TNF and HIV infectious disease: T cells capable of producing multiple anti-viral cytokines (eg. IFN-γ and TNF-α) and/or survival/proliferative cytokines (eg. IL-2) i.e. poly-functional T cells, are desirable outcomes for HIV-1 vaccine development as the presence of these cells appears to correlate with improved control of HIV infection in humans12, 29 and SIV infection in non-human primates22, 23.