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: Oruganti Srinivas, Pierre Larrieu, Eric Duverger, Claire Boccaccio, Marie-Thérèse Bousser, Michel Monsigny, Jean-François Fonteneau, Francine Jotereau, Annie-Claude Roche
• Journal: Bioconjugate chemistry (Bioconjug Chem) 2007 Sep-Oct Vol. 18 Issue 5 Pg. 1547-54 ISSN: 1043-1802 [Print] United States
• PMID: 17602511 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antigens, Neoplasm
• Cancer Vaccines
• Epitopes, T-Lymphocyte
• Fluorescent Dyes
• Glycopeptides
• Lectins, C-Type
• Mannose Receptor
• Mannose-Binding Lectins
• Oligosaccharides
• Receptors, Cell Surface
• galactose receptor
• Polylysine

Topics

• Antigens, Neoplasm (immunology, metabolism)
• CD8-Positive T-Lymphocytes (immunology, metabolism)
• Cancer Vaccines (chemical synthesis, immunology, therapeutic use)
• Dendritic Cells (immunology, metabolism)
• Endocytosis
• Epitopes, T-Lymphocyte (immunology, metabolism)
• Flow Cytometry
• Fluorescent Dyes (chemistry)
• Glycopeptides (chemical synthesis, immunology, therapeutic use)
• Humans
• Lectins, C-Type (metabolism)
• Mannose Receptor
• Mannose-Binding Lectins (metabolism)
• Melanoma (drug therapy, immunology, pathology)
• Microscopy, Confocal
• Oligosaccharides (chemistry)
• Polylysine (chemistry)
• Receptors, Cell Surface (metabolism)
• Surface Plasmon Resonance
• Time Factors
• Tumor Cells, Cultured