SINGLE-CELL CYTOKINE ANALYSIS OF GAMMA-DELTA T-CELL RESPONSES TO NONPEPTIDE MYCOBACTERIAL ANTIGENS

TCR gamma delta T cells are considered important in the rapid immune r esponse to intracellular infection, We investigated the early response of peripheral blood gamma delta T cells to the nonpeptide Ag isopente nyl pyrophosphate and to its synthetic analogue ethyl pyrophosphate. I n healthy donors, an increase in the number of gamma delta T cells was detected as soon as 4 days after stimulation with the nonpeptide Ags, Single-cell analysis of cytokine production was performed by intracel lular staining of IFN-gamma and IL-4, gamma delta T cells were found r e, rapidly expand and produce IFN-gamma in response to nonpeptide Ags, Furthermore, IL-12 augmented the IFN-gamma response. In contrast, gam ma delta T cells from the majority of HIV+ donors did not expand or ex press IFN-gamma in response to nonpeptide Ags, even in the presence of IL-12, These findings indicate a role for nonpeptide-reactive gamma d elta T cells in effective cell-mediated immunity for intracellular pat hogens.