A decision between life and death during TNF-alpha-induced signaling.

Tumor necrosis factor-alpha (TNF-alpha), a proinflammatory cytokine, exerts its biological activity by signaling via its two receptors, TNF-RI and TNF-RII, and by activating NF-kappaB. NF-kappaB is essential for survival of many cell types; however, TNF-alpha also induces cell death. In this article, both the survival and cell death signaling by TNF-alpha and the role of caspases in turning off NF-kappaB survival signal are reviewed. Furthermore, a role of DAP kinase in TNF-induced apoptosis is discussed. Finally, the molecular basis of the effect of age on TNF-alpha-induced apoptosis in human T cells is reviewed.