Abstract
CD4+ T cells predominate lymphocytic foci found in the salivary glands (SGs) of Sjögren’s disease (SjD) cases. Yet little is known about T cell receptor (TCR) repertoire features that distinguish cases from healthy controls (HCs), the relationship between SG and peripheral blood (PB) repertoires of cases, and antigens recognized by pathogenic T cell clones. We performed deep sequencing of bulk-sorted CD4+CD45RA– PB T cells from SjD cases and matched HCs, and single-cell TCR sequencing of the same T cell population from labial SG biopsies of these cases. We found that clonally expanded SG CD4+ T cells expressed complementarity-determining region 3 (CDR3) sequences that were also detected in multiple copies in the blood of the same individuals with SjD. SjD cases displayed a “private” and restricted PB TCR repertoire with reduced clonotype diversity. We identified SjD-associated TCR motifs with the same putative antigen specificity shared between SGs and PB of cases. Their abundances in PB correlated with reduced salivary flow, linking these T cells with pathogenic disease features. Finally, we discovered 2 Ro60 epitopes eliciting an HLA-restricted immune response from expanded SG T cell clones. The comprehensive characterization of SjD TCR repertoires enables the discovery of target antigens and therapeutic strategies.
Authors
Ananth Aditya Jupudi, Michelle L. Joachims, Christina Lawrence, Charmaine Lopez-Davis, Bhuwan Khatri, Astrid Rasmussen, Kiely Grundahl, R. Hal Scofield, Judith A. James, Joel M. Guthridge, Christopher J. Lessard, Linda F. Thompson, A. Darise Farris
