Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 18 3 2023 09 22 301 312 Zahra Hosseininejad Toxoplasmosis Research Center, Communicable Disease Institute, Mazandaran University of Medical Sciences, Sari, Iran 2. Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran Ahmad Daryani Toxoplasmosis Research Center, Communicable Disease Institute, Mazandaran University of Medical Sciences, Sari, Iran Mahdi Fasihi-Ramandi Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran Hossein Asgarian-Omran Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran a Reza Valadan Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran Tooran Nayeri Toxoplasmosis Research Center, Communicable Disease Institute, Mazandaran University of Medical Sciences, Sari, Iran 2. Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran Samira Dodangeh Department of Medical Parasitology and Mycology, Medical Microbiology Research Center, Qazvin University of Medical Sciences, Qazvin, Iran Shahabeddin Sarvi Toxoplasmosis Research Center, Communicable Disease Institute, Mazandaran University of Medical Sciences, Sari, Iran 2022 06 20 2023 09 22 Background: We aimed to design a B and T cell recombinant protein vaccine of Toxoplasma gondii with in silico approach. MIC13 plays an important role in spreading the parasite in the host body. GRA1 causes the persistence of the parasite in the parasitophorous vacuole. SAG1 plays a role in host-cell adhesion and cell invasion. Methods: Amino acid positions 73-272 from MIC13, 71-190 from GRA1, and 101-300 from SAG1 were selected and joined with linker A(EAAAK)A. The structures, antigenicity, allergenicity, physicochemical properties, as well as codon optimization and mRNA structure of this recombinant protein called MGS1, were predicted using bioinformatics servers. The designed structure was synthesized and then cloned in pET28a (+) plasmid and transformed into Escherichia coli BL21. Results: The number of amino acids in this antigen was 555, and its antigenicity was estimated to be 0.6340. SDS-PAGE and Western blotting confirmed gene expression and successful production of the protein with a molecular weight of 59.56kDa. This protein will be used in our future studies as an anti-Toxoplasma vaccine candidate in animal models Conclusion: In silico methods are efficient for understanding information about proteins, selecting immunogenic epitopes, and finally producing recombinant proteins, as well as reducing the time and cost of vaccine design. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/3656 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/3656/1302