Abstract: | The interaction of antibodies and lymphocytes in their immune reaction against human transitional cell carcinomas was studied using the in vitro microcytotoxicity assay. A non-complement dependent, IgG antibody was detected in the serum of occasional transitional cell carcinoma patients, which induced cytotoxicity against transitional cell carcinoma target cells by lymphocytes from donors with and without transitional cell carcinoma. The observation that lymphocytes from transitional cell carcinoma donors were more sensitive to activation by this anti-transitional cell carcinoma, lymphocyte dependent antibody is compatible with the hypothesis that the surface of lymphocytes from some transitional cell carcinoma donors is coated in vivo with an anti-transitional cell carcinoma lymphocyte dependent antibody and that this antibody may be a significant factor in immunity to transitional cell carcinomas of the urinary tract. |