Salmonella typhimurium invasion induces apoptosis in infected macrophages.

• DOI: 10.1073/pnas.93.18.9833
• Publication Date: 2002-07-26T14:43:20Z
• Authors: D M Monack; B Raupach; A E Hromockyj; S Falkow
• Keywords: Membrane ruffling; Vacuolization; Fragmentation

Invasive Salmonella typhimurium induces dramatic cytoskeletal changes on the membrane surface of mammalian epithelial cells and RAW264.7 macrophages as part its entry mechanism. Noninvasive S. strains are unable to induce this ruffling. invade in 2 h with 7- 10-fold higher levels than noninvasive strains. typhi, independent their ability replicate intracellularly, cytotoxic and, a greater degree, murine bone marrow-derived macrophages. Here, we show that macrophage cytotoxicity mediated by invasive is apoptosis, shown nuclear morphology, cytoplasmic vacuolization, host cell DNA fragmentation. enter causing ruffles but mutant for subsequent intracellular replication also initiate apoptosis. Mutant incapable inducing ruffling fail The activation state plays significant role response invasion, perhaps indicating signal or receptor initiating programmed death upregulated activated promote apoptosis may be important initiation infection, bacterial survival, escape immune response.