title: Synthesis of glycocluster-tumor antigenic peptide conjugates for dendritic cell targeting.
abstract: The use of dendritic cells (DC) for the development of therapeutic cancer vaccines is attractive because of their unique ability to present tumor epitopes via the MHC class I pathway to induce cytotoxic CD8+ T lymphocyte responses. C-Type membrane lectins, DC-SIGN and the mannose receptor (MR), present on the DC surface, recognize oligosaccharides containing mannose and/or fucose and mediate sugar-specific endocytosis of synthetic oligolysine-based glycoclusters. We therefore asked whether a glycotargeting approach could be used to induce uptake and presentation of tumor antigens by DC. To this end, we designed and synthesized glycocluster conjugates containing a CD8+ epitope of the Melan-A/Mart-1 melanoma antigen. These glycocluster-Melan-A conjugates were obtained by coupling glycosynthons: oligosaccharyl-pyroglutamyl-beta-alanine derivatives containing either disaccharides, a dimannoside (Manalpha-6Man) or lactoside, or a Lewis oligosaccharide, to Melan-A 16-40 peptide comprising the 26-35 HLA-A2 restricted T cell epitope, extended with an oligolysine stretch at the C-terminal end. We showed by confocal microscopy and flow cytometry that fluorescent-labeled Melan-A glycoclusters containing either dimannoside or Lewis oligosaccharide were taken up by DC and concentrated in acidic vesicles; conversely lactoside glycopeptides were not at all taken up. Furthermore, using surface plasmon resonance, we showed that dimannoside and Lewis-Melan-A conjugates bind MR and DC-SIGN with high affinity. DC loaded with these conjugates, but not with the lactose-Melan-A conjugate, led to an efficient presentation of the Melan-A epitope eliciting a CD8+ T-lymphocyte response. These data suggest that synthetically designed glycocluster-tumor antigen conjugates may induce antigen cross-presentation by DC and represent a promising tool for the development of tumor vaccines.
authors.affiliation: Glycobiologie, Vectorologie et Traffic Intracellulaire, Centre de Biophysique Moléculaire CNRS, Rue Charles-Sadron, 45071 Orléans, Cedex 2, France.
authors.forename: Oruganti
authors.initials: O
authors.lastname: Srinivas
authors.forename: Pierre
authors.initials: P
authors.lastname: Larrieu
authors.forename: Eric
authors.initials: E
authors.lastname: Duverger
authors.forename: Claire
authors.initials: C
authors.lastname: Boccaccio
authors.forename: Marie-Thérèse
authors.initials: MT
authors.lastname: Bousser
authors.forename: Michel
authors.initials: M
authors.lastname: Monsigny
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Fonteneau
authors.forename: Francine
authors.initials: F
authors.lastname: Jotereau
authors.forename: Annie-Claude
authors.initials: AC
authors.lastname: Roche
mesh_terms: D000951:Antigens, Neoplasm / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D019496:Cancer Vaccines / Q000138:chemical synthesis* / Q000276:immunology / Q000627:therapeutic use; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D004705:Endocytosis; D018984:Epitopes, T-Lymphocyte / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000737:chemistry; D006020:Glycopeptides / Q000138:chemical synthesis* / Q000276:immunology / Q000627:therapeutic use; D006801:Humans; D037181:Lectins, C-Type / Q000378:metabolism; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000378:metabolism; D008545:Melanoma / Q000188:drug therapy / Q000276:immunology / Q000473:pathology; D018613:Microscopy, Confocal; D009844:Oligosaccharides / Q000737:chemistry; D011107:Polylysine / Q000737:chemistry; D011956:Receptors, Cell Surface / Q000378:metabolism; D020349:Surface Plasmon Resonance; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D018984:Epitopes, T-Lymphocyte; D005456:Fluorescent Dyes; D006020:Glycopeptides; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D009844:Oligosaccharides; D011956:Receptors, Cell Surface; C039707:galactose receptor; D011107:Polylysine