Characterization of Membrane-associated Progesterone Receptor Component-2 (MAPRC2) From Trichinella spiralis and Its Interaction With Progesterone and Mifepristone

Abstract Background: Trichinellosis is a food-borne zoonotic disease caused by nematode viz., Trichinella spiralis. Physiologically, the high progesterone (P4) doses cause new borne larvae (NBL) mortality in the parasite, while the low doses maintain pregnancy. In contrast, Mifepristone (RU486) works as an antagonist against the progesterone receptor (PR) and possesses abortifacient activities. Methods: In the present study, T. spiralis membrane-associated progesterone receptor component-2 (Ts-MAPRC2) gene was cloned and characterized by protein sequencing. Furthermore, the expression, purification, immunoblot assay, binding ability with progesterone antibody, and immunofluorescence assay were performed. A direct effect of progesterone (P4) and mifepristone (RU486) on the Ts-MAPRC2 gene was determined using in-vitro cell culture that showed different expression levels at all developmental stages [muscle larvae (ML), female adult worm (F-AL), male adult worm (M-AL) and new borne larvae (NBL)]. Subsequently, the in-vitro phenotypic effect of P4, RU486, and rTs-MAPRC2-Ab on F-AL and ML stages were measured. Later on, the in-vivo phenotypic effect and relative mRNA expression of mifepristone on the F-AL stage were studied. Results: Our results revealed that the Ts-MAPRC2 gene is critical to maintaining pregnancy in the female adult worm (F-AL) of T. spiralis. The P300 ng/mL of P4 and M100 ng/mL of RU486 showed downregulation of the Ts-MAPRC2 gene in F-AL (P ≤ 0.05). This plays an important role in abortion and possibly decreases the worm burden of T. spiralis in the host. Only P30 ng/mL showed significant upregulation in F-AL (P ≤ 0.05). Conclusions: The current study provides new insights regarding the antihormone (P4 & RU486) drug design and vaccine therapy of recombinant (rTs-MAPRC2) protein as well as their combined effects to control T. spiralis infection.