Bystander adjuvant activity of PhAg-stimulated Vδ2 T cells. (A) Schematic representation of the in vitro model to study the Vδ2 T-cell bystander adjuvant activity on antigen presenting cell maturation (1) and on viral specific αβ T-cell response (2). (B-C) The expressions of CD86 and HLA-DR on monocytes (A) and on Vδ2 T cells (B) were compared between unstimulated and PhAg-stimulated PBMCs from HDs (n = 10) and HSCT recipients (n = 9). Differences between unstimulated and PhAg-stimulated cells were evaluated by Wilcoxon paired test ∗P < .05; ∗P < .01; Differences between HDs and HSCT recipients were evaluated by Mann-Whitney U test; §P < .05. Representative histograms showing the significantly different expression of CD86 and HLA-DR on monocytes and Vδ2 T cells are shown. (D) The frequency of CMV-specific T cells was compared between unstimulated and PhAg-stimulated PBMCs from HDs (n = 10). Differences between unstimulated and PhAg-stimulated PBMCs were evaluated by Wilcoxon paired test ∗∗∗∗P < .001; ∗∗P < .01. Representative dot plots showing IFN-γ/TNF-α production are shown. MFI, median fluorescence intensity.