Properties of myelin altered peptide ligand cyclo(87-99)(Ala91,Ala96)MBP87-99 render it a promising drug lead for immunotherapy of multiple sclerosis

George Deraos; Maria Rodi; Hubert Kalbacher; Kokona Chatzantoni; Fotios Karagiannis; Loukas Synodinos; Panayiotis Plotas; Apostolos Papalois; Nikolaos Dimisianos; Panagiotis Papathanasopoulos; Dimitrios Gatos; Theodore Tselios; Vasso Apostolopoulos; Athanasia Mouzaki; John Matsoukas

doi:10.1016/j.ejmech.2015.06.015

Properties of myelin altered peptide ligand cyclo(87-99)(Ala91,Ala96)MBP87-99 render it a promising drug lead for immunotherapy of multiple sclerosis

Eur J Med Chem. 2015 Aug 28:101:13-23. doi: 10.1016/j.ejmech.2015.06.015. Epub 2015 Jun 17.

Authors

Affiliations

¹ Department of Chemistry, University of Patras, Patras, Greece; Eldrug S.A., Pharmaceutical Company, 26504, Platani, Patras, Greece.
² Division of Hematology, Department of Internal Medicine, Faculty of Medicine, University of Patras, Patras, Greece.
³ Interfaculty Institute of Biochemistry, University of Tubingen, Tubingen, Germany.
⁴ Experimental Research Unit of ELPEN, ELPEN Pharmaceutical Co. Inc., 19009, Pikermi, Greece.
⁵ Eldrug S.A., Pharmaceutical Company, 26504, Platani, Patras, Greece.
⁶ Department of Neurology, Patras University Hospital, Patras, Greece.
⁷ Department of Chemistry, University of Patras, Patras, Greece.
⁸ College of Health and Biomedicine, Centre for Chronic Disease Prevention and Management, Victoria University, Melbourne, VIC 3021, Australia.
⁹ Division of Hematology, Department of Internal Medicine, Faculty of Medicine, University of Patras, Patras, Greece. Electronic address: [email protected].
¹⁰ Department of Chemistry, University of Patras, Patras, Greece; Eldrug S.A., Pharmaceutical Company, 26504, Platani, Patras, Greece. Electronic address: [email protected].

PMID: 26112377
DOI: 10.1016/j.ejmech.2015.06.015

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.

Keywords: Cyclic peptide; Cytokines; Experimental autoimmune encephalomyelitis; HLA-DR4(DRB*0401); Lysosomal enzymes; Multiple sclerosis; Myelin basic protein peptides.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Aged
Animals
Cell Proliferation / drug effects
Encephalomyelitis, Autoimmune, Experimental / drug therapy
Encephalomyelitis, Autoimmune, Experimental / pathology
Female
Humans
Immunotherapy*
Leukocytes, Mononuclear / drug effects
Ligands
Male
Middle Aged
Molecular Structure
Multiple Sclerosis / drug therapy*
Multiple Sclerosis / immunology*
Multiple Sclerosis / pathology
Myelin Basic Protein / chemical synthesis
Myelin Basic Protein / chemistry
Myelin Basic Protein / pharmacology*
Peptide Fragments / chemical synthesis
Peptide Fragments / chemistry
Peptide Fragments / pharmacology*
Rats
Rats, Inbred Lew
Young Adult

Substances

Ligands
Myelin Basic Protein
Peptide Fragments
myelin basic protein 87-99