Toxoplasma gondii ?-amylase deletion mutant is a promising vaccine against acute and chronic toxoplasmosis.

ABSTRACT: Individuals with inhibited immunity may develop lethal toxoplasmosis; thus, a safe and effective vaccine is urged to be developed. Toxoplasma gondii (T. gondii) ?-amylase (?-AMY) is one of the enzymes responsible for starch digestion. In the present study, we first generated a ME49??-amy mutant and discovered that loss of ?-AMY robustly grew in vitro but contributed to significant virulence attenuation in vivo. Therefore, we established a mouse model to explore the protective immunity of ??-amy mutant against acute and chronic toxoplasmosis. The results indicated that the survival rates of short-term or long-term immunized mice re-infected with the tachyzoites of multiple T. gondii strains were nearly 100%. ME49??-amy not only could provide protective immunity against tachyzoites infection but also could resist the infection of tissue cysts. Furthermore, we detected that ME49??-amy vaccination could effectively eliminate the proliferation of parasites in mice and prevent the formation of cysts. The significant increases of Th1-type cytokines, Th2-type cytokines and specific total IgG and IgG subclasses (IgG2a and IgG1) confirmed efficiency of a combination of cellular and humoral immunity against infection. In conclusion, ME49??-amy attenuated strain can produce strong immune responses to provide efficient protection against toxoplasmosis, which signifies that ME49??-amy mutant may be a potential vaccine candidate.

SUBMITTER: Yang J 

PROVIDER: S-EPMC7533317 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature