Influence of heat shock protein 90 on the replication of spring viremia of carp virus

Spring viremia of the carp virus (SVCV) infection leads to a lethal acute hemorrhagic viral illness that causes substantial damage to the global aquaculture industry. Heat shock protein 90 (HSP90) is a highly conserved ATP-dependent molecular chaperone that plays important roles with intracellular proteins. Currently, little is known about the effect of HSP90 on SVCV replication. Therefore, in this study, we examined the transcription and expression levels of HSP90 in various organs of Cyprinus carpio var. Jian fish, including the brain, spleen, kidneys, liver, intestine, gills, heart, eyes, and muscles. We found that HSP90 was expressed at the highest levels in the liver, intestine, and gills and at the lowest levels in the spleen, eyes, and muscles. The SVCV-G and HSP90 levels in kidney, spleen, liver, and gill tissues peaked on day 3 following SVCV infection. We also constructed a recombinant HSP90 plasmid and demonstrated HSP90 overexpression in Epithelioma papulosum cyprinid (EPC) transfectants, using Pcs2 + 8CmCherry vector as a negative control. Laser confocal microscopy demonstrated that HSP90 was present in the cytoplasm of EPC cells. HSP90 expression gradually increased in EPC cells as the SVCV infection progressed. To gain insight into the influence of HSP90 on SVCV infection and its interconnectedness, we assessed apoptosis and immune gene expression by overexpressing and silencing HSP90. EPC cells infected with SVCV and overexpressing HSP90 showed considerably higher apoptosis, mortality, and IRF3 and IRF7 expression that EPC cells that were subjected to SVCV infection alone. HSP90 suppression increased the ability of cells to survive. Our initial investigation into the involvement of HSP90 in SVCV infection offers valuable insights. In addition, our findings offer novel approaches and techniques for constructing efficient systems to prevent and treat viral infections.