Bioinformatics Analysis And Evaluation Of Immune Responses In Murine After DNA Vaccines Based On Toxoplasma Gondii GRA16 And NF3 Gene

Toxoplasma gondii,an obligate intracellular protozoan,which is responsible for a widespread opportunistic toxoplasmosis for all warm-blooded animals.As so far,nearly one third of the world population was reported to be T.gondii seroprevalence.Because of its complex polymorphic life cycle and the host's diversity,there are no available and safe drugs against T.gondii.Therefore,it's urgent to development the effective vaccine to against T.gondii infection.Toxoplasma gondii dense granule protein 16(TgGRA 16)can restrict the inflammatory response in the host through maintaining levels of p53,which is a key molecule in controlling the inflammation during glucocorticoid responses via regulation of the expression of NF-?B gene.TgGRA 16 is also considered a virulent factor for T.gondii genotype II strains with functions related to metabolism and cell cycle regulation.Toxoplasma gondii nuclear factor 3(TgNF3)is localized in the nucleus ofT.gondii,belongs to a characteristic member ofT.godii nuclear factors,a regulator of parasite transcription,metabolism and translation.The gene encoding TgNF3 is confined to both virulent tachyzoties and avirulent bradyzoties of T.gondii,and has the ability to regulate the levels of transcription and translations.TgNF3,as.a dynamic chromatin-associated component,play a significant role in regulating nucleolar architecture and modulating parasite virulence.However,to evaluate whether TgGRA16 and TgNF3 genes are suitable for developing the plasmid vaccines against T.Gondii.A first,the sequence variation on TgGRA16 and TgNF3 genes were analyzed amongT.gond T.isolates from different hosts and geographical regions.Then TgNF3 gene sequences were translated into amino acid sequences,furthermore,the structure and its potential epitopes were analyzed by using multiple bioinformatics approaches.The result indicated that there are mainly 6 and 9 potential epitopes in TgGRA 16 and TgNF3 proteins,suggesting that TgGRA 16,TgNF3 gene were not the ideal marker for studying genetic relationships of T.gondii isolates,but may represent the good vaccines candidate against toxoplasmosis.In the end,we constructed the DNA vaccines expressing Toxoplasma gondii dense granule protein 16(GRA16)and Toxoplasma gondii nuclear factor(TgNF3),respectively.Then further explored its protective efficacy against Tgondii infection in Kunming mice.The mice were immunized with recombinant DNA plasmid pVAX-GRA16,pVAX-NF3 by intramuscular route.After 6 weeks of the last immunization,this resulted showed that mice immunized with pVAX-GRA16,pVAX-NF3 can elicited a high level of specific humeral antibodies and specific lymphocyte proliferative responses.The DNA vaccination generated a mixed Th1/Th2 response.Those results revealed TgGRA16 and TgNF3 should be regarded as the promising vaccine candidates for further development of an effective vaccine against chronic T.gondii or acute T.gondii infection in Kunming mice.