Influence of IgG1 and IgG2 antibodies to streptococcal group A carbohydrate on neutrophil chemiluminescence.
IgG antibodies to streptococcal group A carbohydrate (A-CHO) were isolated from normal human serum and from pooled Cohn fraction II using N-acetyl-D-glucosamine affinity chromatography columns. They consisted of the subclasses IgG1 and IgG2 in variable proportions depending on the pH of the elution buffer and on the subclass composition of anti-A-CHO in the starting material. Streptococcal group A particles exposing the antigen A-CHO were opsonized with various concentrations of these antibodies and incubated with normal human polymorphonuclear leukocytes (PMN). The luminol-enhanced chemiluminescence (CL) elicited with these particles was recorded over a 60-min period. With 12 of the 14 antibody preparations tested, the observed CL signal was dose-dependent. When used at comparable concentrations for opsonization, the antibodies enriched in IgG1 induced markedly stronger CL signals than those consisting predominantly of IgG2. It was concluded that the observed CL differences reflect mainly the preferential recognition of IgG1 molecules by Fc gamma receptors of PMN.
Ruefenacht
R
R
Central Laboratory Swiss Red Cross Blood Transfusion Service, Bern.
Chase
P
P
Jungi
T W
TW
Morell
A
A
D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000907:Antibodies, Bacterial / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008163:Luminescent Measurements; D009504:Neutrophils / Q000648:ultrastructure; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D011961:Receptors, Fc / Q000378:metabolism; D013297:Streptococcus pyogenes / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D011135:Polysaccharides, Bacterial; D011961:Receptors, Fc