Integrated, high-dimensional analysis of CD4 T cell epitope specificities and phenotypes reveals unexpected diversity in the response to Mycobacterium tuberculosis
Immunity to Mycobacterium tuberculosis (Mtb), like many pathogens, is encoded jointly by the antigen specificities and functions of responding CD4 T cells. However, these features span a large two-dimensional possibility space - defined on one axis by the Mtb proteome, and on the other by the T cell transcriptome - that exceeds the dimensionality of existing technologies. Here we present an approach ("CRESTA") that combines highly-multiplexed DNA-barcoded epitope probes, single cell sequencing, and clonal analysis of T Cell Receptors (TCRs) to robustly detect rare antigen-specific CD4 T cells across hundreds of epitopes simultaneously and reveal their transcriptome-wide phenotypes. By comprehensively assaying known epitopes in Mtb-infected participants, we reveal polyclonal and multi-epitope responses across a spectrum of differentiation states, uncover previously-unobserved phenotypic diversity within and between epitopes, and increase the total number of known Mtb epitope-mapped TCR:{beta}s by [~]8-fold. We expect CRESTA to enable high-dimensional analyses of CD4 T cell responses in various settings, including infection, cancer, autoimmunity and allergy.