Effects of alpha and theta toxins from Clostridium perfringens on human polymorphonuclear leukocytes.

Two toxins, alpha (phospholipase C) and theta (oxygen-labile hemolysin), were purified from Clostridium perfringens type A and assayed for toxic effects on human polymorphonuclear leukocytes (PMNLs). Crude preparations containing both toxins totally inhibited chemotaxis and chemiluminescence responses of PMNLs and reduced PMNL viability. Purified alpha toxin did not alter PMNL viability, chemotactic responsiveness, or morphology but did enhance opsonized zymosan-induced PMNL chemiluminescence over a wide range of toxin concentrations. theta Toxin, at 12.5 hemolytic units (HU) per 10(5) PMNLs, reduced cell viability and induced marked PMNL morphological changes. Concentrations of theta toxin between 4 and 32 HU per 10(5) PMNLs inhibited PMNL chemiluminescence in a dose-dependent manner, whereas a lower concentration enhanced the PMNL chemiluminescent response to opsonized zymosan. Effects on chemotaxis were also dose dependent. Increased PMNL random migration was observed at a concentration of theta toxin of 0.06 HU per 2.5 X 10(5) PMNLs (P less than .05), whereas concentrations of greater than 0.08 HU per 2.5 X 10(5) PMNLs reduced both directed and random migration (P less than .05).