Hojo H, Endoh Y S, Hashimoto Y
Jpn J Cancer Res. 1985 Jan;76(1):53-60.
In vitro cytotoxicity against tumor cells of lymphocytes in sc implanted BC47 bladder tumor of ACI/N rats with or without Propionibacterium avidum (P. avidum) treatment was studied. Tumor-associated lymphoid cells (TAL) were obtained from tumor tissues by mechanical treatment (NDi fraction) and by enzymatic treatment with Dispase I, a proteolytic enzyme (Di fraction), followed by passage through glass wool columns to deplete tumor cells. NDi fraction of TAL from P. avidum-treated animals showed a significant cytolytic activity against BC47 cells, but not against other ACI/N bladder tumor cell lines, BC12 and BC50. These TAL lost the cytolytic activity on treatment with anti-rat thymocyte serum or anti-rat T cell monoclonal antibodies, R1-3B3 and R1-10B5, and complement. Natural killer activity determined with YAC-1 cells was low in the cells of NDi fraction and scarcely detectable in the cells of Di fraction from both P. avidum-treated and untreated rats. These results indicate that the antigen-specific cytotoxic T cells in the tumor in situ are induced by in vivo P. avidum treatment. On the other hand, P. avidum treatment augmented nonspecific cytolytic activity of peripheral lymphoid cells such as plastic-nonadherent peritoneal cells, spleen cells and blood lymphocytes in normal and BC47-bearing rats. However, the antigen-specific cytolytic T cells were predominantly induced and recovered in the plastic nonadherent peritoneal cells of BC47-bearing rats by the treatment with P. avidum.
