The overall goal of this program is to test critically the general hypothesis that myelin antigen reactive T cells and the MS risk-associated HLA-DR2 allele contribute to the pathogenesis of multiple sclerosis (MS). To this end we developed a recombinant TCR ligand (RTL), a single chain two domain human HLA-DR2 class II molecule covalently linked to the immunodominant MOG-35-55 epitope that induced long-term tolerance and reversed established clinical signs of MOG-peptide-induced EAE in transgenic (Tg) DR2-expressing mice. The initial DR2/MOG-35-55 construct (VG312) that we produced had self-adherent surfaces and tended to form stable oligomers with an average composition of 14-subunits. The effect of oligomerization on the inhibitory function of the constructs is unknown, but potentially the oligomers might have a lower functional molarity and thus less inhibitory activity in vivo than the monomers. On the other hand, the oligomers might be able to cross-link the TCRs more efficiently than monomers, resulting in more or different signaling through the TCR that might affect inhibitory activity. We have now produced a DR2/MOG-35-55 monomer (VG342) by modifying amino acid residues in the self-contact surface that will allow a functional comparison with the 14-mer VG312 construct. Additionally, we have produced constructs that contain mouse (m)MOG versus human (h)MOG peptides with different affinities for TCRs from mice with EAE, and a new monomeric form (VG342-T) that lacks the thrombin (T) cleavage site that was engineered into the peptide-joining region of the original construct. Our goal in this application is to compare these five forms of the DR2/MOG-35-55 construct for therapeutic efficacy, induction of tolerance, and effects on mouse and human MOG-35-55 specific T cell lines, clones, and a hybridoma that we recently developed from the DR2 mice. Specifically, in this application we will address the specific hypothesis that the degree and mechanism of tolerance is governed or influenced by 1) differences in the affinity of the RTL for the TCR, 2) differences in functional avidity of RTL binding to the TCR, and 3) cleavage and release of free peptide from the RTL. Finally, we will evaluate the degree of bystander suppression induced by RTLs and follow the fate of RTL-treated T cells. These are the first studies ever to evaluate the effect on tolerance of monomeric versus oligomeric TCR blockage in vivo, and will provide the necessary foundation for clinical application of these recombinant TCR ligands (RTLs) in patients with MS.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS047661-02
Application #
7020685
Study Section
Hypersensitivity, Autoimmune, and Immune-mediated Diseases Study Section (HAI)
Program Officer
Utz, Ursula
Project Start
2005-04-01
Project End
2010-03-31
Budget Start
2006-04-01
Budget End
2007-03-31
Support Year
2
Fiscal Year
2006
Total Cost
$340,061
Indirect Cost
Name
Oregon Health and Science University
Department
Neurology
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
Meza-Romero, Roberto; Benedek, Gil; Leng, Lin et al. (2016) Predicted structure of MIF/CD74 and RTL1000/CD74 complexes. Metab Brain Dis 31:249-55
Benedek, Gil; Meza-Romero, Roberto; Jordan, Kelley et al. (2015) HLA-DR?1-mMOG-35-55 treatment of experimental autoimmune encephalomyelitis reduces CNS inflammation, enhances M2 macrophage frequency, and promotes neuroprotection. J Neuroinflammation 12:123
Benedek, Gil; Meza-Romero, Roberto; Bourdette, Dennis et al. (2015) The use of flow cytometry to assess a novel drug efficacy in multiple sclerosis. Metab Brain Dis 30:877-84
Bodhankar, Sheetal; Chen, Yingxin; Lapato, Andrew et al. (2015) PD-L1 Monoclonal Antibody Treats Ischemic Stroke by Controlling Central Nervous System Inflammation. Stroke 46:2926-34
Benedek, Gil; Zhu, Wenbin; Libal, Nicole et al. (2014) A novel HLA-DR?1-MOG-35-55 construct treats experimental stroke. Metab Brain Dis 29:37-45
Meza-Romero, Roberto; Benedek, Gil; Yu, Xiaolin et al. (2014) HLA-DR?1 constructs block CD74 expression and MIF effects in experimental autoimmune encephalomyelitis. J Immunol 192:4164-73
Benedek, Gil; Meza-Romero, Roberto; Andrew, Shayne et al. (2013) Partial MHC class II constructs inhibit MIF/CD74 binding and downstream effects. Eur J Immunol 43:1309-21
Loftis, Jennifer M; Wilhelm, Clare J; Vandenbark, Arthur A et al. (2013) Partial MHC/neuroantigen peptide constructs: a potential neuroimmune-based treatment for methamphetamine addiction. PLoS One 8:e56306
Vandenbark, Arthur A; Meza-Romero, Roberto; Benedek, Gil et al. (2013) A novel regulatory pathway for autoimmune disease: binding of partial MHC class II constructs to monocytes reduces CD74 expression and induces both specific and bystander T-cell tolerance. J Autoimmun 40:96-110
Adamus, Grazyna; Brown, Lori; Andrew, Shayne et al. (2012) Neuroprotective effects of recombinant T-cell receptor ligand in autoimmune optic neuritis in HLA-DR2 mice. Invest Ophthalmol Vis Sci 53:406-12

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