title: The effect of peritoneal macrophages from mice injected with Leishmania braziliensis on the in vitro growth of tumor cells.
abstract: Leishmania braziliensis reportedly is capable of producing a reduction in the growth of solid and ascites murine leukemia and lymphomas. The possibility that the inhibitory effect on the ascites tumor was produced by the activation of the macrophage peritoneal cell population was explored. It was observed that adherent cells from the peritoneal cavity of L. braziliensis injected mice caused a marked inhibitory effect on the in vitro growth of the 6C3HED lymphoma and EL-4 leukemia cells. This effect was dependent on the degree of the macrophage activation, was not produced by supernatants from cultures of activated macrophages, and it seems that contact cell between target and effector cells is necessary. In addition to being cytostatic, this effect was also cytotoxic. The L. braziliensis activated macrophages were also capable of suppressing the multiplication of normal cells induced by mitogen, but this was not observed if the cells were already undergoing multiplication. A similar cytostatic effect on the tumor cells was observed to be produced by the peritoneal non-adherent cell population of the L. braziliensis injected mice.
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002471:Cell Transformation, Neoplastic; D003602:Cytotoxicity, Immunologic; D007891:Leishmania / Q000276:immunology*; D007942:Leukemia, Experimental / Q000276:immunology; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D009374:Neoplasms, Experimental / Q000276:immunology; D013997:Time Factors