Peptide 15-mers of defined sequence that substitute for random amino acid copolymers in amelioration of experimental autoimmune encephalomyelitis

Abstract

Myelin basic protein (MBP) is a major candidate autoantigen in multiple sclerosis (MS).Cop1 ͉ HLA-DR ͉ multiple sclerosis ͉ T cells M ultiple sclerosis (MS), an autoimmune inflammatory disease of the CNS, is associated with the HLA-DR2 haplotype (DRA*0101, DRB1*1501, DQA1*0102, DQB1*0602) (1-3). Myelin basic protein (MBP) is one of the major candidate autoantigens in the pathogenesis of MS. Particularly, T cell reactivity to the immunodominant MBP 85-99 epitope is found in subjects carrying human leukocyte antigen (HLA)-DR2, a genetic marker for susceptibility to MS. HLA-DR2-restricted MBP-specific T cells are clonally expanded and activated in MS patients (4-9). Furthermore, HLA-DR2͞MBP 85-99 complexes have been detected in the CNS plaques of these patients (10). Critical residues for binding to HLA-DR2 and for T cell antigen receptor (TCR) recognition of the MBP 85-99 epitope have been defined (11,12).Several therapeutic approaches to MS have been attempted by using cytokines, copolymers, dimers of class II major histocompatibility complex-peptide complexes, peptide antigens that induce anergy, vaccination with TCR, and an altered peptide ligand (13)(14)(15)(16)(17)(18)(19). Many of these studies aimed to interfere with the MBP 85-99-specific T cell recognition and͞or to deviate the T cell response from the Th1 to the Th2 phenotype. Copolymer 1 [Cop1, Copaxone, Glatiramer Acetate, poly(Y, E, A, K)n], the only approved drug known to reduce MBP-specific T cell responses, reduces the relapse rate by Ϸ30% in relapsingremitting forms of MS (20-26). Cop1 binds to several human HLA-DR molecules, including HLA-DR2, and blocks modestly the presentation of MBP 85-99 (27, 28). The effectiveness of amino acid copolymers with in vitro and in vivo assays was greatly improved by modifications that enhanced their binding to HLA-DR2 (29, 30). We hypothesized that by similarly improving the binding of synthetic peptide mimetics (13, 29, 30), their effectiveness might also be greatly enhanced. Thus, T cell recognition of MBP 85-99 might be more effectively inhibited and͞or additional immunosuppressive functions of the copolymers might be enhanced by the peptide mimetics. In this paper we report generation of three peptide inhibitors based on the binding motif of MBP 85-99 to HLA-DR2 with improved functions in inhibiting T cell responses and experimental autoimmune encephalomyelitis (EAE). These 15-mers (J2, J3, and J5) competed with MBP 85-99 for binding to HLA-DR2, inhibited IL-2 secretion by MBP 85-99-specific T cell clones and induced production of Th2 cytokines by splenocytes. Additionally they did not crossreact with MBP 85-99-or PLP 139-151-specific T cells. They also suppressed EAE in two different murine disease models in a manner equivalent to that achieved by using the modified random amino acid copolymers. Materials and MethodsGeneration of Peptide-Specific Short-Term T Cell Lines and Proliferative Responses to Peptides. Mice were immunized with proteolipid protein (PLP) 139-151 or peptide 15-mers (100 g per mouse) em...

Differential induction of IgE-mediated anaphylaxis after soluble vs. cell-bound tolerogenic peptide therapy of autoimmune encephalomyelitis

“…However, as previously mentioned, glatiramer acetate appears to be well tolerated (38). In addition, we have shown that the J5 peptide, a peptide inhibitor designed to compete with MBP 85-99 for binding to HLA-DR2 with the ability to also suppress PLP 139 -151 -induced disease in SJL mice (20), has no harmful effects on mice when administered i.v. during ongoing disease (Table 1).…”

T cell receptors in an IL-10-secreting amino acid copolymer-specific regulatory T cell line that mediates bystander immunosuppression

“…This is not surprising because these 2 random copolymers, FYAK and GA (YEAK), share 3 amino acids. In addition, the ''␣␤1'' TCR transfectant that recognizes both FYAK and GA must recognize an epitope distinct from the epitope in GA that cross-reacts with the J5 immunomodulatory peptide (26) (that can also induce regulatory T cells) because J5 stimulates neither the TCR transductant nor the cell line from which the ''␣␤1'' TCR was obtained (10). In further experiments, it will be important to use J5 and other immunomodulatory peptides with defined sequences to examine these issues.…”

“…T cell lines were established from spleens of SJL mice as described, using either the random amino acid copolymer FYAK or the autoantigen PLP139-151 as the immunogen (10,(24)(25)(26). The primary lines were restimulated 3 times at 2-week intervals in IL-2.…”

“…5A). Sorted GFP ϩ or GFP ϩ /TCR ϩ recipient T-hybridoma cells were stimulated with FYAK, GA, J5 [an immunomodulatory peptide whose sequence was based on a binding motif for GA (26)], and PLP139 -151. All 4 BW-1 or 4G4.CD4 cell lines that received TCR␣␤-containing vectors were functional as evidence by secretion of IL-2 on stimulation with FYAK.…”

Strategies for the identification of loci responsible for the pathogenesis of multiple sclerosis

“…There are a variety of animal models of MS namely Experimental Allergic Encephalomyelitis (EAE) which immunization with an encephalogenic peptides or proteins (MOG, MBP, PLP, myelin extract) is used to induce MS like disease. EAE can be induced in animal species including rats, mice, guinea pigs, rabbits, marmosets, macaques and rhesus monkeys [1][2][3][4][5][6][7][8][9]. Studies suggest that there are both environmental and genetic risk factors contributing to the pathogenesis of MS [10,11].…”