Figure 4: Viral MAIT cell activation is dependent on cytokines.

(a–d,f,h) Isotype control, anti-MR1, anti-IL-12, anti-IL-15 and/or anti-IL-18 antibodies were added to a co-culture exposed to DENV (a,d, n=3–6), IAV (b,f, n=5–29) or HCV (c,h, n=7–16). IFN-γ expression by MAIT cells (gated on live CD3⁺CD8⁺CD161⁺⁺Vα7.2⁺ cells) was analysed by flow cytometry and is shown relative to the isotype control. (e,g,i) IL-12p70, IL-15 and IL-18 levels secreted by virus-exposed APC’s. (e) DENV-exposed DC’s (n=4) at 42 h. (g) IAV-exposed macrophages (n=7) at 48 h. (i) HCV-exposed macrophages (n=7) at 48 h. Data are representative from at least two independent experiments. Bars represent means±s.e.m. Statistical significance was determined with the Mann–Whitney test (a–c,e,g,i) or the Kruskal–Wallis test followed by the Dunns’ test or the Mann–Whitney test (d,f,h). ns>0.05, *P 0.05, ***P≤0.001, ****P≤0.0001. ND, not detected.