Phagocytosis of Serratia marcescens by leukocytes of fresh defibrinated human blood: failure of "natural" human specific anti-O IgG antibodies to enhance phagocytosis.
Defibrination of fresh, peripheral, venous blood from three human adult volunteers resulted in the removal of from 1/5 to 1/2 of leukocytes, as compared with EDTA-anticoagulated aliquots from identical blood samples. However, differential white blood cell proportions were altered only marginally. Bacterial inocula (approximately 1.5 X 10(4) bacteria/ml at 0 time) of selected assay strains of Serratia marcescens were killed by 65 vol% of fresh, defibrinated human blood to the extent of greater than or equal to 97% within 2 hours after exposure, regardless of serum susceptibility or -resistance of the test strains. The addition of 25 vol% of either undiluted or 1:2 diluted commercially available, intravenously applicable, human IgG immunoglobulin preparations. (Gamma-Venin, Sandoglobulin) ot 65 vol% of fresh, defibrinated blood from all three human volunteers failed to enhance combined phagocytic and serum bactericidal activity against all assay strains of S. marcescens examined, despite documented O-agglutinin activity of the IgG immunoglobulin preparations against the majority of the test strains. It was concluded tentatively that "natural" human specific anti-O IgG antibodies failed to enhance phagocytosis in this in vitro system.
D000373:Agglutinins / Q000032:analysis; D000907:Antibodies, Bacterial / Q000276:immunology*; D001770:Blood Bactericidal Activity; D005337:Fibrin / Q000302:isolation & purification; D006801:Humans; D007106:Immune Sera / Q000032:analysis; D007074:Immunoglobulin G / Q000276:immunology*; D007962:Leukocytes / Q000276:immunology*; D010587:Phagocytosis; D012706:Serratia marcescens / Q000276:immunology*
D000373:Agglutinins; D000907:Antibodies, Bacterial; D007106:Immune Sera; D007074:Immunoglobulin G; D005337:Fibrin