title: Generation and preclinical characterization of an NKp80-Fc fusion protein for redirected cytolysis of natural killer (NK) cells against leukemia.
abstract: The capacity of natural killer (NK) cells to mediate Fc receptor-dependent effector functions, such as antibody-dependent cellular cytotoxicity (ADCC), largely contributes to their clinical application. Given that activation-induced C-type lectin (AICL), an identified ligand for the NK-activating receptor NKp80, is frequently highly expressed on leukemia cells, the lack of therapeutic AICL-specific antibodies limits clinical application. Here we explore a strategy to reinforce NK anti-leukemia reactivity by combining targeting AICL-expressing leukemia cells with the induction of NK cell ADCC using NKp80-Fc fusion proteins. The NKp80-Fc fusion protein we generated bound specifically to leukemia cells in an AICL-specific manner. Cell binding assays between NK and leukemia cells showed that NKp80-Fc significantly increased NK target cell conjugation. In functional analyses, treatment with NKp80-Fc clearly induced the ADCC effect of NK cells. NKp80-Fc not only promoted NK-mediated leukemia cell apoptosis in the early stage of cell conjugation but also enhanced NK cell degranulation and cytotoxicity activity in the late stage. The bifunctional NKp80-Fc could redirect NK cells toward leukemia cells and triggered NK cell killing in vitro. Moreover, NKp80-Fc enhanced the lysis of NK cells against tumors in leukemia xenograft non-obese diabetic/severe combined immunodeficiency mice. Taken together, our results demonstrate that NKp80-Fc potently amplifies NK cell anti-leukemia effects in vitro and in vivo through induction of the NK cell ADCC effect. This method could potentially be useful for molecular targeted therapy, and the fusion proteins may be a promising drug for immunotherapy of leukemia.
authors.affiliation: From the Institute of Immunology and Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Deng
authors.affiliation: From the Institute of Immunology and Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China, zhxdd@ustc.edu.cn.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zheng
authors.affiliation: From the Institute of Immunology and Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhou
authors.affiliation: From the Institute of Immunology and Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China, the Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230027, China.
authors.forename: Haiming
authors.initials: H
authors.lastname: Wei
authors.affiliation: From the Institute of Immunology and Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China, the Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230027, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Tian
authors.affiliation: From the Institute of Immunology and Chinese Academy of Sciences Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China, the Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230027, China the State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, Fujian 361005, China, and sunr@ustc.edu.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Sun
mesh_terms: D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity / Q000187:drug effects; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D045744:Cell Line, Tumor; D064593:Heterografts; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use; D007938:Leukemia / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D055607:Receptors, Natural Killer Cell / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D023041:Xenograft Model Antitumor Assays
chemical_list: D007141:Immunoglobulin Fc Fragments; C431711:KLRF1 protein, human; D037181:Lectins, C-Type; D055607:Receptors, Natural Killer Cell; D011993:Recombinant Fusion Proteins
keywords: ADCC; AICL; Fc receptor; NKp80; fusion protein; immunotherapy; leukemia; natural killer (NK) cells