Figure 6: MAIT cells respond to type I interferons in vitro and in vivo.

(a) PBMC’s from healthy individuals were directly stimulated for 24 h with IFN-α, IFN-β, IL-12, IL-15, IL-18 or indicated combinations thereof. IFN-γ expression by MAIT cells (gated on live CD3⁺CD8⁺CD161⁺⁺Vα7.2⁺ cells) was analysed by flow cytometry. (b–d) B18R (IFN-α/β neutralizing protein) or PBS control were added to the co-culture (n=6–11). IFN-γ (b), CD69 (c) and Granzyme B (d) expression is shown relative to the control. Data are representative from at least two independent experiments. (e) PBMC’s from healthy controls or HCV patients at baseline, during or end of treatment with either SOF+RBV or SOF+RBV/PEG-IFN were analysed by flow cytometry. CD69 expression on MAIT cells (gated on live CD3⁺CD8⁺CD161⁺⁺Vα7.2⁺ cells) was measured. Bars represent means±s.e.m. Statistical significance was determined with the Kruskal–Wallis test followed by the Dunns’ test (a) or the Mann–Whitney test (b–e). ns>0.05, *P 0.05, ***P≤0.001, ****P≤0.0001. HC, healthy controls.