Protective Effect of a Prime-Boost Strategy with the Ts87 Vaccine againstTrichinella spiralisInfection in Mice

Abstract

Trichinellosis is a widespread zoonosis primarily caused byTrichinella spiralis. Mucosal immunity is crucial for preventingTrichinella spiralisinfection. In our previous study, a DNA vaccine with theTrichinellaantigen Ts87 delivered by an attenuatedSalmonella typhimuriumelicited partial protection againstTrichinella spiralisinfection in mice. In the current study, to elicit a more robust immune response and develop a potent vaccination strategy against trichinellosis, a heterologous prime-boost vaccination regimen for Ts87 was used in mice and the protective efficacy was evaluated compared to the homologous DNA prime-boost or protein prime-boost immunization alone. The results revealed that the DNA-prime/protein-boost vaccination with Ts87 induced higher levels of both humoral and cellular immune responses. The challenge results showed that mice with the DNA-prime/protein-boost vaccination displayed higher muscle larval reduction than those immunized with DNA prime-boost or protein prime-boost. The results demonstrated that mice vaccinated with Ts87 in a DNA-prime/protein-boost strategy effectively elicited a local IgA response and mixed Th1/Th2 immune response that might be responsible for improved protection againstTrichinella spiralisinfection.