Relationships among differentiated T-cell subpopulations

Following subcutaneous inoculation with rat tumour cells (SLC, AH-130, or MNC), rat tumours grew progressively in nude mice (nu/nu) but not in their normal littermates (nu/+) or in normal AKR mice or sublethally irradiated AKR mice. Suppression of tumour growth appeared to depend on radio-resistant cytotoxic T cells which were detected in in vivo neutralization tests (Winn's test) with spleen cells of mice immunized with rat lymphocytes or tumour cells 5 days previously. Radioresistant cytotoxic activity was detected by 51Cr-release test in glass-non-adherent peritoneal exudate cells 5 days after intraperitoneal immunization with rat lymphocytes. These results suggested that immune lymphocytes might differentiate to mature cytotoxic cells at the site of direct graft rejection. (author)