Relationship between type 1/type 2 immune responses and occurrence of vertical transmission in BALB/c mice infected with Neospora caninum.
To examine the relationship between occurrence of vertical transmission and type 1/type 2 immune responses induced by Neospora caninum infection in BALB/c mice, pregnant (group 1 p) and non-pregnant mice (group 1 np) were inoculated with 2 x 10(6) of the N. caninum parasites and then we examined the vertical transmission rate and production of IFN-gamma and IL-4. We also studied chronically infected mice, which were bred at 4 weeks or more after infection (group 2), and mice inoculated during pregnancy and re-bred at 4 weeks or more after delivery (group 3). In groups 1p, 2 and 3, vertical transmission was observed in 27.4, 41.4, and 50% of the offspring, respectively. The serum IFN-gamma level increased on days 1 and 5 post-inoculation (p.i.) in groups 1 p and 1 np, while no increase level was observed in groups 2 and 3 during pregnancy or after delivery. When the mice in groups 2 and 3 were re-inoculated, all mice showed a transient increase in serum IFN-gamma on day 1 post-re-inoculation. The serum IL-4 level in both of groups 1p and np increased in a similar manner following infection. In group 3, the serum IL-4 level was somewhat higher than that in group 2 after re-inoculation. The anti-N. caninum antibody IgG1 titer in group 3 increased on day 10 post-re-inoculation. These results suggest that the mice infected during pregnancy may acquire a weaker immune response to the parasite than mice infected when they are not pregnant, and that mice infected during pregnancy may show an enhanced type 2 immune response in the recrudescence of the infection.
Kano
R
R
Department of Basic Veterinary Science, School of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro 080-8555, Japan.
Masukata
Y
Y
Omata
Y
Y
Kobayashi
Y
Y
Maeda
R
R
Saito
A
A
D000818:Animals; D000831:Animals, Newborn; D003048:Coccidiosis / Q000453:epidemiology / Q000276:immunology / Q000635:transmission / Q000662:veterinary*; D004195:Disease Models, Animal; D005260:Female; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary*; D007371:Interferon-gamma / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D018688:Neospora / Q000276:immunology*; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000453:epidemiology / Q000276:immunology* / Q000469:parasitology
D015847:Interleukin-4; D007371:Interferon-gamma