MxA is a crucial antiviral effector, produced in cells as a response to virus detection. VHSV is a contagious and lethal RNA virus in aquatic environments. This study addresses the role of MxA on VHSV infection to better understand the host pathogen interactions, which would be important to seek remedies for viral infection in aquaculture. In this study, first MxA ablated zebrafish were generated using the CRISPR/Cas9 method. Then fish survival and the disease symptoms were evaluated by challenging the modeled fish with VHSV intraperitoneally. From the VHSV challenged fish, internal organs were collected, RNA extracted, and the gene expression was analyzed by RT-qPCR
Comparatively higher external and internal pathological symptoms were observed in MxA KO model, which was corresponding to VHSV dose. Injection of high dose of VHSV into the MxA KO fish resulted in a 100% mortality within 26 days, whereas the WT fish reached a 65% mortality within the same period. VHSV infected MxA-/- fish had a significantly higher VHSV copy number compared to WT. This high virus titter in the MxA KO model indicates the reduced antiviral function towards the viral genome replication. The expression of immune-related genes including, ifn, viperin, isg and irf7 were significantly modulated in the MxA KO fish compared to WT siblings, indicating the role of MxA on the gene expression regulation. The research is still ongoing, and the future work is to decipher the immune cell modulation, using the Tg line of MxA Tg(mpx:mcherry) and Tg(mpeg:EGFP).