Antiphagocytic effects of staphylococcal protein A.

By J. Dossett, Göran Kronvall, Ralph C. Williams, P. G. Quie. 1969

Strains of Staphylococcus aureus possessing large amounts of protein A tended to resist phagocytosis more than strains that contain lesser amounts or none of this protein. Protein A extracted from S. aureus inhibited phagocytosis of both S. aureus and Escherichia coli in in vitro phagocytosis systems. The antiphagocytic effect was produced by nonspecific reaction of protein A with the Fc piece of γG globulin.