The regulatory role of adenosine activated T-lymphocyte subset on the immune response in humans. II. Adenosine induced expression of T8 antigen.

Adenosine sensitive suppressor T cells (ESen) were isolated from healthy donors and continuous cultures of these cells were established. It was found that the continuous proliferation of ESen cells required IL-2, Adenosine and ConA. The reactivity of ESen cells with OKT3, OKT4 and OKT8 monoclonal antibodies was studied before and after incubation with adenosine. The majority of freshly isolated ESen cells were OKT8+ cells. During culture, the majority of the proliferating ESen cells were OKT4; however, following a brief incubation of cultured ESen cells with adenosine, an increase in OKT8+ cells and a decrease in OKT4+ cells were observed. A fraction of ESen cells exhibited simultaneously OKT4+ and OKT8+ antigens similar to thymocytes. Furthermore, adenosine treatment of thymocytes resulted in a small increase in OKT8+ and OKT3+ cells and a parallel decrease in OKT4+ cells. These results indicate that adenosine may play a regulatory role in the differentiation of lymphocytes programmed to carry out a specific function.