title: Antigen-specific downregulation of T cells by doxorubicin delivered through a recombinant MHC II--peptide chimera.
abstract: As the number of drugs with potential therapeutic use for T-cell-mediated diseases increases, there is a need to find methods of delivering such drugs to T cells. The major histocompatibility complex (MHC)--peptide complexes are the only antigen-specific ligands for the T-cell receptor (TCR) expressed on T cells, and they may be an appropriate drug delivery system. We engineered a soluble bivalent MHC class II-peptide chimera on the immunoglobulin scaffold (I-E(d)alpha beta/Fc gamma 2a/HA110-120, DEF) that binds stably and specifically to CD4 T cells recognizing the HA110-120 peptide. Doxorubicin, a powerful antimitogenic anthracycline, was enzymatically assembled on the galactose residues of a DEF chimera. The DEF-gal-Dox construct preserved both the binding capacity to hemagglutinin (HA)-specific T cells, and the drug toxicity. Brief exposure of HA-specific T cells to DEF-gal-Dox construct in vitro was followed by drug internalization in the lysosomes, translocation to the nucleus, and apoptosis. Administration of DEF-gal-Dox to mice expressing the TCR-HA transgene reduced the frequency of TCR-HA T cells in the spleen and thymus by 27% and 42%, and inhibited HA proliferative capacity by 40% and 60%, respectively. It has not been demonstrated previously that pharmacologically active drugs able to modulate T-cell functions can be delivered to T cells in an antigen-specific manner by soluble, bivalent MHC II-peptide chimeras.
authors.affiliation: Mount Sinai School of Medicine, Department of Microbiology, New York, NY 10029, USA.
authors.forename: S
authors.initials: S
authors.lastname: Casares
authors.forename: A C
authors.initials: AC
authors.lastname: Stan
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; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004247:DNA / Q000737:chemistry; D004317:Doxorubicin / Q000008:administration & dosage* / Q000494:pharmacology*; D004337:Drug Carriers; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D005690:Galactose; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*
chemical_list: D004337:Drug Carriers; D000939:Epitopes; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D010446:Peptide Fragments; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011993:Recombinant Fusion Proteins; D004317:Doxorubicin; D004247:DNA; D005690:Galactose