title: Mic1-3KO tachyzoite a live attenuated vaccine candidate against toxoplasmosis derived from a type I strain shows features of type II strain.
abstract: Vaccination with live attenuated parasites has been shown to induce high level of protection against Toxoplasma gondii. In this study we compared the Mic1-3KO tachyzoite (a live attenuated strain) with the parental wild type (WT) tachyzoite in terms of virulence in mice in vivo, dissemination in mouse tissues and persistence in mouse brain. Survival of mice infected with the Mic1-3KO parasites correlated with reduced parasite burden in mouse tissues compared to the parental strain. Like the WT parasite, Mic1-3KO is able to form tissue cysts in vivo which are not, in our experimental conditions, infectious when given by oral route. Infection with the attenuated tachyzoite induced lower levels of cytokine and chemokine than with the parental strain. These data demonstrate that the deleted strain derived from a type I strain behaves like type II strain in outbred mice in terms of virulence, dissemination in mouse tissue and persistence in brain.
authors.affiliation: Université François Rabelais de Tours, INRA UMR Université-INRA d'Immunologie Parasitaire et Vaccinologie, Biothérapie anti-infectieuse, IFR agents transmissibles et infectiologie, UFR de Pharmacie, Parc Grandmont, Tours, France. nathalie.moire@univ-tours.fr
authors.forename: Nathalie
authors.initials: N
authors.lastname: Moiré
authors.forename: Sarah
authors.initials: S
authors.lastname: Dion
authors.forename: Maryse
authors.initials: M
authors.lastname: Lebrun
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Dubremetz
authors.forename: Isabell
authors.initials: I
authors.lastname: Dimier-Poisson
mesh_terms: D000818:Animals; D001921:Brain / Q000469:parasitology; D015815:Cell Adhesion Molecules / Q000172:deficiency / Q000235:genetics*; D018925:Chemokines / Q000096:biosynthesis; D016207:Cytokines / Q000096:biosynthesis; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D051379:Mice; D008808:Mice, Inbred CBA; D015800:Protozoan Proteins / Q000235:genetics*; D016052:Protozoan Vaccines / Q000009:adverse effects / Q000145:classification / Q000276:immunology; D014122:Toxoplasma / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D014124:Toxoplasmosis, Animal / Q000401:mortality / Q000469:parasitology / Q000517:prevention & control*; D014613:Vaccines, Attenuated / Q000009:adverse effects / Q000145:classification / Q000276:immunology; D014774:Virulence
chemical_list: D015815:Cell Adhesion Molecules; D018925:Chemokines; D016207:Cytokines; C105877:MIC1 protein, Toxoplasma gondii; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D014613:Vaccines, Attenuated