Gene-modified NK-92MI cells expressing a chimeric CD16-BB-ζ or CD64-BB-ζ receptor exhibit enhanced cancer-killing ability in combination with therapeutic antibody

// Ying Chen 1, 2 , Fengtao You 1, 2, 3, 4 , Licui Jiang 3, 4 , Jialu Li 1, 2 , Xuejun Zhu 5 , Yangyi Bao 6 , Xiang Sun 6 , Xiaowen Tang 2, 7 , Huimin Meng 1, 2 , Gangli An 1, 2 , Bozhen Zhang 3, 4 , Lin Yang 1, 2, 3 1 The Cyrus Tang Hematology Center, Soochow University, Suzhou, Jiangsu, PR China 2 Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, PR China 3 Suzhou Cancer Immunotherapy and Diagnosis Engineering Center, Suzhou, Jiangsu, PR China 4 Persongen BioTherapeutics Co., Ltd., Suzhou, Jiangsu, PR China 5 Division of Hematology, Department of Medicine, Jiangsu Provincial Traditional Chinese Medical Hospital, Nanjing, Jiangsu Province, PR China 6 Binhu Hospital, The First People’s Hospital of Hefei Group, Hefei, Anhui, PR China 7 Department of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, PR China Correspondence to: Lin Yang, email: yanglin@suda.edu.cn Keywords: NK-92MI, chimeric CD16/CD64-BB-ζ receptor, therapeutic antibody Received: October 07, 2016      Accepted: March 04, 2017      Published: March 15, 2017 ABSTRACT Natural killer (NK) cells play a pivotal role in monoclonal antibody-mediated immunotherapy through the antibody-dependent cell-mediated cytotoxicity (ADCC) mechanism. NK-92MI is an interleukin-2 (IL-2)-independent cell line, which was derived from NK-92 cells with superior cytotoxicity toward a wide range of tumor cells in vitro and in vivo . Nonetheless, the Fc-receptor (CD16) that usually mediates ADCC is absent in NK-92 and NK-92MI cells. To apply NK-92MI cell-based immunotherapy to cancer treatment, we designed and generated two chimeric receptors in NK-92MI cells that can bind the Fc portion of human immunoglobulins. The construct includes the low-affinity Fc receptor CD16 (158F) or the high-affinity Fc receptor CD64, with the addition of the CD8a extracellular domain, CD28 transmembrane domains, two costimulatory domains (CD28 and 4-1BB), and the signaling domain from CD3ζ. The resulting chimeric receptors, termed CD16-BB-ζ and CD64-BB-ζ, were used to generate modified NK-92MI cells expressing the chimeric receptor, which were named NK-92MI hCD16 and NK-92MI hCD64 cells, respectively. We found that NK-92MI hCD16 and NK-92MI hCD64 cells significantly improved cytotoxicity against CD20-positive non-Hodgkin’s lymphoma cells in the presence of rituximab. These results suggest that the chimeric receptor-expressing NK-92MI cells may enhance the clinical responses to currently available anticancer monoclonal antibodies.