An autoreactive T cell clone generated in the autologous mixed lymphocyte reaction in a patient with gastric carcinoma.

Autoreactive T cell clones were established from a patient with early gastric carcinoma and a healthy control in order to investigate the mechanism of suppression of autologous mixed lymphocyte reaction (AMLR) and its significance in immune surveillance against tumor. Clone 3F6 from the gastric carcinoma patient responded to only autologous non-T cells with less reactivity than 4 clones from the control subject. The proliferative response of clone 3F6 to interleukin-2 and immobilized anti-CD3 antibody was also suppressed when compared with the control clones. Autoreactive T cells were able to kill tumor cells and autologous PHA-blasts. The cytotoxic activity of clone 3F6 was also markedly suppressed when compared with the control clones. This data suggests that autoreactive T cells may be impaired in cancer patients and that this immunological disorder might cause the defective immune surveillance against tumors.