Avian leukosis virus subgroup J triggers caspase-1-mediated inflammatory response in chick livers

•Elevated mRNA levels of caspase-1, NLRP3 and cytokines were detected in the livers of chicks after Avian leukosis virus subgroup J (ALV-J) infection.•Caspase-1 protein expression and inflammatory cell infiltration can been detected in ALV-J infection livers.•Our results provide insight into understanding of the inflammatory response in ALV-J infection. Many pathogens trigger caspase-1-mediated innate immune responses. Avian leukosis virus subgroup J (ALV-J) causes serious immunosuppression and diverse tumors in chicks. The caspase-1 inflammasome mechanism of response to ALV-J invading remains unclear. Here we investigated the expression of caspase-1, the inflammasome adaptor NLRP3, IL-1β and IL-18 in response to ALV-J infection in the liver of chick. We found caspase-1 mRNA expression was elevated at 5dpi and peaked at 7dpi in ALV-J infected animals. Corresponding to this, the expressions of NLRP3 and proinflammatory cytokines IL-1β and IL-18 were significantly increased at 5 or 7dpi. In addition, caspase-1 protein expression and inflammatory cell infiltration were induced after virus infection. These results indicated that ALV-J infection could trigger the caspase-1- mediated inflammatory response in chicks. Thus, an understanding of the inflammatory responses can provide a better insight into the pathogenicity of ALV-J and a possible anti-virus target for ALV-J infection.