Antibody inhibition of polymorphonuclear phagocytosis. Dissociation of bacterial attachment and bacterial killing.
The inhibition of killing of Staphylococcus aureus 502A by PMNs treated with the IgG fraction of serum from a group of patients with demonstrable leukocyte antibodies was investigated. The uptake of opsonized thymidine-labeled S. aureus 502A by PMNs treated with allogeneic antibody was essentially unimpaired, despite significantly decreased killing. The findings were similar to bacteria opsonized by serum complement or bacteria opsonized with specific lapine antibody. An increased proportion of PMN-bound bacteria susceptible to lysis by lysostaphin indicated a reduced rate of translocation of bacteria from the surface of allogeneic antibody-treated PMNs. Antibody did not stimulate the basal oxidative metabolism, but the oxidative metabolism of antibody-treated PMNs during phagocytosis was increased. Although the precise mechanism of inhibition of PMN killing by antibody is uncertain, the data suggest that the impairment of bacterial killing by PMNs treated with allogeneic leukocyte antibody is associated with inefficient translocation of bacteria into phagolysosomes rather than by interference with the binding of bacteria to specific PMN opsonic receptors.
D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D001433:Bacteriolysis; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology / Q000494:pharmacology; D009504:Neutrophils / Q000276:immunology*; D010587:Phagocytosis; D013211:Staphylococcus aureus / Q000276:immunology*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007074:Immunoglobulin G