MAIT cells are activated during human viral infections

Mucosal-associated invariant T (MAIT) cells are abundant in humans and recognize bacterial ligands. Here, we demonstrate that MAIT cells are also activated during human viral infections in vivo. MAIT cells activation was observed during infection with dengue virus, hepatitis C virus and influenza virus. This activation-driving cytokine release and Granzyme B upregulation-is TCR-independent but dependent on IL-18 in synergy with IL-12, IL-15 and/or interferon-α/β. IL-18 levels and MAIT cell activation correlate with disease severity in acute dengue infection. Furthermore, HCV treatment with interferon-α leads to specific MAIT cell activation in vivo in parallel with an enhanced therapeutic response. Moreover,…

• WT
  Wellcome Trust

  Award: WT091663MA
• NI
  National Institute for Health and Care Research

  Award: U19AI082630
• IC
  Imperial College London
• NI
  National Institutes of Health

  Award: U19AI082630
• MR
  Medical Research Council

  Awards: MR/K010239/1, MC_UU_12014/9, MR/N012658/1, MR/K01532X/1, MR/K000241/1, MC_PC_12020, MR/K000241/1