Treatment of Human Glioblastoma with a Live Attenuated Zika Virus Vaccine Candidate Qi Chen, a Jin Wu, b,h Qing Ye, a,c Feng Ma, d,e Qian Zhu, f Yan Wu, f Chao Shan, g Xuping Xie, g Dapei Li, d,e Xiaoyan Zhan, b Chunfeng Li, a,d,e Xiao-Feng Li, a Xiaoling Qin, a Tongyang Zhao, a Haitao Wu, f Pei-Yong Shi, g Jianghong Man, b Cheng-Feng Qin a a State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China b State Key Laboratory of Proteomics, National Center of Biomedical Analysis, Beijing, China c Guangzhou No.8 People's Hospital, Guangzhou Medical University, Guangzhou, China d Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China e Suzhou Institute of Systems Medicine, Suzhou, China f Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China g Department of Biochemistry and Molecular Biology, Department of Pharmacology and Toxicology, Sealy Center for Structural Biology & Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas, USA h Tianjin Key Laboratory of Risk Assessment and Control Technology for Environment and Food Safety, Institute of Environmental Medicine, Academy of Military Medical Sciences, Tianjin, China ABSTRACT Glioblastoma (GBM) is the deadliest type of brain tumor, and glioma stem cells (GSCs) contribute to tumor recurrence and therapeutic resistance. Thus, an oncolytic virus targeting GSCs may be useful for improving GBM treatment. Be- cause Zika virus (ZIKV) has an oncolytic tropism for infecting GSCs, we investigated the safety and efficacy of a live attenuated ZIKV vaccine candidate (ZIKV-LAV) for the treatment of human GBM in a GSC-derived orthotopic model. Intracerebral injection of ZIKV-LAV into mice caused no neurological symptoms or behavioral abnormali- ties. The neurovirulence of ZIKV-LAV was more attenuated than that of the licensed Japanese encephalitis virus LAV 14-14-2, underlining the superior safety of ZIKV-LAV for potential GBM treatment. Importantly, ZIKV-LAV significantly reduced intracere- bral tumor growth and prolonged animal survival by selectively killing GSCs within the tumor. Mechanistically, ZIKV infection elicited antiviral immunity, inflammation, and GSC apoptosis. Together, these results further support the clinical development of ZIKV-LAV for GBM therapy. IMPORTANCE Glioblastoma (GBM), the deadliest type of brain tumor, is currently in- curable because of its high recurrence rate after traditional treatments, including surgery to remove the main part of the tumor and radiation and chemotherapy to target residual tumor cells. These treatments fail mainly due to the presence of a cell subpopulation called glioma stem cells (GSCs), which are resistant to radiation and chemotherapy and capable of self-renewal and tumorigenicity. Because Zika vi- rus (ZIKV) has an oncolytic tropism for infecting GSCs, we tested a live attenuated ZIKV vaccine candidate (ZIKV-LAV) for the treatment of human GBM in a human GSC-derived orthotopic model. Our results showed that ZIKV-LAV retained good effi- cacy against glioblastoma by selectively killing GSCs within the tumor. In addition, ZIKV-LAV exhibited an excellent safety profile upon intracerebral injection into the treated animals. The good balance between the safety of ZIKV-LAV and its efficacy against human GSCs suggests that it is a potential candidate for combination with the current treatment regimen for GBM therapy. KEYWORDS Zika virus, anticancer therapy, glioblastoma, vaccine Received 2 August 2018 Accepted 21 August 2018 Published 18 September 2018 Citation Chen Q, Wu J, Ye Q, Ma F, Zhu Q, Wu Y, Shan C, Xie X, Li D, Zhan X, Li C, Li X-F, Qin X, Zhao T, Wu H, Shi P-Y, Man J, Qin C-F. 2018. Treatment of human glioblastoma with a live attenuated Zika virus vaccine candidate. mBio 9:e01683-18. https://doi.org/10.1128/mBio .01683-18. Editor W. Ian Lipkin, Mailman School of Public Health, Columbia University Copyright © 2018 Chen et al. This is an open- access article distributed under the terms of the Creative Commons Attribution 4.0 International license. Address correspondence to Pei-Yong Shi, peshi@utmb.edu. or Jianghong Man, jhman@ncba.ac.cn, or Cheng-Feng Qin, qincf@bmi.ac.cn. Q.C., J.W., Q.Y., and F.M. contributed equally to the article. This article is a direct contribution from a Fellow of the American Academy of Microbiology. Solicited external reviewers: Kristen A. Bernard, University of Wisconsin— Madison; Eng Eong Ooi, Duke NUS Graduate Medical School. RESEARCH ARTICLE Host-Microbe Biology crossm September/October 2018 Volume 9 Issue 5 e01683-18 ® mbio.asm.org 1