Effect of Haemophilus influenzae type b lipopolysaccharide on complement activation and polymorphonuclear leukocyte function.

摘要: ABSTRACT. Purified lipopolysaccharide (I.PS) from Haemophilus influenzae type b (Hib) was examined for its capacity to interact with human hemolytic complement, generate conversion products of C3, C4, and factor B. stimulate C5a activity, affect neutrophil chemiluminescence phagocytosis. Salmonella typhimurium LPS minnesota Rb (R345 mutant) were comparison. Incubation Hib serum deficient in globulin or normal containing 10mM EGTA 7 mM MgCl2 resulted some depletion complement C3 degradation (determined by inhibition passive hemolysis electrophoresis/immunofixation, respectively), indicating that activation occurred the alternative pathway. Complement S. similar, but significantly less effective than LPS, (p < 0.01). Solubilized lipid A, not induced C 4 hypogammaglobulinemic serum, classical Similar levels activity generated incubation tryphimurium as determined shape change aggregation. directly stimulated chemiluminescence, whereas had little effect. Phagocytosis radiolabeled, opsonized neutrophils diminished solubilized A 0.001). slightly increased LPS. Neither oligosaccharide capsular polysaccharide capable interacting altering These results indicate comparison at activating more impairing polymorphonuclear leukocyte function.