m6A RNA methylation modulates antiviral response in celiac disease.

N6-methyladenosine (m6A) RNA modifications and reovirus infections have recently been implicated in the development of celiac disease. While viral infections are known to alter the RNA modification machinery of the host, their interplay in autoimmune tissue damage remains unexplored. In this study we employed an in vitro model combining a viral mimic with gliadin peptides to simulate celiac disease conditions, alongside the analysis of serum and intestinal biopsies from controls and patients to investigate the link between m6A methylation and viral infections in inducing autoimmune inflammation. We found elevated anti-reovirus reactivity in patients, increased antiviral gene expression and enhanced m6A levels. Notably, the expression of IRF7 was synergistically induced by the combined exposure to the viral mimic and gliadin peptides, and this is mediated through m6A methylation in its coding region and interaction with the reader protein YTHDC2. Furthermore, the reduction of m6A through METTL3 silencing or simvastatin treatment reduced IRF7 mRNA methylation and downstream proinflammatory gene expression both in vitro and ex vivo. These findings highlight m6A methylation as a modulator of antiviral responses and a potential therapeutic target in autoimmune disorders.