Two T lymphocyte subpopulations isolated from human peripheral blood following "in vitro" treatment with adenosine.

Incubation of human peripheral blood lymphocytes (PBL) with adenosine resulted in a decrease in the level of E-rosette forming cells (ERFC). Isolated ERFC rerosetted with sheep erythrocytes in the presence of adenosine yielded two T lymphocyte subpopulations: a major one, rosetting or "E(R)" and a minor one, non-rosetting or "E(S)" T cells. Characterization of the two isolated subpopulations revealed that both E(R) and E(S) cells were positive for human T lymphocyte antigen. However, in contrast to E(R) cells, E(S) cells had low rosetting capacity, high spontaneous thymidine incorporation and low PHA proliferative response.