title: Use of a Th1 Stimulator Adjuvant for Vaccination against Neospora caninum Infection in the Pregnant Mouse Model.
abstract: Vertical transmission from an infected cow to its fetus accounts for the vast majority of new Neospora caninum infections in cattle. A vaccine composed of a chimeric antigen named recNcMIC3-1-R, based on predicted immunogenic domains of the two microneme proteins NcMIC1 and NcMIC3, the rhoptry protein NcROP2, and emulsified in saponin adjuvants, significantly reduced the cerebral infection in non-pregnant BALB/c mice. Protection was associated with a mixed Th1/Th2-type cytokine response. However, the same vaccine formulation elicited a Th2-type immune response in pregnant mice and did not prevent vertical transmission or disease, neither in dams nor in offspring mice. In this study, an alternative vaccine formulation containing recNcMIC3-1-R emulsified in Freund's incomplete adjuvant, a stimulator of the cellular immunity, was investigated. No protection against vertical transmission and cerebral infection in the pregnant mice and a very limited protective effect in the non-pregnant mice were observed. The vaccine induced a Th1-type immune response characterized by high IgG2a titres and strong IFN-γ expression, which appeared detrimental to pregnancy.
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.affiliation: Institute of Infectious Diseases, University of Berne, Friedbühlstrasse 51, CH-3010 Berne, Switzerland. denis.grandgirard@ifik.unibe.ch.
authors.forename: Denis
authors.initials: D
authors.lastname: Grandgirard
authors.affiliation: Institute of Infectious Diseases, University of Berne, Friedbühlstrasse 51, CH-3010 Berne, Switzerland. stephen.leib@babs.admin.ch.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Leib
authors.affiliation: Institute of Parasitology, Vetsuisse Faculty, University of Berne, Länggass-Strasse 122, CH-3012 Berne, Switzerland. andrew.hemphill@vetsuisse.unibe.ch.
authors.forename: Andrew
authors.initials: A
authors.lastname: Hemphill