Hindawi Publishing Corporation Clinical and Developmental Immunology Volume 2012, Article ID 238924, 8 pages doi:10.1155/2012/238924 Research Article Improved Activation toward Primary Colorectal Cancer Cells by Antigen-Specific Targeting Autologous Cytokine-Induced Killer Cells Claudia Schlimper, 1 Andreas A. Hombach, 2 Hinrich Abken, 2, 3 and Ingo G. H. Schmidt-Wolf 3, 4 1 Department of Neurosurgery, University of Bonn, 53127 Bonn, Germany 2 Center for Molecular Medicine Cologne and Department I of Internal Medicine, University of Cologne, 53901 Cologne, Germany 3 Center for Integrated Oncology Cologne-Bonn, Germany 4 Department of Internal Medicine III, University Hospital Bonn, Sigmund-Freud-Straße 25, 53105 Bonn, Germany Correspondence should be addressed to Ingo G. H. Schmidt-Wolf, picasso@uni-bonn.de Received 2 September 2011; Revised 3 November 2011; Accepted 17 November 2011 Academic Editor: Ana Lepique Copyright © 2012 Claudia Schlimper et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Adoptive therapy of malignant diseases with cytokine-induced killer (CIK) cells showed promise in a number of trials; the activation of CIK cells from cancer patients towards their autologous cancer cells still needs to be improved. Here, we generated CIK cells ex vivo from blood lymphocytes of colorectal cancer patients and engineered those cells with a chimeric antigen receptor (CAR) with an antibody-defined specificity for carcinoembryonic antigen (CEA). CIK cells thereby gained a new specificity as defined by the CAR and showed increase in activation towards CEA + colon carcinoma cells, but less in presence of CEA − cells, indicated by increased secretion of proinflammatory cytokines. Redirected CIK activation was superior by CAR-mediated CD28- CD3ζ than CD3ζ signaling only. CAR-engineered CIK cells from colon carcinoma patients showed improved activation against their autologous, primary carcinoma cells from biopsies resulting in more efficient tumour cell lysis. We assume that adoptive therapy with CAR-modified CIK cells shows improved selectivity in targeting autologous tumour lesions. 1. Introduction Although a variety of therapeutic options for metastatic colon cancer were evaluated during the last decade, most pa- tients in advanced stages of the disease have no hope for cure by standard therapies. Alternative therapeutic approaches including immunotherapy are currently explored [1]. One of the major pitfalls in the adoptive immunotherapy of cancer is the strikingly low activation of T cells from cancer patients compared to healthy donors due to reduced expression of TCR/CD3 components [2]. The need for alternative effector cells in targeting colorectal carcinoma becomes obvious by the fact that T cells infiltrating colon cancer metastases have reduced CD3ζ chain expression and lack tumour-specific activation [3]. Compared to firstly activated effector T cells, ex vivo generated cytokine-induced killer (CIK) cells have a number of advantages since they exhibit properties different from effector or central memory T cells, that is, CIK cells are activated in an MHC-independent fashion [4, 5], produce proinflammatory cytokines, mainly IFN-γ and IL-4 [6, 7], and exhibit antigen-independent cytolytic activities against a variety of tumour cells. CIK cells are generated ex vivo by extensive stimulation of CD3 + CD56 − CD8 + T cells with IFN-γ and CD3 and prolonged propagation in presence of high-dose IL-2 [4]. After 2-3 weeks in culture, the majority of cells exhibit a large granular lymphocyte morphology and express both NK and T-cell markers including CD8, CD11a, CD49d, CD56, and NKG2D, while lacking most NK- cell-associated activating and inhibitory receptors [8]. The CD45RA + CCR7 − CD62L (+) , CD27 + , CD28 − , MIF-1a + CIK phenotype coincides with that for terminally differentiated memory T cells [9]. CIK cells display extraordinary cytolytic