[BCG-induced production of a factor inhibiting macrophage migration and growth of melanoma B16]

Abstract

The effect of BCG on the growth of melanoma B16 and production of the macrophage migration inhibitory factor (MMIF) by spleen lymphocytes as well as on phytohemagglutinin and tuberculin was studied in C57BL/6 mice. It was also studied how these parameters changed under the effect of transplanting splenocytes from syngeneic donors. Subcutaneous or intraperitoneal injection of BCG in a dose of 1 mg stimulated melanoma growth. Acceleration of the tumor growth entailed a more pronounced decrease in MMIF production. The inhibition of melanoma growth was noted after transplantation of splenocytes from syngeneic donors on the 11th day following inoculation of the tumor wherein MMIF production was normal. Transplantation of splenocytes from mice immunized with BCG resulted in an abrupt stimulation of melanoma growth and complete reversal of MMIF production by lymphocytes. The data obtained suggest the accumulation of suppressor cells by the spleen of mice treated with high doses of BCG, leading to the acceleration of melanoma B16 growth.