title: Properties of myelin altered peptide ligand cyclo(87-99)(Ala91,Ala96)MBP87-99 render it a promising drug lead for immunotherapy of multiple sclerosis.
abstract: Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system, and it has been established that autoreactive T helper (Th) cells play a crucial role in its pathogenesis. Myelin basic protein (MBP) epitopes are major autoantigens in MS, and the sequence MBP87-99 is an immunodominant epitope. We have previously reported that MBP87-99 peptides with modifications at principal T-cell receptor (TCR) contact sites suppressed the induction of EAE symptoms in rats and SJL/J mice, diverted the immune response from Th1 to Th2 and generated antibodies that did not cross react with the native MBP protein. In this study, the linear and cyclic analogs of the MBP87-99 epitope, namely linear (Ala91,Ala96)MBP87-99 (P2) and cyclo(87-99)(Ala91,Ala96)MBP87-99 (P3), were evaluated for their binding to HLA-DR4, stability to lysosomal enzymes, their effect on cytokine secretion by peripheral blood mononuclear cells (PBMC) derived from MS patients or healthy subjects (controls), and their effect in rat EAE. P1 peptide (wild-type, MBP87-99) was used as control. P2 and P3 did not alter significantly the cytokine secretion by control PBMC, in contrast to P1 that induced moderate IL-10 production. In MS PBMC, P2 and P3 induced the production of IL-2 and IFN-γ, with a simultaneous decrease of IL-10, whereas P1 caused a reduction of IL-10 secretion only. The cellular response to P3 indicated that cyclization did not affect the critical TCR contact sites in MS PBMC. Interestingly, the cyclic P3 analog was found to be a stronger binder to HLA-DR4 compared to linear P2. Moreover, cyclic P3 was more stable to proteolysis compared to linear P2. Finally, both P2 and P3 suppressed EAE induced by an encephalitogenic guinea pig MBP74-85 epitope in Lewis rats whereas P1 failed to do so. In conclusion, cyclization of myelin altered peptide ligand (Ala91,Ala96)MBP87-99 improved binding affinity to HLA-DR4, resistance to proteolysis and antigen-specific immunomodulation, rendering cyclo(87-99)(Ala91,Ala96)MBP87-99 an important candidate drug for MS immunotherapy.
authors.affiliation: Department of Chemistry, University of Patras, Patras, Greece; Eldrug S.A., Pharmaceutical Company, 26504, Platani, Patras, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Deraos
authors.affiliation: Division of Hematology, Department of Internal Medicine, Faculty of Medicine, University of Patras, Patras, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Rodi
authors.affiliation: Interfaculty Institute of Biochemistry, University of Tubingen, Tubingen, Germany.
authors.forename: Hubert
authors.initials: H
authors.lastname: Kalbacher
authors.affiliation: Division of Hematology, Department of Internal Medicine, Faculty of Medicine, University of Patras, Patras, Greece.
authors.forename: Kokona
authors.initials: K
authors.lastname: Chatzantoni
authors.affiliation: Division of Hematology, Department of Internal Medicine, Faculty of Medicine, University of Patras, Patras, Greece.
authors.forename: Fotios
authors.initials: F
authors.lastname: Karagiannis
authors.affiliation: Experimental Research Unit of ELPEN, ELPEN Pharmaceutical Co. Inc., 19009, Pikermi, Greece.
authors.forename: Loukas
authors.initials: L
authors.lastname: Synodinos
authors.affiliation: Eldrug S.A., Pharmaceutical Company, 26504, Platani, Patras, Greece.
authors.forename: Panayiotis
authors.initials: P
authors.lastname: Plotas
authors.affiliation: Experimental Research Unit of ELPEN, ELPEN Pharmaceutical Co. Inc., 19009, Pikermi, Greece.
authors.forename: Apostolos
authors.initials: A
authors.lastname: Papalois
authors.affiliation: Department of Neurology, Patras University Hospital, Patras, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Dimisianos
authors.affiliation: Department of Neurology, Patras University Hospital, Patras, Greece.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Papathanasopoulos
authors.affiliation: Department of Chemistry, University of Patras, Patras, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Gatos
authors.affiliation: Department of Chemistry, University of Patras, Patras, Greece.
authors.forename: Theodore
authors.initials: T
authors.lastname: Tselios
authors.affiliation: College of Health and Biomedicine, Centre for Chronic Disease Prevention and Management, Victoria University, Melbourne, VIC 3021, Australia.
authors.forename: Vasso
authors.initials: V
authors.lastname: Apostolopoulos
authors.affiliation: Division of Hematology, Department of Internal Medicine, Faculty of Medicine, University of Patras, Patras, Greece. Electronic address: mouzaki@upatras.gr.
authors.forename: Athanasia
authors.initials: A
authors.lastname: Mouzaki
authors.affiliation: Department of Chemistry, University of Patras, Patras, Greece; Eldrug S.A., Pharmaceutical Company, 26504, Platani, Patras, Greece. Electronic address: imats@upatras.gr.
authors.forename: John
authors.initials: J
authors.lastname: Matsoukas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000188:drug therapy / Q000473:pathology; D005260:Female; D006801:Humans; D007167:Immunotherapy; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D008024:Ligands; D008297:Male; D008875:Middle Aged; D015394:Molecular Structure; D009103:Multiple Sclerosis / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology; D004676:Myelin Basic Protein / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D011917:Rats, Inbred Lew; D055815:Young Adult
chemical_list: D008024:Ligands; D004676:Myelin Basic Protein; D010446:Peptide Fragments; C115314:myelin basic protein 87-99
keywords: Cyclic peptide; Cytokines; Experimental autoimmune encephalomyelitis; HLA-DR4(DRB*0401); Lysosomal enzymes; Multiple sclerosis; Myelin basic protein peptides