The unique activity of the bone morphogenetic protein TGH4 affects the embryonic development of Trichinella spiralis and the establishment of vaccine protection.

In recent years, animal outbreaks of trichinellosis have been reported in Mexico, China, Algeria, Croatia and others, which is a challenge to meat safety and public health. Vaccination is an important means to control trichinellosis, but one of the main challenges in vaccine development is screening for protective candidate antigens. Bone morphogenetic proteins (BMP)), which are potential vaccine research targets, play key roles in the growth and development of metazoans. The BMP homologue TGH4 was identified from Trichinella spiralis (T. spiralis), and recombinant C-terminal mature rTGH4-m had BMP activity and exerted regulatory effects on both mouse fibroblast and T. spiralis embryonic development. The construction of a protein mutant without activation potential confirmed that BMP activity had a negative regulatory effect on the establishment of immune protection by affecting the innate, adaptive, and humoral immunity of mice. Stripping protein activity can enhance immune protection and host resistance to T. spiralis. Our findings demonstrate that the TGH4 mutant is an important vaccine candidate antigen that blocks embryonic development, kills larvae, and provides insight into parasite vaccine research.