A putative model of Nampt's role in activated T lymphocytes.

<p>Nampt activity is responsible for providing sufficient NAD⁺ supplies during T cell activation. NAD⁺, in turn, is required for ATP synthesis, metabolic reactions, and to replenish NADPH levels. In addition, NAD⁺ represents the substrate of NAD⁺-degrading enzymes such as PARP, CD38, and the sirtuins. Among these, Sirt6 appears to have a central role in IFN-γ and TNF-α production. Nampt inhibitors such as FK866 (and possibly Sirt6 inhibitors) could be used to modulate T cell-mediated immune responses and thereby be beneficial in immune disorders.