ABSTRACT
Sequence homology between SARS-CoV-2 and common-cold human coronaviruses (HCoVs) raises the possibility that memory responses to prior HCoV infection can affect T cell response in COVID-19. We studied T cell responses to SARS-CoV-2 and HCoVs in convalescent COVID-19 donors and identified a highly conserved SARS-CoV-2 sequence, S811-831, with overlapping epitopes presented by common MHC class II proteins HLA-DQ5 and HLA-DP4. These epitopes are recognized by low-abundance CD4 T cells from convalescent COVID-19 donors, mRNA vaccine recipients, and uninfected donors. TCR sequencing revealed a diverse repertoire with public TCRs. T cell cross-reactivity is driven by the high conservation across human and animal coronaviruses of T cell contact residues in both HLA-DQ5 and HLA-DP4 binding frames, with distinct patterns of HCoV cross-reactivity explained by MHC class II binding preferences and substitutions at secondary TCR contact sites. These data highlight S811-831 as a highly conserved CD4 T cell epitope broadly recognized across human populations.
Subject(s)
COVID-19 , SARS-CoV-2 , Alleles , CD4-Positive T-Lymphocytes , COVID-19 Vaccines , Epitopes, T-Lymphocyte , HLA Antigens , Humans , Receptors, Antigen, T-Cell , mRNA VaccinesABSTRACT
BACKGROUND: Since December 2019, there have been many cases of viral pneumonia of unknown causes in Wuhan City, Hubei Province. During the period of novel coronavirus, according to the observation of limited autopsy and biopsy pathological results, pulmonary interstitial fibrosis appeared in some pathological changes of lung. Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial pneumonia with unknown etiology and pathological changes limited to the lung. At present, there is still a lack of reevaluation of systematic evaluation of traditional Chinese medicine treatment IPF. Therefore, a systematic re-evaluation of the systematic evaluation of traditional Chinese medicine in the treatment of pulmonary fibrosis may help to understand the effective treatment scheme of traditional Chinese medicine in the treatment of pulmonary fibrosis and provide more reliable evidence for the first-line clinicians to treat novel coronavirus. METHODS: We will search 3 foreign electronic databases (Cochrane Library, Embase, PubMed) and 4 Chinese electronic databases (China National Knowledge Infrastructure [CNKI], WangFang Database, Chinese Biomedical Literature Database [CBM], and Chinese Scientific Journal Database [VIP]) to collect potential systematic reviews from their inceptions to February 2020. The language of publication is limited to Chinese or English. We will consider SRs and meta-analysis of Traditional Chinese Medicine for the Treatment of pulmonary fibrosis. Two reviewers will identify relevant studies, and then assess the methodological quality by assessment of multiple systematic reviews-2 tool. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) report checklist to assess the quality of reports included in the study. In order to better evaluate the systematic evaluation included in this research, risk of bias in systematic review tool is included in this research to evaluate the methodological quality. The quality of evidence of the included systematic reviews was assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The Primary outcomes include: Clinical total effective rate, curative effect of TCM symptoms, pulmonary function and blood gas analysis. RESULTS: The results of this study will be published in a peer-reviewed journal. CONCLUSIONS: We expect to obtain reliable evidence from systematic analysis of traditional Chinese medicine treatment of pulmonary fibrosis in an available and useful document. REGISTRATION NUMBER: INPLASY202060029.