PMID: 2509612Dec 1, 1989Paper

Role of C5a in the induction of tumoricidal activity in C3H/HeJ (Lpsd) and C3H/OuJ (Lpsn) macrophages

Journal of Leukocyte Biology
M M HoganS N Vogel

Abstract

Thioglycollate-elicited macrophages from C3H/HeJ (Lpsd) and C3H/OuJ (Lpsn) mice were cultured in a two-signal, tumoricidal assay using recombinant interferon-gamma (rIFN-gamma) as the "priming" signal and recombinant human C5a (rC5a) as the "trigger" signal. These experiments were compared directly with a well established, two-signal tumoricidal assay in which rIFN-gamma was used as the "priming" signal and protein-rich, butanol-extracted lipopolysaccharide (But-LPS) as the "trigger" signal. These studies showed that rIFN-gamma-primed macrophages can be triggered in a dose-dependent manner by rC5a to effect high levels of tumoricidal activity. Maximum levels of cytotoxicity achieved using this endogenously produced, biologically active peptide as a "trigger" signal were comparable to those obtained using But-LPS. Moreover, experiments in which anti-C5 antibody was included in macrophage cultures stimulated with rIFN-gamma and But-LPS showed a significant reduction (P less than .05) in tumoricidal activity. Because LPS has been shown to induce macrophage C5 production and enzyme release, these findings suggest that macrophage-derived C5 is locally converted to C5a (or some other biologically active C5 cleavage fragment), which f...Continue Reading

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