title: Selective immunotargeting of diabetogenic CD4 T cells by genetically redirected T cells.
abstract: The key role played by islet-reactive CD8 and CD4 T cells in type 1 diabetes calls for new immunotherapies that target pathogenic T cells in a selective manner. We previously demonstrated that genetically linking the signalling portion of CD3-ζ onto the C-terminus of β2 -microglobulin and an autoantigenic peptide to its N-terminus converts MHC-I complexes into functional T-cell receptor-specific receptors. CD8 T cells expressing such receptors specifically killed diabetogenic CD8 T cells, blocked T-cell-induced diabetes in immunodeficient NOD.SCID mice and suppressed disease in wild-type NOD mice. Here we describe the immunotargeting of CD4 T cells by chimeric MHC-II receptors. To this end we chose the diabetogenic NOD CD4 T-cell clone BDC2.5, which recognizes the I-A(g7) -bound 1040-31 mimotope. We assembled several constructs encoding I-A(g7) α- and β-chains, the latter carrying mim or hen egg lysozyme peptide as control, each supplemented with CD3-ζ intracellular portion, either with or without its transmembrane domain. Following mRNA co-transfection of reporter B3Z T cells and mouse CD8 and CD4 T cells, these constructs triggered robust activation upon I-A(g7) cross-linking. A BDC2.5 T-cell hybridoma activated B3Z transfectants expressing the mimotope, but not the control peptide, in both configurations. Potent two-way activation was also evident with transgenic BDC2.5 CD4 T cells, but peptide-specific activation required the CD3-ζ transmembrane domain. Chimeric MHC-II/CD3-ζ complexes therefore allow the selective immunotargeting of islet-reactive CD4 T cells, which take part in the pathogenesis of type 1 diabetes.
authors.affiliation: Laboratory of Immunology, MIGAL Galilee Research Institute, Kiryat Shmona, Israel; Department of Biotechnology, Tel-Hai College, Upper Galilee, Israel.
authors.forename: Shira
authors.initials: S
authors.lastname: Perez
authors.forename: Sigal
authors.initials: S
authors.lastname: Fishman
authors.forename: Amos
authors.initials: A
authors.lastname: Bordowitz
authors.forename: Alon
authors.initials: A
authors.lastname: Margalit
authors.forename: F Susan
authors.initials: FS
authors.lastname: Wong
authors.forename: Gideon
authors.initials: G
authors.lastname: Gross
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D002460:Cell Line; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D018390:Gene Targeting; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D010455:Peptides / Q000235:genetics / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism
chemical_list: D000949:Histocompatibility Antigens Class II; C407099:I-A g7 antigen; D010455:Peptides; D011948:Receptors, Antigen, T-Cell
keywords: T-cell activation; adoptive T-cell immunotherapy; chimeric receptors; mRNA transfection; type 1 diabetes