Ontogenic development and tissue distribution of Vγ1-expressing γ/δ T lymphocytes in normal mice

Abstract

A hamster monoclonal antibody (mAb) recognizing an epitope in the Vγ1- Jγ4-Cγ4 chain of the γ/δ T cell receptor has been generated. Using this mAb, we have quantitated the occurrence of Vγ1-bearing γ/δ T cells in the developing thymus and in the lymphoid organs and several epithelia of adult mice. The Vγ1-expressing cells constitute a minor γ/δ T cell subpopulation during fetal and early postnatal life, but they constitute a major population of γ/δ T cells in the thymus and in the peripheral lymphoid organs in adult mice. In addition, we found that Vγ1-bearing cells comprise a large proportion (15-60%) of the γ/δ T cells present in the intestinal epithelium (i-IEL) in all strains of mice tested. Vγ1+ i-IEL are present in athymic (nude) mice and in antigen-free mice, demonstrating that they can develop extrathymically and that their presence in the intestinal epithelium is independent of the antigenic load of the gut. Our results show that Vγ1- bearing lymphocytes account for the largest population of γ/δ T cells in the mouse. This population includes a thymus-dependent component that homes to the secondary lymphoid organs and a thymus-independent component that constitutes a major fraction of the γ/δ i-IELs.