Staphylococcus aureus and Streptoccocus pyogenes both produce superantigens that initiate apoptosis in T cells by protein kinase activation. Bordetella pertussis , the cause of whooping cough, stimulates apoptosis in respiratory epithelial cells by increasing cyclic AMP production. Shigella dysenteriae uses an invasion plasmid antigen to bind ICE, thus activating apoptosis and assisting intestinal penetration via M cells. Salmonella also causes apoptosis, but the mechanism has yet to be determined. Listeria monocytogenes causes apoptosis in dendritic cells and hepatocytes, thus reducing the risk of an effective host response until systemic infection has been established.
Many viral pathogens trigger apoptotic events.
Connections between viral latency and apoptosis are now being explored. Epstein-Barr virus appears to produce a bcl homologue during its cell cycle. Oncogenesis Apoptosis and the genes that control it have a profound effect on the malignant phenotype. Some oncogenic mutations disrupt apoptosis and cause tumor initiation, progression or metastasis. Other oncogenic changes promote apoptosis and override apoptosis during multistage carcinogenesis.