Regulation of host antiviral factors expression by TET2-mediated DNA demethylation

Host antiviral innate immune response is regulated by epigenetic mechanisms. TET2 oxidizes the methyl group of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) in a process that activates demethylation of CpG DNA. Here, we characterize the genome-wide distribution of 5hmC in both wild-type and TET2-knockout THP-1 cells infected with the influenza A virus (IAV) using DNA immunoprecipitation by anti-5hmc antibody coupled with high-throughput DNA sequencing. 5hmC marks signature genes associated with host innate immune response against IAV infection. Moreover, TET2 expression is inhibited by IAV infection via viral endoribonuclease PA-X . Deletion of the TET2 gene in THP-1 cells decreased expression of genes related to interferon signaling. We further verified that TET2 plays a critical role in the expression of STAT1 and some interferon-stimulated genes through demethylation. Collectively, our findings demonstrate a key role of TET2-mediated active DNA demethylation in anti-IAV immunity. Hydroxymethylated DNA immunoprecipitation-sequencing (hMeDIP-Seq) in IAV-infected wild-type and TET2-knockout THP-1 cells. Overall design: Yixiang, Hu