A vaccine based on exosomes secreted by a dendritic cell line confers protection against T. gondii infection in syngeneic and allogeneic mice

• Published in: Microbes and infection 2007-11, Vol.9 (14), p.1614-1622
• Main Authors: Beauvillain, Céline, Ruiz, Sophie, Guiton, Rachel, Bout, Daniel, Dimier-Poisson, Isabelle
• Format: Article
• Language: English
• Subjects: Adoptive Transfer; Animals; Antibodies, Protozoan - blood; Antigens, Protozoan - immunology; Applied microbiology; Biological and medical sciences; Cell Line; Cytoplasmic Vesicles - secretion; Dendritic cells; Dendritic Cells - immunology; Dendritic Cells - transplantation; Dendritic Cells - ultrastructure; Exocytosis; Exosomes; Female; Fundamental and applied biological sciences. Psychology; Life Sciences; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Inbred CBA; Microbiology; Protozoan Vaccines - administration & dosage; Protozoan Vaccines - immunology; Toxoplasma; Toxoplasma - immunology; Toxoplasma - pathogenicity; Toxoplasma gondii; Toxoplasmosis, Animal - immunology; Toxoplasmosis, Animal - prevention & control; Transplantation, Homologous; Transplantation, Isogeneic; Vaccine; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects)
• ISSN: 1286-4579; 1769-714X
• DOI: 10.1016/j.micinf.2007.07.002

Our results show that exosomes secreted by SRDC pulsed in vitro with Toxoplasma gondii-derived antigens (Exo-TAg) induced protective responses against infection with the parasite in both syngeneic and allogeneic mice. After oral infection, syngeneic CBA/J mice exhibited significantly fewer cysts in their brains and allogeneic C57BL/6 mice survived. This protection was associated with strong humoral responses in vivo in serum from both CBA/J and C57BL/6 mice, and with high levels of anti-TAg IgA antibodies in intestinal secretions from CBA/J mice alone. Furthermore, strong cellular responses in vivo were observed in both mouse models. Cellular proliferation was associated with cytokines production by spleen and mesenteric lymph node cells. The results presented here show that exosomes are nucleic acid free vesicles that are able to induce immune responses correlated with protection against parasitic infections in both syngeneic and allogeneic mice. They could constitute an efficient tool for use in vaccination and antitumor strategies based on exosomes.