Opsonic effect of fibronectin on staphylococcal phagocytosis by human polymorphonuclear leukocytes: its relative inefficiency in post-phagocytic metabolic activities and in intracellular killing.
The binding of 125I-labeled human plasma fibronectin (FN) to two strains of live Staphylococcus aureus (S. aureus) (a coagulase-positive Cowan I and a coagulase-negative Newman D2C) and the opsonic effect of FN on phagocytosis of these bacteria by human polymorphonuclear leukocytes (PMN) have been studied. 125I-FN bound to a similar extent in both staphylococcal strains. The 125I-FN-binding was significantly inhibited by human fibrinogen as well as unlabeled FN. The FN-binding was also reduced markedly by trypsinization of these bacteria, but the extent of its decrease did not correlate with their tryptic susceptibility of protein A and clumping factor. FN enhanced the uptake of these bacteria by PMN. However, its binding had no effect on superoxide anion (O2-) generation. The FN-binding definitely stimulated staphylococcal ingestion and intracellular killing by PMN, but the extent of such promotion was dissimilar between these two strains of bacteria. These results suggest that post-phagocytic metabolic activities as well as intracellular killing of these Staphylococci may also be greatly influenced by FN-unrelated factors as are other bacteria having no FN-receptors.
Yonemasu
K
K
Department of Bacteriology, Nara Medical College.
Sasaki
T
T
Hashimoto
H
H
Kashiba
S
S
D000371:Agglutination; D001422:Bacterial Adhesion / Q000187:drug effects; D001770:Blood Bactericidal Activity / Q000187:drug effects; D005353:Fibronectins / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D009895:Opsonin Proteins; D010587:Phagocytosis / Q000187:drug effects*; D011485:Protein Binding; D013211:Staphylococcus aureus / Q000276:immunology* / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014357:Trypsin / Q000494:pharmacology
D005353:Fibronectins; D009895:Opsonin Proteins; D013481:Superoxides; D014357:Trypsin