MSCs do not affect IFN-γ production from EBV- or CMV-specific CTL. (A) Proportion of EBV-CTL (n = 6), CMV-CTL (n = 2), or alloantigen-CTL (n = 2) producing IFN-γ in response to irradiated autologous LCL, pp65-pulsed LCL, or irradiated allogeneic PBMCs, respectively, in the presence or absence of MSCs were analyzed with Elispot (ND = normal donor). (B) Representative FACS plots of intracellular IFN-γ staining of EBV-CTL gated on CD3⁺CD8⁺ or CD3⁺CD4⁺ T cells and CMV-CTL gated on CD3⁺CD8⁺ T cells that were stimulated with corresponding viral antigen in the presence or absence of MSCs. (C) Representative stainings of EBV- and CMV-pentamer positive cells producing IFN-γ in response to viral antigens in CTL cultured in the presence or absence of MSCs.