Identification of apolipoprotein B–reactive CDR3 motifs allows tracking of atherosclerosis-related memory CD4+T cells in multiple donors. Identification of apolipoprotein B–reactive CDR3 motifs allows tracking of atherosclerosis-related memory CD4+T cells in multiple donors

Atherosclerosis is a major pathological condition that underlies many cardiovascular diseases (CVDs). Its etiology involves breach of tolerance to self, leading to clonal expansion of autoreactive apolipoprotein B (APOB)–reactive CD4+T cells that correlates with clinical CVD. The T-cell receptor (TCR) sequences that mediate activation of APOB-specific CD4+T cells are unknown. Methods: In a previous study, we had profiled the hypervariable complementarity determining region 3 (CDR3) of CD4+T cells that respond to six immunodominant APOB epitopes in most donors. Here, we comprehensively analyze this dataset of 149,065 APOB-reactive and 199,211 non-reactive control CDR3s from six human leukocyte antigen–typed donors. Results: We identified 672 highly expanded (frequency threshold > 1.39E-03) clones that were significantly enriched in the APOB-reactive group as compared to the controls (log10 odds ratio ≥1, Fisher’s test p 80% of the donors and were highly enriched in the APOB-reactive TCR repertoire. Discussion: The identified APOB-reactive expanded CD4+T cell clones and conserved motifs can be used to annotate and track human atherosclerosis-related autoreactive CD4+T cells and measure their clonal expansion. Overall design: To identify APOB-reactive TCRs and track them within the antigen-experienced memory repertoire, we conducted high-throughput TCR sequencing of five CD4+T cell subsets from six donors - APOB-reactive (APOB_AIMpos), control non-APOB-reactive (APOB_AIMneg), naïve, central memory (TCM) and effector memory (TEM) T cells. The naive and memory T cell were sorted ex vivo at Day 0, while the AIM+ and AIM- subsets were isolated after 14 days of APOB-dependent expansion and restimulation. *************************************************************** Adaptive Biotechnologies does not release raw data. ***************************************************************