Evaluation of vaccine candidate antigens in Toxoplasma gondii

Background and Aim : Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii. The parasite has infected almost a third of the world's population, and no suitable vaccine or drug is available. In this study, we examined vaccine candidate antigens in Toxoplasma gondii and reported the best antigens based on scores on the Vaxijen server.Methods : A Vaxquery server was used to find vaccine candidate antigens as well as their protein sequences. Toxicity and allergenicity of these antigens were evaluated with ToxinPred and AllerTOP v.۲.۰ servers, respectively, and finally, their antigenicity for the immune system was measured by the Vaxijen server.Results : A total of ۱۰ proteins GRA۵, hsp۷۰, MIC۱۳, MIC۳, OMPDC, P۳۰, Rop۲, ROP۸, SAG۲, and SOD were examined in this study, ۳ of which (MIC۳, P۳۰, and SAG۲) were identified as allergens, and all except GRA۵ had toxic sequences for humans. GRA۵, MIC۱۳, MIC۳, P۳۰, Rop۲, SAG۲, and SOD antigen scores for the human immune system were more significant than ۰.۵, which is an acceptable score.Conclusion : According to the results, GRA۵ protein with a Vaxijen score of ۱.۰۲۵۴ as the highest score and non-toxicity and non-allergenicity for humans is the best option for predicting epitopes and vaccine design.

Keywords:

Toxoplasmosis , Toxoplasma gondii , Vaccine