Mg2+ inhibits infection of spring viraemia of carp virus (SVCV) by enhancing IRF3 expression.

Magnesium ions (Mg2+), essential divalent cations, play a pivotal role in orchestrating a myriad of physiological and biochemical processes. However, the intricate relationship between Mg2+ homeostasis and antiviral immunity in fish remains largely unexplored. In this study, we found that Mg2+ enhances the interferon (IFN) response by increasing the expression of IFN regulatory factor 3 (IRF3) to inhibit spring viraemia of carp virus (SVCV) infection. In vivo studies showed Mg2+ increases the survival rate of SVCV-infected zebrafish while reducing viral transcription and load in liver tissues. Consistent results were obtained in vitro. Further investigations revealed that Mg2+ can enhance the endogenous expression of IRF3. Additionally, upon SVCV infection, Mg2+ rescues the virus-induced degradation of IRF3. These findings underscore the pivotal role of Mg2+ in the antiviral response of lower vertebrates, presenting a promising avenue for addressing fish viral diseases.