title: Chicken interleukin-21 is costimulatory for T cells and blocks maturation of dendritic cells.
abstract: In mammals, interleukin-21 (IL-21) is an immunomodulatory cytokine with pleiotropic effects on the proliferation, differentiation and effector functions of T, B, NK and dendritic cells. A cDNA encoding the chicken orthologue of IL-21 (chIL-21) was cloned by RT-PCR from RNA isolated from activated chicken splenocytes and consists of 438 nucleotides, encoding an open reading frame of 145 amino acids (aa). Chicken IL-21 has 20-30% aa identity to its orthologues in mammals, Xenopus and fish, but is more highly conserved within Aves (50-80%). The four alpha-helical bundle structure of mammalian IL-21 appears to be conserved in the predicted chicken protein, as are the four cysteine residues required for the formation of two disulphide bridges. A glutamine residue in aa position 129, which has been implicated in the binding of IL-21 to the IL-2 receptor γ-chain in mammals, is also conserved. ChIL-21 is expressed in most lymphoid tissues, predominantly by CD4+ TCRαβ+ T cells. As in mammals, chIL-21 synergistically enhances T-cell proliferation and inhibits maturation of dendritic cells.
authors.affiliation: Institute for Animal Health, Compton, Berkshire, UK. lisa.rothwell@roslin.ed.ac.uk
authors.forename: Lisa
authors.initials: L
authors.lastname: Rothwell
authors.forename: Tuanjun
authors.initials: T
authors.lastname: Hu
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Wu
authors.forename: Pete
authors.initials: P
authors.lastname: Kaiser
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001681:Biological Assay / Q000662:veterinary; D002645:Chickens / Q000276:immunology*; D003001:Cloning, Molecular / Q000379:methods; D017124:Conserved Sequence; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D007378:Interleukins / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D012313:RNA / Q000737:chemistry / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013047:Specific Pathogen-Free Organisms; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D000098546:Interleukin-21
chemical_list: D007378:Interleukins; D012313:RNA; D000098546:Interleukin-21