Specificity and Suppressor Function of Human T Cells Responsive to Autologous Non-T Cells

Abstract

Human T cells proliferate in response to autologous non-T cells. This reaction, called the autologous MLR has been shown to have both immunologic specificity and memory. Our present study first demonstrates that specific secondary responses can be demonstrated in the autologous MLR. A BUdR and light technique was then used to ablate cells proliferating in response to either autologous or allogeneic non-T cells. The removal of T cells responsive to autologous non-T cells left the responsiveness to allogeneic T cells relatively intact, and conversely the removal of T cells responsive to allogeneic non-T cells left the responsiveness to autologous non-T cells relatively intact. Thus, the T cells responsive to autologous non-T cells and those responsive to allogeneic non-T cells are largely separate cell populations.

Since the lymphocytes from patients with SLE fail to demonstrate a normal autologous MLR and also have a defect in the development of Con A-induced suppressor cells, we investigated whether the T cell population responsive in the autologous MLR was particularly enriched in cells capable of developing suppressor capacity. A BUdR and light treatment was used to remove T cells responsive to either autologous or allogeneic non-T cells. The remaining cells were then activated by Con A, and their subsequent suppressor activity was measured. Removal of T cells proliferating in response to autologous non-T cells produced significantly greater failure of suppressor cell development than did the removal of T cells responsive to allogeneic non-T cells. Thus, T cells capable of responding to autologous non-T cells are particularly enriched in cells capable of becoming suppressor cells.