Georges Barski

Effect of BCG treatment on the evolution of cell-mediated immunity in mice bearing transplantable syngeneic tumors.

Abstract The effect of BCG administration on the evolution of in vitro cell-mediated immunity in relation to tumor growth was studied in C3HeB/Fe mice carrying transplantable, syngeneic mammary TM 1 tumors. Intradermal (i.d.) injection of BCG, 7 days before inoculation of tumor cells, inhibited significantly the tumor growth, whereas similar injection of BCG, 7 days after tumor graft, when the mice had already a palpable nodule, showed no effect. These results were correlated to a great extent with those obtained from in vitro colony inhibition (CI) tests using peritoneal cells (PC) of the same mice: from the beginning of the tumor growth, the CI activity of PC from mice which received BCG before tumor graft was significantly higher than those of the other groups of mice and this elevated activity was still high at the 35 th day after tumor graft, when the PC from control non-treated mice or from mice which received BCG after tumor graft were entirely inactive. When BCG was inoculated directly into the growing tumors, significant retardation of the tumor growth was observed. This tumor inhibiting effect following intratumoral (i.t.) inoculation of BCG was much more pronounced in mice that had been presensitized with BCG before tumor graft. The in vitro PC-mediated immunity of these mice showed concurrently a significant increase at 2 weeks after i.t. inoculation of BCG, while that of the control non-treated mice was still at the lowered level of activity. Intradermal injection of BCG 7 days before tumor operation accelerated significantly the post-operative recovery of PC-mediated immunity, whereas similor inoculation of BCG 3 days after tumor operation resulted a rather adverse effect.

Immunization against gross malignant lymphoma with mouse cell lines chronically infected with non-oncogenic murine C-type viruses

Abstract Three in vitro mouse cell lines, chronically infected with non-oncogenic C-type viruses, were used for immunization of C57BL 6 mice against isograft of highly malignant Gross virus-induced lymphoma. The most effective immunizations were obtained with the 2 cell lines originating from C3H and BALB c mice respectively, showing high degree of Gross virus-induced surface antigen. A third cell line, derived from a clone of L cells and similarily infected with a C-type virus, had no immunizing capacity. Protection of mice was obtained only after inoculation with the living cells. Cell-free culture supernatants were inefficient.