In Vitro Cellular Cytotoxicity Against Human Bladder Carcinoma Cell Lines

Abstract

Clinical trials of intravesical BCG immunotherapy against superficial urothelial bladder carcinoma recurrences have yielded significant results, which seem to be superior to those of intravesical chemotherapy (Herr et al. 1987). However, the mechanisms by which BCG exerts its antitumor effects are still largely unknown. In previous immunohistological examinations we were able to demonstrate the local induction of mononuclear effector cells in the bladder wall such as helper T-cells, macrophages, and B-cells after intravesical BCG (Böhle et al. 1990 a). Furthermore, a significant increase of certain cytokines in the urine, such as interleukin-1, interleukin-2, and tumor necrosis factor, has been detected after intravesical BCG therapy (Haaf et al. 1986; Böhle et al. 1990 b). These findings suggest different possible effector mechanisms which might be involved in tumor rejection. In an attempt to analyse these effects in vitro and obtain more information on their cytotoxic effectiveness against human bladder carcinoma cell lines, we performed a study to evaluate in vitro the cellular cytotoxicity of different mononuclear cells and the cytokines involved.