Vaccination of colorectal cancer patients with CEA-loaded dendritic cells: antigen-specific T cell responses in DTH skin tests

PMID: 16600979
Journal: Annals of oncology : official journal of the European Society for Medical Oncology (volume: 17, issue: 6, Ann. Oncol. 2006 Jun;17(6):974-80)
Published: 2006-04-06

Authors:
Lesterhuis WJ, de Vries IJ, Schuurhuis DH, Boullart AC, Jacobs JF, de Boer AJ, Scharenborg NM, Brouwer HM, van de Rakt MW, Figdor CG, Ruers TJ, Adema GJ, Punt CJ

ABSTRACT

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.