title: Genomic structure, molecular characterization and functional analysis of Pekin duck interleukin-10.
abstract: Here we describe the cloning and expression of Pekin duck IL-10 (duIL-10) and a six exon-5 intron structure of an IL-10 gene. Two transcripts encoding duIL-10 with an alternatively spliced 3'UTR, and a transcript lacking exon 5 with a novel coding sequence for its C-terminus (duIL-10ΔE5) were isolated from splenocytes. The duIL-10 protein has an amino acid identity of 79% and 47% with chicken and human IL-10, respectively. The duck IL-10 gene shares a similar structure of the respective exons 1-5 with the IL-10 genes of other vertebrates but has an alternative exon. The duIL-10 3D structure by homology modeling was similar to that of the human IL-10 monomer, whereas the predicted duIL-10ΔE5 protein lacks helix F. DuIL-10 and duIL-10ΔE5 transcripts were most abundant in primary and secondary immune organs and lung. Recombinant duIL-10 suppressed duck IL-2 transcripts in mitogen-activated PBMCs. Our observation suggests evolutionary conservation of structure and function of the duIL-10 protein but the roles of the novel IL-10 splice variants in the regulation of duck immune responses and evolution of vertebrate immunity remain to be elucidated.
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, AB, Canada.
authors.forename: Qingxia
authors.initials: Q
authors.lastname: Yao
authors.forename: Karl P
authors.initials: KP
authors.lastname: Fischer
authors.forename: D Lorne
authors.initials: DL
authors.lastname: Tyrrell
authors.forename: Klaus S
authors.initials: KS
authors.lastname: Gutfreund
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D004372:Ducks / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D016753:Interleukin-10 / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D016753:Interleukin-10