Molecular Characterization of Fructose-1,6-bisphosphate Aldolase From Trichinella spiralis and Its Potential in Inducing Immune Protection.

Yong Yang,Xue Bai,Mingyuan Liu,Chengyao Li,Xiaolei Liu,Mingwei Tong,Peihao Zhang,Wei Cai

doi:10.3389/fcimb.2019.00122

Abstract

Trichinella spiralis is a major food-borne parasite worldwide. Trichinellosis caused by T. spiralis is not only a public health problem, but also an economic hazard in food safety. The development of effective vaccines to prevent Trichinella infection in domestic animals and humans is urgently needed for controlling of this zoonosis. Fructose-1, 6-bisphosphate aldolase (FBPA) is involved in energy production in glycolysis and is also associated with many non-glycolysis functions in the parasite, such as adhesion to host cells, plasminogen binding, and invasion. FBPA has been considered as a potential vaccine candidate or as a target for chemotherapeutic treatment. Here, we report for the first time the characterization of FBPA of T. spiralis and an evaluation of its potential as a vaccine candidate antigen against T. spiralis infection in mice. The results of qPCR and western blot analysis showed that the Ts-FBPA gene was expressed at various developmental stages of T. spiralis and was also detected in excretory–secretory products (ES) of T. spiralis muscle larvae (ML). Immunostaining with anti-Ts-FBPA mouse sera indicated that it localized principally to the surface and embryos of this parasitic nematode. Vaccination of mice with recombinant Ts-FBPA (rTs-FBPA) resulted in a Th1/Th2 mixed humoral and cellular immune response with Th2 predominant, as well as remarkably elevated IgE levels. Moreover, mice vaccinated with rTs-FBPA displayed a 48.7% reduction in adult worm burden and 52.5% reduction in muscle larval burden. These studies indicated that Ts-FBPA is a promising target for developing an effective vaccine to prevent and control Trichinella infection.

Highlights

Trichinella spiralis (T. spiralis) can infect a wide variety of mammalian animals including humans, and it is one of the most widespread food-borne parasites throughout the world
The results revealed that Ts-FBPA is genetically relevant to Ts-FBPA from T. nativa and T. nelsoni, and is much closer to nematode FBPAs than vertebrate FBPAs
Enzymes associated with the glycolytic pathway that is used to generate energy in nematodes play important roles in parasite survival in the host

Summary

Introduction

Trichinella spiralis (T. spiralis) can infect a wide variety of mammalian animals including humans, and it is one of the most widespread food-borne parasites throughout the world. Human trichinellosis has been found in 66 countries and pork is the main source of occurrence of human Trichinella infection in China (Cui et al, 2011; Jiang et al, 2016). On account of extensive distribution of domesticated and wild animal reservoirs, as well as the sources of human trichinellosis, this foodborne parasitosis is hard to prevent and control (Bai et al, 2017). The development of effective vaccines against Trichinella infection in pigs and humans is a promising measures to control trichinellosis (Bai et al, 2017; Zhang et al, 2018)

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Conclusion