Cloning and Expression of a New Trichinella spiralis Serine  Protease and Its Role in Invading Host Intestinal Epithelium

Fang Liu; Yan Yan Song; Ru Zhang; Ruo Dan Liu; Peng Jiang; Jing Cui; Zhong Quan Wang

doi:10.18502/ijpa.v17i3.10628

Fang Liu Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, P. R. China
Yan Yan Song Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, P. R. China
Ru Zhang Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, P. R. China
Ruo Dan Liu Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, P. R. China
Peng Jiang Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, P. R. China
Jing Cui Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, P. R. China
Zhong Quan Wang Department of Parasitology, Medical College, Zhengzhou University, Zhengzhou, P. R. China

DOI: https://doi.org/10.18502/ijpa.v17i3.10628

Keywords: Trichinella spiralis; Serine protease 1.1; Intrusion; Intestinal epithelium

Abstract

Background: In previous studies, a new Trichinella spiralis serine protease 1.1 (TsSP1.1) was identified in surface proteins of T. spiralis muscle larvae (ML) by proteomics analysis, but its functions in T. spiralis infection are unknown. The aim of this study was to investigate the roles of TsSP1.1 during larval intrusion of gut epithelium.

Methods: From January 2019 to March 2021, complete TsSP1.1 cDNA sequence was cloned and expressed in Escherichia coli BL21 at the Department of Parasitology, Medical College of Zhengzhou University, Zhengzhou, China. Expression and location of TsSP1.1 in the parasite were investigated using indirect immunofluorescence assay (IIFA) and Western blotting. The in vitro intestinal epithelium cells (IECs) intrusion assay was used to ascertain the roles of TsSP1.1 during larval intrusion of IECs and gut epithelium.

Results: TsSP1.1 was a surface and secretory protein, which was expressed at various T. spiralis stages, and principally localized at cuticle, stichosome and embryos of the nematode. rTsSP1.1 accelerated larval intrusion of IECs, whereas anti-rTsSP1.1 antibodies impeded larval intrusion. The acceleration and inhibtion was dose-dependently related to rTsSP1.1 and anti-TsSP1.1 antibodies. Block of the IIL with anti-rTsSP1.1 serum also impeded larval intrusion of gut mucosa.

Conclusion: TsSP1.1 participates in T. spiralis intrusion of gut epithelium.