IL-15 and IL-2 possess similar properties, including the ability to induce T cell proliferation. However, whereas IL-2 can promote apoptosis and limit CD8 ؉ memory T cell survival and proliferation, IL-15 helps maintain a memory CD8 ؉ T cell population and can inhibit apoptosis. We sought to determine whether IL-15 could enhance the in vivo function of tumor͞self-reactive CD8 ؉ T cells by using a T cell receptor transgenic mouse (pmel-1) whose CD8 ؉ T cells recognize an epitope derived from the self͞melanoma antigen gp100. By removing endogenous IL-15 by using tumor-bearing IL-15 knockout hosts or supplementing IL-15 by means of exogenous administration, as a component of culture media or as a transgene expressed by adoptively transferred T cells, we demonstrate that IL-15 can improve the in vivo antitumor activity of adoptively transferred CD8 ؉ T cells. These results provide several avenues for improving adoptive immunotherapy of cancer in patients.

Scar formation, with persistent alteration of the normal tissue structure, is an undesirable and significant result of both wound healing and fibrosing disorders. There are few strategies to prevent or to treat scarring. The transforming growth factor beta (TGF-β) superfamily is an important mediator of tissue repair. Each TGF-β isoform may exert a different effect on wound healing, which may be context-dependent. In particular, TGF-β1 may mediate fibrosis in adults' wounds, while TGF-β3 may promote scarless healing in the fetus and reduced scarring in adults. Thus, TGF-β3 may offer a scar-reducing therapy for acute and chronic wounds and fibrosing disorders.