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Abstract

Analysis of the paired i.e. matching TCR alpha- and beta-chain rearrangements of single human T cells is required for a precise investigation of clonal diversity, tissue distribution and specificity of protective and pathologic T-cell mediated immune responses. Here we describe a multiplex RT-PCR based technology, which for the first time allows for an unbiased analysis of the complete sequences of both alpha- and beta-chains of TCR from single T cells. We validated our technology by the analysis of the pathologic T-cell infiltrates from tissue lesions of two T-cell mediated autoimmune diseases, psoriasis vulgaris (PV) and multiple sclerosis (MS). In both disorders we could detect various T cell clones as defined by multiple T cells with identical alpha- and beta-chain rearrangements distributed across the tissue lesions. In PV, single cell TCR analysis of lesional T cells identified clonal CD8(+) T cell expansions that predominated in the epidermis of psoriatic plaques. An MS brain lesion contained two dominant CD8(+) T-cell clones that extended over the white and grey matter and meninges. In both diseases several clonally expanded T cells carried dual TCRs composed of one V beta and two different V alpha-chain rearrangements. These results show that our technology is an efficient instrument to analyse alpha beta-T cell responses with single cell resolution in man. It should facilitate essential new insights into the mechanisms of protective and pathologic immunity in many human T-cell mediated conditions and allow for resurrecting functional TCRs from any alpha beta-T cell of choice that can be used for investigating their specificity.