ARS | Publication request: CLONING AND FUNCTIONAL CHARACTERIZATION OF CHICKEN INTERLEUKIN-17D

Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 1, 2008
Publication Date: September 2, 2008
Repository URL: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TD5-4SSG4R4-1&_user=6956098&_coverDate=11%2F15%2F2008&_rdoc=2&_fmt=high&_orig=browse&_srch=doc-info(%23toc%235189%232008%23998739998%23701375%23FLA%23display%23Volume)&_cdi=5189&_sort=d&_docanchor=&_ct=21&_acct=C000052423&_version=1&_urlVersion=0&_userid=6956098&md5=69d941e1ac7477fb756431097b8f7736
Citation: Hong, Y.H., Lillehoj, H.S., Park, D., Lee, S., Han, J., Shin, J., Park, M., Kim, J. 2008. Cloning and functional characterization of chicken interleukin-17D. Veterinary Immunology and Immunopathology. 126(1-2):1-8.

Interpretive Summary: With the completion of human genome sequences and the availability of public genomic databases, a number of homologous proteins comprising an important member of immune genes have been described in poultry. IL-17 family genes including IL-17A , -17B, -17C, -17D, -17E and -17F, as well as their cognate receptors, have no sequence similarity to any other known cytokines or receptors and thus appears to represent a distinct ligand-receptor signaling system and not much is known about these proteins in chickens. Among IL-17d families, IL-17D gene appeared to be most homologous to IL-17B and was preferentially expressed in resting CD4+ T cells, skeletal muscle, brain, pancreas, heart, lung and adipose tissue. IL-17 family members have been linked to many disease processes such as rheumatoid arthritis, pulmonary disease, psoriasis, and allograft rejection. ARS scientists previously cloned IL-17A and showed this cytokine is important in coccidiosis. In this study, ARS scientists collaborated with scientists in Korea and cloned chicken IL-17d from a chicken testis cDNA library. The proinflammatory cytokine IL-17D was cloned from a testis cDNA library prepared from the Korean native chicken. Comparison of the deduced amino acid sequence of chIL-17D with homologous proteins from human, mouse and opossum revealed 64%, 53% and 76% and chIL-17D gene transcript was expressed in a wide range of tissues, and highest levels were in pancreas, thymus and lung. Following Eimeria maxima infection, levels of the chIL-17D mRNA were up-regulated in the intestinal jejunum, bursa, lung, and spleen but decreased in the thymus, indicating their role in gut immunity. These results demonstrate for the first time that chicken IL-17D protein has structural and functional similarities to mammalian IL-17Ds and that this cytokine plays an important role in local gut innate immune responses during experimental coccidiosis.

Technical Abstract: The proinflammatory cytokine IL-17D was cloned from a testis cDNA library prepared from the Korean native chicken. The full-length chicken IL-17D (chIL-17D) cDNA consisted of a 348 nucleotide sequence encoding an open reading frame of 116 amino acids with a predicted molecular mass of 17.0 kDa. Comparison of the deduced amino acid sequence of chIL-17D with homologous proteins from human, mouse and opossum revealed 64%, 53% and 76% identity respectively, including six conserved cysteine residues present in the mammalian polypeptides. The chIL-17D gene transcript was expressed in a wide range of tissues, and highest levels were in pancreas, thymus and lung. Following Eimeria maxima infection, levels of the chIL-17D mRNA were up-regulated in the intestinal jejunum, bursa, lung, and spleen but decreased in the thymus. Infected chickens also expressed greater levels of chIL-17D mRNA in CD4+, CD8+ and TCR1+ intestinal intraepithelial lymphocytes while decreased expression was seen in TCR2+ cells. Treatment of CHCC-OU2 fibroblasts with chIL-17D recombinant protein induced the expression of IL-6 and IL-8. Collectively, these results suggest that chL-17D has structural and functional similarities to mammalian IL-17Ds and that it plays an important role in local gut innate immune responses during experimental coccidiosis.