Effect of dietary sodium butyrate on the innate immune response of Procambarus clarkii and disease resistance against white spot syndrome virus

Abstract

Sodium butyrate is a compound used as a feed additive in animal production. Sodium butyrate regulates electrolyte balance, gastrointestinal micro-ecology, intestinal mucosal nutrients, and also acts as an immunostimulant. It has great potential research value. The effect of sodium butyrate on the innate immunity of crustaceans was investigated in this study. Procambarus clarkii (crayfish) was used as a model organism and healthy crayfish were challenged with White spot syndrome virus (WSSV). The results showed that the group treated with sodium butyrate had significantly lower levels of mortality caused by WSSV, and the replication of WSSV was also reduced to a certain extent. Fluorescence quantitative PCR showed that sodium butyrate could up-regulate the expression of two immune-related genes, including C-type-lectin and prophenoloxidase. It was found that sodium butyrate treatment had positive effects on the total number of hemocyte (THC), phenoloxidase activity (PO), superoxide dismutase activity (SOD), and CAT activity of crayfish. In addition, we found that whether infected with WSSV or not, sodium butyrate treatment can significantly reduce the hemocyte apoptosis rate of crayfish. The results show that sodium butyrate can regulate the innate immunity of crayfish and reduce crayfish mortality following WSSV infection. This study provides evidence for the novel use of sodium butyrate to regulate the immunity of crayfish, treat WSSV infection, and provide a new theoretical basis for the research of sodium butyrate on crustaceans as a new additive for aquatic feed.