title: Recombinant GRA4 or ROP2 protein combined with alum or the gra4 gene provides partial protection in chronic murine models of toxoplasmosis.
abstract: The efficacy of vaccination with Toxoplasma gondii recombinant GRA4 (rGRA4) and ROP2 (rRPO2) proteins and a mix of both combined with alum were evaluated in C57BL/6 and C3H mice. In C57BL/6 mice, rGRA4 and rGRA4-rROP2 immunizations generated similar levels of immunoglobulin G1 (IgG1) and IgG2a isotypes against GRA4, whereas immunizations with rROP2 and the mix induced a predominant IgG1 production against ROP2. All groups of C3H vaccinated mice exhibited higher levels of IgG1 than IgG2a. rGRA4-stimulated splenocytes from vaccinated mice produced primarily gamma interferon while those stimulated with rROP2 produced interleukin-4. Challenge of rGRA4- or rGRA4-rROP2-vaccinated mice from both strains with ME49 cysts resulted in fewer brain cysts than the controls, whereas vaccination with rROP2 alone only conferred protection to C3H mice. Immunization with a plasmid carrying the entire open reading frame of GRA4 showed a protective level similar to that of rGRA4 combined with alum. These results suggest that GRA4 can be a good candidate for a multiantigen anti-T. gondii vaccine based on the use of alum as an adjuvant.
authors.affiliation: Departamento de Parasitología, Instituto Nacional de Enfermedades Infecciosas, ANLIS Dr. Carlos G. Malbran, Ciudad de Buenos Aires, Argentina.
authors.forename: Valentina
authors.initials: V
authors.lastname: Martin
authors.forename: Alicia
authors.initials: A
authors.lastname: Supanitsky
authors.forename: Pablo C
authors.initials: PC
authors.lastname: Echeverria
authors.forename: Silvana
authors.initials: S
authors.lastname: Litwin
authors.forename: Tamara
authors.initials: T
authors.lastname: Tanos
authors.forename: Adolfo R
authors.initials: AR
authors.lastname: De Roodt
authors.forename: Eduardo A
authors.initials: EA
authors.lastname: Guarnera
authors.forename: Sergio O
authors.initials: SO
authors.lastname: Angel
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000534:Alum Compounds / Q000494:pharmacology*; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001921:Brain / Q000473:pathology; D003560:Cysts / Q000276:immunology / Q000473:pathology; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D008565:Membrane Proteins / Q000276:immunology*; D051379:Mice; D015800:Protozoan Proteins / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology*; D014122:Toxoplasma / Q000235:genetics / Q000276:immunology; D014124:Toxoplasmosis, Animal / Q000517:prevention & control*; D014611:Vaccination; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D000534:Alum Compounds; D000913:Antibodies, Protozoan; C079248:GRA4 protein, Toxoplasma gondii; D007074:Immunoglobulin G; D008565:Membrane Proteins; D015800:Protozoan Proteins; C090555:ROP 2 protein, Toxoplasma gondii; D011994:Recombinant Proteins; D019444:Vaccines, DNA; D015847:Interleukin-4; C041524:aluminum sulfate; D007371:Interferon-gamma