Cloning, expression and functional characterization of recombinant tumor necrosis factor α1 (TNFα1) from white crucian carp in gut immune regulation.

Abstract

TNF&#x3b1; is one of important cytokines belonging to TNF superfamily, which can exhibit a pleiotropic effect in immune modulation, homeostasis as well as pathogenesis. However, its immunoregulatory function on mucosal immunity in fish gut are still unclear. In this study, we aimed to investigated the immunoregulatory role of TNF&#x3b1;1 in midgut of white crucian carp (WCC). WCC-TNF&#x3b1;1 sequence and its deduced structure were firstly identified in WCC. Then, tissue-specific analysis revealed that high-level WCC-TNF&#x3b1;1 expression was detected in gill. After Aeromonas hydrophila and lipopolysaccharide (LPS) stimulated, increased trends of WCC-TNF&#x3b1;1 expressions were detected in immune-related tissues and cultured fish cells, respectively. WCC anal-intubated with WCC-TNF&#x3b1;1 fusion protein showed the increased levels of edema and fuzzy appearance in impaired villi, along with atrophy and reduction of goblet cells (GC). Moreover, the expression levels of tight junction (TJ) genes and mucin genes were consistently lower than those of the control (P&#xa0;<&#xa0;0.05). WCC-TNF&#x3b1;1 treatment could sharply decrease antioxidant status in midgut, while the expression levels of caspase (CASP) genes, unfolded protein response (UPR) genes and redox response genes increased dramatically. Our results suggested that WCC-TNF&#x3b1;1 could exhibit a detrimental effect on antioxidant and mucosal immune regulation in midgut of WCC.