Setsuko Jitsukawa

CD3.TCR1, A Human CD3 epitope expressed on viable γδ lymphocytes exclusively

Abstract T lymphocytes express either the α β or the γ δ receptor (TCR) in a mutually exclusive fashion. Both structures are associated on the cell membrane with the CD3 proteins which are thought to transduce signals resulting from antigen recognition. The CD3 complex is present in both γ β and γ δ cells and includes at least five proteins (designated γ, δ, ϵ, ξ and η). We have developed here a novel mAb, anti-CD3.TCR1, which immunoprecipitates the CD3 molecules from both γ β and γ δ cells lysates following solubilization with Triton X-100. While the SDS-PAGE migration profile of the material recognized by either anti-CD3.TCR1 or anti-OKT3 are superimposable in both cell types, this mAb recognizes viable untreated γ δ T lymphocytes exclusively. These findings further support the view that molecular interactions within the TCR CD 3 protein complex are distinct in the two T lymphocyte populations.