ABSTRACT
BACKGROUND: The expression of the scavenger receptor for advanced glycation end products (RAGE) and various ligands of RAGE correlate significantly with cancer progression. However, the mechanism of RAGE/sRAGE-induced cancer cell activation and ligand usage remain largely unknown. METHODS: Androgen-independent, highly invasive, as well as androgen-dependent, non-invasive human prostate carcinoma (CaP) cells were investigated for their interaction with the soluble form of RAGE (sRAGE). Using neutralizing antibodies and soluble proteins, the ligand for RAGE was identified on CaP cells and ligand binding with sRAGE was biochemically characterized. RESULTS: Both androgen-independent, highly invasive and androgen-dependent, non-invasive CaP cells interacted with immobilized sRAGE in a surprisingly strong manner. Using C-terminal truncation variants of RAGE we identified the V domain being responsible for the adhesion of CaP cells to sRAGE. Moreover, we demonstrate that this adhesion cannot be blocked by S100B or neutralizing antibodies against beta integrins, or amphoterin. However, the CaP cell-RAGE interaction was inhibited with either AGE-modified proteins, or with neutralizing antibodies against AGE or RAGE. Despite similar binding kinetics between AGE-modified BSA and different RAGE domains, only applying an excess of sRAGE, but not the VC1 or V domain of RAGE, was able to block the CaP cell-RAGE interaction. CONCLUSIONS: We identified AGEs as the ligand for RAGE on both invasive and non-invasive prostate cancer cells.
Subject(s)
Glycation End Products, Advanced/metabolism , Prostatic Neoplasms/metabolism , Receptors, Immunologic/metabolism , Antibodies, Blocking/pharmacology , Binding Sites , Binding, Competitive , Cell Adhesion/drug effects , Cell Line, Tumor , Glycation End Products, Advanced/chemistry , HMGB1 Protein/immunology , Humans , Ligands , Male , Nerve Growth Factors/metabolism , Prostatic Neoplasms/immunology , Receptor for Advanced Glycation End Products , Receptors, Immunologic/chemistry , Receptors, Immunologic/immunology , S100 Calcium Binding Protein beta Subunit , S100 Proteins/metabolismABSTRACT
Dendritic cell (DC)-based immunotherapy has been hampered by the lack of suitable methods for antigen delivery. Here, we use biodegradable poly(D,L-lactide-co-glycolide) microspheres (PLGA-MS) as carriers of peptides and proteins for antigen delivery to human monocyte-derived DC (MoDC). Compared to soluble proteins, MHC classes I and II-restricted presentation of PLGA-MS-encapsulated proteins and peptides by MoDC was markedly prolonged and proteins were presented 50-fold more efficiently on class I molecules. The vaccination of mice with DC loaded with PLGA-MS-encapsulated proteins raised strong and persisting cytotoxic T cell responses. In conclusion, antigen delivery via PLGA-MS markedly enhanced the duration of antigen presentation by human MoDC and the potency of DC-based vaccination.
Subject(s)
Dendritic Cells/immunology , Lactic Acid , Microspheres , Peptides/immunology , Polyglycolic Acid , Polymers , Proteins/immunology , Animals , Antigen Presentation , Cell Line , Cytotoxicity Tests, Immunologic , Delayed-Action Preparations , Humans , Mice , Mice, Inbred C57BL , Peptide Fragments/administration & dosage , Peptide Fragments/immunology , Peptide Fragments/metabolism , Peptides/administration & dosage , Peptides/metabolism , Polylactic Acid-Polyglycolic Acid Copolymer , Proteins/administration & dosage , Proteins/metabolism , T-Lymphocytes, Cytotoxic/immunology , Tetanus Toxoid/administration & dosage , Tetanus Toxoid/immunology , Tetanus Toxoid/metabolism , Vaccination/methods , Viral Matrix Proteins/administration & dosage , Viral Matrix Proteins/immunology , Viral Matrix Proteins/metabolismABSTRACT
BACKGROUND: Dendritic cell (DC)-based vaccination has been investigated as immunotherapy for several types of cancer. A potential drawback to vaccination with autologous monocyte-derived DCs (MoDCs) could be that MoDCs from patients are functionally impaired. In case of androgen-independent prostate cancer (CaP), the cancer itself, diverse prior therapies, and the hormone manipulation may affect the immune system. METHODS: MoDCs from patients suffering from androgen-independent CaP were generated according to a clinically applicable protocol to evaluate the phenotype, maturation capacity, migration, and T-cell stimulation of these cells compared with those generated from tumor-free donors. RESULTS: MoDCs generated from CaP patients could be fully matured and efficiently migrated towards the chemokine CCL21. They had a strong potency to activate allogeneic CD4+ and CD8+ T-cells and to present antigens to specific CTL. CONCLUSIONS: Our data suggest that MoDCs from patients with androgen-independent CaP are functionally intact and hence qualify as cellular vaccines for immunotherapy of advanced stage CaP.
