EFFECT OF NOCARDIA-RUBRA CELL-WALL SKELETON ON T-CELL-MEDIATED CYTO-TOXICITY IN MICE BEARING SYNGENEIC SARCOMA

  • 1 January 1981
    • journal article
    • research article
    • Vol. 41  (2) , 660-666
Abstract
Cell-mediated cytotoxicity against syngeneic [mouse methylcholanthrene-induced] MC104 fibrosarcoma cells was detected in C57BL/6N mice 7 days after tumor inoculation in the hind foot. This cytotoxicity was undetectable by day 14 in the Winn test using spleen and draining popliteal lymph node (DPLN) cells. Similar results were obtained with the 51Cr release assay following in vitro activation of these lymphoid cells with mitomycin C-treated tumor cells. The antitumor cytotoxicity was mediated by T cells. Spleen but not DPLN cells from 14-day tumor bearers enhanced tumor growth in the Winn test, suggesting the presence of immunosuppressor cells in the spleen. Two intralesional injections of 50 .mu.g of cell wall skeleton (CWS) of N. rubra on days 2 and 7 resulted in apparent tumor growth inhibition and prolongation of the survival period of tumor bearers. DPLN cells from tumor bearers treated with N. rubra CWS exhibited significant recovery in the cytotoxicity tested on day 14; the recovery in that of spleen cells was not apparent. The cytotoxicity augmented by N. rubra CWS was specific to MC104 tumor cells and was mediated by T cells. These cytotoxic T cells were able to localize in DPLN and in the spleen and tumor in mice receiving the intralesional immunotherapy with N. rubra CWS. T cell-mediated cytotoxicity against syngeneic tumor apparently can be augmented by N. rubra CWS and might play an important role in the systemic development of its antitumor effect, although the effector cell decrease in the spleen might be suppressed by splenic suppressor cells during tumor growth.