High-throughput identification and analysis of antigen-specific CD4+ T cells 4384

Abstract Description Large-scale efforts to identify antigen-specific T cells are predominantly centered on CD8+ T cells, limiting insights into and applications of antigen-specific CD4+ T cells in infectious disease and cancer. Here we present a toolset for the high-throughput detection and analysis of antigen-specific CD4+ T cells using large libraries of single-chain trimers (SCTs) designed to mimic peptide-MHC multimers for class II human leukocyte antigen (HLA). Following platform validation, we executed an unbiased screen to capture and simultaneously analyze over 2000 CD4+ T cells with specificity to the Receptor Binding Domain (RBD) of SARS-CoV-2 Spike protein, from a longitudinal cohort of 22 HLA-DR1 matched participants. We tracked RBD-antigen-specific CD4+ T cell phenotypes out to over two years post-infection, and identified metrics for defining immunogenic class II-restricted viral antigens. We also identified human papilloma virus (HPV)-16 E6-specific CD4+ T cell receptors (TCRs) from HPV16+ patients with precancerous lesions. Those TCRs are analyzed for their therapeutic potential for treating HPV+ cancers. This platform enables detailed investigation of CD4+ T cell immune responses and can accelerate the discovery of both relevant epitopes and TCRs for immunotherapies. Funding Sources Supported by the Parker Institute for Cancer Immunotherapy, NIH CA264090-01, and Merck. Topic Categories Technological Innovations in Immunology (TECH)