Macrophage Activation and Generation of Tumoricidal Activity by Liposome-associated Human C-Reactive Protein1

The effect of human C-reactive protein incorporated into multilamellar vesicles (CRP-MLV) was studied in assays of macro phage function. Peritoneal exÃodate macrophages from C57BL/ 6 mice phagocytosed CRP-MLV in vitro more rapidly than multilamellar vesicles bearing comparable amounts of immunoglobulin G. Exposure of peritoneal exÃodate macrophages in vitro to CRP-MLV resulted in development of tumoricidal activity against syngeneic T241 fibrosarcoma and B-16 melanoma cells and against allogeneic Sarcoma 1 cells. Peritoneal exÃodate macro phages obtained from mice given CRP-MLV i.p. demonstrated antitumor activity against the syngeneic T241 fibrosarcoma in a Winn-type assay, and when challenged in vitro with phorbol myristate acetate, they showed elevated Superoxide aniÃ3npro duction. Administration of CRP-MLV i.p. did not enhance natural killer activity of spleen cells, however. In Superoxide aniÃ3n as says, CRP-MLV were approximately 10 to 100 times more effective than free C-reactive protein. Results indicate that Creactive protein is capable of activating macrophages, thus sup porting the concept of C-reactive protein as an immunomodulator.