SURFACE EXPRESSION OF 2 DISTINCT FUNCTIONAL ANTIGEN RECEPTORS ON HUMAN-GAMMA-DELTA T-CELLS

Lymphocytes recognize antigens with highly variable heterodimeric surface receptors. Although four distinct antigen receptors could in principle be produced by any lymphocyte, only one functional combination of receptor chains has thus far been found expressed on their surface. Examination of human gammadelta T cells revealed a population that violated this rule by expressing on their surface two distinct functional gammadelta T cell receptors (TCRs) that used different TCRgamma gene alleles. Thus, current models for T cell clonal selection may need modification and a possible escape mechanism for autoreactive TCRs is suggested.