Immunogenicity and Protective Effect of a Virus-Like Particle Containing the SAG1 Antigen of Toxoplasma gondii as a Potential Vaccine Candidate for Toxoplasmosis.

Won Hyung Choi,Ji Sun Park

doi:10.3390/biomedicines8040091

Abstract

This study was carried out to evaluate the vaccination effect of a virus-like particle (VLP) including the surface antigen 1 (SAG1) of Toxoplasma gondii as a potential vaccine for toxoplasmosis. The SAG1 virus-like particles (SAG1-VLPs) were expressed by Sf9 cells, and their expression was confirmed through cloning, RT-PCR analysis, and western blot method. The immunogenicity and vaccine efficacy of SAG1-VLPs were assessed by the antibody response, cytokine analysis, neutralization activity, splenocyte assay, and survival rates through a mouse model. In particular, IgG, IgG1, IgG2a, and IgA were markedly increased after immunization, and the survival rates of T. gondii were strongly inhibited by the immunized sera. Furthermore, the immunization of SAG1-VLPs effectively decreased the production of specific cytokines, such as IL-1β, IL-6, TNF-α, and IFN-γ, after parasite infection. In particular, the immunized group showed strong activity and viability compared with the non-immunized infection group, and their survival rate was 75%. These results demonstrate that SAG1-VLP not only has the immunogenicity to block T. gondii infection by effectively inducing the generation of specific antibodies against T. gondii, but is also an effective antigen delivery system for preventing toxoplasmosis. This study indicates that SAG1-VLP can be effectively utilized as a promising vaccine candidate for preventing or inhibiting T. gondii infection.

Highlights

Until recently, infectious diseases such as dengue fever, yellow fever, influenza, malaria, middle east respiratory syndrome (MERS), Zika fever, and Ebola have consistently occurred in various countries in the world, which has been causing a serious global threat to many countries and humans.a new coronavirus has recently emerged in Wuhan city of China, which has the potential to spread as a serious pandemic worldwide through contact and interaction between humans
The results of this study provide the accurate information on virus-like particle (VLP) through their molecular weight when matrix protein 1 includes or does not include the specific antigen as spikes, which indicates the potential and utility of them as an antigen delivery system of vaccination for preventing T. gondii infection
These results show that surface antigen 1 (SAG1)-VLPs increase the protective actions and immunogenicity against T. gondii infection by effectively inducing the production of specific antibodies through the first and second immunization, and induce or accelerate the progressive maturation of antibodies generated through the immune system

Summary

Introduction

Infectious diseases such as dengue fever, yellow fever, influenza, malaria, middle east respiratory syndrome (MERS), Zika fever, and Ebola have consistently occurred in various countries in the world, which has been causing a serious global threat to many countries and humans.a new coronavirus has recently emerged in Wuhan city of China, which has the potential to spread as a serious pandemic worldwide through contact and interaction between humans. Zoonosis induces very serious diseases in human society. From this perspective, Toxoplasma gondii is a parasite that is found in all warm-blooded animals, including birds and marine animals. T. gondii is a zoonotic parasite that induces toxoplasmosis in humans by consuming raw or undercooked meat, and by being infected via physical contact with feces of pets and companion animals such as cats. Gondii is a zoonotic parasite that induces toxoplasmosis in humans by consuming raw or undercooked meat, and by being infected via physical contact with feces of pets and companion animals such as cats It causes serious chronic diseases through its infection at all ages, including both adults and young children. T. gondii has similar intracellular organelles, such as eukaryotic cells, and includes various and unique micro-organelles, such as rhoptries, Biomedicines 2020, 8, 91; doi:10.3390/biomedicines8040091 www.mdpi.com/journal/biomedicines

Methods

Results

Discussion

Conclusion