MAIT cells are activated during human viral infections

• Published in: Nature communications Vol. 7; no. 1; p. 11653
• Main Authors: van Wilgenburg, Bonnie, Scherwitzl, Iris, Hutchinson, Edward C., Leng, Tianqi, Kurioka, Ayako, Kulicke, Corinna, de Lara, Catherine, Cole, Suzanne, Vasanawathana, Sirijitt, Limpitikul, Wannee, Malasit, Prida, Young, Duncan, Denney, Laura, Moore, Michael D., Fabris, Paolo, Giordani, Maria Teresa, Oo, Ye Htun, Laidlaw, Stephen M., Dustin, Lynn B., Ho, Ling-Pei, Thompson, Fiona M., Ramamurthy, Narayan, Mongkolsapaya, Juthathip, Willberg, Christian B., Screaton, Gavin R., Klenerman, Paul
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23-06-2016; Nature Publishing Group; Nature Portfolio
• Subjects: 13; 13/1; 13/106; 13/31; 14; 14/63; 631/250/1619/554; 631/250/2152/1566/1618; 631/250/255/234/2513/1551; 692/308; Adult; Biomedical research; Cells, Cultured; Clinical medicine; Coculture Techniques; Cytokines; Cytokines - metabolism; Dengue fever; Disease; Female; Hepatitis C; Hospitals; Humanities and Social Sciences; Humans; Immunology; Infections; Interferon; Leukocytes, Mononuclear - physiology; Ligands; Lymphocyte Activation - physiology; Male; Medicine; Mucosal-Associated Invariant T Cells - physiology; multidisciplinary; Pathogens; Pediatrics; Rheumatology; Science; Science (multidisciplinary); Viral infections; Virus Diseases - immunology; United Kingdom > UK; Thailand
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms11653

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, TCR-independent activation of MAIT cells leads to a reduction of HCV replication
in vitro
mediated by IFN-γ. Together these data demonstrate MAIT cells are activated following viral infections, and suggest a potential role in both host defence and immunopathology.
Mucosal Associated Invariant T cells have been implicated in response to bacterial pathogens. Here the authors show that in human viral infections, these cells are activated by IL-18 in cooperation with other pro-inflammatory cytokines, producing interferon gamma and granzyme B.