Survival, immune responses and tissue cyst production in outbred (Swiss white) and inbred (CBA/Ca) strains of mice experimentally infected with Neospora caninum tachyzoitesChantal Rettignera, Thierry Leclipteuxb, François De Meerschmana, Charles Focanta and Bertrand Lossona
a Laboratory of Parasitology and Pathology of Parasitic Diseases, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, Boulevard de Colonster, 20, 4000 Liège, Belgium
b Coris Bioconcept, Science Park-Cassiopée, Rue Phocas Lejeune, 30 Bte 9, 5032 Gembloux, Belgium
(Received 15 July 2003; accepted 9 October 2003)
Abstract - The present work compared inbred (CBA/Ca) and outbred (Swiss white) strains of mice for their capacity to cope with a Neospora caninum infection and to consistently produce tissue cysts. In each experiment Swiss white and CBA/Ca mice were given three different doses of NC-1 tachyzoites. Lymphoproliferative and humoral responses as well as cytokine production were evaluated eight weeks after infection (PI) whereas tissue cyst production and histopathology were assessed 4, 6 and 10 weeks PI in immunosuppressed mice. Tissue cysts were observed 10 weeks after infection only in CBA/Ca mice receiving the two highest inoculum doses. Furthermore this strain showed the highest specific lymphoproliferative response. A mixed cytokine response with elevated IFN- and fairly low IL-4 and IL-10 secretion was recorded. In both strains, no lesions were observed in the tissues of infected mice. This study indicates that CBA/Ca female mice infected with 5 × 106 NC-1 tachyzoites represent a useful model for the study of specific maternal immune responses in pregnant animals.
Key words: Neospora caninum / immune response / resistance / cyst / mice
Corresponding author: Chantal Rettigner Chantal.Rettigner@ulg.ac.be
© INRA, EDP Sciences 2004