A study to examine the immunostimulatory properties of Leishmania infantum Hsp83 (83) to elicit humoral and cellular response against the Toxoplasma gondii Rop2 protein in an adjuvant-free vaccination system was conducted. Mice immunized with fusion Rop2-83 elicited a stronger humoral and cellular response in comparison to mice immunized with Rop2 alone, or a mix of LiHsp83 and Rop2. The fusion protein induced a Th1 type response, with predominance of specific IgG2a/IgG2c isotype and IFN-gamma secretions, whereas Rop2 alone or mixed with LiHsp83 produced a Th1/Th2 mixed response. Vaccination with fusion protein conferred a remarkable resistance against oral infection with ME49 cysts in C57BL/6 and C3H mice, in comparison to mice immunized with Rop2 alone or the protein mixture. Following lethal challenge, a significant survival rate was observed in Rop2-83 immunized Balb/c and C57BL/6 mice in comparison to control groups (Echeverria et al., 2006).
Echeverria et al., 2006: Echeverria PC, de Miguel N, Costas M, Angel SO. Potent antigen-specific immunity to Toxoplasma gondii in adjuvant-free vaccination system using Rop2-Leishmania infantum Hsp83 fusion protein. Vaccine. 2006; 24(19); 4102-4110. [PubMed: 16545504].