Fig. 6

IL-15 sustained higher proportions of early/central memory subsets among expanded Vγ2Vδ2 T cells compared to IL-2. a Gating strategy for delineating memory subsets of Vγ2Vδ2 T cells from blood. Memory status of Vγ2Vδ2 T cells was assessed by expression of CD27 and CD28. CD28⁺/CD27⁺ and CD28⁺/CD27⁻ cells are early/central memory cells that express CD45RO. CD28⁻/CD27⁺ cells are intermediate memory cells. CD28⁻/CD27⁻ cells are late memory cells that express CD45RA. b Proportions of human Vγ2Vδ2 T cell memory subsets after expansion with the indicated concentrations of HMBPP or zoledronate by continuous and pulse stimulation and in the presence of IL-2 (left panels) or IL-15 (right panels) for 14 days. Data for four donors is shown. c, left panel Comparison of the proportion of memory subsets of Vγ2Vδ2 T cells expanded by continuous zoledronate stimulation (10 μM) with IL-2 or IL-15. Mean ± SEM for 4 individuals. Right panel, Comparison of the proportion of memory subsets of Vγ2Vδ2 T cells expanded by pulse zoledronate stimulation (100 μM) with IL-2 or IL-15. Mean ± SEM for 4 individuals. ** p < 0.01 using the unpaired t-test