Effect of immunoglobulin G on the responsiveness of human neutrophils to soluble staphylococcal protein A-induced neutrophil migration inhibition factor from T-lymphocytes.

Staphylococcal protein A is a bacterial cell wall product that binds human immunoglobulin G and thereby interferes with opsonization and phagocytosis of Staphylococcus aureus by neutrophils. Phagocytic cells are also responsive to various non-immunoglobulin lymphocyte mediators. We utilized the detection of a newly recognized mediator, a neutrophil migration inhibition factor from T-lymphocytes (NIF-T), to show that aggregates of staphylococcal protein A and immunoglobulins G could inhibit the responsiveness of neutrophils to NIF-T. That such aggregates may alter the responsiveness of neutrophils to lymphocyte mediators that amplify or modulate phagocytic functions may have important pathogenetic implications in staphylococcal infection.