The cell-mediated immune response to Neospora caninum during pregnancy in the mouse is associated with a bias towards production of interleukin-4

• Published in: International journal for parasitology 2004-05, Vol.34 (6), p.723-732
• Main Authors: Quinn, H.E., Miller, C.M.D., Ellis, J.T.
• Format: Article
• Language: English
• Subjects: animal parasites and pests; Animals; Biological and medical sciences; cell-mediated immunity; Cells, Cultured; Coccidiosis - immunology; Cytokine; Experimental protozoal diseases and models; Female; Fundamental and applied biological sciences. Psychology; Immunity; Immunity, Cellular - immunology; Immunoglobulin G - biosynthesis; Infectious diseases; Interferon-gamma - biosynthesis; interferons; Interleukin-10 - biosynthesis; interleukin-12; Interleukin-12 - biosynthesis; interleukin-4; Interleukin-4 - biosynthesis; interleukins; Medical sciences; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; Mice; Neospora - immunology; Neospora caninum; neosporosis; Parasitic diseases; Pregnancy; Pregnancy Complications, Infectious - immunology; Protozoal diseases; Spleen - immunology; splenocytes; Tumor Necrosis Factor-alpha - biosynthesis; tumor necrosis factors; Vectors. Intermediate hosts
• ISSN: 0020-7519; 1879-0135
• DOI: 10.1016/j.ijpara.2004.01.007

Neospora caninum is an obligate intracellular protozoan parasite which is efficiently transmitted transplacentally in cattle where it may cause abortion. A pregnant mouse model was used to characterise the immune response following N. caninum infection; the response in non-pregnant and pregnant mice was compared. Spleen cells from both infected/non-pregnant and infected/pregnant mice produced interferon-γ, interleukin-12 and tumour necrosis factor α; however, the levels of these Th1 cytokines were lower in infected/pregnant mice. Infected/non-pregnant and infected/pregnant mice also produced the Th2 cytokine interleukin-10; however, there was no trend toward a decrease of this in pregnant mice. Interleukin-4 was exclusively produced at high levels by infected/pregnant mice and thus appears responsible for the observed decline in Th1 cytokine production in pregnant mice. A bias towards Th2 cytokines such as IL-4 and IL-10 is normally associated with the maintenance of a viable pregnancy, and not with the control of protozoal infections. Consequently, the importance and role of cytokines and cell-mediated immunity in the control of transplacental transmission and foetal loss due to N. caninum infection are discussed.