Houttuynia cordata intervention mediates the regulation of cellular interleukin expression upon LMBV infection

Largemouth bass virus (LMBV) can induce severe lesions in the liver and intestine of fish. In this study, EPC cells were used as an in vitro model to investigate the immune regulatory mechanism of Houttuynia cordata against LMBV infection. The results demonstrated that Houttuynia cordata alleviated virus-induced tissue damage. It exerted bidirectional regulation on the TGF–TRAF6–TAK1–CERK2 (chitin elicitor receptor kinase 2)–c-Fos–AP-1 signaling cascade and significantly upregulated IL-6 expression at the late stage of infection to boost antiviral immunity, and this regulatory effect was independent of the TLR4-TRIF/NF-κB pathway. This study elucidates the molecular mechanism underlying the anti-LMBV activity of Houttuynia cordata and provides a theoretical foundation for the green prevention and control of viral diseases in aquaculture.