title: Suppression of type 1 diabetes in NOD mice by bifunctional peptide inhibitor: modulation of the immunological synapse formation.
abstract: The aim of this work was to design and utilize a bifunctional peptide inhibitor called glutamic acid decarboxylase-bifunctional peptide inhibitor to suppress the progression of type 1 diabetes in non-obese diabetic mice. The hypothesis is that glutamic acid decarboxylase-bifunctional peptide inhibitor binds simultaneously to major histocompatibility complex-II and intercellular adhesion molecule type 1 on antigen-presenting cell and inhibits the immunological synapse formation during T-cell-antigen-presenting cell interactions. Glutamic acid decarboxylase-bifunctional peptide inhibitor was composed of a major epitope of the type 1 diabetes-associated antigen, glutamic acid decarboxylase 65 kDa, covalently linked to a peptide derived from CD11a of lymphocyte function-associated antigen-1. The suppression of insulitis and type 1 diabetes was evaluated using non-obese diabetic and non-obese diabetic severe combined immunodeficiency mice. Glutamic acid decarboxylase-bifunctional peptide inhibitor had the capacity to suppress invasive insulitis in non-obese diabetic mice. CD4+ T-cells isolated from glutamic acid decarboxylase-bifunctional peptide inhibitor treated mice also suppressed insulitis and hyperglycemia when transferred with diabetogenic non-obese diabetic spleen cells into non-obese diabetic severe combined immunodeficiency recipients. As predicted, the glutamic acid decarboxylase-bifunctional peptide inhibitor cross-linked a significant fraction of major histocompatibility complex class-II molecules to intercellular adhesion molecule type 1 molecules on the surface of live antigen-presenting cell. Intravenous injection of the glutamic acid decarboxylase-bifunctional peptide inhibitor elicited interleukin-4-producing T-cells in non-obese diabetic mice primed against the glutamic acid decarboxylase-epitope peptide. Together, the results indicate that glutamic acid decarboxylase-bifunctional peptide inhibitor induces interleukin-4-producing regulatory cells but does not expand the glutamic acid decarboxylase-specific Th2 population. Given that Th2 effector cells can cause pathology, the glutamic acid decarboxylase-bifunctional peptide inhibitor may represent a novel mechanism to induce interleukin-4 without Th2-associated pathology.
authors: Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS 66047, USA.
authors: Joseph S
authors: JS
authors: Murray
authors: Sabah
authors: S
authors: Oney
authors: Jennifer E
authors: JE
authors: Page
authors: Angela
authors: A
authors: Kratochvil-Stava
authors: Yongbo
authors: Y
authors: Hu
authors: Irwan T
authors: IT
authors: Makagiansar
authors: John C
authors: JC
authors: Brown
authors: Naoki
authors: N
authors: Kobayashi
authors: Teruna J
authors: TJ
authors: Siahaan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy* / Q000201:enzymology / Q000276:immunology* / Q000473:pathology; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000627:therapeutic use; D005260:Female; D005968:Glutamate Decarboxylase / Q000037:antagonists & inhibitors / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology
chemical_list: D004791:Enzyme Inhibitors; D010455:Peptides; D018799:Intercellular Adhesion Molecule-1; D005968:Glutamate Decarboxylase