Further evidence for a sequentially ordered activation of T cell rearranging gamma genes during T lymphocyte differentiation

摘要

AbstractRecently, we have shown that the majority of human peripheral lymphocytes with a T cell receptor (TcR) γ/δ receptor use a unique gamma chain recognized by the anti‐TigammaA monoclonal antibody. This predominantly expressed gamma protein is encoded by a rearranged gene where the V9 segment has joined the JP segment located upstream of the Cγ1 region (TRGC1). Peripheral TigammaA+cells were further studied here to shed light on the relation between the two types of TRG rearrangements namely those involving the first (TRG1) vs. the second (TRG2) J‐C region. Thirteen clones reactive with anti‐TigammaA were tested; it was found that the second TRG allele (i.e., the one which does not involve V9‐JP) of these cells was either in germ‐line configuration or, more frequently, rearranged with a downstream V, gene joined to a J segment of the TRG1 region. These data suggest that productive rearrangements on TRG1 leading to the production of a surface‐expressed y chain occur before rearrangements involving the TRG2 region. It supports the view that TRG genes are subjected to a sequentially ordered activation during the process of T lymphocyte d