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ARS Home » Southeast Area » Fayetteville, Arkansas » Poultry Production and Product Safety Research » Research » Publications at this Location » Publication #246481
Title: Understanding stress-induced immunosupression: exploration of cytokine and chemokine gene profiles in chicken peripheral leukocytes

Author
item SHINI, S - University Of Queensland
item Huff, Geraldine
item KAISER, P - Institute Of Animal Health - United Kingdom

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2009
Publication Date: 4/1/2010
Citation: Shini, S., Huff, G.R., Kaiser, P. 2010. Understanding stress-induced immunosupression: Exploration of cytokine and chemokine gene profiles in chicken peripheral leukocytes. Poultry Science. 89(4):841-851.

Interpretive Summary: It is important to improve chickens’ resistance to stress-mediated disease which can result in vaccination failures and increased sickness and death. Currently several modern cellular and molecular approaches are being used to explore the status of the immune system during stress and disease. It is likely that these new techniques will lead to the development of new strategies for preventing and controlling immunosuppression in poultry. Using genetic assays, a broad spectrum of chemical signals and their receptor genes can be quantified in birds, and then be used as markers to assess the effects of stress on the immune system. Currently, we are investigating immune and hormone interactions in the chicken, in particular the cells and molecules that are known to be involved in such interactions in mammals. We have evaluated the effects of a stress hormone added to drinking water on gene expression of chemical signals from immune cells found in the blood. Chemical signals known to be involved in inflammation are initially upregulated and may be involved in modulating the adaptive immune response. Chronic treatment with this stress hormone can suppress the immune response. It appears that the balance between helper and regulatory aspects of immune cells is altered when stress hormone concentrations are changed. Experiments are underway to determine how vaccination and bacterial challenge is affected during stress.

Technical Abstract: At present, the poultry meat and egg industry has gained a lot of ground, being viewed as provider of a healthy alternative to red meat and other protein sources. If this trend is to be maintained, solutions must be found to improve chickens’ resistance to disease, which often is weakened by stressful conditions. In poultry, stress-induced immunosuppression is manifested with failures in vaccination and increased morbidity and mortality of flocks. Currently several modern cellular and molecular approaches are being used to explore the status of the immune system during stress and disease. It is likely that these new techniques will lead to the development of new strategies for preventing and controlling immunosuppression in poultry. Using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) assays, a broad spectrum of cytokine, chemokine, and their receptor genes can be quantified in birds, and then be used as markers to assess the effects of stress on the immune system. Currently, we are investigating immune and endocrine interactions in the chicken, in particular the cells and molecules that are known to be involved in such interactions in mammals. We have evaluated the effects of corticosterone administration in drinking water on peripheral lymphocyte and heterophil cytokine and chemokine gene profiles. In particular, there seem to be effects on cytokine and chemokine mRNA expression levels from both lymphocytes and heterophils, especially expression of the proinflammatory cytokines, interleukin (IL)-1beta, IL-6, and IL-18, and chemokines, CCLi1, CCLi2, CCL5, CCL16, CXCLi1 and CXCLi2, which are initially upregulated and are potentially involved in modulating the adaptive immune response. A chronic treatment with corticosterone downregulates proinflammatory cytokines and chemokines suggesting that the delayed effects of chronic stress can suppress the immune response. Gene expression levels of transforming growth factor (TGF)-beta 4 are also upregulated in cortisosterone treated birds. It appears that the balance between T helper (Th) 1 and Th2/Treg cytokine productions is altered in conditions associated with significant changes in plasma corticosterone concentration. Experiments are underway to decipher the cytokine and chemokine responses to vaccination and bacterial challenge on the background of stress-induced immunosuppression.