[Experimental and clinical studies on the significance of human T cells bearing IgG-Fc receptor (T gamma cells) in gastric cancer patients].

In gastric cancer patients the proliferative response of T gamma cells to phytohemagglutinin and Pokeweed mitogen was depressed, while that to Concanavalin-A was maintained as compared with that in T non-gamma cells. T gamma cells were activated by Concanavalin-A to suppress the proliferative response of responder cells. Furthermore, T gamma cells from gastric cancer patients contained the suppressor cells which had been already activated in-vivo. On the other hand, natural cell mediated cytotoxic activities of T gamma cells were greater than those of T non-gamma cells. Thus, it is likely that T gamma cells consisted of the heterogenic populations, containing the suppressor and cytotoxic cells, and that suppressor cells were present dominantly in cancer patients. Furthermore, suppressor cells belonged to the distinct OKT8 positive fractions. Significant increase of T gamma cells in cancer patients was observed and the proportion of T gamma cells was positively correlated with advance of the disease. As for the tissue distribution, T gamma cells were present dominantly in the spleen and scantly in the lymph nodes, however, the increase of T gamma cells was observed in the lymph nodes with metastasis. The increase of IgG-Fc receptors on T cells and the induction of suppressor cells were observed simultaneously by co-culture with cancer sera.