Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2002
Publication Date: N/A
Interpretive Summary: Limited information concerning basic immunobiology of livestock and poultry hinders rapid progress in the development of novel immunological control strategy against many diseases. Basic information concerning the immunology of how various lymphocytes of chickens respond to foreign antigens is needed in order to better understand host immune system in poultry. In this sreport, ARS scientists investigated the role of a major chicken cytokine, interleukin-2 (IL-2), which is produced by T-lymphocytes and is necessary for T lymphocyte proliferation following infection with coccidia parasites. Using the enzyme-linked immunoassay which is developed by ARS scientists, IL-2 production in serum and intestine was assessed and the results indicate that chicken IL-2 plays an important role in host protection against intracellular parasite infection. These findings will provide important knowledge that will be used for the development of immunological control method for this parasites.
Technical Abstract: Kinetic changes of interleukin (IL)-2 levels in serum, intestinal washing, and splenic culture supernatant were evaluated in chickens experimentally infected with Eimeria tenella using a monoclonal antibody-based antigen capture ELISA. The IL-2 levels in serum and concanavalin A- or E. tenella sporozoite-stimulated splenic lymphocyte culture supernatant from the infected chickens transiently increased on day 7 post primary infection an on day 2 post secondary infection compared to those of the uninfected chickens. At primary infection, the increases of IL-2 levels in serum and splenic lymphocyte culture supernatant coincided with the increase of the lesions in cecum, whereas, at secondary infection, the increases of IL-2 levels in those preceded the appearance of lesions in cecum. In general the infected chickens produced more IL-2 than the uninfected chickens in cecum throughout experimental period. The IL-2 levels in duodenum and cecum increased sooner than those in serum and splenic lymphocyte culture supernatant following primary infection. These results suggest that IL-2 is secreted locally and systemically following E. tenella infection and may be involved in the induction of protective immunity against E. tenella in chickens.