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Objective Toxoplasma gondii is a ubiquitous protozoan intracellular parasite, the causative agent of toxoplasmosis, and a worldwide zoonosis.Apical membrane antigen-1 (AMA1) and rhoptry neck protein (RON2, RON4) are involved in the invasion of T.gondii.This study chemically synthesized peptides of TgAMA1, TgRON2 and TgRON4 that contained the T-and B-cell epitopes predicted by bioinformatics analysis.We evaluated the systemic response by proliferation, cytokine and antibody measurements as well as the mucosal response by examining the levels of antigen-specific secretory IgA (SIgA) in the nasal, vesical and intestinal washes obtained from mice after nasal immunization with single (AMA1, RON2, RON4) or mixtures of peptides (A1+R2, A1+R4, R2+R4, A1+R2+R4).We also assessed the parasite burdens in the liver and brain as well as the survival of mice challenged with a virulent strain.The results showed that the mice immunized with single or mixed peptides produced effective mucosal and systemic immune responses with a high level of specific antibody responses, a strong lymphoproliferative response and significant levels of gamma interferon (IFN-γ), interleukin-2 (IL-2) and IL-4 production.These mice also elicited partial protection against acute and chronic T.gondii infection.Moreover, our study indicated that mixtures peptides, especially the A1+R2 mixture, were more powerful and efficient than any other single peptides.These results demonstrated that intranasal immunisation with peptides of AMA1, RON2 and RON4 containing T-and B-cell epitopes can partly protect mice against toxoplasmosis, and a combination of peptides as a mucosal vaccine strategy is essential for future Toxoplasma vaccine development.