Characterization of a Trichinella spiralis cathepsin X and its promotion for the larval invasion of mouse intestinal epithelial cells.

• TsCX gene was transcribed and expressed at diverse Trichinella spiralis stages. • There was a specific binding between TsCX and intestinal epithelial cells (IEC). • TsCX binding to IEC was located in IEC cytoplasm. • rTsCX promoted T. spiralis larva invasion of IEC. • TsCX is a potential target of vaccines against T. spiralis enteral stages. The aim of this study was to ascertain the characteristics of a Trichinella spiralis cathepsin X (TsCX) and its role on larval invasion of intestinal epithelial cells (IECs). The full-length of TsCX cDNA sequence was cloned and expressed in Escherichia coli BL21. The results of RT-PCR, IFA and Western blot revealed that TsCX was expressed at T. spiralis muscle larvae (ML), intestinal infective larvae, adult worm and newborn larvae, and it was located in whole worm section. The results of Far western and confocal microscopy demonstrated that there was a specific binding of rTsCX and IEC, and the binding site was located within the IEC cytoplasm. rTsCX promoted T. spiralis larval invasion of mouse IECs while anti-rTsCX antibody inhibited larval invasion into the IECs. Silencing TsCX by specific siRNA reduced the TsCX expression and larval invasive capacity. These results indicated that TsCX specifically binds to IECs and promotes larval invasion of intestinal epithelia, and it might be a potential target of vaccines against enteral stages of T. spiralis. [ABSTRACT FROM AUTHOR]