TRB sequences targeting ORF1a/b are associated with disease severity in hospitalized COVID‐19 patients.

The potential protective or pathogenic role of the adaptive immune response to SARS‐CoV‐2 infection has been vigorously debated. While COVID‐19 patients consistently generate a T lymphocyte response to SARS‐CoV‐2 antigens, evidence of significant immune dysregulation in these patients continues to accumulate. In this study, next generation sequencing of the T cell receptor beta chain (TRB) repertoire was conducted in hospitalized COVID‐19 patients to determine if immunogenetic differences of the TRB repertoire contribute to disease course severity. Clustering of highly similar TRB CDR3 amino acid sequences across COVID‐19 patients yielded 781 shared TRB sequences. The TRB sequences were then filtered for known associations with common diseases such as EBV and CMV. The remaining sequences were cross‐referenced to a publicly accessible dataset that mapped COVID‐19 specific TCRs to the SARS‐CoV‐2 genome. We identified 158 SARS‐CoV‐2 specific TRB sequences belonging to 134 clusters in our COVID‐19 patients. Next, we investigated 113 SARS‐CoV‐2 specific clusters binding only one peptide target in relation to disease course. Distinct skewing of SARS‐CoV‐2 specific TRB sequences toward the nonstructural proteins (NSPs) encoded within ORF1a/b of the SARS‐CoV‐2 genome was observed in clusters associated with critical disease course when compared to COVID‐19 clusters associated with a severe disease course. These data imply that T‐lymphocyte reactivity towards peptides from NSPs of SARS‐CoV‐2 may not constitute an effective adaptive immune response and thus may negatively affect disease severity. [ABSTRACT FROM AUTHOR]