title: A peptidomimetic that specifically inhibits human leukocyte antigen DRB1*0401-restricted T cell proliferation.
abstract: The ability of a peptidomimetic (SC-67655) to block the peptide binding site of the rheumatoid arthritis-linked human leukocyte antigen encoded by the DRB1*0401 allele was evaluated. The inhibitor bound to purified DRB1*0401 molecules with an affinity similar to that of the well-characterized peptide ligand HA307-319. Cell binding assays demonstrated that, in contrast to the promiscuous HA307-319 peptide, the peptidomimetic was highly specific for DRB1*0401. The inhibitor also blocked functional T cell responses to peptide antigens but did not block T cell proliferation in response to protein antigens. Furthermore, it did not appear to be taken up by cells. An analog of the peptidomimetic that was conjugated to a signal peptide sequence did inhibit a T cell proliferative response to protein antigen. Thus, the peptidomimetic must be taken up by cells to block the presentation of peptides derived from protein antigens. These findings have implications for the rational development of inhibitors that block the class II peptide binding groove for the treatment of autoimmune diseases.
authors.affiliation: Department of Immunology/Glycobiology, G.D. Searle & Co., St. Louis, Missouri, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Woulfe
authors.forename: C P
authors.initials: CP
authors.lastname: Bono
authors.forename: M L
authors.initials: ML
authors.lastname: Zacheis
authors.forename: J K
authors.initials: JK
authors.lastname: Welply
authors.forename: D A
authors.initials: DA
authors.lastname: Kirschmann
authors.forename: T A
authors.initials: TA
authors.lastname: Baudino
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: D A
authors.initials: DA
authors.lastname: Stone
authors.forename: G J
authors.initials: GJ
authors.lastname: Hanson
authors.forename: J L
authors.initials: JL
authors.lastname: Vuletich
authors.forename: L J
authors.initials: LJ
authors.lastname: Bedell
authors.forename: B D
authors.initials: BD
authors.lastname: Schwartz
authors.forename: S C
authors.initials: SC
authors.lastname: Howard
mesh_terms: D001665:Binding Sites; D002455:Cell Division / Q000187:drug effects* / Q000276:immunology; D002460:Cell Line; D006684:HLA-DR Antigens / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D059811:HLA-DRB1 Chains; D006801:Humans; D009842:Oligopeptides / Q000378:metabolism / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects*
chemical_list: D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C553505:HLA-DRB1*04:01 antigen; D009842:Oligopeptides; C106006:SC 67655