Protective effects of a novel trimerized sTNFRII on acute liver injury.

TNF α plays a central role in the pathogenesis of inflammatory diseases such as rheumatoid arthritis and murine acute liver injury induced by injection of D-galactosamine and subsequent LPS. Recombinant Fc-fused soluble TNF receptor II (sTNFRII-Fc) has been used in the treatment of rheumatoid arthritis for a decade. We have recently constructed a novel fusion protein sTNFRII-gAD, which is composed of a soluble TNF receptor II and a globular domain of adiponectin. Utilizing the inclination of gAD to form homologous trimer naturally, we sought to explore TNFα antagonism of the novel trimerized sTNFRII-gAD and meantime compare TNFα-neutralizing effects in vitro and in vivo between sTNFRII-Fc and sTNFRII-gAD. Here, we evaluated the TNFα-antagonizing activity of sTNFRII-gAD with TNFα-induced L929 cytotoxicity assay. Furthermore, sTNFRII-Fc or sTNFRII-gAD was administered simultaneously with d-galactosamine 1h prior to LPS injection in the murine model of acute liver injury. Serum TNFα and TNFα-sTNFRII-gAD complex were measured by ELISA and the liver injury was assessed through alanine transaminase measurement and liver histological analysis. sTNFRII-gAD was shown to have higher TNFα-neutralizing activity than sTNFRII-Fc (p<0.05) in the L929 cytotoxicity assay. With a significant attenuation of murine lethality (p<0.05), sTNFRII-gAD showed more protective effects than sTNFRII-Fc in the murine model of acute liver injury. These results demonstrated that sTNFRII-gAD was more efficacious than sTNFRII-Fc as a TNFα antagonist, highlighting the potential of sTNFRII-gAD for the treatment of diseases associated with excessive TNFα.