The survey on Toxoplasma gondii antigens for selection of the best vaccine candidates against toxoplasmosis

Toxoplasma gondii is an obligate intracellular parasite belonging to the phylum Apicomplexa with an exceptionally broad host range such as most species of domestic animals, birds and humans in most parts of the world. Despite our increasing knowledge about T. gondii, we still have a very limited number of treatments to control tachyzoite and cyst stages. Therefore, the development of a effective vaccine would be extremely valuable in fighting against T. gondii infection. Data were systematically collected from the six databases including PubMed, Science Direct, Web of Science, Google Scholar, EBSCO and Scopus. Articles with information on infective stage, pathogenicity, immunogenicity and characterization of antigens were selected. A total of 134 articles were eligible for inclusion criteria in the current systematic review. Evaluation within this systematic review indicates that MIC 3, 4, 13, ROP 2, RON 5, GRA 1, 6, 8,14 are expressed in all three infective stages and have pathogenicity and immunogenicity. MIC 5, ROM 4, GRA 2,4, 15, ROP 5, 16, 17, 38, RON 4, MIC 1, GRA 10, 12, 16, SAG 3 are expressed in only tachyzoites and bradyzoites stages of T. gondii with pathogenicity/immunogenicity. Some antigens appeared to be expressed in a single stage (tachyzoites) but have high pathogenicity and induce immune response. They include enolase2 (ENO2), SAG 1, SAG5D, HSP 70, ROM 1, ROM 5, AMA 1, ROP 18, RON2 and GRA 24. In conclusion, we considered that the ideal and significant vaccines should include a high pathogenicity and immunogenicity and been expressed in all infective stages of the parasite. So, the inroduced antigens in this study are best candidates for use as vaccine and provided a promising approach for protecting humans and animals against toxoplasmosis.

کلیدواژه ها:

Toxoplasma gondii ، Vaccines ، Antigens ، Infective stage ، Pathogenicity ، Immunogenicity