Class II transactivator restricts viral replication, extending its effect to HBV: Editorial on "Novel role of MHC class II transactivator in hepatitis B virus replication and viral counteraction"

The expression of CIITA is highly restricted to cells or tissues expressing MHC class II. [...]CIITA works as a non-DNA-binding co-activator with remarkable specificity for MHC class II genes. [4] have shown that CIITA expression is induced by interferon gamma (IFN-γ) in primary normal human hepatocytes. [...]CIITA has a role in the non-immune cells during the infections including viruses. Furthermore, nuclear bodies containing CIITA bind Tax-1/RelA, thereby blocking the activation of NF-κB-controlled genes in the nucleus [15-18]. [...]CIITA effectively contributes to antiviral defense by promoting antigen presentation against viruses and suppressing viral gene expression through targeting the activity of viral transcriptional activators. [...]Dezhbord et al.’s study provided a novel antiviral mechanism of CIITA that involves the modulation of the ERK pathway to restrict HBV transcription in the hepatocytes.