IgG-coated erythrocytes augment the lipopolysaccharidestimulated increase in serum tumor necrosis factor-alpha.
Previous studies have shown that the injection of IgG-coated erythrocytes (EIgG) caused an increase in the mortality rate due to bacterial lipopolysaccharide (LPS). This observation led to the present evaluation of the effect of EIgG on the LPS-stimulated increase in serum tumor necrosis factor-alpha (TNF-alpha) levels and TNF-alpha secretion by macrophages. The prior injection of EIgG augmented the increase in LPS-stimulated serum TNF-alpha levels ninefold at 1 h after LPS. Serum TNF-alpha levels were augmented when LPS was injected 2 or 6 h after EIgG but not at 0.5 or 12 h after EIgG. Complement activation caused by EIgG may contribute to the priming for TNF-alpha, because activation of complement with cobra venom factor caused a threefold augmentation of the LPS-stimulated serum TNF-alpha levels. Isolated macrophages that had ingested EIgG or were adherent to immobilized IgG showed augmented TNF-alpha secretion in response to LPS. Thus clearance of immune complexes from the blood can augment the LPS-stimulated increase in serum TNF-alpha levels that is due, in part, to complement activation and signaling via FcgammaR.
Richard
C A
CA
Department of Physiology and Cell Biology, Albany Medical College, Albany, New York 12208-3479, USA.
Gudewicz
P W
PW
Loegering
D J
DJ
D000818:Animals; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004546:Elapid Venoms / Q000494:pharmacology; D017707:Erythrocyte Transfusion; D007074:Immunoglobulin G / Q000008:administration & dosage* / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D004546:Elapid Venoms; D007074:Immunoglobulin G; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; C016310:cobra venom factor