Abstract

This study investigates the antiviral, immunomodulatory, and antioxidant effects of VD 3 on Channel catfish kidney (CCK) cells infected with Yellow Catfish Calicivirus (YcCV). CCK cells were treated with various concentrations of VD 3 (0, 60, 120, 180 pM) and infected with YCCV, and 180 pM VD 3 was determined as the optimal dose. The experimental groups included a control group, a YcCV group, and a VD 3  + YcCV group. We assessed oxidative stress, immune response, and apoptosis in these groups. Our results demonstrated that VD 3 significantly increased cell viability in the VD 3  + YCCV group compared with the YcCV group, with no significant cytotoxicity observed. Antioxidant analysis demonstrated that VD 3 plays a promising role in regulating virus-induced oxidative stress, significantly reducing malondialdehyde (MDA) levels (P < 0.05). Furthermore, VD 3  + YcCV treatment also increased both superoxide dismutase (SOD) and Lysozyme (LZM) activities (P < 0.05). Moreover, compared with the viral group, VD 3  + YcCV also significantly reduced ROS activities (P < 0.05). Additionally, VD 3 demonstrated its effect by a decrease in apoptosis, reducing the apoptotic cell population from 30% in the YcCV group to 17% in the VD 3  + YcCV group. VD 3 also induced the upregulation of immune-related genes ( vdr, irf3, ifn-α, jak-1, stat-1, mx-1, and ifp-35 ). These results demonstrate that VD 3 enhances cellular antiviral immune responses, reduces oxidative stress, and modulates immune gene expression, suggesting its potential as an immunostimulant for viral infections.