title: Human peritoneal macrophages. Production in vitro of the active terminal complement components C5 to C9 and a functional alternative pathway of complement. Brief report.
abstract: Endotoxin-stimulated human peritoneal macrophages were cultured in serum-free medium with agarose beads. Monospecific antibodies to human C3c, C3g, C5, C6, C7, C8, C9 and to C9-neoantigen bound to the beads. This shows that activated C3 and the terminal complement complex (TCC), made from complement components C5 to C9, were generated on the beads. De novo synthesis was confirmed by agarose binding of tritium-labelled protein. Moreover, C3-derivatives and C9-neoantigen were detected on normal serum-treated agarose beads but not on beads kept in factor B-depleted or heat-inactivated sera, implying that an intact alternative complement pathway was required for our findings. The macrophages thus synthesize the active complement components of the alternative and terminal pathways in vitro.
authors.affiliation: Institute of Medical Biology, University of Tromsø, Norway.
authors.forename: G
authors.initials: G
authors.lastname: Hetland
authors.forename: L
authors.initials: L
authors.lastname: Bungum
mesh_terms: D001202:Ascitic Fluid / Q000166:cytology; D003167:Complement Activation; D003182:Complement C5 / Q000096:biosynthesis; D003183:Complement C6 / Q000096:biosynthesis; D003184:Complement C7 / Q000096:biosynthesis; D003185:Complement C8 / Q000096:biosynthesis; D003186:Complement C9 / Q000096:biosynthesis; D015938:Complement Membrane Attack Complex; D003170:Complement Pathway, Alternative; D003165:Complement System Proteins / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008264:Macrophages / Q000276:immunology*
chemical_list: D003182:Complement C5; D003183:Complement C6; D003184:Complement C7; D003185:Complement C8; D003186:Complement C9; D015938:Complement Membrane Attack Complex; D003165:Complement System Proteins