title: Interleukin-2 carbohydrate recognition modulates CTLL-2 cell proliferation.
abstract: Interleukin-2 (IL-2) specifically recognizes high-mannose type glycans with five or six mannosyl residues. To determine whether the carbohydrate recognition activity of IL-2 contributes to its physiological activity, the inhibitory effects of high-mannose type glycans on IL-2-dependent CTLL-2 cell proliferation were investigated. Man(5)GlcNAc(2)Asn added to CTLL-2 cell cultures inhibited not only phosphorylation of tyrosine kinases but also IL-2-dependent cell proliferation. We found that a complex of IL-2, IL-2 receptor alpha, beta, gamma subunits, and tyrosine kinases was formed in rhIL-2-stimulated CTLL-2 cells. Among the components of this complex, only the IL-2 receptor alpha subunit was stained with Galanthus nivalis agglutinin which specifically recognizes high-mannose type glycans. This staining was diminished after digestion of the glycans with endo-beta-N-acetylglucosaminidase H or D, suggesting that at least a N-glycan containing Man(5)GlcNAc(2) is linked to the extracellular portion of the IL-2 receptor alpha subunit. Our findings indicate that IL-2 binds the IL-2 receptor alpha subunit through Man(5)GlcNAc(2) and a specific peptide sequence on the surface of CTLL-2 cells. When IL-2 binds to the IL-2Ralpha subunit, this may trigger formation of the high affinity complex of IL-2-IL-2Ralpha, -beta, and -gamma subunits, leading to cellular signaling.
authors.affiliation: Department of Biochemistry, Sasaki Institute, 2-2 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Fukushima
authors.forename: K
authors.initials: K
authors.lastname: Yamashita
mesh_terms: D000818:Animals; D050260:Carbohydrate Metabolism; D002455:Cell Division; D004305:Dose-Response Relationship, Drug; D027801:Galanthus; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism* / Q000502:physiology*; D053613:Janus Kinase 1; D053616:Janus Kinase 3; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D010766:Phosphorylation; D011134:Polysaccharides / Q000378:metabolism; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D007376:Interleukin-2; D011134:Polysaccharides; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D011505:Protein-Tyrosine Kinases; C507904:JAK1 protein, human; C507933:JAK3 protein, human; C507905:Jak1 protein, mouse; C507935:Jak3 protein, mouse; D053613:Janus Kinase 1; D053616:Janus Kinase 3; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D008358:Mannose