Macrophage activation and generation of tumoricidal activity by liposome-associated human C-reactive protein.
The effect of human C-reactive protein incorporated into multilamellar vesicles (CRP-MLV) was studied in assays of macrophage function. Peritoneal exudate macrophages from C57BL/6 mice phagocytosed CRP-MLV in vitro more rapidly than multilamellar vesicles bearing comparable amounts of immunoglobulin G. Exposure of peritoneal exudate 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 exudate macrophages 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 anion production. Administration of CRP-MLV i.p. did not enhance natural killer activity of spleen cells, however. In superoxide anion assays, CRP-MLV were approximately 10 to 100 times more effective than free C-reactive protein. Results indicate that C-reactive protein is capable of activating macrophages, thus supporting the concept of C-reactive protein as an immunomodulator.
D000818:Animals; D002097:C-Reactive Protein / Q000627:therapeutic use / Q000633:toxicity*; D003602:Cytotoxicity, Immunologic; D005354:Fibrosarcoma / Q000188:drug therapy*; D006801:Humans; D007074:Immunoglobulin G; D007694:Killer Cells, Natural / Q000276:immunology; D008081:Liposomes / Q000008:administration & dosage*; D008262:Macrophage Activation / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D008297:Male; D008545:Melanoma / Q000188:drug therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D010587:Phagocytosis
D007074:Immunoglobulin G; D008081:Liposomes; D002097:C-Reactive Protein