaustion markers are being developed and evaluated in clinical studies.PET imaging of cytotoxic T cells is a powerful non-invasive method for characterising immune responses to cancer immunotherapies and, consequently, to aid clinical decision-making for cancer treatment. Despite the growing success of many immunotherapeutic agents, they still face challenges. Therefore, the identification of novel predictive biomarkers and the characterisation of the TME may improve patient selection and treatment evaluation. In this review, we discussed the most recent developments in PET imaging of immune response. The high sensitivity of PET in combination with T cell-specific probes enables quantification of cytotoxic T cell dynamics. Although PET tracers for CD8


Combinatory approaches of epigenetic regulators in T cell-based immunotherapy”, a diverse range of examples are included that cover methodological approaches of multi-omics analysis and biomarker exploration, together with clinical studies and literature reviews of research progress made in current epigenetic and immunotherapy combinatory approaches.T cell-based immunotherapy, which developed based on the understanding of T-cell capacity for antigen-directed cytotoxicity, has emerged as a powerful tool in the armamentarium against cancer . NeverthZhou et al.).Chimeric antigen receptor T (CAR-T) immunotherapy, which utilized genetically modified autologous T cells, has shown promising results in treating patients with blood cancers. The paper by Zhou et al. describes a clinical trial study of anti-CD19 CAR-T cell therapy in patients with relapsed/refractory B-cell lymphoma. Besides therapeutic benefit, they demonstrated that the side effects caused by this CAR-T cell therapy can be successfully managed by administering interleukin 6 antagonist, glucocorticoids, and/or plasmapheresis, which provides an effective and safe treatment regimen for B-cell lymphoma .Leveraging the power of technological advances in molecular biology, recent multi-omics studies, including single-cell RNA sequencing, single-cell assay for transposase-accessible chromatin (ATAC) sequencing, and single-cell chromatin immunoprecipitation (ChIP) sequencing, have provided mechanistic insights into understanding the features of immunotherapy-responsive or resistant T cells, i.e., in T-cell fate determination . Combinivia non-coding RNAs, DNA methylation, and histone modifications are demonstrated to have a strong effect on the phenotypic stability and anti-tumor function of CD8+T cells, leading to varied response rates and therapeutic resistance of T cell-based immunotherapy. One comprehensive review paper in this issue summarizes the current understanding of epigenetic modifications in determining CD8+T-cell fate in cancers. They describe the epigenetic enzymes and intracellular microRNAs in imprinting T-cell epigenomes that drive T-cell functional exhaustion. They also discuss the potential epigenetic interventions to rescue T-cell function for combinatory immunotherapy approaches in cancers . In addition, the paper provided by Carlos-Reyes et al. focuses on non-coding RNAs, in particular circular RNAs (circRNAs), in regulating T-cell functions in response to cancers . This knowledge collectively implies that regulating the complex epigenome of T cells may provide translational implications to advance current immunotherapy for cancer treatments.T cells undergo extensive epigenome remodeling in response to different microenvironmental cues. Epigenetic modifications in vivo imaging technologies that interrogate T-cell responses, metabolic activities, and the immune microenvironment provides promising opportunities. One aspect of in vivo imaging utilizing novel specific positron emission tomography (PET) probes to target key molecules related to immunotherapy also offers a powerful tool to monitor patient response .The importance of developing novel non-invasive biomarkers in monitoring the immunotherapeutic response in patients should also be noted. The recent emergence of quantitative imaging biomarkers, like response . For exaIn conclusion, the burgeoning field of cancer immunotherapy continues to grow as indications for currently approved combinatory therapies expand and the search for novel druggable targets continues. Further investigations into the molecular mechanisms of fate determinations for T cells and also other immune cells will allow us to achieve durable responses and survival benefits for the majority of patients with different cancers.


Data from multiple omics domains were increasingly generated in large-scale tumour studies to enhance our understanding of molecular mechanisms of cancer. We present an integrated cartography of three omics layers combining the transcriptome, methylome, and genome (copy number variations) into a unique mapping scheme which enabled us to decipher functional links within and between the omics domains. Application to lower grade gliomas reveals distinct networks governed either by methylation or copy number variations, both affecting transcriptomics modes of cell activity. The integrated maps provide an intuitive view on tumour heterogeneity across the omics layers distinguishing, e.g., astrocytoma- and oligodendroglioma-like glioma types. In a wider sense, multi-omics cartography deciphers the effect of different omes on tumour phenotypes and their molecular hallmarks with individual resolution.Multi-omics high-throughput technologies produce data sets which are not restricted to only one but consist of multiple omics modalities, often as patient-matched tumour specimens. The integrative analysis of these omics modalities is essential to obtain a holistic view on the otherwise fragmented information hidden in this data. We present an intuitive method enabling the combined analysis of multi-omics data based on self-organizing maps machine learning. It “portrays” the expression, methylation and copy number variations (CNV) landscapes of each tumour using the same gene-centred coordinate system. It enables the visual evaluation and direct comparison of the different omics layers on a personalized basis. We applied this combined molecular portrayal to lower grade gliomas, a heterogeneous brain tumour entity. It classifies into a series of molecular subtypes defined by genetic key lesions, which associate with large-scale effects on DNA methylation and gene expression, and in final consequence, drive with cell fate decisions towards oligodendroglioma-, astrocytoma- and glioblastoma-like cancer cell lineages with different prognoses. Consensus modes of concerted changes of expression, methylation and CNV are governed by the degree of co-regulation within and between the omics layers. The method is not restricted to the triple-omics data used here. The similarity landscapes reflect partly independent effects of genetic lesions and DNA methylation with consequences for cancer hallmark characteristics such as proliferation, inflammation and blocked differentiation in a subtype specific fashion. It can be extended to integrate other omics features such as genetic mutation, protein expression data as well as extracting prognostic markers. Multi-omics high-throughput technologies are producing a steeply increasing number of data sets which are not restricted to only one but consist of multiple omics modalities extracted from the same samples, e.g., in patient-matched tumour specimens. Such multi-omics data offer tremendous opportunities for enhancing our molecular understanding of biological systems, particularly regarding different but mutually linked layers of genomics regulation usually subsumed as the basic “omes” genome, epigenome, transcriptome, proteome and metabolome regulation of gene activity . AberranFor single-omics analysis, we developed a data “portrayal” method based on machine learning using self-organizing maps (SOM) ,19,20. TThis combined double-omics SOM portrayal is not restricted to expression and methylation data. It can be extended to integrate other omics features such as genetic mutation or copy number data to consider their effect directly. In this publication, we pursue this way and present a triple-omics SOM portrayal method which combines patient-matched gene expression (Gex), DNA methylation (Dme), and copy number variation (CNV) data. We applied this method to lower-grade gliomas (LGG) by following another way of our previous research, namely the multi-omics characterization of this tumour type. Thus far, it has been performed by separately analysing each of the different omics modalities and linking the results only in the final step ,35. Our IDH1 or IDH2 gene (IDH-mut) and no co-deletion of Chr1p and Chr19q (Chr1/Chr19 intact), oligodendrogliomas (IDH-O) with IDH-mut and Chr1p/19q codeletions (codel) and IDH-wt astrocytoma/glioblastoma-like tumours. In addition, we collected IDH-A gliomas with single Chr19q deletions without Chr1p co-deletions into a separate class IDH-A’. A schematic workflow of the data analysis is provided in We here studied 122 WHO grade II and III adult-type gliomas  collected from patients which were previously analysed by microarray-based gene expression profiling ,35. The ew, mw, cw, for Gex, Dme, and CNV data, respectively. They were chosen from the interval  and meet the condition ew + mw + cw = 1 (Gene-centric expression (Gex), methylation (Dme), and copy number data (CNV) were preprocessed as described previously  and thenew = mw = cw = 1/3), ensuring balanced couplings between the Gex, Dme and CNV domains in the resulting SOM. Alternatively, one can apply “dominant weights”  resulting in a single-ome topology of the resulting SOM.The combined profile vectors were then clustered into so-called metagene profiles  between their metagene profiles in a pairwise fashion, e.g., between the Gex and Dme, the Gex and CNV; and between the Dme and CNV profiles  to the respective omics score .Function mining was performed using a repository of about 6000 gene sets implemented in oposSOM, which refer to different functional context and which were taken from literature, gene ontology and other sources . The genIDH-wt group collects unmutated (wild type) IDH1 and/or IDH2 (IDH) gliomas. LGG carrying IDH-mutations split into the IDH-O (oligodendroglioma) group with co-deletions at Chromosome1p and Chr.19q (Chr1/19codel), the IDH-A and IDH-A’ (IDH-mut astrocytomas) groups without Chr1/19codel where IDH-A’ in contrast to IDH-A carries a deletion at Chr.19q. Combined gains of Chr.7 (Chr7+) and losses of Chr.10 (Chr10-) constitute a characteristic of WHO grade IV glioblastomas (GBM). These tumours accumulate in IDH-wt LGG . In IDH-mut, LGG Chr7+ and Chr10- appear mostly uncombined in IDH-A and IDH-A’ where the number of tumours with Chr7+ exceed that with Chr10- in IDH-A . IDH-O LGG are characterized by a high amount of TERT promoter methylation. The tumours in each LGG group were ranked with increasing score of the CpG-Island Phenotype (GCIMP)-signature taken from ..35]. HenProfiles of the most pronounced spots illustrate the variations of Gex, Dme and CNV features across the LGG groups and subtypes, e.g., antagonistic overexpression and hypermethylation of IDH-wt which allocates the affected genes in opposite corners (lower left versus upper right) of the map b. This awe = wm = wc = 1/3; see e + wm + wc = 1 would increase or to decrease the relative effect of each of the different modalities. In a previous two-modality (Gex and Dme) combiSOM approach on WHO grade IV glioblastoma data, we tuned the weighting factor between dominant weighting of Gex (we = 0.99) and Dme (wm = 0.99) [we = 0.99 (and wm = wc = 0.005) for the Gex dominant SOM and analogously wm = 0.99 or wc = 0.99 for Dme- and CNV dominance, respectively. As the main result, we found that group-averaged portraits and variance maps of the Gex and Dme-dominated SOM show mostly similar topologies governed by the high variant modules of gene expression and DNA methylation, respectively  would generate SOM landscapes governed by the co-variance between two of the omics domains, thus providing a third option for studying relationships between the omes.Our integrative SOM approach combined the Gex, Dme and CNV modalities applying equal weight to each of them ( = 0.99) . We founectively . In contectively . In geneIDH-gene and/or co-losses on chromosomes 1 and 19. These changes together cause large-scale effects on DNA methylation and gene expression, and in final consequence, associate with cell fate decisions towards oligodendroglioma- (IDH-O) or astrocytoma- (IDH-A), as well as GBM(IDH-wt)-like tumour cell lineages with different prognostic impact [DNA methylation of CpGs in gene promoters, CNV, and gene expression are mutually dependent effects that affect activity of cellular programs. We here presented a method enabling the combined analysis of multi-omics data based on SOM machine learning. It “portrays” the expression, methylation, and CNV landscapes using the same “gene-centred” coordinate system which enables their combined visual evaluation and direct comparison on a personalized and class-related basis for each tumour and subtype, respectively. We applied this combined SOM portrayal to LGG, a relatively well characterized tumour entity which classifies into a series of molecular subtypes defined by genetic key aberrations such as the mutation of the c impact .IDH mutation generates such peaks in the left lower and right upper part of the map which hypermethylate in tumours carrying either the mutated or the intact IDH gene, respectively. Conversely, key CNV associating with IDH-wt and IDH-O tumours more distribute along the other diagonal from the left upper towards the right lower part of the map. This virtually orthogonal distribution of DNA methylation and genetic CNV effects reflects their partial independence. In contrast, variant transcriptome modules spread throughout the whole map because gene expression is modulated by methylation as well as by CNVs preferentially via repressive and direct interactions, respectively. Certain modules such as the G-protein coupled receptor (GPCR) that peak strongly protrude only in the methylation map, thus illustrating that variations in one of the omes does not necessarily transform into variations in another omics layer , Gex (gene expression), and CNV (copy number variation) features . Our mete, e.g.,  for a deIDH1/2 gene(s) are the driving event behind IDH-mut LGG [IDH1/2 proteins in the TCA cycle induces widespread alterations of DNA methylation via an onco-metabolic mechanism. The aberrant oncometabolite 2-hydroxyglutarate (2-HG) inhibits the activity of a series of enzymes erasing or writing methylation marks at the DNA and at histone side chains, which deregulates the epigenetic machinery of the cells, making them more plastic and forming a common progenitor of both IDH-A and IDH-O subtypes. IDH-O gliomas arise after the Chr. 1p/19q co-deletion as genetic hallmark. It deactivates CIC (at Chr. 19q), a transcriptional repressor, which in consequence promotes proliferation, blocks differentiation and, in combination with activating mutations in the promoter of the TERT-gene, supporting survival of IDH-O tumour cells via a telomerase-driven telomere maintenance mechanism (TEL-TMM). IDH-A, in contrast, lacks the Chr. 1p/19q co-deletion, but instead, its pathogenesis is driven by a triple hit mechanism. First, deactivating mutations of the TP53 gene (hit 1), a stereotypical tumour suppressor deactivated in more than 50% of all cancers, accumulate excessive mutations and genomics damage in the progressing cells. Second, deactivating mutations of ATRX (hit 2), encoding a chromatin remodelling enzyme of the SWI/SNF family, alter the chromatin structure in the telomeric regions and promotes cell survival by an alternative telomere maintenance mechanism (ALT-TMM). Third, hit 3 downregulates transcription of SOX2, a transcription factor essential for cell differentiation, via a promoter-enhancer dissociation mechanism induced by aberrant local DNA-hypermethylation, which disrupts CTNF-induced chromatin looping. In consequence, hit 3 blocks differentiation of the neuronal progenitors. Pathogenesis of IDH-wt gliomas is affected by blocked differentiation driven by key CNV at Chr. 7 and 10 and aberrant function of PRC2 and of its components such as EZH2.Particularly, mutations in the -mut LGG ,45. The Hence, overall pathogenesis of LGG is governed by a complex interplay of genetic and epigenetic mechanisms giving rise to different modes of genomics regulation which associate with key functions such as proliferation, inflammation, and cell differentiation in a subtype specific fashion. Our combiSOM identifies mutual relations between these modes in and between the omics layers. For example, one finds that IDH-wt gliomas selectively share activated proliferation with IDH-O while activated inflammatory features are shared with IDH-A. Increasing inflammatory characteristics of IDH-A associates with decaying GCIMP and overall DNA methylation while, conversely, GPCR methylation increases. Our combiSOM maps directly visualize the mutual association between the Gex and Dme layers, which in independent single omics analytics, are not obvious and required additional analytic efforts for their identification. The prognostic maps link molecular features in all three omics layers with potential impact for molecular marker selection.Our analysis provides intuitive answers to important questions such as “What is the best?”, which is frequently asked about multi-omics settings.What omics modality is the best? CNV and DNA methylation are “structural” modalities affecting genes with or without explicit functional consequences, e.g., by copy number losses of whole chromosome arms, e.g., of Chr. 10p, 1p or 19q in LGG  or by laIDH gene, although probably the most distinctive genetic marker, shows only weak differential expression and methylation between the IDH-mut and IDH-wt groups, while conversely, CIC located at Chr. 19 is a suited expression marker to discriminate between IDH-A and IDH-O. Multi-omics cartography in terms of prognostic maps provides a tool to extract such gene signatures of maximum/minimum HR from the different omics domains. Novel genetic and functional markers and signatures for brain tumours are under discussion [What modality provides the best markers? Correlation of characteristic genetic markers with clinical outcome defined three major prognostic groups  considerscussion . Note thscussion  or B-celscussion  show lesWhat subtyping is the best? We independently used expression and methylation data, to refine the genetic groups regarding neuronal-type (NL) LGG of low tumour content distributed over all genetic groups and regarding three to four IDH-A subtypes differing in immunogenic properties partly resembling that observed in pilocytic or mesenchymal astrocytomas  with posWhat integration method is the best? Our combiSOM method enables integrating the different domains with variable weights. Equal-weighting combines the omics layers in a balanced fashion, thus revealing mutually integrating features in the gene state space reflecting the inter-omics network of genomics regulation. Tuning the weights towards single-ome dominated landscapes conversely reveals co-variant genes regarding the dominant layer and particularly, non-covariant ones, e.g., if GPCR expression on the average is weakly affected by methylation. We recently used these dominant-omics settings to decipher the cooperation between epigenetics and transcription factor networks for cell fate decisions . Hence, the overall answer on all these questions is a Solomonic “it depends” one, where the multi-omics view provides more flexibility and a wider, holistic view in data space for selecting markers and subtypes. More importantly, multi-omics data are mandatory for the comprehensive understanding of the whole repertoire of genomics regulation underlying cancer genesis and development. A similar “Solomonic” conclusion was drawn in a systematic benchmark study comparing multi-omics integration methods on cancer data . The effOur publication illustrates the potential of multi-omics SOM cartography. We selected a hitherto well-characterized LGG data set as a worked example for illustration ,25,35. OMulti-omics SOM cartography allows for disentangling the diversity of regulatory modes of cell functions in terms of easy-to-interpret gene-centric data landscapes. They visualize aberrant changes related to complex diseases such as cancer. The method is not restricted to the triple-omics data used here. It can be extended to integrate other omics features such as genetic mutation or protein expression data. “Phenotype” association with survival of the patients and other clinical characteristics potentially extends the visualization options of the method. Due to the growing use of multi-omics data, we expect that these options will become important for future progress in cancer bioinformatics.


Immune checkpoint inhibitors (ICIs) are the most notable breakthrough in tumor treatment. ICIs has been widely used in tumor patients, but its wide range of immune-related adverse events (irAEs) should not be ignored. irAEs can be involved in any organ system, including immune-related cardiotoxicity. Although the cardiotoxicity induced by immune checkpoint inhibitors is rare, it is extremely lethal and has attracted increasing attention. PD-1 and PD-L1 are expressed in human cardiomyocytes, so the application of PD-1/PDL-1 inhibitors can cause many adverse reactions to the cardiovascular system. This review summarizes the latest epidemiological evidence on the cardiovascular toxicity of programmed cell death protein-1(PD-1)/programmed cell death ligand-1(PD-L1) inhibitors and the clinical manifestations, as well as the potential pathological mechanisms. These updates may provide a novel perspective for monitoring early toxicity and establishing appropriate treatment for patients with ICI-related cardiotoxicity. Tumor immunotherapy is an important clinical strategy for the treatment of various solid and hematological malignancies . Immune The therapeutic mechanism of ICIs is based on targeting immunosuppressive checkpoints, including cytotoxic T lymphocyte-associated protein-4 (CTLA-4), programmed cell death protein-1 (PD-1), and PD-1 ligand (PD-L1), which prevents the immune escape response of tumor cells through reactivating inoperative cellular immunity mediated by these molecules . CurrentWhile activating T cell anti-tumor effects, ICIs can produce a series of autoimmune toxicities due to the activation of more responsive T cells, resulting in the occurrence of immune-related adverse events (irAEs) . ApproxiIn tumor immunotherapy, ICIs can lead to the development of immune-related cardiotoxicity. Although ICI-related cardiotoxicity is rare, the mortality rate is extremely high . The fatReports of cardiotoxicity in ICI clinical trials are rare. The most common manifestation of cardiotoxicity is myocarditis . A retroA meta-analysis of 22 clinical trials of ICI treatment for patients with lung cancer reported that the incidence of ICI-related myocardial infarction was 1% . Rapid pAt present, there are no standard diagnostic criteria for the clinical diagnosis of ICI-related cardiotoxicity. A diagnosis of exclusion is generally based on clinical manifestations and auxiliary examination results. The results of the ICI clinical trial and reports of current practice suggest that the manifestations of ICI-related cardiotoxicity are diverse, including myocarditis, pericardial disease, arrhythmia, myocardial infarction, and left ventricular (LV) dysfunction without evidence of myocarditis, such as Tako-Tsubo cardiomyopathy (TTC)  Figure . Some ofICI-related myocarditis is the leading early ICI-related cardiovascular adverse event, and it can be acute and fulminant . AccordiICI treatment can be associated with pericardial diseases, including pericarditis, pericardial effusion, and pericardial tamponade. ICI-related pericarditis can occur in isolation or alongside myocarditis . Pericar+ T cells. CTLA-4 inhibits T cell activation by binding to the ligands B7-1 and B7-2. CTLA-4 has a stronger affinity for B7-1 and B7-2 than CD28. Ipilimumab (anti-CTLA-4 antibody) can broadly enhance the immune response dependent on CD4+ cells and was initially approved for the treatment of melanoma. ICIs that are neutralizing antibodies against CTLA-4 and PD-1 can activate the anti-tumor immune response and inhibit the growth of tumor cells by blocking the negative inhibitory effect of PD-1 and CTLA-4 on T cells. However, because the “PD-1–PD-L1 axis” and CTLA-4 pathway also mediate autoimmune damage,  have different effects on the heart. Some cells can promote whereas some can inhibit the occurrence and development of cardiovascular diseases . GisterAccording to the severity of the condition, ICI-related cardiotoxicity is divided into four levels: 1) level 1, which includes asymptomatic with laboratory abnormalities ; 2) level 2, which includes mild symptoms with screening test; 3) level 3, which includes moderately abnormal or mildly active symptoms; and 4) level 4, which includes moderate to severe, even life-threatening, decompensated heart damage requiring abnormal intravenous medication or interventional therapy. . The firDue to the long functional half-life of ICIs, terminating ICI treatment may not immediately reverse its cardiotoxicity. The decision to stop ICI treatment requires a thorough discussion between an oncologist and a cardiovascular expert. Current guidelines recommend ending ICI treatment when patients develop grade 3 or 4 ICI-related toxicities. However, stopping ICI treatment for patients with asymptomatic abnormalities in the laboratory (level 1) or abnormal detection and mild symptoms (level 2) remains controversial. Some studies reported that after the test is normalized, for patients with grade 1 or 2 ICIs-related toxicity, ICI treatment can be considered again, but ICI treatment should be permanently discontinued in case of grade 3 and 4 toxicity. According to the latest guidelines of ASCO, patients with any ICI-related toxicity greater than grade 1 (asymptomatic biomarker elevation) should permanently stop ICI treatment .If necessary, patients with ICI-related heart injuries can receive effective supportive treatment. For example, patients with heart failure should receive medications recommended by the guidelines, including β-blockers and ACEI/ARB. Patients with life-threatening tachyarrhythmia can use appropriate antiarrhythmic drugs, such as intravenous amiodarone. According to the needs of advanced conductive disease, temporarily or possibly permanently placing a pacemaker should be considered. . If the Immunosuppressive therapy can also be applied to overactive T cell responses. Corticosteroids are currently considered as the first-line immunosuppressive drug for ICI-related myocarditis. .However,ICIs has a significant anti-tumor effect, which brings good news for the treatment of many refractory or advanced tumors. As ICI treatment has expanded to encompass a variety of cancer types, and more novel ICIs are entering clinical trials, more patients receive the benefit from the novel immunotherapy. But they will also experience serious irAEs, which usually force them to abandon treatment or lead to death. Actually, ICI-mediated cardiotoxicity is relatively rare, but when it does occur clinically, it is often serious and potentially fatal. Current treatment strategies still struggle to correct heart injury and cardiac dysfunction. Most deaths have been reported so far. Meanwhile, ICI-related cardiotoxicity also limits the participation of patients with underlying cardiovascular diseases in clinical trials of ICIs, which tremendously narrows the application. At present, the pathological mechanism of cardiotoxicity after ICI treatments is unclear, and the explanation of cardiotoxicity induced by excessive activation of T cells is still incomplete and controversial, which thus greatly restricts the modification of clinical treatment plans and the development of novel therapy. Therefore, it is inevitably urgent to understand ICI-related cardiovascular side effects, predisposing risk factors, and the underlying pathological mechanisms. Moreover, it is indeed important to monitor early toxicity and establish appropriate treatment for patients with ICI-related cardiotoxicity. Close collaboration between cardiologists and oncologists is needed to improve the outcomes and survival of patients with cancer receiving ICIs. Additionally, prospective studies aiming to record and characterize cardiac function during ICI therapy are necessary, and systematic registration of patients with ICI-related cardiotoxicity will help to develop standardized treatment recommendations for this collective.


Sex determination in dioecious plants has been broadly and progressively studied with the blooming of genome sequencing and editing techniques. This provides us with a great opportunity to explore the evolution and genetic mechanisms underlining the sex-determining system in dioecious plants. In this study, comprehensively reviewing advances in sex-chromosomes, sex-determining genes, and floral MADS-box genes in dioecious plants, we proposed a convergent model that governs plant dioecy across divergent species using a cascade regulation pathway connecting sex-determining genes and MADS-box genes e.g., B-class genes. We believe that this convergent mechanism of sex determination in dioecious plants will shed light on our understanding of gene regulation and evolution of plant dioecy. Perspectives concerning the evolutionary pathway of plant dioecy are also suggested. Populus spp.), kiwifruit (Actinidia spp.), garden asparagus , papaya (Carica papaya L.), spinach (Spinacia oleracea L.), hemp (Cannabis sativa L.), hardy rubber tree (Eucommia ulmoides Oliver), and pistachio (Pistacia vera L.). Notably, some widely-cultivated crops such as hexaploid persimmon (Diospyros kaki Thunb.), grape (Vitis vinifera L.), and strawberry (Fragaria × ananassa Duch.) are domesticated from their close dioecious relatives  of species are dioecious, distinct from the animal kingdom where gonochorism is common  was published  before the fineX (21.9 Mb) and Y (22.6 Mb) chromosomes were fully constructed with Hi-C reads (500–700 bp) . There are three stages in deciphering SDR of dioecious plants that have been undertaken: (i) Traditional molecular techniques stage: genetic linkage mapping and bacterial artificial chromosome (BAC) were employed to overcome the encountered difficulties, for example, when assembling the Y chromosome of papaya in 2004  and garden asparagus   is a type-C cytokinin response regulator. Transgenic expression of SyGI in Arabidopsis thaliana (L.) Heynh. and Nicotiana tabacum L. resulted in suppression of carpel development but no effect on stamen  is critical for viable pollens formation, functioning as an M factor. Transgenic expression of FrBy converted A. chinensis females into hermaphroditic individuals  . Most spA. officinalis, Asparagaceae) also has XX/XY sex chromosomes and a similar small-sized SDR (~1 Mb) as seen in kiwifruit  and aspTDF1 (Defective in Tapetum Development and Function 1) expressed specifically in males  resulted in asexual neuters where neither carpels nor stamens developed normally. When both SOFF and aspTDF1 genes underwent knockout, males directly changed into females. All these findings provided robust evidence that the two Y-encoded genes SOFF (SuF factor) and aspTDF1 (M factor) were physically linked at SDR to co-determine the sex of the garden asparagus. Most notably, the male-promoting genes in kiwifruit (FrBy) and asparagus (aspTDF1) both function in tapetum for male flower fertility  and date palm (Phoenix dactylifera L.), but the “two-gene model” can most likely be applied to them  that were specifically expressed in male flowers were determined as strong sex-determining candidates   of Caucasian persimmon (D. lotus) contained one pseudogene OGI (Oppressor of MeGI) which exhibited male-specific expression. The OGI had an autosome-located duplicate gene, MeGI  which showed female-biased expression in floral buds. Importantly, OGI housed two identical inverted repeat sequences (IRs) which generated hairpin RNAs and 21-nt small RNAs (sRNAs) to return silence MeGI via RNA interference (RNAi) . They consequently revealed an XX/XY system presence in species belonging to both section Tacamahaca  and Aigeiros . A small-sized (~100 Kb) SDR was identified in the Y chromosome (Chr. 19) of P. trichocarpa. It contained 12 protein-coding genes, including A. thaliana orthologs ARR17 (Arabidopsis Response Regulator 17) and MET1 (Methyltransferase 1). Subsequent studies on P. balsamifera further revealed that ARR17 probably played a direct role in poplar sex determination   was seated at the SDR of P. deltoids and P. tremula   at the SDR of the W chromosome , B-class genes AP3 (APETALA3) and PI (PISTILLATA), and C-class gene AG (AGAMOUS) were first discovered in A. thaliana, the model plant   and C-class (SpAG) genes documented that suppression of B-class expression converted male flowers into a female, indicating that regulation of B-class genes was associated with dioecy establishment in spinach  of Thalictrum dioicum L. (Ranunculaceae) were known to be only expressed in male flowers but not in any stage of female flowers  and Diospyros (Ebenaceae). In P. tremula, B-class gene PI was highly expressed in the arr17 CRISPR mutants , in contrast to its low expression level in the isogenic females (ARR17)  was simultaneously and highly derepressed in arr17 mutants. On the other hand, UFO encoded an F-box protein as a transcriptional cofactor with LFY (LEAFY) to activate the expression of B-class genes -ARR17-UFO-PI controlled the sex of P. tremula  which is an upstream repressor of floral B- and C-class genes . In D. kaki, a 268-bp SINE-like element inserted into the promoter region of the OGI gene repressed its expression and subsequently produced female flowers  that is toggled on off by its SDR-located pseudogene  on the Y chromosome. On the other hand, in both lineages, sex-determining genes ultimately function on B-class genes forming a regulatory cascade, i.e., (ΨARR17-IR)-ARR17-UFO-PI in Populus and OGI-MeGI-SVP-PI in Diospyros. Moreover, earlier work on S. latifolia  overlaps with the C-class gene (AG) and ultimately gets fixed at the population level. Only male flowers develop when B-class genes are normally expressed (Persimmon (Ebenaceae) and poplar  diverged ~150 million years ago and possess distinct unisexual flowers as described previously  Diggle , but thexpressed , and onlxpressed .AP3/PI), such as the ARR17 in poplar  in D. lotus  and ZZ/ZW  in a simple way  gene acting alone as a sex determinant   may be directly regulated by the feminized genes, omitting the middle module of activators  or repressors . Yet this possibility remains to be further verified. And third, plant sex determination may also affect other important traits in addition to floral characteristics  and the Innovation Project for Forestry Science and Technology in Guangdong (2021KJCX015).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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The importance of biologically active lipid mediators, such as prostanoids, leukotrienes, and specialized pro-resolving mediators, in the regulation of inflammation is well established. While the relevance of cholesterol in the context of atherosclerosis is also widely accepted, the role of cholesterol and its biosynthetic precursors on inflammatory processes is less comprehensively described. In the present mini-review, we summarize the current understanding of the inflammation-regulatory properties of cholesterol and relevant biosynthetic intermediates taking into account the implications of different subcellular distributions. Finally, we discuss the inflammation-regulatory effect of cholesterol homeostasis in the context of SARS-CoV-2 infections. The high incidence of hypercholesteremia, i.e., pathologically elevated plasma cholesterol levels, remains a matter of great concern, as the concomitantly elevated levels of low-density lipoprotein (LDL) cholesterol pose a major risk factor for the development of cardiovascular diseases such as atherosclerosis . In atheWith the recent advent of the concept of immunometabolism , the tigde novo synthesis, storage, and export. Cells take up cholesterol from the plasma, where it is transported predominantly packaged in LDL particles, via LDL receptor (LDLR)-mediated endocytosis  to satisfy their cholesterol demands (via ATP-binding cassette A1 (ABCA1) or ABCG1 and loaded onto high-density lipoprotein (HDL)  .The delicate cholesterol balance is largely controlled by two opposing transcription factors: Sterol response element-binding protein 2 (SREBP2), which, in response to cholesterol depletion at the ER, is escorted by SREBP cleavage-activating protein (SCAP) from ER to Golgi, where it is cleaved by site 1 protease (S1P) and S2P. The N-terminal transcription factor domain then localizes to the nucleus, and facilitates the expression of target genes, which are important for cholesterol biosynthesis and import . In contCholesterol homeostasis and immune responses are tightly intertwined in a bidirectional manner. Since the present mini-review focuses on the effects of cholesterol (and cholesterol precursors) on inflammatory responses in innate immune cells, we refer the readers to excellent reviews for details on the reprogramming of cholesterol metabolism upon infections .A general reduction in the cholesterol biosynthetic flux was described to spontaneously induce interferon-stimulated genes (ISGs) , and to As exemplified by the pro-inflammatory character of foam cells laden with modified LDL-cholesterol in atherosclerosis , high chIn addition to total cellular cholesterol levels, its intracellular distribution appears critical for the inflammatory functions. For example, undisturbed cholesterol trafficking to the ER was required to enable activation of nuclear factor ‘kappa-light-chain-enhancer’ of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling, and consequently enhanced expression of the pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in response to excess amounts of free cholesterol . SimilarFurthermore, cholesterol, like other membrane lipids, affects the localization of various pattern-recognition receptors (PRRs) to specific organelles and/or membrane microdomains known as lipid rafts, which again is critical for the regulation of their activity. For further details, readers are referred to comprehensive reviews . Therefode novo synthesis, cellular export of cholesterol by ABCA1/G1 transporters controls total and subcellular cholesterol levels, and consequently influences inflammatory responses. For example, intracellular cholesterol accumulation in ABCA1-deficient macrophages increased the expression of a broad range of inflammatory mediators upon LPS stimulation , which is characterized by mevalonate kinase deficiency (MKD) accompanied by elevated mevalonate levels , further correlated with progression of atherosclerosis, as well as with enhanced type I IFN responses and NLRP3-dependent inflammasome activation , reduced the expression of ISGs and pro-inflammatory cytokines after LPS treatment of murine macrophages . Reducedtivation . Of noteDesmosterol is the direct precursor of cholesterol in the Bloch pathway. It was described to exert mostly anti-inflammatory functions by activating LXR. Accordingly, the above-described atherosclerosis-promoting phenotype in mice overexpressing DHCR24 in myeloid cells was proposed to result from the depletion of desmosterol, leading to impaired LXR activation and mitochondrial reactive oxygen species formation . Along tIn contrast, 7-DHC, the direct precursor of cholesterol in the Kandutsch-Russell pathway, was shown to exert pro-inflammatory functions. Specifically, elevated cellular 7-DHC levels, due to deficiency of 7-DHC reductase (DHCR7) or exogenous supplementation of 7-DHC, activated PI3K/AKT3, which contributed to increased IRF3 phosphorylation and type I IFN responses upon viral infections .via alterations of membrane compositions (via an activator protein-1 (AP-1)-dependent increase in TLR expression in macrophages in the context of viral infections  induce massive inflammatory responses. In severe cases of the resulting coronavirus disease 2019 (COVID-19), inflammatory events progress to a systemic inflammatory disease syndrome (SIRS), which correlates with poor disease prognosis . ImportaConclusively, we speculate that the cholesterol biosynthetic flux and/or levels of certain intermediates or cholesterol itself, as well as their intracellular distribution, might be directly involved in the systemic inflammatory progress of severe COVID-19 cases. This might provide novel opportunities for the development of molecular-targeted, disease stage-tailored interventions for COVID-19 patients. Specifically, while general cholesterol lowering measures bear protective potential during early stages of the disease by attenuating viral entry, the multi-facetted, partially contradictory effects of cholesterol and its biosynthetic intermediates likely require more sophisticated interventions strategies to prevent the detrimental hyper-inflammatory systemic course of the disease.