Porcine Coccidiosis – Investigations on the Cellular Immune Response against Isospora suis
Porcine neonatal coccidiosis is caused by the protozoan Isospora suis and affects mainly piglets in the first three weeks of life. High morbidity with diarrhoea and reduced weight gain lead to economic losses, affecting pig-breeding worldwide. Infection causes damage of the mucosal surface in the jejunum and ileum and transient non-haemorhagic diarrhoea. Secondary infections with other enteric pathogens may lead to increased mortality. Despite its economic and veterinary importance, the immunology of porcine isosporosis is still poorly understood. A striking feature of the infection is the rapidly increasing age resistance prohibiting the development of clinical disease in piglets older than 3–4 weeks irrespective of the immune status. It can be hypothesised that the development of the innate immune system in the first weeks of life and subsequently its interplay with the adaptive immune system is closely related to this phenomenon. Infections with I. suis induce migration of TcR-γδ+ cells to the gut during primary infection and lead to induction of IFN-γ production by TcR-γδ+ cells and CD4+ T-helper cells in blood and various lymphoid tissues. Like in other coccidial infections both innate as well as adaptive response mechanisms are activated during infection. They might be both not completely developed in the first weeks of life and therefore leaving a time frame for successful infection.
Unable to display preview. Download preview PDF.
- Baekbo P, Christensen J, Henriksen SA, Nielsen K (1994) Attempts to induce colostral immunity against Isospora suis infections in piglets. Proceedings of the 13th IPVS Congress, Bangkok, Thailand, 26–30 June 1994:13.Google Scholar
- Lindsay DS, Blagburn BL, Powe TA (1992) Enteric coccidial infections and coccidiosis in swine. Comp Cont Ed Pract Vet 14:698–702.Google Scholar
- Roberts SJ, Smith AL, West AB, Wen L, Findly RC, Owen MJ, Hayday AC (1996) T-cell alpha beta + and gamma delta + deficient mice display abnormal but distinct phenotypes toward a natural, widespread infection of the intestinal epithelium. Proc Natl Acad Sci USA 93:11774–11779.PubMedCrossRefGoogle Scholar
- Seydel KB, Zhang T, Champion GA, Fichtenbaum C, Swanson PE, Tzipori S, Griffiths JK, Stanley SL Jr (1998) Cryptosporidium parvum infection of human intestinal xenografts in SCID mice induces production of human tumor necrosis factor alpha and interleukin-8. Infect Immun 66:2379–2382.PubMedGoogle Scholar
- Taylor JR (1984) Immune response of pigs to Isospora suis (Apicomplexa, Eimeriidae). Dissertation, Auburn University, Auburn, Alabama.Google Scholar
- Wakelin D, Rose M (1990) Immunity to coccidiosis. Coccidiosis of man and domestic animals. Long PL. CRC Press, Inc, Boca Raton.Google Scholar
- Worliczek HL, Buggelsheim M, Alexandrowicz R, Witter K, Schmidt P, Gerner W, Saalmüller A, Joachim A (2009) Changes in lymphocyte populations in suckling piglets during primary infections with Isospora suis. (submitted).Google Scholar