Subject:
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N4i 1: Pathogenesis and modulation of inflammation NCMLS 1: Immunity, infection and tissue repair NCMLS 2: Immune Regulation ONCOL 1: Hereditary cancer and cancer-related syndromes ONCOL 3: Translational research UMCN 1.1: Functional Imaging UMCN 1.4: Immunotherapy, gene therapy and transplantation UMCN 4.1: Microbial pathogenesis and host defense |
Organization:
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Medical Oncology Tumorimmunology Paediatrics Surgery |
Abstract:
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BACKGROUND: Dendritic cells (DCs) are the professional antigen-presenting cells of the immune system. As such they are currently used in clinical vaccination protocols in cancer patients. PATIENTS AND METHODS: We evaluated the ability of mature DCs pulsed with carcinoembryonic antigen (CEA)-peptide to induce CEA-specific T cell responses in patients with resectable liver metastases from colorectal cancer. CEA-specific T cell reactivity was monitored in peripheral blood, biopsies of vaccination sites and post-treatment DTH skin tests, and when available also in resected abdominal lymph nodes and tumor tissue. RESULTS: Ten patients were vaccinated intradermally and intravenously with CEA-peptide pulsed mature DCs three times prior to resection of liver metastases. High numbers of CEA-specific T cells were detected in post-treatment DTH biopsies in seven out of 10 patients, which produced high amounts of interferon (IFN)-gamma upon stimulation with CEA-loaded target cells. These responses were not found in biopsies of first vaccination sites, indicating a de novo T cell induction or at least a strong potentiation by the vaccine. In addition, CEA-specific T cells were detected in a resected lymph node in one patient, but not in peripheral blood or tumor tissue. CONCLUSIONS: Vaccination with CEA-peptide loaded mature DCs induced potent CEA-specific T cell responses in advanced colorectal cancer patients. In this study, antigen-specific T cell responses were readily detected in DTH skin tests, much less in abdominal lymph nodes, and not in peripheral blood and tumor tissue.
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