Vγ2Vδ2 T cells bearing high-density TCR nanoclusters were still capable to rerecognize phosphoantigen and to exert effector function during the phosphoantigen-mediated clonal expansion. (A) Flow cytometry histogram indicating that expanded Vγ2Vδ2 T cells bearing high-density TCR nanoclusters were able to rerecognize phosphoantigen and exert better effector function of IFNγ or perferin production compared with the nonstimulating Vγ2Vδ2 T cells that had few or no nanoclusters. Shown are the representative data from one of 3 monkeys on day 4 after HMBPP/IL-2 treatment. The cells shown in the histograms were CD3-gated (P < .05 for the difference in perforin or IFNγ levels between day 4 and pretested cells). Negative controls using medium alone or an irrelevant peptide did not induce detectable numbers of Vγ2Vδ2 T effector cells. (B) The percentage of Vγ2 T cells that expressed either IFNγ or perforin in response to phosphoantigen HMBPP. Data were derived from PBLs collected from 2 monkeys on day 7 after phosphoantigen Picostim/IL-2 treatment. Error bars represent SEM.