Participation of normal human immunoglobulins M, G, and A in opsonophagocytosis and intracellular killing of Bacteroides fragilis and Bacteroides thetaiotaomicron by human polymorphonuclear leukocytes.

Restoration of the ability of hypogammaglobulinemic serum to support opsonophagocytosis and intracellular killing of Bacteroides fragilis and Bacteroides thetaiotaomicron by human polymorphonuclear leukocytes was achieved by supplementation with normal human immunoglobulin M, but not with normal human immunoglobulin G. Polymorphonuclear leukocyte bactericidal activity in the presence of immunoglobulin A-deficient human serum was equivalent to that observed in the presence of normal human serum.