IFN-γ decreases PD-1 in T lymphocytes from convalescent COVID-19 patients via the AKT/GSK3ß signaling pathway.

Post-COVID-19 syndrome may be associated with the abnormal immune status. Compared with the unexposed age-matched elder group, PD-1 in the CD8+ T cells from recovered COVID-19 patients was significantly lower. IFN-γ in the plasma of COVID-19 convalescent patients was increased, which inhibited PD-1 expression in CD8+ T cells from COVID-19 convalescent patients. scRNA-seq bioinformatics analysis revealed that AKT/GSK3ß may regulate the INF-γ/PD-1 axis in CD8+ T cells from COVID-19 convalescent patients. In parallel, an IFN-γ neutralizing antibody reduced AKT and increased GSK3ß in PBMCs. An AKT agonist (SC79) significantly decreased p-GSK3ß. Moreover, AKT decreased PD-1 on CD8+ T cells, and GSK3ß increased PD-1 on CD8+ T cells according to flow cytometry analysis. Collectively, we demonstrated that recovered COVID-19 patients may develop long COVID. Increased IFN-γ in the plasma of recovered Wuhan COVID-19 patients contributed to PD-1 downregulation on CD8+ T cells by regulating the AKT/GSK3ß signaling pathway.

What Remains up to 7 Months after Severe and Moderate Pneumonia in Non-Vaccinated Patients with Long COVID? Results of a CT Study.

BACKGROUND: There is a growing evidence of long-lasting lung changes after COVID-19. Our aim was to assess the degree of lung injury and evaluate the recovery process of 4-7-month-non-vaccinated convalescent patients discharged from hospital after moderate and severe COVID-19 pneumonia, who presented with symptoms of long-COVID. METHODS: On control lung CT after mean 5-month recovery period, we classified and determined the prevalence of residual radiological abnormalities in 39 symptomatic patients. To assess the advancement of the persisting changes we used the total severity score (TSS) and the chest CT score and then correlated the results with clinical data. RESULTS AND CONCLUSIONS: On follow-up CT images, 94.9% of patients showed persistent radiological abnormalities. The most frequent changes were ground-glass opacities (74.4%), reticular pattern (64.1%), fibrotic changes (53.8%), nodules (33.3%), bronchiectasis (15.4%), vascular enlargement (10.3%), and cavitation (5.1%). The median TSS score was 4.1 points (interquartile range 3), whereas the median of the chest CT score 5.4 points (interquartile range of 4.5). No significant differences were observed between sex subgroups and between the severe and moderate course groups. There were no association between both CT scores and the severity of the initial disease, indicating that, mean 5 months after the disease, pulmonary abnormalities reduced to a similar stage in both subgroups of severity.

Minimal Crossover between Mutations Associated with Omicron Variant of SARS-CoV-2 and CD8+ T-Cell Epitopes Identified in COVID-19 Convalescent Individuals.

There is a growing concern that ongoing evolution of SARS-CoV-2 could lead to variants of concern (VOC) that are capable of avoiding some or all of the multifaceted immune response generated by both prior infection or vaccination, with the recently described B.1.1.529 (Omicron) VOC being of particular interest. Peripheral blood mononuclear cell samples from PCR-confirmed, recovered COVID-19 convalescent individuals (n = 30) infected with SARS-CoV-2 in the United States collected in April and May 2020 who possessed at least one or more of six different HLA haplotypes were selected for examination of their anti-SARS-CoV-2 CD8+ T-cell responses using a multiplexed peptide-major histocompatibility complex tetramer staining approach. This analysis examined if the previously identified viral epitopes targeted by CD8+ T cells in these individuals (n = 52 distinct epitopes) are mutated in the newly described Omicron VOC (n = 50 mutations). Within this population, only one low-prevalence epitope from the Spike protein, restricted to two HLA alleles and found in 2/30 (7%) individuals, contained a single amino acid change associated with the Omicron VOC. These data suggest that virtually all individuals with existing anti-SARS-CoV-2 CD8+ T-cell responses should recognize the Omicron VOC and that SARS-CoV-2 has not evolved extensive T-cell escape mutations at this time. IMPORTANCE The newly identified Omicron variant of concern contains more mutations than any of the previous variants described to date. In addition, many of the mutations associated with the Omicron variant are found in areas that are likely bound by neutralizing antibodies, suggesting that the first line of immunological defense against COVID-19 is compromised. However, both natural infection and vaccination develop T-cell-based responses in addition to antibodies. This study examined if the parts of the virus, or epitopes, targeted by the CD8+ T-cell response in 30 individuals who recovered from COVID-19 in 2020 were mutated in the Omicron variant. Only one of 52 epitopes identified in this population contained an amino acid that was mutated in Omicron. These data suggest that the T-cell immune response in previously infected, and most likely vaccinated, individuals should still be effective against Omicron.

Exploring Rapid and Effective Screening Methods for Anti-SARS-CoV-2 Neutralizing Antibodies in COVID-19 Convalescent Patients and Longitudinal Vaccinated Populations.

Assessing the duration of neutralizing antibodies (nAbs) following SARS-CoV-2 infection or vaccination is critical to evaluate the protective immunity and formulate public health strategies. In this study, SARS-CoV-2 Ab ELISA (enzyme-linked immunosorbent assay), chemiluminescent microparticle immunoassay (CMIA), as well as pseudovirus neutralization test (PVNT) were performed in two cohorts, convalescent patients (CP) from coronavirus disease 2019 (COVID-19) and BBIBP-CorV vaccinated population. It was found that nAbs and binding antibodies emerged at 14 days post the 1st dose of vaccination, reached peaks at 28 days after 2nd dose vaccination and then gradually declined over time. CP-6M (convalescent patients up to 6 months) from COVID-19 presented stronger nAbs or binding antibodies responses than vaccinees 90 days or 180 days after 2nd dose vaccination. CMIA or SARS-CoV-2 Ab ELISA correlated well with PVNT with high consistency in the two cohorts. It shown that nAbs and binding antibodies can keep 6 months both in CP and vaccinees. Most importantly, our data show the application of using CMIA and SARS-CoV-2 Ab ELISA as rapid screening tests for nAb titer and could be used as alternative strategies for quickly evaluating SARS-CoV-2 nAbs responses in vaccine research.

Long-term perturbation of the peripheral immune system months after SARS-CoV-2 infection.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly infectious respiratory virus which is responsible for the coronavirus disease 2019 (COVID-19) pandemic. It is increasingly clear that recovered individuals, even those who had mild COVID-19, can suffer from persistent symptoms for many months after infection, a condition referred to as "long COVID", post-acute sequelae of COVID-19 (PASC), post-acute COVID-19 syndrome, or post COVID-19 condition. However, despite the plethora of research on COVID-19, relatively little is known about the molecular underpinnings of these long-term effects. METHODS: We have undertaken an integrated analysis of immune responses in blood at a transcriptional, cellular, and serological level at 12, 16, and 24 weeks post-infection (wpi) in 69 patients recovering from mild, moderate, severe, or critical COVID-19 in comparison to healthy uninfected controls. Twenty-one of these patients were referred to a long COVID clinic and > 50% reported ongoing symptoms more than 6 months post-infection. RESULTS: Anti-Spike and anti-RBD IgG responses were largely stable up to 24 wpi and correlated with disease severity. Deep immunophenotyping revealed significant differences in multiple innate (NK cells, LD neutrophils, CXCR3+ monocytes) and adaptive immune populations (T helper, T follicular helper, and regulatory T cells) in convalescent individuals compared to healthy controls, which were most strongly evident at 12 and 16 wpi. RNA sequencing revealed significant perturbations to gene expression in COVID-19 convalescents until at least 6 months post-infection. We also uncovered significant differences in the transcriptome at 24 wpi of convalescents who were referred to a long COVID clinic compared to those who were not. CONCLUSIONS: Variation in the rate of recovery from infection at a cellular and transcriptional level may explain the persistence of symptoms associated with long COVID in some individuals.

CD8+ T-Cell Responses in COVID-19 Convalescent Individuals Target Conserved Epitopes From Multiple Prominent SARS-CoV-2 Circulating Variants.

This study examined whether CD8+ T-cell responses from coronavirus disease 2019 convalescent individuals (n = 30) potentially maintain recognition of the major severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants (alpha, beta, gamma; n = 45 mutations assessed). Only 1 mutation found in Beta variant-spike overlapped with a previously identified epitope (1/52), suggesting that virtually all anti-SARS-CoV-2 CD8+ T-cell responses should recognize these newly described variants.

Over 1-year duration and age difference of SARS-CoV-2 antibodies in convalescent COVID-19 patients.

Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglouilin G (IgG) and immunoglouilin M (IgM) antibodies have been widely used to assist clinical diagnosis. Our previous study reported a discrepancy in SARS-CoV-2 antibody response between male and female coronavirus disease 2019 (COVID-19) patients. However, the duration and discrepancy between ages as well as sexes of SARS-CoV-2 antibody in convalescent COVID-19 patients have not been clarified. In this study, a total of 538 health-examination individuals who were confirmed with SARS-CoV-2 infection a year ago were enrolled. Blood samples were collected and detected for IgM and IgG antibodies. Among these convalescent patients, 12.80% were detected positive for IgM antibodies. The positive rates for IgM antibody were close between sexes: for males, this is 9.17% and for females 13.75%. However, the IgG antibody was detected positive in as much as 82.90% convalescent patients and the positive rates were nearly the same between males (82.57%) and females (82.98%). Besides this, the level of IgM and IgG antibodies showed no difference between male and female convalescent patients. The level of IgG antibodies showed a significant difference between ages. The elder patients (over 35 years old) maintained a higher level of IgG antibody than the younger patients (under or equal 35 years old) after recovering for 1 year. In addition, IgG antibody was more vulnerable to disappear in younger patients than in elder patients. Overall, our study identified over 1-year duration of SARS-CoV-2 antibody and age difference of IgG antibody response in convalescent COVID-19 patients. These findings may provide new insights into long-term humoral immune response, vaccines efficacy and age-based personalized vaccination strategies.

Landscape of epitopes targeted by T cells in 852 individuals recovered from COVID-19: Meta-analysis, immunoprevalence, and web platform.

Knowledge of the epitopes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) targeted by T cells in recovered (convalescent) individuals is important for understanding T cell immunity against coronavirus disease 2019 (COVID-19). This information can aid development and assessment of COVID-19 vaccines and inform novel diagnostic technologies. Here, we provide a unified description and meta-analysis of SARS-CoV-2 T cell epitopes compiled from 18 studies of cohorts of individuals recovered from COVID-19 (852 individuals in total). Our analysis demonstrates the broad diversity of T cell epitopes that have been recorded for SARS-CoV-2. A large majority are seemingly unaffected by current variants of concern. We identify a set of 20 immunoprevalent epitopes that induced T cell responses in multiple cohorts and in a large fraction of tested individuals. The landscape of SARS-CoV-2 T cell epitopes we describe can help guide immunological studies, including those related to vaccines and diagnostics. A web-based platform has been developed to help complement these efforts.

Alterations in T and B cell function persist in convalescent COVID-19 patients.

BACKGROUND: Emerging studies indicate that some coronavirus disease 2019 (COVID-19) patients suffer from persistent symptoms, including breathlessness and chronic fatigue; however, the long-term immune response in these patients presently remains ill-defined. METHODS: Here, we describe the phenotypic and functional characteristics of B and T cells in hospitalized COVID-19 patients during acute disease and at 3-6 months of convalescence. FINDINGS: We report that the alterations in B cell subsets observed in acute COVID-19 patients were largely recovered in convalescent patients. In contrast, T cells from convalescent patients displayed continued alterations with persistence of a cytotoxic program evident in CD8+ T cells as well as elevated production of type 1 cytokines and interleukin-17 (IL-17). Interestingly, B cells from patients with acute COVID-19 displayed an IL-6/IL-10 cytokine imbalance in response to Toll-like receptor activation, skewed toward a pro-inflammatory phenotype. Whereas the frequency of IL-6+ B cells was restored in convalescent patients irrespective of clinical outcome, the recovery of IL-10+ B cells was associated with the resolution of lung pathology. CONCLUSIONS: Our data detail lymphocyte alterations in previously hospitalized COVID-19 patients up to 6 months following hospital discharge and identify 3 subgroups of convalescent patients based on distinct lymphocyte phenotypes, with 1 subgroup associated with poorer clinical outcome. We propose that alterations in B and T cell function following hospitalization with COVID-19 could affect longer-term immunity and contribute to some persistent symptoms observed in convalescent COVID-19 patients. FUNDING: Provided by UKRI, Lister Institute of Preventative Medicine, the Wellcome Trust, The Kennedy Trust for Rheumatology Research, and 3M Global Giving.

COVID-19 Vaccines Currently under Preclinical and Clinical Studies, and Associated Antiviral Immune Response.

With a death toll of over one million worldwide, the COVID-19 pandemic caused by SARS-CoV-2 has become the most devastating humanitarian catastrophe in recent decades. The fear of acquiring infection and spreading to vulnerable people has severely impacted society's socio-economic status. To put an end to this growing number of infections and deaths as well as to switch from restricted to everyday living, an effective vaccine is desperately needed. As a result, enormous efforts have been made globally to develop numerous vaccine candidates in a matter of months. Currently, over 30 vaccine candidates are under assessment in clinical trials, with several undergoing preclinical studies. Here, we reviewed the major vaccine candidates based on the specific vaccine platform utilized to develop them. We also discussed the immune responses generated by these candidates in humans and preclinical models to determine vaccine safety, immunogenicity, and efficacy. Finally, immune responses induced in recovered COVID-19 patients and their possible vaccine development implications were also briefly reviewed.

A Review of Viral Shedding in Resolved and Convalescent COVID-19 Patients.

As of August 06, 2020, 18.9 million cases of SARS-CoV-2 and more than 711,000 deaths have been reported. As per available data, 80% of the patients experience mild disease, 20% need hospital admission, and about 5% require intensive care. To date, several modes of transmission such as droplet, contact, airborne, blood borne, and fomite have been described as plausible. Several studies have demonstrated shedding of the virus from patients after being free from symptoms, i.e. prolonged virus shedding. While few studies demonstrated virus shedding in convalescent patients, i.e. those testing negative for presence of virus on nasopharyngeal and/or oropharyngeal swabs, yet virus shedding was reported from other sources. Maximum duration of conversion time reported among the included studies was 60 days, while the least duration was 3 days. Viral shedding from sources other than nasopharynx and oropharynx, like stools, urine, saliva, semen, and tears, was reported. More number of studies described virus shedding from gastrointestinal tract (mainly in stools), while least a number of cases tested positive for the virus in tears. Prolonged viral shedding is important to consider while discontinuing isolation procedures and/or discharging SARS-CoV-2 patients. The risk of transmission varies in magnitude and depends on the infectivity of the shed virus in biological samples and the patient population involved. Clinical decision-making should be governed by clinical scenario, guidelines, detectable viral load, source of detectable virus, infectivity, and patient-related factors.

The role played by traditional Chinese medicine in preventing and treating COVID-19 in China.

Traditional Chinese medicine (TCM), an ancient system of alternative medicine, played an active role in the prevention and control of COVID-19 in China. It improved the clinical symptoms of patients, reduced the mortality rate, improved the recovery rate, and effectively relieved the operating pressure on the national medical system during critical conditions. In light of the current global pandemic, TCM-related measures might open up a new channel in the control of COVID-19 in other countries and regions. Here, we summarize the TCM-related measures that were widely used in China, including TCM guidelines, the Wuchang pattern, mobile cabin hospitals, integrated treatment of TCM and modern medicine for critical patients, and non-medicine therapy for convalescent patients, and describe how TCM effectively treated patients afflicted with the COVID-19. Effective TCM therapies could, therefore, be recommended and practiced based on the existing medical evidence from increased scientific studies.

Clinical features of COVID-19 convalescent patients with re-positive nucleic acid detection.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a pandemic that has rapidly spread worldwide. Increasingly, confirmed patients being discharged according to the current diagnosis and treatment protocols, follow-up of convalescent patients is important to knowing about the outcome. METHODS: A retrospective study was performed among 98 convalescent patients with COVID-19 in a single medical center. The clinical features of patients during their hospitalization and 2-week postdischarge quarantine were collected. RESULTS: Among the 98 COVID-19 convalescent patients, 17 (17.3%) were detected positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid during 2-week postdischarge quarantine. The median time from discharge to SARS-CoV-2 nucleic acid re-positive was 4 days (IQR, 3-8.5).The median time from symptoms onset to final respiratory SARS-CoV-2 detection of negative result was significantly longer in re-positive group (34 days [IQR, 29.5-42.5]) than in non-re-positive group (19 days [IQR, 16-26]). On the other hand, the levels of CD3-CD56 + NK cells during hospitalization and 2-week postdischarge were higher in re-positive group than in non-re-positive group (repeated measures ANOVA, P = .018). However, only one case in re-positive group showed exudative lesion recurrence in pulmonary computed tomography (CT) with recurred symptoms. CONCLUSION: It is still possible for convalescent patients to show positive for SARS-CoV-2 nucleic acid detection, but most of the re-positive patients showed no deterioration in pulmonary CT findings. Continuous quarantine and close follow-up for convalescent patients are necessary to prevent possible relapse and spread of the disease to some extent.

Isolation of Monoclonal Antibodies from Zika Virus-Infected Patient Samples.

The combination of sorting antigen-specific memory B cells with determining immunoglobulin (Ig) genes at the single-cell level enables the isolation of monoclonal antibodies (mAbs) in individuals. This method requires a small amount of blood (usually 10 mL) and is rapid (less than 2 weeks to isolate antigen-specific mAbs). Due to the application of antigens as the bait to capture the specific memory B cells, the majority of isolated mAbs are true binders to the antigen, which increases the isolation efficiency. Here, applying this approach, we describe the characterization of mAbs against Zika virus from a convalescent patient sample. From 10 mL whole blood, we sorted 33 Zika envelope (E) protein-interacting single memory B cells. The Ig genes from 15 cells were determined, and 13 mAbs were found that bind to Zika E protein with varied binding affinities.

Specific neutralizing response in plasma from convalescent patients of Ebola Virus Disease against the West Africa Makona variant of Ebola virus.

BACKGROUND: The current outbreak of Ebola Virus Disease in West Africa is caused by a new variant of Ebola virus (EBOV) named Makona 2014, whose sequence differs 3% from isolates from Central Africa such as Mayinga 1976 EBOV. The specificity and kinetics of the neutralizing antibody response induced by the circulating Makona EBOV has not been thoroughly studied. METHODS: We have used a lentiviral EBOV-glycoprotein (GP)-pseudotyped infection assay to measure Makona-GP and Mayinga-GP specific neutralizing activity of plasma from three convalescent Ebola Virus Disease patients from the current EBOV outbreak at 2, 3, 4 and 9 months post-infection. Total anti-EBOV GP IgG was measured by a commercial ELISA assay. FINDINGS: In convalescent Ebola Virus Disease patients, Makona-GP-specific neutralizing titers increased from 2 months (mean IC50 1/59), 3 months (IC50 1/212), 4 months (IC50 1/239) and up to 9 months (IC50 1/268) post-infection. Neutralizing activity of plasma from the three convalescent Ebola Virus Disease patients was more vigorous against the current Makona-GP pseudotyped EBOV variant than against Mayinga-GP pseudotyped EBOV and this difference was observed at each time point tested: Mayinga vs Makona mean IC50 fold=4.92 at 2 months post-infection, 2.89 fold at 3 months post-infection, 2.23 at 4 months post-infection and 2.98 at 9 months post-infection (all differences p<0.01). Total level of IgG against EBOV-GP did not evolve significantly during the follow up. DISCUSSION: In convalescent Ebola Virus Disease patients, EBOV-GP specific neutralizing activity increases over time, at least up to 9 months post-infection, which suggests that active affinity maturation of antibodies takes place long after clinical recovery. EBOV-GP specific neutralizing response is significantly higher against Makona EBOV circulating in West Africa than against the variants included in the currently approved vaccines. Correlates of protection for EBOV vaccines have not been completely established and the relevance of a lower neutralizing activity in convalescent plasma from the current outbreak against one of the EBOV-GPs contained in the vaccines in terms of its potential efficacy does not necessarily preclude its efficacy. However, this observation highlights the concern regarding the natural diversity of EBOV and its subsequent challenge for diagnosis, therapy and vaccine design. EBOV-GP neutralizing activity varies considerably over time in convalescent Ebola Virus Disease patients. Titering of convalescent blood products would be desirable to standardize and evaluate their potential therapeutic value.

3 Models of Rehabilitation Service on Stroke Patients Following Hemiplegia in Community / 中国康复理论与实践

@#Objective To compare the effect of 3 models of rehabilitation service on stroke patients following hemiplegia in community.Methods 87 stroke patients were randomly divided into rehabilitation training group (n=29), intensive training group (n=30) and followed-up group (n=28). Fugl-Meyer Assessment (FMA) was used to evaluate the limbs motor function and Modified Barthel Index (MBI) was used to evaluate the activities of daily living before, 3 months and 6 months after intervention. Results There was no significantly difference in scores of FMA and MBI among the groups. Both the rehabilitation training group and the intensive training group improved in scores of FMA and MBI 3 months after intervention (P<0.01). The intensive training group and the rehabilitation training group improved further 6 months after intervention, while follow-up group had no improvement. Conclusion Stroke patients following hemiplegia can improvemotor function and activities of daily living through systematic, standard, and ongoing rehabilitation training from professionals in community.