Mechanism of Bacillus Calmette-Guérin-induced suppression of metastases in a poorly immunogenic fibrosarcoma.
Bacillus Calmette-Guérin (BCG) reduces the rate of spontaneous pulmonary metastases from a poorly immunogenic fibrosarcoma. To be effective, BCG (1 X 10(6) organisms) must be given in admixture with (1 X 10(6)) tumor cells at the time of transplantation. Reduction of metastasis at this dosage of BCG occurs without a change in the size of the primarytumor or the extent of necrosis within it. Tumors transplanted in admixture with spleen cells from BCG-exposed donors reduced the number of metastases, while spleen cells from normal or tumor-bearing donors had no effect on metastases. Fewer total tumor cells and clumps are collected from the venous effluent of tumors transplanted with BCG than from control tumors. The BCG-treated tumors have more host macrophages intimately associated with the effluent tumor cells then did controls. These data indicate that BCG can inhibit the metastatic potential of a weakly immunogenic fibrosarcoma. The mechanism of this effect appears to be a depression of entry or tumor cells into the tumor vascular channels which may be related to the interaction of tumor cells with BCG-stimulated macrophages.
D000818:Animals; D001500:BCG Vaccine; D005354:Fibrosarcoma / Q000276:immunology / Q000628:therapy*; D007167:Immunotherapy; D008175:Lung Neoplasms / Q000517:prevention & control; D051379:Mice; D008810:Mice, Inbred C57BL; D009163:Mycobacterium bovis / Q000276:immunology*; D009362:Neoplasm Metastasis; D012513:Sarcoma, Experimental / Q000276:immunology / Q000628:therapy; D013154:Spleen / Q000276:immunology
D001500:BCG Vaccine