title: Enzymatically mediated engineering of multivalent MHC class II-peptide chimeras.
abstract: We previously reported the genetic engineering of the first soluble, bivalent major histocompatibility complex (MHC) class II-peptide ligand for T-cell receptor (TCR). This ligand binds stably and specifically to cognate T-cells and exhibits immunomodulatory effects in vitro and in vivo. The increase in valence of MHC class II-peptide ligands was shown to parallel their avidity for cognate TCRs and potency in stimulating cognate T-cells. We describe a new enzymatic method to increase the valence of MHC-peptide ligands by cross-linking the N-glycan moieties of dimeric MHC II-peptide units through a flexible, bifunctional polyethylene glycol linker. Using this method, we generated covalently stabilized tetravalent and octavalent MHC II-peptide ligands which bound stably and specifically to cognate TCR and preserved their structural integrity in blood and lymphoid organs for 72 h. Depending on the TCR/CD4 occupancy and degree of TCR/CD4 co-clustering, the multivalent MHC II-peptide ligands polarized efficiently the antigen-specific CD4(+) T-cells toward type 2 cell differentiation or induced T-cell anergy and apoptosis. The enzymatically mediated engineering of multivalent MHC-peptide ligands for cognate TCRs may provide rational grounds for the development of new therapeutic agents endowed with strong modulatory effects on antigen-specific T-cells.
authors.affiliation: Department of Microbiology, Mount Sinai School of Medicine, 1 Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: S
authors.initials: S
authors.lastname: Casares
authors.forename: C A
authors.initials: CA
authors.lastname: Bona
authors.forename: T D
authors.initials: TD
authors.lastname: Brumeanu
mesh_terms: D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D003432:Cross-Linking Reagents / Q000737:chemistry; D016207:Cytokines / Q000032:analysis / Q000276:immunology; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005802:Genes, MHC Class II / Q000276:immunology*; D008024:Ligands; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D011092:Polyethylene Glycols / Q000737:chemistry / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D015202:Protein Engineering; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D012995:Solubility; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*
chemical_list: D003432:Cross-Linking Reagents; D016207:Cytokines; D008024:Ligands; D011134:Polysaccharides; D011948:Receptors, Antigen, T-Cell; D011092:Polyethylene Glycols