Human γδ T cells express a higher TCR/CD3 complex density than αβ T cells

The aim of our study was to compare CD3 expression on gamma delta T cells and alpha beta T cells in human patients. The antigen density of TCR and CD3 on both subsets was assessed by a quantitative method in eight patients. In parallel, we developed and validated a reliable direct tricolor staining protocol that we tested on samples from hospitalized and healthy individuals (n = 60). Our results demonstrate that human gamma delta T cells constitutively express approximately twofold more of the TCR/CD3 complex than alpha beta T cells. We suggest that this enhanced expression of the TCR/CD3 complex could contribute to the higher reactivity of gamma delta T cells compared to alpha beta T cells. These clinical laboratory results confirm the fundamental data described elsewhere. gamma delta T cells deserve further clinical investigations to understand their precise role in human immunity. (C) 2001 Academic Press.