The NIH operationally defines PASC as the failure to recover from acute COVID-19, or those persistently symptomatic for > 30 days from onset of infection, with any pattern of tissue injury that remains evolving including the nervous system. Online hosted surveys enrolling thousands of subjects employing mobile apps for symptom tracking to obtain real-world data and evidence provide useful information substantiating PASC in adults [The 2019 novel coronavirus (2019‐nCoV [COVID-19]) epidemic is caused by the novel severe acute respiratory syndrome-coronavirus-2 (SARS-nCoV-2 or SARS-CoV-2). There are reviews of the acute neurological illness in adults [This paper describes the detailed evaluation and treatment of an adolescent with PASC manifesting progressive post-infectious central, peripheral, and autonomic nervous system .18Fluorodeoxyglucose (FDG) positron emission tomography (PET) fused to 3-Tesla non-contrast brain magnetic resonance imaging (MRI) with 3D rendering was performed using volumetric software. Mayo Clinic  serum autoantibody (ENS2) panel screened for autoimmune encephalopathy. Twenty-channel electroencephalography (EEG) was performed in the awake and drowsy states. Lumbar cerebrospinal fluid (CSF) was assayed for infectious, immunological, and cytologic parameters.The initial diagnosis of acute COVID-19 infection and immunity was confirmed by a positive reverse-transcriptase polymerase-chain-reaction (RT-PCR) on a nasopharyngeal swab, and acquired immunity was ascertained by the presence of elevated serum SARS-CoV-2 IgG-specific antibody. Electrodiagnostic studies (EDX) were performed in three limbs according to standard methods . EpidermA 12-year-old girl without significant past medical history was initially well until March 2020 when following exposure to other family members who tested positive for COVID-19 infection she contracted an upper respiratory infection (URI), loss of taste, and excessive fatigue. She failed to recover by July 2020 while developing progressive burning pain, limb weakness, and slurred speech and impaired cognition, such that by July 2020 she was bedbound. There was no history of seizures. There was concern that she might be suffering from a conversion disorder. Examination in September 2020 showed mild delirium. There was weakness versus gravity in the legs, resistance in the arms, with stocking sensory loss to vibration, cold temperature, and pin prick, and areflexia. EDX showed mixed chronic distal demyelinating and axonal changes. Thigh ENF density was 16.3 ENF/mm skin  and calf ENF density was 8.9 ENF/mm  , as in this patient, exhibit similar pathogenic SARS-CoV-2 IgG anti-spike (S) antibody profiles with comparatively lower levels of neutralizing activity and anti-nucleocapsid (N)-specific antibodies associated with a reduced protective serologic response . Second,There are no reported studies of brain PET/MRI studies in pediatric COVID-19 neurological illness; however, affected adults show hypometabolism in multiple cortical areas in acute  and lateLaRovere and colleagues  describe123I-meta-iodobenzylguanidine (MIBG) in suspected cases of sympathetic denervation associated with dysautonomia in PASC to assess the integrity of the cardiac ANS [Dysautonomia has been reported in COVID-19-related GBS  with frediac ANS .3) that posits a multiplier effect of infection, immunity, and inflammation; which conditioned by environmental and genetic predisposing factors, may be the source of host autoimmunity [PASC can be described by the acronym, I-Cubed (Iimmunity . The undimmunity  as well immunity . It is u


Plasmodium falciparum, aspartyl proteases of P. falciparum (plasmepsins) and the Sars-CoV-2 viral proteases. Despite some unfulfilled expectations over previous decades, the three reviewed targets clearly demonstrate that selective protease inhibitors provide effective therapeutic solutions for the two most impacting infectious diseases nowadays—malaria and COVID-19.Therapeutic agents with novel mechanisms of action are urgently needed to counter the emergence of drug-resistant infections. Several decades of research into proteases of disease agents have revealed enzymes well suited for target-based drug development. Among them are the three recently validated proteolytic targets: proteasomes of the malarial parasite  Babesia, vectored by Ixodes ticks, can be passed from animals to people and cause zoonotic diseases (zoonoses) [Infectious diseases, along with starvation, limited water resources and the lack of shelter, are among the main factors threatening the health and prosperity of the world’s growing human population. Significant proportions of infectious diseases are caused by parasites , the mosoonoses) .Proteolysis is the breakdown of proteins via enzymatic hydrolysis of peptide bonds linking their amino acid chains. Uncatalyzed proteolysis is extremely slow, which is why living organisms have developed enzymes catalyzing peptide bond hydrolysis. These enzymes, collectively referred to as proteases, have been present since the beginning of evolution . ProteasTargeting proteases with low-molecular-weight inhibitors is a valid therapeutic approach and some protease inhibitors have been developed into highly successful drugs for various diseases including hypertension, diabetes and specific types of cancer . ProteolTrypanosoma cruzi, causing Chagas disease. Studies with vinyl-sulfone, an irreversible inhibitor of cruzain K777 (aka K11777), displayed its effectiveness in preclinical models of T. cruzi infection, including immunocompetent and immunodeficient mice and dogs, and has been shown to be effective against other parasitic infections including schistosomiasis, hookworm infections and cryptosporidiosis [Since the discovery and approval of HIV-PIs, targeted protease inhibition by low-molecular-weight compounds is considered to be a potential strategy against parasite infections. The papain-like cysteine protease cruzain (aka cruzipain) has been shown to be essential for the viability and virulence of ridiosis . In the following years, inhibition of proteolytic enzymes fell far short of initial expectations as a therapeutic strategy . This reTight regulation of the cellular proteome is critical for normal cellular function, survival and proliferation. Part of the regulatory network is the control of protein synthesis and degradation. In most eukaryotic cells, this control is maintained by the ubiquitin–proteasome system (UPS) . Its finPlasmodium species [P. falciparum [P. falciparum infection during its asexual multiplication in host erythrocytes [Because certain cancer cells are sensitive to proteasome inhibitors, selective proteasome inhibition has become a therapeutic strategy for some types of oncologic disorders. Three proteasome inhibitors—carfilzomib, bortezomib and ixazomib—have been approved for the treatment of multiple myeloma . Moreove species ,22. It wlciparum . Notablyhrocytes .P. falciparum by bortezomib and MG-132 [P. falciparum replication, being able to reduce parasitic loads in Plasmodium berghei-infected mice [P. falciparum when compared with human foreskin fibroblasts [P. falciparum compared with the mammalian proteasome, with potential for a further increase in their selectivity indexes by chemical modifications [P. falciparum proteasomes [P. falciparum proteasome [P. falciparum proteasome inhibitors act on parasite strains that are resistant to treatment with currently used antimalarials. The effectiveness of various inhibitors against different proteasomal subunits underscores the potential value of treating malaria with combinations of inhibitors in order to minimize the emergence of drug resistance [Numerous new generations of compounds have been identified since the initial discovery of the selective inhibition of d MG-132 ,25. Librted mice . An exteroblasts . Screeniications . Construications . To aid teasomes . More reoteasome . The selsistance . Proteassistance .P. falciparum, plasmepsins , are structurally and evolutionarily related to human pepsin and lysosomal cathepsin D . These enzymes use two aspartic acid residues in their active site and excel in their ability to specifically find a unique cleavage site within protein bonds to cleave proteins into large peptides. Therefore, they often function as specific endopeptidases performing important biological functions. In Apicomplexan parasites, the cathepsin-D-like aspartyl proteases (ASPs) underwent function-driven evolution by duplication and mutation of the ancestral ASP protease-encoding gene. The subsequent development into six evolutionary subgroups (ASP clades A–F) is associated with various functions important for the parasitic way of life and the complicated course of apicomplexan lifecycles [P. falciparum genome encodes ten related ASPs, collectively referred to as plasmepsins (abbreviated as PfPMI-X), with plasmepsin III being tagged as a histo-aspartyl protease (HAP) [P. falciparum host red blood cells, hemoglobin is used as a source of amino acids to meet the parasite’s nutritional requirements for growth and maturation. Therefore, PfPMI, PfPMII, PfPMIV and HAP, located in the digestive vacuole of merozoites, were initially considered to be the enzyme targets of HIV-PIs. However, this was later refuted with reference to considerable functional redundancy of the P. falciparum vacuolar digestive system, where plasmepsins and cysteine hemoglobinases  act synergistically, greatly reducing the effects of targeted inhibition of digestive plasmepsins [P. falciparum and are important for the development of malaria in mosquito vectors. The roles of residual plasmepsins PfPMV (ASP clade D), PFPMIX and PfPMX (both ASP clade C) were elucidated for the first time over the last decade. This was due to remarkable progress in designing functional genomic tools for P. falciparum. At present, these enzymes represent one of the most promising molecular targets for the development of new antimalarials.Aspartyl protease of fecycles ,35. The se (HAP) . Plasmepse (HAP) . During smepsins . PfPMVI,P. falciparum produces hundreds of effector proteins that are released to the parasite-surrounding parasitophorous vacuole and beyond into the infected host cell. This is modified to enable intracellular survival and multiplication of the parasite [P. falciparum [Plasmodium translocon of exported proteins (tagged as PTEX) [P. falciparum, PfPMV represents a dual therapeutic as well as transmission-blocking drug target [P. falciparum asexual stages in vitro. The structural properties of WEHI-916 have been further improved by the substitution of P3 arginine with canavanine (cav) [P. falciparum asexual stages than WEHI-842 [Upon invasion of host erythrocytes, parasite . An impolciparum . PfPMV ilciparum , enablinas PTEX) . PfPMV ig target . PfPMV cg target . The firne (cav) . The novne (cav) . Thus faWEHI-842 .Toxoplasma gondii homologue TgASP3 [P. falciparum includes a non-secretory structural part consisting of a conoid, polar rings and subpellicular microtubules. These structures are accompanied by several types of secretory organelles, namely filamentous micronemes, claviform rhoptries, dense granules and exonemes. These organelles secrete a vast number of proteins that mediate invasion and egress of host cells and modify both the surface of infected erythrocytes and their surrounding environment. Many of the secreted effector proteins are produced in the form of inactive precursors requiring proteolytic activation by specific proteases. This regulatory mechanism consists of a whole series of proteolytic events that are essential for egress and invasion of host erythrocytes  is involved in merozoite surface remodeling and parasite egress . Subtilie TgASP3 .PfPMIX/X are considered great antimalarial targets, because they can be selectively inhibited by small compounds such as the hydroxy-ethylamine inhibitor 49c  or amidopro  and cysteine papain-like protease PLpro [pro have been reported to date. Among them are repurposed drugs designed for other applications as well as de novo designed compounds based on the 3-dimensional structure of Mpro , which emerged in 2002–2003, was found to recognize the tetrapeptide LXGG motif in coronavirus polyproteins. Hydrolysis of peptide bonds on the carboxyl side of glycine at the P1 position leads to the release of nsp1, nsp2 and nsp3 proteins, which are essential for viral replication [pro activity fundamentally alters the host’s immune responses to viral infection [pro protease of the currently emerging coronavirus (S-CoV-2-PLpro) possesses a high level of sequence and structural similarity to S-CoV-PLpro and has been characterized for identical roles in virus reproduction and alterations of immune responses [pro can therefore inhibit its dual role in promoting viral replication and in inhibiting innate immune responses during acute COVID-19 infection. Analogous enzyme characteristics enable immediate application of previous knowledge about SARS-CoV-1 in the search for effective drugs based on the inhibition of S-CoV-2-PLpro. Several pieces of work have already described S-CoV-1-PLpro drug-repurposing studies against S-CoV-2-PLpro [pro are protein-substrate and protein-inhibitor 3D structural studies. The first approach helped to explain the specificity of S-CoV-2-PLpro for ISG15 and longer Lys48-linked ubiquitin chains, leading to the identification of inhibitors that show promising antiviral activity in a SARS-CoV-2 infection model [pro [pro in a complex with GRL0617 indicates that GRL0617 is a non-covalent inhibitor that resides in the ubiquitin-specific protease (USP) domain of S-CoV-2-PLpro. Moreover, GRL0167 prevents binding of ISG15 C-terminus to S-CoV-2-PLpro and the binding pocket in S-CoV-2-PLpro contributes disproportionately to the binding energy, which makes it a hot spot for drug discovery [The third example confirming the establishment of protease-inhibition-based drug development can be found among the recent approaches employed to develop an effective COVID-19 chemotherapy. Coronaviruses, including SARS-CoV-2, contain a genome composed of a long single-stranded RNA molecule that encodes two long polyproteins, pp1a and pp1(a)b. These polyproteins include a complex of proteins for replication/transcription of genetic information in host cells, several structural viral proteins and two proteases: SARS-CoV-2 major protease Mse PLpro . Both eniewed in ). The folication . In vitrlication , S-CoV-Pnfection ,58. Thisesponses . Targete-2-PLpro ,58,59. Aon model . The secThe analogy with SARS-CoV also helped to quickly describe the molecular mechanism of SARS-CoV-2 invasion into cells of the human respiratory system . ShortlyThe initial disillusionment with protease-based chemotherapy originated from the intolerable toxicity of protease inhibitors and their limited bioavailability. Although the clinical introduction of HIV-PIs and their constant use as a part of a highly effective antiretroviral therapy (HAART) has resulted in a dramatic decline in HIV-related morbidity and mortality, reflected in the prolonged lifespan of HIV patients, it often resulted in serious side effects such as insulin resistance leading to type 2 diabetes . AlthougWhile previous chapters outlined novel protease targets for malaria and COVID-19, here we will assess the potential drawbacks of small molecule inhibitors designed to inhibit these enzymes. “Tailoring” molecular structures of novel compounds can certainly lead to more effective and lower toxicity drugs. The danger of off-target effects can be initially limited by the characterization of the exact biological roles of target proteases and by correct estimations of unwanted cross-activity of inhibitory compounds. Molecular structuring has now been assisted by the accessibility of multiple DNA and protein sequence datasets, the availability of reliable functional genomic tools and rapid advances in protein structure observation, prediction and design. The adverse effects of inhibitors of the HIV-PIs result from the lack of specificity for the HIV proteases, which is a more distantly related enzyme to human cathepsin D, E and pepsin enzymes, than malarial plasmepsins. This highlights the potential toxicological risks caused by inadequate selectivity for plasmepsins in the treatment of malaria, as reported recently . This woP. falciparum is still comparable to the parental compound [S. cerevisiae, biochemical assays and molecular modeling studies confirm that this activity is due to specific inhibition of the β5 subunit of the proteasome. Altogether, these findings create a strong premise for minimal toxicity and side effects of new antimalarials based on proteasome inhibition. Additionally, the emergence and rapid spreading of novel SARS-CoV-2 across the globe enhanced the use of in silico tools such as integrated machine-learning-based drug-repurposing strategies. Although the outputs of such studies await further experimental confirmation, compounds resulting from these analyses have much better in silico safety profiles when compared to existing antivirals inhibiting SARS-CoV-2 proteases [A good example of tailoring effective inhibitors that widen the therapeutic window by reducing host toxicity are malarial proteasome inhibitors based on carmaphycin B, a natural proteasome inhibitor consisting of four structural subunits: leucine epoxyketone (P1), methioninesulfone (P2), valine (P3) and hexanoic acid (P4) moieties . Studiescompound . The learoteases .pro). This further confirms rational design of protease inhibitors as an established platform for drug development, applicable to such challenges as the ongoing COVID-19 outbreak. In addition, monoclonal antibodies (mAbs) should be considered for future applications because they have already been demonstrated to inhibit pathogenic proteases with desired selectivity [This review focuses on the three most significant examples of successful progress in determining enzymatic targets for novel protease-based drug therapies. Inhibitors of these proteolytic enzymes represent novel drug candidates for the treatment of the two most affecting infectious diseases of human populations to date. The overall goal of this review is not to provide a comprehensive insight into the topic, but rather it should serve as a brief yet timely summary for readers working on identification and characterization of molecular targets in the development of novel therapeutic strategies for various other infectious diseases. We believe that the proteolytic targets described here for malaria and COVID-19 provide sufficient evidence to return the spotlight to protease-based drug development as an established approach to innovative therapies. This especially resonates in these times of the persisting COVID-19 pandemic, when research teams and pharmaceutical companies are designing and testing novel inhibitors based on the protein structure and physicochemical properties of the active site of SARS-CoV-2 and associated host proteases. Some of these compounds have already entered clinical trials (e.g., the phase 1 study of oral antiviral clinical candidate PF-07321332 by Pfizer, the inhibitor of the SARS-CoV-2 major protease M


There is a high incidence of cerebral findings in COVID-19, and likewise evidence of gastrointestinal involvement. Artificial intelligence, notably machine learning is emerging as an effective method for diagnostic image analysis, with performance in the discriminative diagnosis of diagnosis of COVID-19 pneumonia comparable to that of human practitioners.Medical imaging methods are assuming a greater role in the workup of patients with COVID-19, mainly in relation to the primary manifestation of pulmonary disease and the tissue distribution of the angiotensin-converting-enzyme 2 (ACE 2) receptor. However, the field is so new that no consensus view has emerged guiding clinical decisions to employ imaging procedures such as radiography, computer tomography (CT), positron emission tomography (PET), and magnetic resonance imaging, and in what measure the risk of exposure of staff to possible infection could be justified by the knowledge gained. The insensitivity of current RT-PCR methods for positive diagnosis is part of the rationale for resorting to imaging procedures. While CT is more sensitive than genetic testing in hospitalized patients, positive findings of ground glass opacities depend on the disease stage. There is sparse reporting on PET/CT with [ Th. Th30]. Although imaging findings of pulmonary involvement are relatively characteristic of COVID-19, they are not specific for this disease. Underlying conditions might influence the imaging presentation, requiring careful consideration of any previous patient history –43. OtheOver the course of the COVID-19 illness, the relative proportion of ground glass opacities decreases, whereas the proportion of consolidations and reticular abnormalities tends to increase , 46. TheLung ultrasound (LUS) findings in COVID-19 pneumonia depend primarily on the phase of the disease, as well as disease extent. In earlier stages, in which CT shows primarily ground-glass opacities, LUS is characterized by an increased number of the so-called B-lines, which are defined as hyperechoic lines radiating vertically from the pleura into the lung parenchyma –62. The LUS is used as a decision-making and disease-monitoring tool in COVID-19 patients . As suchThe aim of many prognostic studies has been to assess prospectively the risk of critical illness calling for mechanical ventilation and potentially leading to death, where the restricted availability of ventilators and staff at critical care facilities has been an important vexation. This kind of risk prediction remains quite challenging and must accommodate various factors such as comorbidities and laboratory findings, as well as treatment, which has been evolving over time in the pandemic. Thus, interpretations of the results of prognostic studies require some caution in light of these considerations.A meta-analysis including 13 studies and 3027 patients identified age > 65, current smoking, and various comorbidities such as hypertension, diabetes, cardiovascular disease, and chronic lung disease as risk factors for progression to critical and mortal outcomes . MultiplIn addition to consideration of patient characteristics and clinical parameters, imaging has also played an important role in the prediction of patient outcome. Among the findings that have been proposed as indicators of disease severity are visual assessment of >25% involved lung parenchyma , which mA number of CT severity scores have been proposed based on visual assessment of involved lung parenchyma, using either small increments  or asseAs for CT, there are a number of publications using a reading of the admission chest radiograph (CXR) together with clinical and laboratory finings for risk predication. While Toussie et al. targeted only patients <50 years and did not consider laboratory findings , Liang eWe note that the risk and occurrence of pulmonary embolism was not included in the risk models mentioned above. While concentration and increases of D-dimer have emerged as an important risk factor, we are not aware of any publications yet showing an association between the extent of parenchymal findings and the occurrence of pulmonary embolism.18F]-FDG-PET/CT imaging findings in patients with RT-PCR-confirmed SARS-CoV-2 infection . In contrast, the same search for the year 2020 yielded 72 hits. This is noteworthy, since at least three pandemics of respiratory pathogens have occurred subsequent to the advent of multimodal PET/CT imaging , not to mention the annual influenza season, which frequently leads to excess winter mortality and places significant strain upon health systems. While there are significant differences between COVID-19 and previous outbreaks, not least in its magnitude, this dearth of data prior to the current pandemic may nevertheless suggest that there had hitherto been limited clinical requirement for additional [18F]-FDG-PET/CT imaging in the management of individuals with viral pneumonias. Alternately, this phenomenon may indicate what has been termed a “covidisation” of research in 2020 [18F]-FDG-PET/CT for COVID-19, which calls for cautious interpretation of any suggestive findings. It is in this context that we provide a critical overview of the currently available data.A large body of historical literature exists on the molecular imaging of infection, including the use of  in 2020 . Indeed,18F]-FDG PET/CT for the 2012–2015 Middle East respiratory syndrome (MERS-CoV) pandemic. Similar to findings with SARS-CoV-2, there was increased metabolic activity associated with the ground-glass opacities in the lung [18F]-FDG uptake in ferrets with H1N1pdm09 virus reported by Jonsson et al. showed a correlation between lesion standardized uptake value (SUV) and bronchiolitis-related pathologic scoring, thus suggesting a relationship between viral pathophysiology and PET findings, albeit in an animal model [18F]-FDG PET/CT for the characterization of HIV-related bronchiectasis in children, Masekela et al. found no correlation between PET findings and disease activity [18F]-FDG PET/CT has been investigated previously as a means of therapy monitoring in respiratory infections and as a diagnostic tool in cases of cryptogenic infection, such as nosocomial or ventilator-associated pneumonia, although these data are of a preliminary nature [18F]-FDG PET/CT data.The SARS-CoV-1 pandemic (2002–2004) was associated with a considerably higher individual morbidity and mortality in the acute phase than has been observed in 2020 with SARS-CoV-2. For this earlier outbreak, occurring only shortly after the advent of dual modality PET/CT in clinical routine, only sparse data using conventional imaging modalities are available. The few reports describe similar changes to those now seen SARS-CoV-2, being indistinguishable from findings in other viral pneumonias , 81. Thethe lung . The spaal model . In contactivity . [18F]-Fy nature . Therefo18F]-FDG PET/CT from around the world have been published, ranging from various coincidental COVID-19-related findings [18F]-FDG PET scans over an 8-day period in March 2020 showed six scans with findings suggestive for COVID-19 (9.2%), although, in accordance with the local guidelines, confirmatory laboratory testing was not done in all patients -FDG PET [68Ga]-PSMA-11 PET/CT  [18F]-fluorocholine PET/CT for recurrent prostate cancer (with fluorocholine-avid disease and lymphadenopathy present) [18F]-FDG-PET/CT is a well-established modality for the imaging of inflammation [18F]-FDG-PET/CT reports of Kawasaki-like vasculitis have been prominent in the literature [18F]-FDG PET. Coagulopathy is a notable extrapulmonary feature in patients suffering from severe COVID-19  or [13N]-ammonia myocardial perfusion PET is available, it is preferable to myocardial perfusion scintigraphy due to its better efficiency, such that the complete rest-stress study acquisition last only 30 to 45 min -Sestamibi showed stress-induced ischemia in the apical septal segment. Furthermore, there were multifocal ground glass opacities with pathologically increased uptake of [99mTc]-Sestamibi in both lungs, which were interpreted as typical features of COVID-19 lung involvement. However, there was no confirmation of the suspected infection by testing for SARS-CoV-2. Nevertheless, the patient was placed under quarantine and monitored. In another case report, myocardial perfusion scintigraphy with 99mTc-Sestamibi was performed on a D-SPECT® camera, which showed normal gated stress images but also high signal in both lungs -FDG-PET/CT scans in asymptomatic patients and those with symptoms not primarily suggestive of COVID-19, but dating from the period of the lockdown, were reviewed retrospectively for incidental findings in the lungs and in extrapulmonary sites [18F]-FDG-PET/CT the inflammatory status at the presumed peak of the inflammatory phase in non-critically ill patients (n = 13) admitted for COVID-19 [18F]-FDG PET/CT examination from day 6 to day 14 after onset of symptoms. Only one of these patients had significant physiological myocardial FDG uptake, even though there had been no intervention to suppress physiologic myocardial glucose metabolism prior to scanning, such that one might normally have expected substantial myocardial tracer uptake in most individuals. The authors suggested that the myocardial metabolic pathway may disfavor glycolysis during COVID-19 infection, perhaps due to a loss of sympathetic tone that would otherwise promote myocardial FDG uptake [123I]-MIBG scintigraphy.In a study from the UK, 160 -FDG-PET/CT and [18F]-FDG-PET/MRI examinations. The [18F]-FDG-PET/CT showed focal ground-glass opacities in both lungs without hypermetabolism, suggestive of the absorption phase of SARS-CoV-2 infection, and revealed normal-sized but hypermetabolic and probably inflammatory mediastinal lymph nodes. A subsequent [18F]-FDG-PET/MRI did not show any pathological cardiac findings, but did reveal a diffuse increase in hepatic [18F]-FDG-uptake consistent with a systemic inflammatory response. Due to the lack of cardiovascular involvement, the authors suggested that their case study did not indicate a clear association between the tissue distribution of ACE2 and organ damage [18F]-FDG-PET/CT was used to check for superficial and deep lead tract infection of his left ventricular assist device. Results showed an inflammatory pattern at the second and third level  of driveline tunneling suggestive of a locally active infection and potential evolution into a subcutaneous abdominal fistula [18F]-FDG-uptake that were suggestive of COVID-19. A subsequent RT-PCR test was negative, but a second test 8 days later was positive for SARS-CoV-2.In another case report, a 57-year-old COVID-19-positive man with no history of cardiovascular disease had ground-glass opacities on CT detected on the day of hospital admission . Due to n damage . As ACE2 fistula . FurtherIn conclusion, nuclear cardiology imaging is not presently playing a major role in the evaluation of cardiac involvement in COVID-19. Nevertheless, practitioners should be alert to the possibility of incidental pulmonary findings, especially since patients with cardiologic illnesses are a high-risk group in the event of COVID-19 infections. Furthermore, guidelines call for adaptation of imaging procedures to minimize the risk of transmission between patients and medical staff.Central nervous system (CNS) involvement is a known complication of viruses with neurotropic characteristics. There are also reports of neurological symptoms in patients with SARS-CoV-2 infection, indicative of the neurotropic nature of the virus . AdverseRecent experimental evidence demonstrates that a human CoV strain, HCoV OC43, can travel from the nasal cavity to the olfactory bulb, and then spread to the piriform cortex and ultimately to the brainstem, via both passive diffusion and axonal transport , 207. AnIn the first small series from the USA, five cases of large-vessel stroke in patients with severe acute respiratory syndrome were reported . A retroAnother scantly explored neurological manifestation of COVID-19 is meningitis/encephalitis. The first report on SARS-CoV-2-associated meningitis/encephalitis from Japan reported high signal intensity in the mesial temporal lobe . InteresOnce entering the CNS, the virus can induce a dysregulated host immune response known as “cytokine storm” . The cytHaemophilus influenzae, Campylobacter jejuni, ZIKA virus, and cytomegalovirus are the most common pathogens involved. Bickerstaff’s encephalitis overlapping with Guillain-Barré syndrome, intensive care unit-acquired weakness, or other toxic or infectious neuropathies have been reported during or after Middle East respiratory syndrome (MERS-CoV) treatment. Two patients infected with SARS-CoV-2 presented with Miller-Fisher syndrome and polyneuritis cranialis -FDG-PET/CT) have been used. For example, brain MRI, CSF testing, and [18F]-FDG-PET/CT were performed in the case of a 72-year-old man with a positive oropharyngeal swab test for SARS-CoV-2 who presented with a subacute cerebellar syndrome and myoclonus following general infectious symptoms. Brain MRI and CSF testing did not show any pathological findings, whereas brain [18F]-FDG-PET/CT showed diffuse cortical hypometabolism along with hypermetabolism in the putamen and cerebellum, consistent with encephalitis, and especially cerebellitis. Furthermore, this patient had high serum and CSF titers of IgG autoantibodies against the nuclei of Purkinje cells as well as against striatal and hippocampal neurons. The case revealed a possible relationship between SARS-CoV-2 infection and autoimmune encephalitis, where [18F]-FDG-PET/CT had diagnostic advantages over brain MRI -FDG-PET/CT, all four patients showed a common pattern of hypometabolism in the prefrontal or orbito-frontal cortices and hypermetabolism in the cerebellar vermis, despite their distinctly different neurological presentations. The authors supposed that the central focal neurological signs or seizures, the absence of meningitis and of SARS-CoV-2 in the CSF, and the [18F]-FDG-PET/CT findings were suggestive of a parainfectious cytokine-storm with post-infectious autoantibody- or cell-mediated immune mechanisms rather than a direct viral neuroinvasion. They further argued that the elevated CSF level of interleukin-6 (in both patients examined for this), as well as the clinical improvement after immunotherapy, was indicative of a transient immune process -FDG-PET/CT examination was performed in a 27-year-old right-handed woman, who had been earlier diagnosed with COVID-19 by RT-PCR and suffered from isolated anosmia persisting for 6 weeks -FDG-PET/CT -FDG-PET/CT for this indication becomes more widely appreciated [18F]-FDG-PET/CT could serve as a cerebral quantitative biomarker of neuronal involvement [18F]-FDG-PET/CT and distinct neurological disorders such as persistent cognitive or emotional disturbances as well as pain syndromes. Furthermore, longitudinal [18F]-FDG-PET/CT studies could prove to be useful to determine whether pathological PET findings are attributable to a transient functional inactivation or rather to irreversible brain damage [18F]-FDG-PET findings in patients with chronic fatigue syndrome [18F]-FDG-PET may assume a growing importance in the years to follow the present pandemic.Although molecular imaging currently plays a minor role in neuroimaging of SARS-CoV2 infections, it might yet gain importance in the diagnosis of autoimmune encephalitis once the clinical use of [reciated , 242. Threciated , 243. Asolvement , 245 andolvement . Howevern damage . We furtsyndrome , which iSymptomatic patients suffering of COVID-19 typically present with symptoms caused by acute lung injury such as fever, cough, and dyspnea. However, rising testing capacities and case numbers have led to the emerging understanding of COVID-19 as a systemic disease, affecting not only the pulmonary, cardiovascular, or neurological systems, as reviewed above, but also extending to other systems such as the renal, gastrointestinal (GI), or the hepatobiliary system. Against this background, there is an increasing awareness of these manifestations and their associated imaging findings.The pathophysiological mechanism of abdominal organ damage by COVID-19 derives from the type II pneumocytes of the lung. As in the case of pulmonary and vascular infections, the virus probably gains access to visceral organs via their surface expression of ACE2. This docking site has broad expression in the human viscera, thus enabling direct or indirect tissue damage of the liver, biliary ducts, pancreas, spleen, intestine, or kidneys , 247–253Gastrointestinal manifestations in COVID-19 patients are also of great clinical importance, considering that bowel wall abnormalities were a frequent finding upon admission to an ICU . The incThe most commonly reported gastrointestinal imaging finding is bowel wall thickening, which can include all parts of the bowel –260. In Acute kidney injury (AKI) presenting with proteinuria and hematuria is a severe possible complication of COVID-19, which imparts high mortality –273. In Although myalgia is a commonly reported symptom among COVID-19 patients , 281, muAnother rare manifestation of COVID-19 is cutaneous lesions including maculopapular rash, vesicular lesions, and livedoid/necrotic lesions, with the latter possibly being associated with a more severe course of COVID-19 . A singlRecent advances in artificial intelligence (AI) and specifically in deep learning (DL), along with the availability of large datasets and powerful computational hardware based on graphics processing units (GPUs), have led to substantial changes in medical imaging. AI extends human powers of the perception of information in data, and may surpass human performance in some situations , 288. AIAI-based analysis of CRX images mainly focuses on the development of support systems for the rapid diagnosis and differentiation of COVID-19 from other types of pneumonia. Various DL-based approaches have been published , 292–294Since the very beginning of the COVID-19 pandemic, several studies have examined the AI-based analysis of lung CT images. This was initially applied to the task of differentiating COVID-19 from other lung diseases , 302, anLUS image analysis was proposed in  to evaluAlthough there is a long history of nuclear imaging in infectious diseases of the chest, there is no current indication for the use of PET/CT in routine clinical diagnosis or management of COVID-19. However, in this still poorly understood disease, multi-modal imaging may shed light on the underlying pathophysiological processes involved. Furthermore, well-established nuclear medicine research tools such as the radiolabeling of immune or inflammatory cells for PET imaging , 313 serWe aimed in this comprehensive review article to provide an overview of the current knowledge on COVID-19 and imaging. It is apparent that SARS-CoV-2 infection is a systemic disease that can affect multiple organ systems besides the lungs. Radiological exams have played a pivotal role in the detection and diagnosis as well as patient management since the very beginning of the pandemic. The authors of this article gathered evidence from all across the field of medical imaging and summarized the state-of-knowledge on COVID-19 in late 2020 and early 2021. However, we acknowledge that knowledge is lacking for many aspects of COVID-19, including the imaging results for mid- and long-term effects, which is a research topic for the coming years.


Ankylosing spondylitis (AS) is characterized by inflammation of the sacroiliac joint and the attachment point of the spine. Herein, we aimed to investigate the effect of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes on apoptosis of fibroblast-like synoviocytes (FLSs) and explored its molecular mechanism. Exosomes were isolated from BMSCs and verified by transmission electron microscope and nanoparticle tracking analysis. FLSs were isolated and co-incubated with BMSC exosomes. Cell apoptosis was assessed using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling analysis and flow cytometry. The results showed that BMSC exosomes increased apoptosis of FLSs. MiR-5189-3p was downregulated, while basic leucine zipper transcription factor ATF-like 2 (BATF2) was upregulated in FLSs by treatment of BMSC exosomes. As a direct target of miR-5189-3p, BATF2 inactivates the JAK2/STAT3 pathway. MiR-5189-3p suppressed apoptosis of FLSs and BATF2 exerted an opposite effect. In conclusion, BMSCs-derived exosomes suppress miR-5189-3p to facilitate the apoptosis of FLSs via the BATF2/JAK2/STAT3 signaling pathway, which facilitates the understanding of the therapeutic effect of BMSCs on AS and the underlying molecular mechanism.  Ankylosing spondylitis (AS) is a systemic disease dominated by chronic inflammation of the axial joints . The lesin vitro . Apoptosis induction of FLSs is an important molecular mechanism in treating AS [In the present study, we found that BMSCs exosomes promoted the apoptosis of FLSs, suggesting that BMSCs exosomes play essential roles in the development of AS. The ating AS , suggestIncreasing number of studies have demonstrated that MSCs exosome-mediated miRNAs play essential roles in regulating the status of FLSs. For example, exosomal miR-320a derived from MSCs regulates FLS activation by suppressing C-X-C motif chemokine ligand 9 expression . MSC-oriIt has been demonstrated that miRNAs participate in many biological processes in the development of AS by targeting downstream genes ,36. In tSeveral studies revealed that the JAK2/STAT3 signaling plays an important role in AS ,39,40. JBMSCs exosomes promote the apoptosis of FLSs. MiR-5189-3p is downregulated in FLSs by BMSC exosomes and inhibits apoptosis of FLSs by downregulating BATF2 via the JAK2/STAT3 pathway. Moreover, BMSC exosome or miR-5189-3p alleviates clinical symptoms in curdlan-induced SKG mouse model of AS. Our findings may provide more insights for the molecular mechanisms of AS progression and will be helpful for the development of novel and effective treatment strategies for AS by BMSCs exosomes.Click here for additional data file.


The development ofmaterials with outstanding performance for sensitiveand selective detection of multiple analytes is essential for thedevelopment of human health and society. Luminescent metal–organicframeworks (LMOFs) have controllable surface and pore sizes and excellentoptical properties. Therefore, a variety of LMOF-based sensors withdiverse detection functions can be easily designed and applied. Furthermore,the introduction of energy transfer (ET) into LMOFs (ET-LMOFs) couldprovide a richer design concept and a much more sensitive and accuratesensing performance. In this review, we focus on the recent five yearsof advances in ET-LMOF-based sensing materials, with an emphasis onphotochemical and photophysical mechanisms. We discuss in detail possibleenergy transfer processes within a MOF structure or between MOFs andguest materials. Finally, the possible sensing applications of theET-LMOF-based sensors are highlighted. These luminescent metal–organic frameworks (LMOFs)15 have attracted tremendous attention over the past several yearsbecause of their abundant photophysical properties and enormous potentialin sensing applications.28 The rational design of LMOFs with energy transfer (ET) characteristicscould maximally adjust the luminescent properties of these materials.37 Because of the outstanding level of structural and compositionalcontrol via the flexible selection of organic linkers and metal clusters,energy transfer (ET) LMOFs (ET-LMOFs) are excellent candidates fora variety of potential applications including sensing, photocatalysis,solar cells, X-ray imaging scintillators, and many others.44 In addition, the coordination between organic linkers and metalnodes in MOFs allows a high degree of chromophore alignment and organization,46 which is crucial for the modeling and understanding of the short-and long-distance energy transfer mechanisms.51 The highly ordered and structured periodicity of MOFs also providean ideal model for density functional theory (DFT) calculations,56 which is one of the powerful tools for the predetermination of electronicstructures and in-depth investigations of the mechanism that underpinsthe functions of MOFs.Metal–organic frameworks(MOFs) are porous-crystalline materialsconstructed from metal ions or metal clusters coordinated to organicligands to form one-, two-, or three-dimensional structures, withan outstanding level of structural and compositional control.64 Thus, processing MOF nanocrystals into specific polymer matricesthat are robust and exhibit operational flexibility is highly desired.Such technology not only preserves the individual advantages of MOFsbut also overcomes their drawbacks, which greatly expands their practicalapplications.72MOFs synthesized via traditional techniquesusually lead to theformation of fine powders or tiny particles/crystals with nonthermoplasticproperties, insolubility, and difficulty in molding.In this review, we mainly focus on the recent 5 years of developmentof LMOF crystalline nanoparticles and LMOF-based mixed-matrix membranes(MMMs) with efficient energy transfer processes for sensing multipleanalytes. In 287 Research on MOFs received momentum in the 1990s because of theirsimple yet intriguing structures and newly discovered properties.88 For instance, their high porosity and surface areas and excellentstructural and functional tunability make them one of the most attractivematerials in the chemistry and materials science communities.95 Luminescent metal–organic frameworks are a subclass of MOFs,96 with controllable and tunablephotophysical and photochemical properties via alternating the structureof organic linkers, metal clusters, and guest species. The emissionsof LMOFs can be roughly divided into four categories, organic linker-centeredemission, metal-centered emission, charge transfer induced emission,and guest-centered emission -9H-carbazol-9-yl)-terephthalate)as the organic linker. The BUT-88-based probe could selectively andsensitively recognize dual tumor biomarkers tetrabenzoicacid) LMOF (NU-1000) was applied for accurate sensing of polycyclicaromatic hydrocarbons (PAHs). Because of the efficient preconcentrationof 1-hydroxypyrene (1-HP) in NU-1000 and the strong charge transferinteractions between the conjugated 1-HP and pyrene cores, this LMOFexhibited efficient emission quenching-based sensing for 1-HP as the organic linker. Because of the free rotation properties ofthe central phenyl ring of the linker, the coplanar arrangement graduallytransformed into a twisted configuration under high pressure, leadingto the red-shift in both the fluorescence and UV/vis absorption  to an electronacceptor tetrazolyl (Tz). The enhanced intermolecular charge transferthrough multiple donor–acceptor, donor−π, andacceptor−π interactions considerably suppressed the nonradiativedecay, resulting in efficient linker-centered phosphorescence  of Ln3+ is low because of the forbidden transitions. In some MOFs, the lowPLQY can be improved by the antenna effect of appropriate organiclinkers. Liu’s group reported a series of Ln3+-basedLMOFs, using nitrates and 2-(6-carboxypyridin-3-yl)terephthalic acidas the linkers.105 Both of these LMOFsexhibited efficient Ln3+ metal-centered emission with highselectivity toward Ce3+ or Fe3+ ions -10--4,40-bipyridiniumdichloride), this Eu-MOF exhibited excellent sensitivity toward light)di-isophthalicacid as the organic linker.107 The constructedmixed matrix membrane with the Eu0.3Tb0.7-MOFexhibited clear emission from both Eu3+ and Tb3+ ions and could thus be used as ratiometric self-calibrating luminescentprobes for the sensing of various antibiotics , linker-to-metal charge transfer (LMCT), metal-to-linkercharge transfer (MLCT), and metal-to-metal charge transfer (MMCT)could be involved. Among them, LMCT is generally observed in Zn4+ MOF (TiMOF-NH2), with efficient photocatalytic performance in hydrogen production.108 It was found that the photocatalytic propertyresulted from photoinduced electron transfer from triethanolamineto the catalytically active titanium-oxo cluster. The photoinducedcharge transfer within the organic linker (2-amino-benzenedicarboxylicacid) also boosted its photocatalytic performance  and X-ray transient absorption (XTA) measurements upon the photoexcitationof the spin allowed d-d transition of Co2+ ion in ZIF-67,the long-lived intermediate state within a picosecond time scale wasclearly demonstrated. The long-lived charge-separated state and intrinsichybrid nature endow these materials with high potentials for heterogeneousphotocatalysis and energy conversion  depends on the inverse sixth power of the separationdistance between the donor and the acceptor. It should be noted thatFRET requires strong spectral overlap between the donor’s emissionand the acceptor’s absorption spectra to ensure the thermodynamicfeasibility of energy transfer.Förster resonance energytransfer (FRET) is a short-rangeR) and increases exponentially as steeply as the rate ofhypothetical electron transfer between the same molecules with a decreasein R.Dexter energy transfer reliesheavily on the orbital overlap betweendonor and acceptor. The electron exchange mechanism can be describedas an intuitive two-step electron transfer that effectively exchangeselectronic excitation. The rate of the Dexter energy transfer dependsexponentially on the distance between the donor and the acceptor  and N,N′-di(4-pyridyl)thiazolo-thiazole (DPTTZ). Because of the highly ordered arrangementbetween the donor (NDC) and acceptor (DPTTZ), and the good spectraloverlap, a high energy transfer efficiency was achieved. In addition,this ET-LMOF exhibited high sensitivity and selectivity toward Hg2+.123Linker-to-linker energytransfer can be achieved by coupling boththe energy donor and acceptor within the same MOF structure. The energytransfer processes in these systems can be controlled by externalstimuli, such as the excitation wavelength, temperature, or pH. Thisconcept was recently realized by Mohammed’s and Eddaoudi’sgroups. In this work, the efficient linker-to-linker energy transfer(approximately 90% efficiency) from the benzimidazole (energy donor)to the benzothiadiazole (energy acceptor)-functionalized linkers withinone MOF structure was observed. The similar molecular structural featuresof the donor and acceptor enabled the successful synthesis of thecolinker MOF with a large degree of spectral overlap 6a.121 Thfcu-MOFs 6b,c. Sa12 Thesestrategies always show a fast discoloration process, and it is difficultto integrate them into specific physical forms for practical applications.Feringa and co-workers inserted a visible-light-driven molecular motorinto a dual-function MOF and realized efficient energy transfer betweendifferent linkers. They selected a palladium-porphyrin photosensitizer and an overcrowded alkene-basedmolecular motor (bispyridine-derived linker 1) as the linkers . The efficient triplet–tripletenergy transfer from the porphyrin linker to the molecular motor makesthe framework capable of harvesting low-energy green light to powerthe rotary motion of the molecular motor  as the organic linker. An in-depththeoretical and experimental analysis demonstrated that the organiclinker acted as the antenna (energy donor) and that Ln3+ acted as the emission-center (energy acceptor). The linkers harvestthe excitation energy and then transfer it to the emitting levelsof Ln3+ ions, leading to the enhanced photoluminescence.41 With a similar mechanism, Spodine and co-workerssuccessfully improved the Tb3+-centered luminescence bytuning the linker-to-metal energy transfer efficiency. The authorstuned the energy gap between the triplet state of the linker -imino]di(methylene)]-bis(4-R-phenol))and the emissive 5D4 level of Tb3+ by regulating the substituents on the linker. Finally, the linker’semission could be quenched completely, indicating efficient energytransfer from the linker to the metal center.112In linker-to-metalenergy transfer LMOFs, after the organic linkeris optically excited, the excitation energy is quickly transferredto metal ions and then emit from the metal center. Murugesu and co-workersreported a class of three-dimensional Ln LMOFs by using H2.3.3124 Energy transferfrom Tb3+ to Eu3+ is another important and well-studiedmetal-to-metal energy transfer system that has been widely used inthe design of ratiometric thermometers.128 For example, Jin and co-workers systematically investigated theenergy transfer from Tb3+ to Eu3+ in a mixedMOF by using 2,5-dimethoxy-1,4-benzenedicarboxylic acid as the organiclinker. The energy transfer dynamics were studied in detail by usingtime-resolved spectroscopy. In addition, the energy transfer efficiencyand the emission color could be finely tuned by adjusting the ratioof Tb3+ to Eu3+.125Metal-to-metal energy transfer in LMOFs is usuallyused in noninvasiveluminescent thermometers with a broad working temperature range. In2010, Lin and co-workers systematically investigated the energy transferfrom Ru to Os in isomorphous MOFs. They studied the energy transferdynamics by using two-photon excitation methods. A decrease in theemission lifetime at 620 nm of Ru from 171 to 29 ns was observed asthe doping ratio of Os increased to 2.6 mol %, while the emissionintensity of Os increased at the same time. Both of these resultsindicate rapid and efficient energy transfer from Ru to Os ions inthese isomorphous MOFs.2.3.419 Because the guest molecules can serve as a simple luminescence probeor as the analyte, the LMOF-guest is promising system for sensingapplications. Recently, Zhang and co-workers proposed a strategy foreffectively encapsulating hydrophobic guests inside MOF capsules (MOF-Cs).They synthesized the MOF-Cs by the self-assembly of surface-modifiedMOF nanoparticles (UiO-66-NH2) at the water–oilinterface to form oil-in-water emulsions, and then poly(methyl methacrylate)(PMMA) was deposited into the emulsions by an internal phase separationmethod (129 Another interesting near-infrared (NIR)-excitednanosensor was constructed by Tang and co-workers by using a biologicalMOF  asa matrix to encapsulate a donor (rare-earth-doped upconversion nanoparticles(UCNPs))-acceptor ([Ru(dpp)3]2+Cl2: tris ruthenium(II) dichloride)energy transfer system. Under NIR excitation, the core/satellite nanosensorsexhibit enhanced FRET efficiency and high sensitivity toward hypoxicatmosphere 2(adenine)(H2O)) was selected as the host material, anda thermosensitive organic fluorophore was used as the acceptor to establish a temperature-tunable FRET system(benzimidazole). Due to the slow energy transfer from the MOFsto the dyes, a series of stable persistent LMOFs with different emissioncolors were obtained. These composites exhibit high potentials indata anticounterfeiting.130 Moreover, Yaoand co-workers developed an efficient energy and circularly polarizedluminescence (CPL) transfer system. They encapsulated an achiral stilbazoliumdye (DSM: (4-p-(dimethylamino)styryl)-1-methylpyridiniumiodide) into homochiral lanthanide MOFs (TbBTC), in which the P- orM-configuration of the dye is unidirectionally generated via spatialconfinement of the MOF and solidified by the dangling water moleculesin the channel. By tuning the ratio between the donor and acceptor,a series of color-tunable CPL luminescent materials were successfullyfabricated  that takes into account the gradientof the electron density, such as the parametrizations developed byPerdew, Burke, and Ernzerhof (PBE);134 therevised PBE for solids (PBEsol);135 andPW91.136 The next rung contains meta-GGAsthat include the second derivative of the electron density and theorbital kinetic energy density, such as TPSS.137Density functionaltheory (DFT) calculations have become a powerful theoretical toolfor investigating the structural, electronic, and optical propertiesof MOFs because of the development of advanced DFT functions and thewidespread availability of high-performance computing resources. Inparticular, DFT calculations can be used to study the interactionsand the mechanism underlying the charge and energy transfer betweenorganic linkers and metal clusters in MOFs and between MOFs and targets8a. For a138 PBE0,139 and B3LYP.140 These hybrid functionshave been commonly used for modeling MOFs. By climbing Jacob’sladder and applying more sophisticated exchange and correlation functions,one may expect to obtain improved accuracy from the DFT calculations.However, this is always accompanied by an increased computationalcost, and hence, a compromise between accuracy and computational costshould be carefully considered in the DFT calculations. In the following,we review the recent DFT studies on molecular adsorption, the interactionsbetween MOFs and guests, and the charge and ET in MOF-based structures.Hybrid functions replace a predefined fraction of the underlyingexchange and correlation energy with a Hartree–Fock exact exchangeterm, such as the parametrizations developed by Heyd, Scuseria, andErnzerhof (HSE),2 and N2 adsorption properties in severalcoordinatively unsaturated MOFs based on DFT calculations (at thePBE level with D3(BJ) corrections).54 Theydemonstrated the possibility of tuning O2 affinity at theopen metal sites of MOFs and found that the O2 affinitywas much stronger than the N2 adsorption. They also foundthat replacing the anion exchange of bridging ligands μ-Cl– of M2Cl2(BBTA) with μ-OH– significantly enhanced the O2 adsorptionability but not the N2 affinity. Chibani and co-workersstudied the adsorption behavior of RuO4 onto MOFs and zeolitesto mitigate ruthenium release from the porous matrix by using DFTcalculations (at the PBE level with DFT-D3 corrections).141 They found that the nature of the porous materialshad an inconspicuous effect on the adsorption energy of RuO4, but the generation of hydrogen bonds between the H atoms of watermolecules and the O atoms of RuO4 made a major contribution.142Employing the standard DFT functional with van der Waals (vdW)corrections is imperative to exploring the adsorption of moleculesand other materials on MOFs. For example, Rosen et al. investigatedthe O143 They showed that energy wastransferred from the linker’s triplet excited state to the 5D0 state of Eu3+ and then emitted upontransition from the 5D0 to the 7FJ state. Moreover, a mixture of electronic states between theEu-based MOF and aniline was observed, making the molecular orbitalsof aniline appear in the active space that stabilizes the linker andblock the energy transfer to the 5D0 state ofEu3 and an organic chromophore was recently reported.144 In this MOF-chromophore structure, a short intercomponentdistance of 10.9 Å was estimated, resulting in a nearly 100%energy transfer efficiency. In addition, the type-1 energy alignmentsbetween the MOF and the organic chromophore also suggest feasibleenergy transfer from the MOF to the organic chromophore.144Revealing the charge and energy transfermechanisms between organiclinkers and metal clusters in MOFs and between MOFs and targets stronglyrelies on DFT calculations. Hidalgo-Rosa et al. investigated the detectionmechanism of an Eu-based MOF toward aniline by using simplified time-dependentDFT (sTD-DFT) calculations (at the GGA/BP86 and CAM-B3LYP levels oftheory).e ofEu3 9. An eff3.211 The luminescence intensity, decay profile, and emission wavelengthcan be used alone or in combination to recognize the presence of interactingspecies. Additionally, introducing energy transfer into LMOFs greatlyenhances their luminescent properties29 and leadsto highly sensitive recognition of the detected analytes by regulatingthe energy transfer between the LMOFs and analytes  with O donor linkers (hard bases) would greatly enhancethe chemical stability.154 The high-valent metal ions notonly provide high charge density (hard acids) but also lead to a highcoordination number of the metal center and further enhance its stability.It should be noted that if low-valent metal ions  need to beused as the metal center, a suitable N-containing linker could enhancethe basic and moisture stability of the MOFs.155Moreover,stability is another significant parameter that mustbe considered carefully in the process of LMOF selection to obtainhigh-efficiency ET-LMOF-based sensors. Most of the reported MOFs showbad stability in moisture/aqueous environments because of the inevitabledecomposition of the metal-linker bond. To date, several works havebeen conducted to investigate the stability of MOFs to broaden theirapplications in real-time detection. For example, coordinating high-valentmetal ions -MOF was quenched. The detection limit of this “turn-off”fluorescent biosensor is 0.04 ppb (ng mL–1), whichprovides a highly promising method for the diagnosis of lung and breastcancers (38 Huang and co-workers reported acomposite ratiometric sensor by entrapping carbon dot (CD) and curcumin(CCM) in ZIF-8 (CD/CCM@ZIF-8) for hypochlorous acid sensing. Becauseof the confinement effect of ZIF-8, the energy transfer from the carbondots to curcumin is 68.7%, and the energy transfer process could bedisrupted by hypochlorous acid, leading to the enhancement of thedonor’s luminescence and the quenching of the acceptor’sluminescence to obtain a ratiometric sensor for the selective detection of Fe3+, Cr2O72–, and 2-nitrophenolwith excellent stability and high reversibility  for ultrasensitive ratiometric sensing of phosphate (Pi) witha detection limit of 4.4 nM. An enhanced emission from the Eu3+ was achieved because of the efficient energy transfer fromciprofloxacin (CIP). After adding Pi to the solution of BTEC-Eu-MOF,CIP was released rapidly, and the energy transfer between CIP andEu3+ was disrupted, leading to the recovery of the blueemission of CIP as a colorimetric luminescence sensor for dipicolinic acid (DPA) sensing.DPA was combined with the Tb3+ LMOF by replacing the coordinatedwater and enhancing the green fluorescence of the LMOF. This changedthe luminescence color from red-orange to yellow-green (159Gu’s group reported a substitution-typeLMOFs based sensorfor selective cholesterol detection in blood serum. Carboxymethylβ-cyclodextrin was grafted onto the LMOF (NU-1000) with an inclusionsite for cholesterol recognition. After having contact with the freecholesterol inside the serum, the encapsulated guest Rh6G was replacedby cholesterol to form a more stable inclusion complex. Thus, thequenched fluorescence of the LMOF was restored due to the disruptionof FRET from the LMOF to Rh6G (rhodamine 6G) 12a.146 Tn of CIP 12b.158 Mow-green 12c, d.154164MOFs synthesizedby traditional techniques are commonly fine powdersor tiny particles with intrinsic non thermoplastic properties, brittleness,and insolubility. Thus, processing MOF nanocrystals into specificfilms that are robust and exhibit operational flexibility is highlydesired. Such technology not only preserves the individual advantagesof MOFs and polymer matrices but also overcomes their drawbacks.4.1167 The direct fabrication of LMOF films includessurface-mounted MOFs (SURMOFs) and polycrystalline films.170 Polycrystalline films can be obtained throughdirect synthesis ,seeded growth , electrochemical methods or stepwise dosing ofreagents  casting two MOF inksin discrete regions to obtain spatially separated MMMs; (2) combiningtwo MOFs in one ink and then casting it on a substrate; (3) castingtwo MOFs ink layer by layer (LBL) to obtain discrete layered MMMs.The preparation methods of all the above-mentioned films have beendescribed in detail in other reviews. Because these methods are beyondthe scope of this review, please refer to the references for details, the fabricatedMMMs still exhibited excellent HClO detection performance in aqueoussolution  MOF thin-film-based probe for the selective detection of methanoland humidity. The thin films were fabricated via the LB (Langmuir–Blodgett)method on interdigitated electrode (IDE) chips. Presorption studiesdemonstrated that MIL-96(Al) presented a high affinity toward waterand methanol, among other organic vapors. After depositing the MIL-96(Al)particles onto IDE ships, the selectivity toward methanol and waterwas achieved with short response/recovery times. Once the thin selectivelayer of Parylene C was deposited on top of the MOF LB films, thewater selectivity and sensitivity were greatly enhanced while thoseof methanol showed a huge decrease 14a.25 Dosolution 14b.171 Yntgases 14c.172,15The photophysical and photochemical propertiesof LMOFs can bewell modified by substituting metal nodes/organic linkers, changingtheir connectivity, and performing postsynthetic functionalization.More specifically, the coordination of organic linkers to metal nodesallows a high degree of chromophore organization, which is crucialfor the precise determination of the distances and angles betweenself-assembled organic linkers, and modeling of the short- and long-rangeenergy transfer processes. It should be pointed out that energy transferin MOFs prevents exciton quenching and subsequently enhances the emissionintensity of the energy acceptor unit, allowing the rational designof sensors.Since the light-harvesting, energy transfer, andsensing processescould take place in the porous crystalline framework “three-in-one”sensing platform, MOFs show extraordinary sensing capabilities throughproper structural design. In addition, the diversity of the MOF structuresallows for the integration of light-harvesting units as either frameworkbuilding blocks or guests. Consequently, the directional energy transferbetween different frameworks functionalities , and guest-MOFenergy transfer) could occur in a MOF matrix, which provides excellentsensing modes that could highly improve the sensing performance. Moreover,integrating external stimulus-responsive materials inside a MOF matrixto engineer stimulus-responsive sensors is another research hotspotassociated with MOFs for sensing advancement.Because of thedrawbacks of MOF nanocrystals such as the brittleness,insolubility, difficulty in molding, and low compatibility with othermaterials, processing MOF nanocrystals into specific polymer matricesthat are robust and exhibit operational flexibility is highly desired.Such technology not only preserves the individual advantages of MOFsand overcomes the drawbacks of MOF nanocrystals, but also expandsthe sensing applications to new directions. However, the researchon MOFs-films or MMMs based sensors, especially the thin-films sensorsrelated to energy transfer, is still in the preliminary stage. Asa result, developing sensors based on ET-LMOFs films, and MMMs ishighly demanded and should be one of the meaningful research directionsbecause of their convenience and stability in practical applications.In summary, the energy transfer phenomenon in LMOFs could highlyimprove their sensing capability. The amplified physical and chemicalperformance in the emissive centers by energy transfer processes andstructural modifications of the LMOF matrix has made them excellentcandidates for designing sensors with high sensitivity and selectivity.


Luteovirus. The study discusses BYDV phylogeny, and through a systematic in silico analysis of published primers for YDV detection, the existing gaps in current diagnostic practices for detection of YDVs, proposing primer pairs based on the most recent genomic information for the detection of different BYDV species. Thanks to the rising number of sequences available in databases, continuous updating of diagnostic primers can improve test specificity, e.g., inclusivity and exclusivity at species levels. This is needed to properly survey the geographical and host distribution of the different species of the YDV complex and their prevalence in cereal/barley yellow dwarf disease epidemics.Worldwide, barley/cereal yellow dwarf viruses (YDVs) are the most widespread and damaging group of cereal viruses. In this study, we applied high-throughput sequencing technologies (HTS) to perform a virus survey on symptomatic plants from 47 cereal fields in Estonia. HTS allowed the assembly of complete genome sequences for 22 isolates of cereal yellow dwarf virus RPS, barley yellow dwarf virus GAV, barley yellow dwarf virus PAS (BYDV-PAS), barley yellow dwarf virus PAV (BYDV-PAV), and barley yellow dwarf virus OYV (BYDV-OYV). We also assembled a near-complete genome of the putative novel species BYDV-OYV from Swedish samples of meadow fescue. Previously, partial sequencing of the central part of the coat protein gene indicated that BYDV-OYV represented a putative new species closely related to BYDV-PAV-CN, which currently is recognized as a subtype of BYDV-PAV. The present study found that whereas the 3′gene block of BYDV-OYV shares the closest relationship with BYDV-PAV-CN, the 5′gene block of BYDV-OYV shows the closest relationships to that of BYDV-PAS. Recombination detection analysis revealed that BYDV-OYV is a parental virus for both. Analysis of complete genome sequence data indicates that both BYDV-OYV and BYDV-PAV-CN meet the species criteria of genus  Luteoviridae constitute a complex of ssRNA viruses that are the most widespread group of cereal viruses worldwide (a list of the countries with recorded entries can be found at https://www.cabi.org/isc/datasheet/10539). YDVs are transmitted by more than 25 aphid species in a persistent non-propagative manner  of the family e manner . Perennie manner . Yield l species .Polerovirus, viruses of five recognized species have been found infecting cereals or grasses: Cereal yellow dwarf virus RPV, Cereal yellow dwarf virus RPS (CYDV-RPS), Maize yellow dwarf virus RMV (MYDV-RMV), Maize yellow mosaic virus (MaYMV), and Sugarcane yellow leaf virus. In addition, recent reports have indicated two novel tentative members of the genus Polerovirus: Barley virus G , Barley yellow dwarf virus PAS (BYDV-PAS), Barley yellow dwarf virus MAV, Barley yellow dwarf virus kerII, and Barley yellow dwarf virus kerIII. Currently, Barley yellow dwarf virus GAV (BYDV-GAV) is considered as a subspecies of Barley yellow dwarf virus MAV, and Barley yellow dwarf virus PAV-CN is considered as a subspecies of Barley yellow dwarf virus PAV. Partial sequencing of the coat protein (CP) gene suggested a putative novel cereal-infecting luteovirus Barley yellow dwarf virus OYV (BYDV-OYV), whose taxonomic status remained unclear because of the lack of a complete genome sequence . Interestingly, half of these species have been reported seldomly. Combining the genome sequences generated during this study and the available sequences in the database, we propose also new diagnostic primers for specific detection of the BYDV different species.Festuca pratensis) that were analyzed in this study originated from Sweden  and were collected in 2010.In 2012–2015, the leaf samples of cereal plants  showing chlorotic mottle or stripes, yellowing, reddening, stunting, or other symptoms characteristic of possible viral infection were collected from 47 fields, mainly located in south-eastern Estonia . Two samF. pratensis) plants were used as the source of viral RNA in immunocapture (IC) RT-PCR  RT-PCR  to ampli) RT-PCR  and newl) RT-PCR . cDNA waE. coli DH5α competent cells. Plasmid DNA extracted from three individual colonies was sequenced using a vector-specific primer.Total RNA was extracted from frozen plant material using Trizol reagent (Invitrogen) according to the manufacturer’s protocol. The 5′ RACE reactions were performed using the Roche 5′/3′ RACE kit (ver. 13) for Avinurme2 and Ulvi samples from Estonia. The OYV5pR1 primer  directedDe novo contig assembly was done using the Oases 0.2.08 software  according to the Sample Preparation Guide 02/2013. Depending on the number of collected plant samples, 1–3 HTS libraries were prepared for each field. The libraries were sequenced on HiSeq2500 as described in software  varying software . De novoMapping against the closest reference generated a consensus sequence. If any gaps existed in the sequence that was not filled during re-mapping, the mapping against other isolates was checked and in case the gaps were covered with mapped reads, the gaps were filled accordingly. This combined consensus was used as a draft reference sequence to repeat the mapping to obtain the final consensus sequence. The assembled complete consensus genome sequences were annotated and deposited in GenBank. Incomplete consensus sequences were used only for the identification of the virus species. After assembly of the complete genome consensus sequences, open reading frames (ORFs) were identified using the “Annotate and Predict” function in the Geneious program. The parameters were set for the standard genetic code using a minimum of 100 codons, starting with the AUG initiation codon. For detection of the non-AUG start codon of ORF3a, the near-cognate codons AUU, ACG, AUA, or CUG were considered. The site for -1 programmed ribosomal frameshift was identified according to alignment with other luteoviruses.The identity calculations of nucleotide sequences of the complete genome sequences and individual protein sequences were performed using the MUSCLE multiple sequence alignment tool implemented in the Geneious Prime program. The maximum-likelihood tree of nucleotide sequences for luteoviruses was constructed using PhyML ver. 3.1, implemented in the Seaview 4.6.1 program, with a GTR nucleotide substitution mode and 1000 bootstrap replications .Recombination analysis of Estonian YDV isolates was carried out using the Recombination Detection Program RDP4;  with a sMUSCLE multiple sequence alignment of luteovirus full-length genomes retrieved from GenBank was used for the selection of unique primer binding sites for BYDV-PAV, -GAV, -PAS, and -OYV in the region of ORF3/ORF4. A mix of new species-specific forward primers PasF, OyvF, GavF, and PavF  togetherIn silico binding tests were performed to evaluate the specificity and sensitivity of 32 primer pairs  for two Estonian isolates (Avinurme2 and Ulvi) of the new candidate species. In parallel, BYDV-OYV was identified by IC-RT-PCR using BYDV-PAV antibodies in two meadow fescue samples collected in Sweden. Using the strategy of primer walking, 5,133 nt of the Swedish isolate (MK012642) was sequenced. The obtained sequence of the Swedish isolate covered 90% of the genome length, lacking the 5′-UTR, the beginning of ORF1, and a part of 3′UTR. The complete genome sizes for the seven Estonian BYDV-OYV isolates ranged between 5,664 and 5,681 nt (MK012643- MK012649). The biggest difference for the variation in genome length between the Estonian isolates lies at the beginning of ORF5  where the isolates of Saunja and Rannu have an insertion of 18 nucleotides and the isolates Ulvi, Avinurme1, Avinurme2, and Avinurme3 have an insertion of 6 nucleotides compared to the isolates from Sweden and Õru. The Õru isolate has an additional insertion of a single nucleotide within the 3′-UTR. The Estonian BYDV-OYV isolates sampled from cereal plants shared a nucleotide identity of 93.9–98.6% with each other and showed an identity of 92.7–93.4% with the Swedish BYV-OYV isolate. The identity of the new sequences with the previously sequenced partial 502-bp CP gene sequence fragment of BYDV-OYV  was 95.8–97.0%. Assembly of the complete genome sequences for BYDV-OYV isolates revealed a genome organization and size characteristic of luteoviruses .The sequence of BYDV-OYV Avinurme2 (MK012645) was further used for detailed genome annotation. The length of the BYDV-OYV Avinurme2 genome is 5,670 nt, with 5′- and 3′-UTRs of 143 and 611 nt, respectively. The beginning of the 5′-UTR is conserved between isolates of BYDV-OYV, but slightly different from other BYDVs, being most close to BYDV-PAS isolates. The 3′-UTR ends with the conserved motif CGGCAUCCC, which is also characteristic of BYDV-PAS and BYDV-PAV-CN. The coding region between the terminal UTRs is polycistronic and consists of seven predicted ORFs.UAGGUAGAC) around the ORF3 amber stop codon is conserved. BYDV-OYV ORF4 (nt pos. 2906–3367) encodes the cell-to-cell movement protein P4 with a calculated molecular mass of 17 kDa. Before the beginning of ORF6, there is an internal UTR of 131 nt. ORF6 of BYDV-OYV lies in nt position 4937–5059. The calculated molecular weight of the putative P6 protein is 4 kDa.The ORF1 of BYDV-OYV (nt position 144–1166) encodes a protein P1 with a calculated molecular weight of 38.8 kDa. In case of the event of -1 programmed ribosomal frameshifting at the GGGUUUU just before the ORF1 stop codon, translation can continue from nt position 1163 in the frame of ORF2 until a stop codon at nt position 2747–2749, leading to the synthesis of a 98.8 kDa polyprotein P1-P2 constituting the viral RNA-dependent RNA polymerase (RdRp). Translation of ORF3a is predicted to depend on non-AUG initiation . Here, wPhylogenetic analyses of BYDV genomes supported clustering of cereal-infecting BYDVs . Within Overall genome identity is higher for BYDV-OYV and BYDV-PAS (82.8%) than for BYDV-OYV and BYDV-PAV-CN (79.4%). Between BYDV-PAV-CN and BYDV-PAS, the overall genome identity is 79.7% . PhylogeRecombination detection tests  for putaA multiplex-RT-PCR specifically targeting BYDV-PAS, BYDV-OYV, BYDV-GAV, and BYDV-PAV found in this study was established for simultaneous monitoring. The single sets and the multiplex primer set produced RT-PCR fragments with the expected sizes: 476 bp for BYDV-PAS, 401 bp for BYDV-OYV, 317 bp for BYDV-GAV, and 193 bp for BYDV-PAV . SimultaThe sensitivity and the specificity of the primers were estimated for 32 primer pairs, including the primer pairs designed in this study, are included in the Regarding the new candidate species BYDV-OYV, the novel “OyvF & Yan-R” primer pair shows high sensitivity and specificity. Regarding the BYDV-PAS isolates, both the primer pairs “PasF & Yan-R” and “PASF & PASR” show high specificity. The primer pair “GavF & Yan-R” shows the best complementary to BYDV-GAV isolates whereas the primer pair “MAVF & MAVR” shows the highest sensitivity and specificity to BYDV-MAV subspecies solely. The primer pairs “PavF & Yan-R” and “PAVL1 & PAVR1” show the highest sensitivity and specificity for BYDV-PAV isolates, although these primer pairs may miss and fail to detect several isolates. Theoretically, if three mismatches are allowed, “PavF & Yan-R” shows possible annealing to the BYDV-PAS isolates. However, this was not noticed in our multiplex-RT-PCR . The priSeveral analyzed primer pairs show potential unspecific amplification for isolates belonging to different species. For example, the primer pair “PAV (forward) & PAV (reverse)” does not discriminate BYDV-PAV, BYDV-PAS, and BYDV-MAV/GAV; the primer pair “MAVL1 & MAVR1” does not discriminate BYDV-MAV and BYDV-PAV, and “MAVF2 & Yan-R” recognizes BYDV-GAV instead of BYDV-MAV even if no mismatches to the target are allowed. If mismatches are allowed, the probability of unspecific recognition also shows up for several other primer pairs.Among the universal primers designed to recognize multiple BYDV species, the primer pair “Luteo1F & YanR-New” is the most universal — theoretically, it only fails to detect BYDV-KerII and -KerIII isolates, two isolates of BYDV-PAV and one BYDV-PAV-CN isolate.By high throughput sequencing of field samples from a country-wide survey in Estonia, we identified five species of cereal/barley YDVs – CYDV-RPS, BYDV-GAV, BYDV-PAS, BYDV-PAV, and BYDV-OYV which are described in the current study. The putative novel luteovirus, BYDV-OYV, was also identified in the samples of meadow fescue collected from Sweden and included in our analysis. The same survey identified brome mosaic virus, European wheat striate mosaic virus, oat sterile dwarf virus, and putative cereal closterovirus .In the past, the novel luteovirus BYDV-OYV was detected on one occasion from a neighboring country, Latvia. During this previous study, a 502-nt fragment of the CP gene was amplified and sequenced using the luteovirus universal primer pair Lu1/Lu4. A phylogenetic relationship to a group of Chinese isolates of BYDV-PAV (BYDV-PAV-CN) was proposed but the taxonomic status of BYDV-OYV and BYDV-PAV-CN remained unclear .Luteovirus. However, the authors suggested waiting until the genome of BYDV-OYV is sequenced to determine whether these two viruses could be classified as a single species or two distinct species , but slightly looser relationships between their 5′ gene blocks (P1/RdRp), which instead show the closest relationships between BYDV-PAS and BYDV-OYV. Remarkably, a very highly conserved region  resides between these two gene blocks. Most probably, such a highly conserved region is a suitable template for copy-choice recombination during mixed infection. The template-switching model includes dissociation of the replicase and nascent strand, followed by nascent RNA strand hybridization to the region of complementarity in the acceptor strand. It has been proposed that the subgenomic promoters at the end of the 5′gene block (within the region encoding RdRp) of luteoviruses serve as the “hot spot” sites for recombination during replication . AlternaLuteovirus is a >10% difference in amino acid sequence identity of any gene product from its closest relative. Therefore, considering the sequence analyses described and taking into account that both viruses have been found from several different locations and years, we propose creating two new species in the genus Luteovirus: BYDV-OYV and BYDV-PAV-CN.According to the identity calculations, the multiple gene products of BYDV-OYV show differences of around 10% or higher when compared with the respective gene products of other BYDVs . SpeciesRhopalosiphum padi and Sitobion avenae whereas BYDV-PAS is also transmitted by R. maidis and Metopolophium dirhodium . Interestingly, BYDV-PAV was found only in one sample. The absence of BYDV-PAV, but the abundance of BYDV-PAS, has been reported in Alaska, which is exposed to climatic conditions similar to Northern Europe with long photoperiods and cooler temperatures during the growing season . It has irhodium .Whereas BYDV-PAS was most commonly identified from winter wheat  in our survey, BYDV-OYV was detected from oats and spring wheat. The first discovery of BYDV-OYV was also in oats . Our finIn the case of cereal-infecting YDVs, BYDV-PAV, BYDV-MAV, and MYDV-RMV are generally accepted as being the most prevalent YDV species worldwide . The raiPolerovirus that has been known to not react with antisera raised against MAV, PAV, SGV, RPV, or RMV and has exclusively been detected in China until recently  or amplified by CYDV-RPV primers. According to currently existing data, CYDV-RPS seems to be very rare in comparison to CYDV-RPV although both are transmitted by m Mexico  and Iranm Mexico  were detm Mexico , the Unim Mexico , the Czem Mexico , and Estm Mexico . For a lm Mexico , but recm Mexico  and in Egraminum . The biograminum , lead toin silico primer binding test and the similar analysis carried out by The use of antibody detection or multiplex RT-PCR for simultaneous amplification of different virus templates is helpful to reduce diagnostic costs  can be found below: in silico primer analysis and discussed the data. PS performed the field sampling and collected metadata about the sampled sites. KS sequenced the Swedish isolate of BYDV-OYV. AK supervised KS, performed recombination detection analysis, discussed the interpretation of the data, and took part in finalizing the manuscript. All authors agreed to be accountable for the content of the work.MS designed the study, prepared the HTS libraries and analyzed the data, performed the multiplex-RT-PCR experiment, wrote the manuscript, and prepared the figures and tables. SM advised on HTS data analysis and took part in planning and finalizing the manuscript. LT performed 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.


Age is the single major risk factor for human cancer, but naturally occurring cancers are rarely studied in aging models. Like humans, mice spontaneously develop cancer with age, and standard laboratory strains are predisposed for B-cell lymphoma. Here, we uncover how B-cell lymphoma develops as a consequence of the aging immune system. We found that aged B cells acquire somatic mutations in tumor suppressors and oncogenes  and undergo monoclonal expansions, with some clones representing 86% of splenic B cells. Clonal B cells had hypermethylated promoters and globally silenced expression, suggesting a role of DNA methylation in clonal selection of premalignant B cells. B-cell size, spleen weight, and a novel population of B cells, which we named Myc+ cells, emerged as convenient markers of malignancy. High-throughput analyses of clonal B cells and the use of genetic mouse models revealed that c-Myc drives B-cell size increase and clonal expansion with age. Phoshoproteome and co-culture experiments revealed that c-Myc is activated by signals from the aging microenvironment. Moreover, single-cell RNA-seq suggested that clonal B cells originate from age-associated B cells, further underlying the importance of aging environment in cancer transformation. Longitudinal analyses demonstrated a negative impact of premalignant B cells on mouse lifespan and linked it to age-related myeloid bias. Together, our study revealed cell-autonomous changes that cooperate with the aging microenvironment to give rise to preneoplastic B cells. This stidy established a novel model to study how aging predisposes cells to cancer transformation.