The immune protection induced by a serine protease from the Trichinella spiralis adult against Trichinella spiralis infection in pigs

PLoS Negl Trop Dis. 2021 May 10;15(5):e0009408. doi: 10.1371/journal.pntd.0009408. eCollection 2021 May.

Abstract

Trichinellosis is a major foodborne parasitosis caused by Trichinella spiralis. In the present study, a serine protease gene from an adult T. spiralis (Ts-Adsp) cDNA library was cloned, expressed in Escherichia coli and purified by Ni-affinity chromatography. Previous studies of our laboratory have found that mice vaccinated with recombinant Ts-Adsp protein (rTs-Adsp) exhibited partial protection against T. spiralis infection. In this study, the protective effect of rTs-Adsp against T. spiralis infection in pigs was further explored. The cell-mediated and humoral immune responses induced by rTs-Adsp were measured, including the dynamic trends of specific antibody levels (IgG, IgG1, IgG2a and IgM), as well as the levels of cytokines (IFN-γ, IL-2, IL-4, and IL-10) in the serum. Moreover, the changes in T lymphocytes, B lymphocytes, and neutrophils were measured to evaluate cellular immune responses in pigs vaccinated with rTs-Adsp. The results indicated that a Th1-Th2 mixed immune response with Th1 predominant was induced by rTs-Adsp after vaccination. Flow cytometric analysis showed that the proportions of CD4+ T cells, B cells, and neutrophils in the immunized groups were significantly increased. Furthermore, pigs vaccinated with rTs-Adsp exhibited a 50.9% reduction in the muscle larvae burden, compare with pigs from the PBS group five weeks after challenged. Our results suggested that rTs-Adsp elicited partial protection and it could be a potential target molecule for preventing and controlling Trichinella transmission from pigs to human.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Helminth
  • Cytokines / blood
  • Helminth Proteins / genetics
  • Helminth Proteins / immunology
  • Immunity, Cellular
  • Immunity, Humoral
  • Muscles / parasitology
  • Serine Proteases / genetics
  • Serine Proteases / immunology*
  • Sus scrofa
  • Swine
  • Swine Diseases / immunology*
  • Swine Diseases / prevention & control
  • Trichinella spiralis / enzymology*
  • Trichinella spiralis / genetics
  • Trichinella spiralis / growth & development
  • Trichinellosis / immunology
  • Trichinellosis / veterinary*
  • Vaccination / veterinary

Substances

  • Antibodies, Helminth
  • Cytokines
  • Helminth Proteins
  • Serine Proteases

Grants and funding

MYL was supported by the National Key Research and Development Program of China (2018YFC1602500); National Natural Science Foundation of China (NSFC 31872467, 31520103916); Jilin Provincial Science and Technology Development Project (20180520042JH); and Program for JLU Science and Technology Innovative Research Team(2017TD-32). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.