Staphylococcus aureus is a common cause of sepsis and toxic shock. These processes can result in tissue damage and cell death, presumably by necrosis or apoptosis. Bantel et al. now show that in cultures of Jurkat T cells, apoptosis can be induced not only by infection with S. aureus itself but also by S. aureus culture supernatants. The active ingredient in these supernatants was one of the secreted toxins, a-toxin. Death was not induced when S. aureus strains lacking the toxin were used nor when antibodies that could bind a-toxin were added. The mechanism of apoptosis induction appears to be via the intrinsic death pathway leading directly to cytochrome c release from mitochondria, rather than via death receptors. Given the increasing incidence of antibiotic resistance in S. aureus strains, these findings provide potential leads for therapeutic intervention during staph infections. -- SMH
J. Cell Biol. 155, 637 (2001).
