title: MyD88-dependent protective immunity elicited by adenovirus 5 expressing the surface antigen 1 from Toxoplasma gondii is mediated by CD8(+) T lymphocytes.
abstract: Toxoplasma gondii is an intracellular parasite widely spread around the world. The surface antigens (SAG) 1, 2 and 3 are the main proteins expressed on the surface of T. gondii tachyzoites. Replication-defective adenovirus serotype 5 (rAd5) is one of the most potent recombinant viral vectors for eliciting T cell-mediated immunity in mice and humans. Here we show that vaccination with rAd5 expressing SAG1 (AdSAG1), but neither SAG2 nor SAG3, induces protective immunity in the highly susceptible C57BL/6 mice challenged with T. gondii. Furthermore, we evaluated different immunological components involved on viral induced protective immunity. We observed that host protection elicited by AdSAG1 is highly dependent on IL-12, IFN-γ and CD8(+) T lymphocytes. Importantly, the induction of protective immunity (T cell-derived IFN-γ) was also dependent on Myeloid Differentiation Factor 88 (MyD88), and thus, likely to involve Toll-like Receptors. We conclude that protective parasite specific-CD8(+) T cells are elicited by a mechanism that involves MyD88-dependent induction of IL-12.
authors.affiliation: Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil.
authors.forename: Erica A
authors.initials: EA
authors.lastname: Mendes
authors.forename: Bráulia C
authors.initials: BC
authors.lastname: Caetano
authors.forename: Marcus L O
authors.initials: ML
authors.lastname: Penido
authors.forename: Oscar
authors.initials: O
authors.lastname: Bruna-Romero
authors.forename: Ricardo T
authors.initials: RT
authors.lastname: Gazzinelli
mesh_terms: D000256:Adenoviridae / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D000954:Antigens, Surface / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D053594:Myeloid Differentiation Factor 88 / Q000276:immunology / Q000378:metabolism*; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D014124:Toxoplasmosis, Animal / Q000276:immunology* / Q000469:parasitology / Q000517:prevention & control
chemical_list: D000953:Antigens, Protozoan; D000954:Antigens, Surface; D053594:Myeloid Differentiation Factor 88; D015800:Protozoan Proteins; D016052:Protozoan Vaccines