High-dimensional combinatorial MHC I combinatorial tetramer staining allows for detection and deep phenotyping of antigen-specific CD8 T cells 9006

Abstract Description Detection and quantification of antigen-specific T cells is essential for studying immune responses in cell therapies and vaccines. High-dimensional flow cytometry allows for not only the detection of antigen-specific T cells, but enables detailed analysis of T cell phenotypes and functionality. MHC class I tetramers are the gold standard for detecting antigen-specific T cells, but polyclonal T cell responses often require measuring multiple specificities. Combinatorial tetramer staining techniques have been developed to assess multiple T cell responses simultaneously, but they lack comprehensive functional and phenotypic profiling. We present a combinatorial MHC I tetramer staining technique that detects up to 15 distinct CD8+ T cell specificities and 18 phenotypic markers using spectral flow cytometry. This method enables detailed characterization of memory subsets, T cell activation, terminal differentiation, and innate functions. We leveraged this approach to study the phenotypic differences of CD8+ T cell responses to melanin (MART1) and 14 viral epitopes, including influenza, CMV, and EBV. Our analysis shows that different viruses and even peptides within the same virus elicit distinct CD8+ effector and central memory T cell responses. In conclusion, this assay offers precise detection, quantification and phenotyping of antigen-specific T cells, with broad applications in understanding immune responses across various diseases and therapies. Topic Categories Vaccines and Immunotherapy (VAC)