title: Protease-resistant human GAD-derived altered peptide ligands decrease TNF-alpha and IL-17 production in peripheral blood cells from patients with type 1 diabetes mellitus.
abstract: Glutamic acid decarboxylase 65 (GAD) and proinsulin are major diabetes-associated autoantigens that drive autoreactive T cells. Altered peptide ligands (APL) have been proposed as reagents for the modification of autoimmune reactions. Here, we have prepared GAD-derived protease-resistant APL (prAPL) by cleavage site-directed modification. The resulting prAPL are resistant to lysosomal and serum proteases, bind with high-affinity to HLA-DRB1(*)0401 and have a prolonged half-life in the serum. GAD-derived prAPL significantly decreased the secretion of proinflammatory cytokines by a GAD-specific human T cell clone. Likewise, the production of IL-17, TNF-alpha, and secretion of IL-6 by peripheral blood lymphocytes from patients with type 1 diabetes mellitus (T1D) was reduced, when stimulated with both GAD and GAD-derived prAPL. Thus, prAPL with high affinity for HLA-DRB1(*)0401 mitigate the response of GAD-reactive human Th17 cells. The strategy of designing specific immunomodulatory protease-resistant altered peptide ligands provides the basis for novel avenues of therapeutic intervention.
authors.affiliation: Department of Internal Medicine I, University Medical Center Ulm and Center of Excellence, Germany.
authors.forename: Bernhard O
authors.initials: BO
authors.lastname: Boehm
authors.forename: Silke
authors.initials: S
authors.lastname: Rosinger
authors.forename: Guido
authors.initials: G
authors.lastname: Sauer
authors.forename: Burkhard J
authors.initials: BJ
authors.lastname: Manfras
authors.forename: David
authors.initials: D
authors.lastname: Palesch
authors.forename: Stefan
authors.initials: S
authors.lastname: Schiekofer
authors.forename: Hubert
authors.initials: H
authors.lastname: Kalbacher
authors.forename: Timo
authors.initials: T
authors.lastname: Burster
mesh_terms: D002403:Cathepsins / Q000378:metabolism; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005968:Glutamate Decarboxylase / Q000737:chemistry; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D015851:Interleukin-7 / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013058:Mass Spectrometry; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D010447:Peptide Hydrolases / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D007376:Interleukin-2; D015850:Interleukin-6; D015851:Interleukin-7; D010446:Peptide Fragments; D014409:Tumor Necrosis Factor-alpha; D002403:Cathepsins; D010447:Peptide Hydrolases; D005968:Glutamate Decarboxylase