Chemiluminescence response of human phagocytes against IgG-opsonized staphylococci with and without protein A activities.
The effects of immunological IgG binding to Staphylococcus aureus and IgG binding via protein A on the chemiluminescence (CL) response of human phagocytes were examined. The results obtained by enzyme immunoassay showed a clear correlation between the magnitude of the CL response and amount of IgG on protein A-deficient HL-87 strain. Despite no difference in protein A activity between 209P and Cowan I strains, the CL response to IgG-opsonized 209P cells was lower than that to Cowan I cells similarly opsonized. Moreover, the CL response to opsonized HL-87 cells was identical with that of opsonized Cowan I cells, which was a protein A-rich parent strain of the HL-87. The protein A activity of Cowan I cells was significantly decreased when the cells were treated with the Fc fraction of IgG before opsonization, but such a treatment did not change the phagocytic CL response. These results strongly suggest that IgG bound to protein A via its Fc portion has no effect on the phagocytic CL response and that IgG immunologically bound to S. aureus is responsible for the opsonization of the bacteria.
Yamada
S
S
Department of Microbiology, Kawasaki Medical School, Okayama.
D001665:Binding Sites; D006386:Hemagglutination Tests; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D008163:Luminescent Measurements; D009895:Opsonin Proteins / Q000276:immunology*; D010586:Phagocytes / Q000276:immunology*; D010587:Phagocytosis; D015203:Reproducibility of Results; D013205:Staphylococcal Protein A / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000276:immunology*
D007074:Immunoglobulin G; D009895:Opsonin Proteins; D013205:Staphylococcal Protein A