Application and mechanism of histamine receptor antagonists in treatment of coronavirus disease 2019: research progress.

The coronavirus disease 2019 (COVID-19) has become a global pandemic. It is urgent to find treatments to control the infection and improve symptoms. Homologous modeling and clinical analyses suggest that histamine receptor antagonists have broad prospects in the treatment of COVID-19. This article introduces the research progress of histamine H1 receptor antagonist combined with azithromycin, histamine H2 receptor antagonist famotidine alone or combined with aspirin, and histamine H1 and H2 receptor antagonists used in combination in the treatment of COVID-19. Finally, the possible mechanism of histamine receptor antagonists in the treatment of COVID-19 was introduced and the application prospect of histamine receptor antagonists in the treatment of COVID-19 was analyzed.Copyright © 2022, Second Military Medical University Press. All rights reserved.

Study on potential common action and mechanism of Reduning Injection against SARS, MERS and COVID-19 based on network pharmacology and molecular docking technology.

Objective To explore the potential common mechanism and active ingredients of Reduning Injection against SARS, MERS and COVID-19 through network pharmacology and molecular docking technology. Methods The TCMSP database was used to retrieve the chemical components and targets of Artemisiae Annuae Herba, Lonicerae Japonicae Flos and Gardeniae Fructus in Reduning Injection. The gene corresponding to the target was searched by UniProt database, and Cytoscape 3.8.2 was used to build a medicinal material-compound-target (gene) network. Three coronavirus-related targets were collected in the Gene Cards database with the key words of "SARS""MERS" and "COVID-19", and common target of three coronavirus infection diseases were screened out through Venny 2.1.0 database. The common targets of SARS, MERS and COVID-19 were intersected with the targets of Reduning Injection, and the common targets were selected as research targets. Protein-protein interaction (PPI) network map were constructed by Cytoscape3.8.2 software after importing the common targets into the STRING database to obtain data. R language was used to carry out GO biological function enrichment analysis and KEGG signaling pathway enrichment analysis, histograms and bubble charts were drew, and component-target-pathway network diagrams was constructed. The key compounds in the component-target-pathway network were selected for molecular docking with important target proteins, novel coronavirus (SARS-CoV-2) 3CL hydrolase, and angiotensin-converting enzyme II (ACE2). Results 31 active compounds and 207 corresponding targets were obtained from Reduning Injection. 2 453 SARS-related targets, 805 MERS-related targets, 2 571 COVID-19-related targets, and 786 targets for the three diseases. 11 common targets with Reduning Injection: HSPA5, CRP, MAPK1, HMOX1, TGFB1, HSP90AA1, TP53, DPP4, CXCL10, PLAT, PRKACA. GO function enrichment analysis revealed 995 biological processes (BP), 71 molecular functions (MF), and 31 cellular components (CC). KEGG pathway enrichment analysis screened 99 signal pathways (P < 0.05), mainly related to prostate cancer, fluid shear stress and atherosclerosis, hepatocellular carcinoma, proteoglycans in cancer, lipid and atherosclerosis, human T-cell leukemia virus 1 infection, MAPK signaling pathway, etc. The molecular docking results showed that the three core active flavonoids of quercetin, luteolin, and kaempferol in Reduning Injection had good affinity with key targets MAPK1, PRKACA, and HSP90AA1, and the combination of the three active compounds with SARS-CoV-2 3CL hydrolase and ACE2 was less than the recommended chemical drugs. Conclusion Reduning Injection has potential common effects on the three diseases of SARS, MERS and COVID-19. This effect may be related to those active compounds such as quercetin, luteolin, and kaempferol acting on targets such as MAPK1, PRKACA, HSP90AA1 to regulate multiple signal pathways and exert anti-virus, suppression of inflammatory storm, and regulation of immune function.Copyright © 2022 Drug Evaluation Research. All rights reserved.

SARS-COV-2 Infection in Children and Young People in Bulgaria - A Prospective, Single-Center, Cohort Study

Compared to other respiratory viruses, the proportion of hospitalizations due to SARS-CoV-2 among children is relatively low. While severe illness is not common among children and young individuals, a particular type of severe condition called multisystem inflammatory syndrome in children (MIS-C) has been reported. The aim of this prospective cohort study, which followed a group of individuals under the age of 19, was to examine the characteristics of patients who had contracted SARS-CoV-2, including their coexisting medical conditions, clinical symptoms, laboratory findings, and outcomes. The study also aimed to investigate the features of children who met the WHO case definition of MIS-C, as well as those who required intensive care. A total of 270 patients were included between March 2020 and December 2021. The eligible criteria were individuals between 0-18 with a confirmed SARS-CoV-2 infection at the Infectious Disease Hospital "Prof. Ivan Kirov"in Sofia, Bulgaria. Nearly 76% of the patients were <= 12 years old. In our study, at least one comorbidity was reported in 28.1% of the cases, with obesity being the most common one (8.9%). Less than 5% of children were transferred to an intensive care unit. We observed a statistically significant difference in the age groups, with children between 5 and 12 years old having a higher likelihood of requiring intensive care compared to other age groups. The median values of PaO2 and SatO2 were higher among patients admitted to the standard ward, while the values of granulocytes and C-reactive protein were higher among those transferred to the intensive care unit. Additionally, we identified 26 children who met the WHO case definition for MIS-C. Our study data supports the evidence of milder COVID-19 in children and young individuals as compared to adults. Older age groups were associated with higher incidence of both MIS-C and ICU admissions.Copyright © 2023 P. Velikov et al., published by Sciendo.

A Review on the Effect of COVID-19 in Pregnant Women

Coronavirus Disease 2019 (COVID-19) is an emerging disease with a rapid increase in cases and deaths since its first discovery in December 2019, in Wuhan, China. Limited data are available on COVID-19 effects during pregnancy;however, information on diseases associated with other highly pathogenic coronaviruses (i.e. Severe Acute Respiratory Syndrome [SARS] and the Middle East respiratory syndrome [MERS]) may provide insight into the effects of COVID-19 during pregnancy. Coronaviruses cause illnesses ranging from the common cold to severe respiratory disease and death. The data indicate an average of 5 days incubation period (range: 2-14 days). The average age range of the hospitalized patients was 49-56 years, and a third to half of them have an underlying illness. Children were rarely mentioned. Within hospitalized cases, men were more frequent (54%-73%). Fever, cough, myalgia, vomiting, and diarrhea are common symptoms. This review aims at giving an in-depth understanding of COVID-19 by comparing its effects with SARS and MERS to evaluate its severity in pregnant women1. The results of varied studies show that COVID-19 affects pregnant women seriously and there is an alarming need to look into this aspect to prevent its harmful effects on the fetus.Copyright © 2020

Graph Neural Network Models for Chemical Compound Activeness Prediction For COVID-19 Drugs Discovery using Lipinski's Descriptors

In this study, we implemented graph neural network (GNN) methods to forecast in vitro inhibitory bioactivity or pharmacological concentration of chemical compounds against severe acute respiratory syndrome (SARS) coronaviruses from the graph representation amongst the compounds (i.e., nodes) and their respective features(i.e., node features) obtained by RDKit tool from their respectively SMILES (Simplified MolecularInput Line-Entry System), and we compared GNN models by experiments with our graph data of 375 nodes with 44,475 edges or links. This was done in response to the severe and significant consequences of the ongoing Coronavirus disease 2019 (COVID-19) disease. As a result, we discovered that implemented models, simple graph convolution (SGC), and graph convolution network (GCN) performed significantly well with comparable performance. © 2022 IEEE.

Relationship of Vaccination History and Pregnancy Health Protocol Compliance with Positive Antigen Test Result at Community Health Center in Medan, Indonesia

BACKGROUND: A comprehensive screening at delivery revealed that roughly 14% of pregnant women who tested positive for COVID-19 did not exhibit any symptoms. The SARS-CoV-2 antigen swab test is frequently utilized as a diagnostic technique. Inadequate implementation of health protocol compliance can enhance the vulnerability of a community to the COVID-19 virus, according to previous findings. This suggests that these health protocol compliance and the vaccination program are important for preventing and controlling the spread of the virus. AIM: This study aims to determine the relationship of vaccination history and health protocol compliance with positive antigen swab results among pregnant women at the Community Health Center in Medan. METHOD(S): This is a cross-sectional and observational study that was conducted in February 2022 at the Community Health Center in Medan, North Sumatra, Indonesia. Two hundred pregnant women who met the inclusion and exclusion criteria make up the sample population. Antigen sampling for SARS-CoV-2 was performed in the Pramita laboratory. Following the collection and processing of sample and antigen swab data, IBM SPSS version was utilized to conduct statistical analysis. RESULT(S): The result showed that four of the pregnant women were infected with COVID-19, and they accounted for 2% of the sample population. The health protocol carried out by pregnant women was not significantly related to the swab results. Therefore, vaccination history had no significant association with COVID-19 symptoms, but people who received vaccines had more negative swab test results compared to those who did not, where three out of four positive samples were unvaccinated. CONCLUSION(S): Based on the results, only 2% of pregnant women were infected with COVID-19 at the Community Health Centre in Medan, because this study was carried out when COVID-19 cases had decreased. The statistical analysis results showed that the history of vaccination was not significantly related to SARS-CoV-2 antigen swab results. However, there was a clinical tendency that vaccines can reduce the number of positive cases, where three out of four positive samples were not vaccinated.Copyright © 2023 Sarma Nursani Lumbanraja, Reni Hayati, Khairani Sukatendel, Johny Marpaung, Muhammad Rusda, Edy Ardiansyah.

Pericytes may facilitate SARS-CoV-2 entry into the nervous system

Objective: Although the neurological and olfactory symptoms of coronavirus disease 2019 have been identified, the neurotropic properties of the causative virus, severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2), remain unknown. We sought to identify the susceptible cell types and potential routes of SARS-CoV-2 entry into the central nervous system, olfactory system, and respiratory system. Method(s): We collected single-cell RNA data from normal brain and nasal epithelium specimens, along with bronchial, tracheal, and lung specimens in public datasets. The susceptible cell types that express SARS-CoV-2 entry genes were identified using single-cell RNA sequencing and the expression of the key genes at protein levels was verified by immunohistochemistry. We compared the coexpression patterns of the entry receptor angiotensin-converting enzyme 2 (ACE2) and the spike protein priming enzyme transmembrane serine protease (TMPRSS)/cathepsin L among the specimens. Result(s): The SARS-CoV-2 entry receptor ACE2 and the spike protein priming enzyme TMPRSS/cathepsin L were coexpressed by pericytes in brain tissue;this coexpression was confirmed by immunohistochemistry. In the nasal epithelium, ciliated cells and sustentacular cells exhibited strong coexpression of ACE2 and TMPRSS. Neurons and glia in the brain and nasal epithelium did not exhibit coexpression of ACE2 and TMPRSS. However, coexpression was present in ciliated cells, vascular smooth muscle cells, and fibroblasts in tracheal tissue;ciliated cells and goblet cells in bronchial tissue;and alveolar epithelium type 1 cells, AT2 cells, and ciliated cells in lung tissue. Conclusion(s): Neurological symptoms in patients with coronavirus disease 2019 could be associated with SARS-CoV-2 invasion across the blood-brain barrier via pericytes. Additionally, SARS-CoV-2-induced olfactory disorders could be the result of localized cell damage in the nasal epithelium.Copyright © Wolters Kluwer Health, Inc. All rights reserved.

A cross-sectional study on the seroprevalence of the SARS-CoV-2 IgG antibody in patients with cancer from central Kerala

Background: Patients with cancer are vulnerable to coronavirus disease 2019 (COVID-19). Given the rising number of COVID-19 cases and relaxation of stringent COVID-19 protocols, assessment of the level of protective immunity to COVID-19 in patients with cancer has assumed importance. Objective(s): Our primary objective was to evaluate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in patients with cancer. Material(s) and Method(s): We conducted a cross-sectional study on 100 patients with solid tumors attending our Oncology Department at the Believers Church Medical College, Kerala, India, between December 2020 and June 2021. Seroprevalence was assessed using the VITROS Anti-SARS-CoV-2 IgG test (Ortho-Clinical Diagnostics, Rochester, NY, USA). Additionally, we assessed the factors associated with seropositivity and collected data regarding the general experience of patients with cancer during the pandemic. Result(s): The median age of the participants was 62 years (IQR, 53-69.8);52 (52%) were males. The seroprevalence of the SARS-CoV-2 IgG antibodies was 11% (95% CI, 4.8-17.1). Age < 50 years was the only factor that was significantly associated with a higher rate of COVID-19 antibodies (77% vs 8.9% in patients >= 50 years;P = 0.007), and sex, smoking, and the use of alcohol did not show any association. The majority (77/100, 77%) of the patients were worried about contracting COVID-19 infection;some even deferred cancer-directed treatment because of the fear of visiting health care settings. Conclusion(s): Low seroprevalence of SARS-CoV-2 IgG antibodies in unvaccinated patients with cancer is a matter of concern as it indicates that many of these patients are still vulnerable to infection. There is an urgent need to continue implementing strict safety measures in oncology centers and to encourage widespread COVID-19 vaccination to prevent the uncontrolled spread of COVID-19 among patients with cancer. (Funded by the institution, Believers Church Medical College, Kerala).Copyright © 2023 Neurology India, Neurological Society of India Published by Wolters Kluwer - Medknow.

Risk factors for worsening of somatic symptom burden in a prospective cohort during the COVID-19 pandemic

Aims: Little is known about risk factors for both Long COVID and somatic symptoms that develop in individuals without a history of COVID-19 in response to the pandemic. There is reason to assume an interplay between pathophysiological mechanisms and psychosocial factors in the etiology of symptom persistence. This study investigates specific risk factors for somatic symptom deterioration in a cohort of German adults with and without prior SARS-CoV-2 infection. Method(s): German healthcare professionals underwent SARS-CoV-2 IgG antibody testing and completed self-rating questionnaires at baseline and 21 months later between April 2020 and February 2022. Differences in variables between the time points were analyzed and a regression analysis was performed to predict somatic symptom deterioration at follow-up. Result(s): Seven hundred fifty-one adults completed both assessments. Until follow-up, n = 58 had contracted SARS-CoV-2 confirmed by serology. Between baseline and follow-up, signs of mental and physical strain increased significantly in the sample. Symptom expectations associated with COVID-19 and a self-reported history of COVID-19, but not serologically confirmed SARS-CoV-2 infection, significantly predicted somatic symptom deterioration at follow-up. A further predictor was baseline psychological symptom burden. Conclusion(s): This study supports a disease-overarching biopsychosocial model for the development of burdensome somatic symptoms during the COVID-19 pandemic and supports research findings that symptom burden may be more related to the psychosocial effects of the pandemic than to infection itself. Future studies on Long COVID should include SARS-CoV-2 negative control groups and consider symptom burden prior to infection in order to avoid an overestimation of prevalence rates.Copyright © 2023

Monitoring SARS CoV-2 antibodies positivity in healthcare workers after inactivated CoronaVac vaccine

Introduction In this study, we aimed to monitor anti-spike and anti-nucleocapsid antibodies positivity in healthcare workers (HCWs) vaccinated with two doses of inactivated CoronaVac (Sinovac, China) vaccine. Methods Overall, 242 volunteer HCWs were included. Of the participants, 193 were HCWs without history of prior documented COVID-19 (Group 1), while 49 had history of prior documented COVID-19 before vaccination (Group 2). The participants were followed up for SARS-CoV-2 antibodies positivity at four different blood sampling time points (immediately before the second vaccine dose and at the 1st, 3rd months and 141-150 days after the second dose). We investigated the serum IgG class antibodies against SARS-CoV-2 RBD region and IgG class antibodies against SARS-CoV-2 nucleocapsid antigen by chemiluminescent microparticle immunoassay (CMIA) method using commercial kits. Results We found positive serum anti-RBD IgG antibody in 76.4% of the participants (71% in Group 1;98% in Group 2) 28 days after the first dose. When the antibody levels of the groups were compared at the four blood sampling time points, Group 2 anti-RBD IgG levels were found to be significantly higher than those in Group 1 at all follow-up time points. Although anti-RBD IgG positivity persisted in 95.6% of all participants in the last blood sampling time point, a significant decrease was observed in antibody levels compared to the previous blood sampling time point. Anti-nucleocapsid IgG antibody was positive in 12 (6.2%) of participants in Group 1 and 32 (65.3%) in Group 2 at day 28 after the first dose. At the fourth blood sampling time point, anti-nucleocapsid antibodies were found to be positive in a total of 20 (9.7%) subjects, 10 (6.1%) in Group 1 and 10 (23.8%) in Group 2. Conclusions In this study, it was determined that serum antibody levels decreased in both groups after the third month after the second dose in HCWs vaccinated with CoronaVac vaccine.Copyright © GERMS 2022.

Validating saliva as a biological sample for cost-effective, rapid and routine screening for SARS-CoV-2

Purpose: Compared to nasopharyngeal/oropharyngeal swabs (N/OPS-VTM), non-invasive saliva samples have enormous potential for scalability and routine population screening of SARS-CoV-2. In this study, we investigate the efficacy of saliva samples relative to N/OPS-VTM for use as a direct source for RT-PCR based SARS-CoV-2 detection. Method(s): We collected paired nasopharyngeal/oropharyngeal swabs and saliva samples from suspected positive SARS-CoV-2 patients and tested using RT-PCR. We used generalized linear models to investigate factors that explain result agreement. Further, we used simulations to evaluate the effectiveness of saliva-based screening in restricting the spread of infection in a large campus such as an educational institution. Result(s): We observed a 75.4% agreement between saliva and N/OPS-VTM, that increased drastically to 83% in samples stored for less than three days. Such samples processed within two days of collection showed 74.5% test sensitivity. Our simulations suggest that a test with 75% sensitivity, but high daily capacity can be very effective in limiting the size of infection clusters in a workspace. Guided by these results, we successfully implemented a saliva-based screening in the Bangalore Life Sciences Cluster (BLiSC) campus. Conclusion(s): These results suggest that saliva may be a viable alternate source for SARS-CoV-2 surveillance if samples are processed immediately. Although saliva shows slightly lower sensitivity levels when compared to N/OPS-VTM, saliva collection is logistically advantageous. We strongly recommend the implementation of saliva-based screening strategies for large workplaces and in schools, as well as for population-level screening and routine surveillance as we learn to live with the SARS-CoV-2 virus.Copyright © 2023 Indian Association of Medical Microbiologists

Cellular and humoral immune responses after SARS-CoV-2 vaccination in pediatric kidney recipients

Objective: Humoral and cellular immune responses to SARS-CoV-2 vaccination are reduced in adult kidney recipients. After pediatric kidney transplantation there are only few data available - mostly limited to monitoring of SARS-CoV-2 antibodies. Method(s): Cellular and humoral immune responses have been monitored before and after SARS-CoV-2 vaccination in pediatric kidney recipients. After in vitro stimulation with SARS-CoV-2 antigen (spike glycoprotein) virus-specific CD4 and CD8 T cells (SARS-CoV-2-Tvis) have been identified by cytokine flow cytometry. SARS-CoV-2 IgG was measured by CMIA. Result(s): Immune response after SARS-CoV-2 vaccination was analyzed in a total of 30 pediatric kidney recipients (age at 1st vaccine dose 5.2 - 17.8 years, median 14.8 years;43% male;30/30 2 vaccine doses;23/30 3 vaccine doses). At time of vaccination 22 patients (73%) received a tacrolimus (Tac)-based immunosuppression combined with mycophenolate mofetil (MMF;n = 15) or everolimus (n = 6) or neither of them (n = 1);3 patients were exposed to cyclosporine A and 5 patients to a calcineurin inhibitor (CNI)- free immunosuppression. MMF was used in 18/30 patients. After 1st dose of mRNA vaccine SARS-CoV-2 antibodies were detectable in 50% of pediatric kidney recipients, after 2nd dose in 78% and after 3rd dose in 88%. After the 2nd vaccine dose absence of humoral immune response (< 33.8 BAU/ml) was only found in case of MMF use (predominately combined with Tac). Peak IgG values (> 2,080 BAU/ml) were only detected in MMF-free regimens (6/7). Cellmediated response partially differed from humoral response, e. g., in some patients SARS-CoV2-Tvis were found despite lack of virus-specific antibodies. After 1st vaccine dose SARS-CoV-2-Tvis were detectable in 50% of pediatric kidney recipients, after 2nd dose in 92%. After 2nd vaccine dose absence or very low levels of SARS-CoV-2-Tvis (< 0.3 cells/mul) were only found in Tac-based immunosuppressive regimens, whereas higher levels (> 1.3 cells/mul) were exclusively detected in patients with MMFfree medication. Conclusion(s): After pediatric kidney transplantation humoral and cellular immune responses to SARS-CoV-2 vaccination were suboptimal, but more pronounced than in adult kidney recipients. Use of Tac and MMF was associated with impaired immune response to vaccination. SARS-CoV-2-specific humoral response corresponded only partially to cell-mediated response. Additional monitoring of SARS-CoV- 2-Tvis might be recommendable to improve assessment of the individual vaccine response and thereby to personalize the decision on the necessity of further vaccine doses.

SARS-CoV-2 effects on male reproduction: should men be worried??

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed a global challenge on both healthcare and society. So far, studies have shown that men are more prone to become ill than women and are more likely to die compared to female patients. Higher rates of positive cases and fatality in men than women have drawn the attention of scientists to investigate the possible impacts of SARS-CoV-2 on the male reproductive system. In this review, we tried to summarise so far findings on the effect of the SARS-CoV-2 on the male reproductive function to further assess the potential risks of this novel coronavirus on male reproductive health.

Statins in hospitalized COVID-19 patients: A systematic review and meta-analysis of randomized controlled trials.

This systematic review and meta-analysis aimed to determine the efficacy of statins in hospitalized patients with coronavirus disease-2019 (COVID-19). A systematic search was made of PubMed, Embase, Cochrane Library, and clinicaltrials.gov, without language restrictions. Randomized controlled trials (RCTs) on treatment of COVID-19 with statins, compared with placebo or standard of care, were reviewed. Seven RCTs (enrolling 1830 participants) met the inclusion criteria. There was no statistically significant difference in all-cause mortality (risk ratio [RR]: 0.92, 95% confidence interval [CI]: 0.75-1.13), length of hospital stay (weighted mean difference: -0.21 days, 95% CI: -1.01 to 0.59 days), intensive care unit (ICU) admission (RR: 1.84, 95% CI: 0.45-7.55), and mechanical ventilation (RR: 1.09, 95% CI: 0.70-1.70) between the two groups. Statins failed to reduce mortality, ICU admission, mechanical ventilation, and length of stay in hospitalized patients with COVID-19. Statins probably should not be used routinely in COVID-19 patients.

A mathematical model of SARS-CoV-2 immunity predicts paxlovid rebound.

Nirmatrelvir/ritonavir (Paxlovid), an oral antiviral medication targeting SARS-CoV-2, remains an important treatment for COVID-19. Initial studies of nirmatrelvir/ritonavir were performed in SARS-CoV-2 unvaccinated patients without prior confirmed SARS-CoV-2 infection; however, most individuals have now either been vaccinated and/or have experienced SARS-CoV-2 infection. After nirmatrelvir/ritonavir became widely available, reports surfaced of "Paxlovid rebound," a phenomenon in which symptoms (and SARS-CoV-2 test positivity) would initially resolve, but after finishing treatment, symptoms and test positivity would return. We used a previously described parsimonious mathematical model of immunity to SARS-CoV-2 infection to model the effect of nirmatrelvir/ritonavir treatment in unvaccinated and vaccinated patients. Model simulations show that viral rebound after treatment occurs only in vaccinated patients, while unvaccinated (SARS-COV-2 naïve) patients treated with nirmatrelvir/ritonavir do not experience any rebound in viral load. This work suggests that an approach combining parsimonious models of the immune system could be used to gain important insights in the context of emerging pathogens.

Histone mRNA polyadenylation-mediated inflammation underlies various virus infections and cancers.

The mechanistic understanding of virus infection and inflammation in many diseases is incomplete. Normally, messenger RNA (mRNA) tails of replication-dependent histones (RDH) that safeguard naked nuclear DNAs are protected by a specialized stem-loop instead of polyadenylation. Here, we showed that infection by various RNA viruses (including severe acute respiratory syndrome coronavirus 2) induced aberrant polyadenylation of RDH mRNAs (pARDH) that resulted in inflammation or cellular senescence, based on which we constructed a pARDH inflammation score (pARIS). We further investigated pARIS elevation in various disease conditions, including different types of virus infection, cancer, and cellular senescence. Notably, we found that pARIS was positively correlated with coronavirus disease 2019 severity in specific immune cell types. We also detected a subset of HIV-1 elite controllers characterized by pARDH "flipping" potentially mediated by HuR. Importantly, pARIS was positively associated with transcription of endogenous retrovirus but negatively associated with most immune cell infiltration in tumors of various cancer types. Finally, we identified and experimentally verified two pARIS regulators, ADAR1 and ZKSCAN1, which was first linked to inflammation. The ZKSCAN1 was known as a transcription factor but instead was shown to regulate pARIS as a novel RNA binding protein. Both regulators were upregulated under most infection and inflammation conditions. In conclusion, we unraveled a potential antiviral mechanism underlying various types of virus infections and cancers.

pH-dependent endocytosis mechanisms for influenza A and SARS-coronavirus.

The ongoing SARS-CoV-2 pandemic and the influenza epidemics have revived the interest in understanding how these highly contagious enveloped viruses respond to alterations in the physicochemical properties of their microenvironment. By understanding the mechanisms and conditions by which viruses exploit the pH environment of the host cell during endocytosis, we can gain a better understanding of how they respond to pH-regulated anti-viral therapies but also pH-induced changes in extracellular environments. This review provides a detailed explanation of the pH-dependent viral structural changes preceding and initiating viral disassembly during endocytosis for influenza A (IAV) and SARS coronaviruses. Drawing upon extensive literature from the last few decades and latest research, I analyze and compare the circumstances in which IAV and SARS-coronavirus can undertake endocytotic pathways that are pH-dependent. While there are similarities in the pH-regulated patterns leading to fusion, the mechanisms and pH activation differ. In terms of fusion activity, the measured activation pH values for IAV, across all subtypes and species, vary between approximately 5.0 to 6.0, while SARS-coronavirus necessitates a lower pH of 6.0 or less. The main difference between the pH-dependent endocytic pathways is that the SARS-coronavirus, unlike IAV, require the presence of specific pH-sensitive enzymes (cathepsin L) during endosomal transport. Conversely, the conformational changes in the IAV virus under acidic conditions in endosomes occur due to the specific envelope glycoprotein residues and envelope protein ion channels (viroporins) getting protonated by H+ ions. Despite extensive research over several decades, comprehending the pH-triggered conformational alterations of viruses still poses a significant challenge. The precise mechanisms of protonation mechanisms of certain during endosomal transport for both viruses remain incompletely understood. In absence of evidence, further research is needed.