Effects of Staphylococcus aureus leukocidins on inflammatory mediator release from human granulocytes.

The secretion of the Panton-Valentine leukocidin (Luk-PV) but not of another leukocidin (Luk-R) from Staphylococcus aureus strains is correlated with severe pyodermic infections (dermonecrosis). The effects of both Luk-PV and Luk-R in amounts of 0-5000 ng on inflammatory mediator release from human leukocytes were studied. Luk-PV but not Luk-R induced a pronounced release of the vasodilator histamine from human basophilic granulocytes (up to 55% +/- 7%) and of enzymes (beta-glucuronidase, up to 45% +/- 10%; lysozyme, up to 35% +/- 7%), chemotactic components leukotriene B4 (42 +/- 8 ng/10(7) cells) and interleukin-8 (up to 33 +/- 5 ng/10(7) cells), and oxygen metabolites from human neutrophilic granulocytes. The results indicate that granulocytes play a central role in dermonecrosis; these in vitro data account for the histologic picture of Luk-PV infections, characterized by local vasodilation, infiltration of granulocytes, and a central necrotic area.