Immune responses in pregnant cattle and bovine fetuses following experimental infection with Neospora caninum.
Humoral and cell-mediated immune (CMI) responses [i.e. proliferative responses and gamma interferon (IFN-gamma) production], were elicited in five cows infected between 159 and 169 days of gestation by a combined intravenous-intramuscular inoculation of Neospora caninum tachyzoites. Analysis of antigen-specific immunoglobulin (IgG) subclasses revealed a predominant IgG2 response in two cows, a mixed IgG1-IgG2 response in two other cows and a predominant IgG1 response in one cow. No correlation was found between IgG2 titers and IFN-gamma levels. CD4-T cells were responsible for the CMI responses in peripheral blood mononuclear cells from three infected cows. All five fetuses removed from infected dams at week 9 post-infection (219-231 days of gestation) mounted strong Neospora-specific humoral responses and had a predominant IgG1 response, regardless of their ability to produce IFN-gamma. However, CMI responses were highly variable between fetuses. These data indicate the complexity of the immune mechanisms associated with Neospora infection in both the dams and their fetuses.
Andrianarivo
A G
AG
Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis 95616, USA.
Barr
B C
BC
Anderson
M L
ML
Rowe
J D
JD
Packham
A E
AE
Sverlow
K W
KW
Conrad
P A
PA
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology* / Q000469:parasitology; D003048:Coccidiosis / Q000276:immunology* / Q000469:parasitology / Q000662:veterinary*; D005260:Female; D005333:Fetus / Q000276:immunology*; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000097:blood; D018688:Neospora / Q000276:immunology*; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G