title: Vaccination with the recombinant chimeric antigen recNcMIC3-1-R induces a non-protective Th2-type immune response in the pregnant mouse model for N. caninum infection.
abstract: The major route of transmission of Neospora caninum in cattle is transplacentally from an infected cow to its progeny. Therefore, a vaccine should be able to prevent both the horizontal transmission from contaminated food or water and the vertical transmission. We have previously shown that a chimeric vaccine composed of predicted immunogenic epitopes of NcMIC3, NcMIC1 and NcROP2 (recNcMIC3-1-R) significantly reduced the cerebral infection in BALB/c mice. In this study, mice were first vaccinated, then mated and pregnant mice were challenged with 2×10(6)N. caninum tachyzoites at day 7-9 of pregnancy. Partial protection was only observed in the mice vaccinated with a tachyzoite crude protein extract but no protection against vertical transmission or cerebral infection in the dams was observed in the group vaccinated with recNcMIC3-1-R. Serological and cytokine analysis showed an overall lower cytokine level in sera associated with a dominant IL-4 expression and high IgG1 titers. Thus, the Th2-type immune response observed in the pregnant mice was not protective against experimental neosporosis, in contrary to the mixed Th1-/Th2-type immune response observed in the non-pregnant mouse model. These results demonstrate that the immunomodulation that occurs during pregnancy was not favorable for the protection against N. caninum infection conferred by vaccination with recNcMIC3-1-R.
authors.affiliation: Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, CH-3012 Berne, Switzerland. thierry.monney@vetsuisse.unibe.ch
authors.forename: Thierry
authors.initials: T
authors.lastname: Monney
authors.forename: Karim
authors.initials: K
authors.lastname: Debache
authors.forename: Denis
authors.initials: D
authors.lastname: Grandgirard
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Leib
authors.forename: Andrew
authors.initials: A
authors.lastname: Hemphill
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D003048:Coccidiosis / Q000276:immunology* / Q000517:prevention & control*; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D018688:Neospora / Q000276:immunology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000276:immunology / Q000517:prevention & control; D016052:Protozoan Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*; D014611:Vaccination / Q000379:methods; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000953:Antigens, Protozoan; D016052:Protozoan Vaccines; D014614:Vaccines, Synthetic