Fig. 2.

Granulocytic myeloid-derived suppressor cells inhibited CD8⁺ T cell proliferation. CD8⁺ T cells isolated from DbGagL TCR transgene mice were incubated with dendritic cells loaded with MHC class I-restricted FV-specific CD8⁺ T cell epitope peptide and co-incubated with either gMDSCs or mMDSCs (a). Representative histograms and percentages of CD8⁺ T cells after co-incubation with or without either gMDSC or mMDSCs (in relation 1 CD8⁺ to 10 MDSCs) from FV-infected mice are shown (b). CD8⁺ T cell proliferation was measured after co-incubation with different effector ratios of gMDSCs to CD8⁺ target cells (c). Frequencies of GzmB expressing CD43⁺CD8⁺ cells after incubation of CD8⁺ cells with gMDSCs or mMDSCs from FV-infected mice are shown (d). CD8⁺ T cells incubated with peptide loaded DC serve as a positive control, CD8⁺ T cells incubated with non-loaded DC serve as a negative control. At least three independent experiments were analyzed. Bars represent the mean with SD. For statistical analysis, an ANOVA multiple comparison test was carried out with the group of naïve mice as a reference (*<0.05; ***<0.0005). For statistical analysis a Dunn’s test with the Benjamini–Hochberg correction for multiple testing was performed (*<0.05; **<0.005)