Design And Synthesis of a Novel Potent Myelin Basic Protein Epitope 87−99 Cyclic Analogue:  Enhanced Stability and Biological Properties of Mimics Render Them a Potentially New Class of Immunomodulators

Abstract

A cyclic analogue, [cyclo(87-99)MBP [87][88][89][90][91][92][93][94][95][96][97][98][99] [87][88][89][90][91][92][93][94][95][96][97][98][99] , reported previously for suppressing, to a varying degree, autoimmune encephalomyelitis in a rat animal model, were found in this study to possess the following immunomodulatory properties: (i) they suppressed the proliferation of a CD4 T-cell line raised from a multiple sclerosis patient, (ii) they scored the best in vitro TH2/TH1 cytokine ratio in peripheral blood mononuclear cell cultures derived from 13 multiple sclerosis patients, inducing IL-10 selectively, and (iii) they bound to HLA-DR4, first to be reported for cyclic MBP peptides. In addition, cyclic peptides were found to be more stable to lysosomal enzymes and Cathepsin B, D, and H, compared to their linear counterparts. Taken together, these data render cyclic mimics as putative drugs for treating multiple sclerosis and potentially other Th1-mediated autoimmune diseases.

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

“…Th2/Th1 cytokine ratio in PBMC cultures derived from 13 MS patients, by selectively inducing the secretion of IL-10, (iii) could bind to HLA-DR4, first to be reported for cyclic MBP peptides, and (iv) were more stable to lysosomal enzymes Cathepsin B, D, and H, compared to their linear counterparts [4]. These findings demonstrated that the design and synthesis of linear and cyclic…”

“…In addition, MBP epitopes are major autoantigens in MS, and the MBP87-99 sequence is an immunodominant epitope [3][4][5]12,16].…”

“…The use of cyclic instead of linear peptides as therapeutic entities has many advantages, including (i) stability and resistance to enzymatic degradation, (ii) increased receptor selectivity, consequently resulting in an improved pharmacological profile, (iii) locked conformation allowing identification of active sites, (iv) design of useful templates for the development of a non-peptide (mimetic) drug for oral administration, with potential oral activity if appropriately constrained [4,10,11]. We have previously described [4,12] the rational design and synthesis of cyclic peptides, based on a combination of conformational analysis studies and theoretical calculations carried out on the linear MBP epitope 87-99 using 2D ROESY NMR spectroscopy.…”

“…We have previously described [4,12] the rational design and synthesis of cyclic peptides, based on a combination of conformational analysis studies and theoretical calculations carried out on the linear MBP epitope 87-99 using 2D ROESY NMR spectroscopy.…”

Conformational studies of immunodominant myelin basic protein 1–11 analogues using NMR and molecular modeling

“…However, Gln 3 (TCR contact) was not solvent exposed so as to interact with TCR for the antagonist MBP 1-8 [4A] peptide. Knowledge of the relationship of peptide conformation and bioactivity will facilitate the rational design and synthesis The linear peptides were prepared on 2-chlorotrityl chloride resin (CLTR-Cl) using the Fmoc/tBu solid-phase peptide synthetic method [31][32][33][34][35]. The first N a Fmoc (9-fluorenylmethyloxycarboxyl)-protected amino acid Fmoc-Gly-OH was coupled (esterified) to the resin in the presence of diisopropylethylamine (DIPEA) (4.5 equiv, 0.75 mL) in dichloromethane (DCM) in 1 h at RT.…”