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Dong W, Wu X, Ma S, Wang Y, Nalin AP, Zhu Z, Zhang J, Benson DM, He K, Caligiuri MA, Yu J. The Mechanism of Anti-PD-L1 Antibody Efficacy against PD-L1-Negative Tumors Identifies NK Cells Expressing PD-L1 as a Cytolytic Effector. Cancer Discov 2019; 9:1422-1437. [PMID: 31340937 DOI: 10.1158/2159-8290.cd-18-1259] [Citation(s) in RCA: 205] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 05/07/2019] [Accepted: 07/01/2019] [Indexed: 12/11/2022]
Abstract
Blockade of PD-L1 expression on tumor cells via anti-PD-L1 monoclonal antibody (mAb) has shown great promise for successful cancer treatment by overcoming T-cell exhaustion; however, the function of PD-L1 on natural killer (NK) cells and the effects of anti-PD-L1 mAb on PD-L1+ NK cells remain unknown. Moreover, patients with PD-L1 - tumors can respond favorably to anti-PD-L1 mAb therapy for unclear reasons. Here, we show that some tumors can induce PD-L1 on NK cells via AKT signaling, resulting in enhanced NK-cell function and preventing cell exhaustion. Anti-PD-L1 mAb directly acts on PD-L1+ NK cells against PD-L1 - tumors via a p38 pathway. Combination therapy with anti-PD-L1 mAb and NK cell-activating cytokines significantly improves the therapeutic efficacy of human NK cells against PD-L1 - human leukemia when compared with monotherapy. Our discovery of a PD-1-independent mechanism of antitumor efficacy via the activation of PD-L1+ NK cells with anti-PD-L1 mAb offers new insights into NK-cell activation and provides a potential explanation as to why some patients lacking PD-L1 expression on tumor cells still respond to anti-PD-L1 mAb therapy. SIGNIFICANCE: Targeting PD-L1 expressed on PD-L1+ tumors with anti-PD-L1 mAb successfully overcomes T-cell exhaustion to control cancer, yet patients with PD-L1 - tumors can respond to anti-PD-L1 mAb. Here, we show that anti-PD-L1 mAb activates PD-L1+ NK cells to control growth of PD-L1 - tumors in vivo, and does so independent of PD-1.This article is highlighted in the In This Issue feature, p. 1325.
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Affiliation(s)
- Wenjuan Dong
- Department of Hematology and Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California.,Hematologic Malignancies and Stem Cell Transplantation Institute, City of Hope National Medical Center, Duarte, California
| | - Xiaojin Wu
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio.,Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Shoubao Ma
- Department of Hematology and Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California.,Institute of Blood and Marrow Transplantation, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
| | - Yufeng Wang
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio
| | - Ansel P Nalin
- Medical Scientist Training Program, The Ohio State University, Columbus, Ohio
| | - Zheng Zhu
- Department of Hematology and Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California
| | - Jianying Zhang
- Department of Computational and Quantitative Medicine, City of Hope National Medical Center, Duarte, California
| | - Don M Benson
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio
| | - Kai He
- The Ohio State University Comprehensive Cancer Center, Columbus, Ohio
| | - Michael A Caligiuri
- Department of Hematology and Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California. .,Hematologic Malignancies and Stem Cell Transplantation Institute, City of Hope National Medical Center, Duarte, California.,Department of Immuno-Oncology, Duarte, California.,City of Hope Comprehensive Cancer Center, Duarte, California
| | - Jianhua Yu
- Department of Hematology and Hematopoietic Cell Transplantation, City of Hope National Medical Center, Duarte, California. .,Hematologic Malignancies and Stem Cell Transplantation Institute, City of Hope National Medical Center, Duarte, California.,Department of Immuno-Oncology, Duarte, California.,City of Hope Comprehensive Cancer Center, Duarte, California
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Abstract
Isolated central nervous system (CNS) relapse in acute myeloid leukemia (AML) rarely occurs later than 2 years after remission. We present a child diagnosed with AML (FAB M5) without CNS involvement at diagnosis who was treated with chemotherapy and consolidated with autologous hematopoietic stem cell transplantation. He was in complete remission for >6 years until he had an isolated CNS relapse. He was treated with only intrathecal chemotherapy and achieved a second complete remission, but relapsed in the bone marrow 5 months after the CNS relapse. Treatment of late isolated CNS relapse of AML is discussed.
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