Identification and expression analysis of duck interleukin-17D in Riemeralla anatipestifer infection

Authors: DIAZ, JOYCE - Gyeongsang National University; KIM, WOO - Gyeongsang National University; FERNANDEZ, CHERRY - National Institute Of Environmental Research; JEONG, JIPSEOL - National Institute Of Environmental Research; AFRIN, FAHMIDA - Gyeongsang National University; Lillehoj, Hyun; KIM, SUK - Gyeongsang National University; KIM, SUNGWON - Virginia Tech; DALLOUL, RAMI - Virginia Tech; MIN, WONGI - Gyeongsang National University

Submitted to: Developmental and Comparative Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/6/2016
Publication Date: 8/2/2016
Citation: Diaz, J.A., Kim, W.H., Fernandez, C.Y., Jeong, J., Afrin, F., Lillehoj, H.S., Kim, S., Kim, S., Dalloul, R.A., Min, W. 2016. Identification and expression analysis of duck interleukin-17D in Riemeralla anatipestifer infection. Developmental and Comparative Immunology. 61:190-197. doi: 10.1016/j.dci.2016.04.002.

Interpretive Summary: Poultry serves as an important source of high quality protein for human food system. With increasing demand for food production to feed the growing world population, there is a big challenge to maintain the sustainability of animal agriculture industry. One of the biggest challenges for the poultry production is maintaining a favorable environment for poultry growth simultaneous with a good immune system to fight infectious diseases. Therefore, understanding the host immune system of poultry and developing novel strategies to control field infections will be critical to the sustainability of poultry farming. One infectious disease of poultry that costs industry significant economic losses is coccidiosis which is caused by several different species of Eimeria parasites. In this paper, ARS scientists and scientists in South Korea collaborated to study host immune molecules which belong to IL-17 cytokine family. These proteins play a critical role in controlling the host immune response to infectious diseases and vaccines. This paper reports the discovery and characterization of a full-length gene encoding a bird homologue of mammalian interleukin (IL)-17D which is an immune molecule that promotes inflammatory response when the host is infected with pathogens. This information will be useful to develop a diagnostic tool to identify IL-17D in poultry and to understand how these inflammatory proteins contribute to host resistance to infectious diseases.

Technical Abstract: Interleukin (IL)-17D is a proinflammatory cytokine with limited information on its biological functions. Here we provide the description of the sequence, bioactivity, and mRNA expression profile of duck IL-17D homologue. A full-length duck IL-17D (duIL-17D) cDNA with a 624-bp coding region was identified from the large intestine. The duIL-17D shares approximately 94.7% identity with its chicken counterpart and exhibits 62.6-68.4% and 52.1-53.1% identity with mammalian and piscine homologues, respectively. Recombinant duIL-17D promoted the expression of proinflammatory cytokines such as IL-6, IL-8, and IL-1 in duck embryonic fibroblast cells. Very low levels of duIL-17D transcripts were observed in healthy lymphoid tissues, including bursa, thymus, and spleen, whereas duIL-17D expression was relatively high in the heart. The expression of duIL-17D was examined in the mitogen-stimulated splenic lymphocytes as well as in the tissues affected by R. anatipestifer infection. The levels of duIL-17D were mostly upregulated in the splenic lymphocytes but downregulated in the liver and the R. anatipestifer-infected spleen. These results provide new insights into the roles of IL-17D in host protective immune responses to Riemerella infection that can lead to future research on its biological functions in different disease models of ducks and other avian species.