Identification of Sjogren's Disease associated T cell receptor motifs through deep sequencing

In this study, we directly address whether CD4 positive T cell clones that are expanded in the labial salivary gland tissue of Sjogren's Disease (SjD) cases meeting the 2016 ACR EULAR criteria are also detected and over represented in their blood. We investigate whether potentially pathogenic T cells from multiple SjD cases are likely to share similar antigen specificities by evaluating their T cell receptor (TCR) repertoires.For this submission, CD3 positive CD4 positive CD8 negative CD45RA negative T cells from the peripheral blood mononucelar cells of SjD cases and demographically matched healthy controls (HC) were sorted in bulk and stored at negative 80 C until use. RNA was extracted and subjected to TCR deep sequencing according to the method of Mamedov et al. (Mamedov, I.Z., et al., Preparing unbiased T cell receptor and antibody cDNA libraries for the deep next generation sequencing profiling. Front Immunol, 2013. 4: p. 456). Pooled TCR beta libraries were sequenced on Illumina NovaSeq paired end 150 bp runs. Samples from SjD cases and HCs were sequenced to a median depth of 19.5 million (M) reads (range 1.9M to 72.5M) and 20.2M reads (range 3.9M to 63.9M), respectively.