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Gurley JM, Gmyrek GB, Hargis EA, Bishop GA, Carr DJJ, Elliott MH. The Chx10-Traf3 Knockout Mouse as a Viable Model to Study Neuronal Immune Regulation. Cells 2021; 10:cells10082068. [PMID: 34440839 PMCID: PMC8391412 DOI: 10.3390/cells10082068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/06/2021] [Accepted: 08/09/2021] [Indexed: 12/15/2022] Open
Abstract
Uncontrolled inflammation is associated with neurodegenerative conditions in central nervous system tissues, including the retina and brain. We previously found that the neural retina (NR) plays an important role in retinal immunity. Tumor necrosis factor Receptor-Associated Factor 3 (TRAF3) is a known immune regulator expressed in the retina; however, whether TRAF3 regulates retinal immunity is unknown. We have generated the first conditional NR-Traf3 knockout mouse model (Chx10-Cre/Traf3f/f) to enable studies of neuronal TRAF3 function. Here, we evaluated NR-Traf3 depletion effects on whole retinal TRAF3 protein expression, visual acuity, and retinal structure and function. Additionally, to determine if NR-Traf3 plays a role in retinal immune regulation, we used flow cytometry to assess immune cell infiltration following acute local lipopolysaccharide (LPS) administration. Our results show that TRAF3 protein is highly expressed in the NR and establish that NR-Traf3 depletion does not affect basal retinal structure or function. Importantly, NR-Traf3 promoted LPS-stimulated retinal immune infiltration. Thus, our findings propose NR-Traf3 as a positive regulator of retinal immunity. Further, the NR-Traf3 mouse provides a tool for investigations of neuronal TRAF3 as a novel potential target for therapeutic interventions aimed at suppressing retinal inflammatory disease and may also inform treatment approaches for inflammatory neurodegenerative brain conditions.
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Affiliation(s)
- Jami M. Gurley
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center (OUHSC), 608 Stanton L. Young Blvd., Oklahoma City, OK 73104, USA; (G.B.G.); (E.A.H.); (D.J.J.C.); (M.H.E.)
- Correspondence:
| | - Grzegorz B. Gmyrek
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center (OUHSC), 608 Stanton L. Young Blvd., Oklahoma City, OK 73104, USA; (G.B.G.); (E.A.H.); (D.J.J.C.); (M.H.E.)
| | - Elizabeth A. Hargis
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center (OUHSC), 608 Stanton L. Young Blvd., Oklahoma City, OK 73104, USA; (G.B.G.); (E.A.H.); (D.J.J.C.); (M.H.E.)
| | - Gail A. Bishop
- Department of Microbiology and Immunology, University of Iowa and VAMC, Iowa City, IA 52242, USA;
| | - Daniel J. J. Carr
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center (OUHSC), 608 Stanton L. Young Blvd., Oklahoma City, OK 73104, USA; (G.B.G.); (E.A.H.); (D.J.J.C.); (M.H.E.)
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center (OUHSC), 608 Stanton L. Young Blvd., Oklahoma City, OK 73104, USA
| | - Michael H. Elliott
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center (OUHSC), 608 Stanton L. Young Blvd., Oklahoma City, OK 73104, USA; (G.B.G.); (E.A.H.); (D.J.J.C.); (M.H.E.)
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Zhou Y, Tao T, Liu G, Gao X, Gao Y, Zhuang Z, Lu Y, Wang H, Li W, Wu L, Zhang D, Hang C. TRAF3 mediates neuronal apoptosis in early brain injury following subarachnoid hemorrhage via targeting TAK1-dependent MAPKs and NF-κB pathways. Cell Death Dis 2021; 12:10. [PMID: 33414375 PMCID: PMC7790824 DOI: 10.1038/s41419-020-03278-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 12/15/2022]
Abstract
Neuronal apoptosis has an important role in early brain injury (EBI) following subarachnoid hemorrhage (SAH). TRAF3 was reported as a promising therapeutic target for stroke management, which covered several neuronal apoptosis signaling cascades. Hence, the present study is aimed to determine whether downregulation of TRAF3 could be neuroprotective in SAH-induced EBI. An in vivo SAH model in mice was established by endovascular perforation. Meanwhile, primary cultured cortical neurons of mice treated with oxygen hemoglobin were applied to mimic SAH in vitro. Our results demonstrated that TRAF3 protein expression increased and expressed in neurons both in vivo and in vitro SAH models. TRAF3 siRNA reversed neuronal loss and improved neurological deficits in SAH mice, and reduced cell death in SAH primary neurons. Mechanistically, we found that TRAF3 directly binds to TAK1 and potentiates phosphorylation and activation of TAK1, which further enhances the activation of NF-κB and MAPKs pathways to induce neuronal apoptosis. Importantly, TRAF3 expression was elevated following SAH in human brain tissue and was mainly expressed in neurons. Taken together, our study demonstrates that TRAF3 is an upstream regulator of MAPKs and NF-κB pathways in SAH-induced EBI via its interaction with and activation of TAK1. Furthermore, the TRAF3 may serve as a novel therapeutic target in SAH-induced EBI.
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Affiliation(s)
- Yan Zhou
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China
| | - Tao Tao
- Department of Neurosurgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China
| | - Guangjie Liu
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China
| | - Xuan Gao
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China
| | - Yongyue Gao
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China
| | - Zong Zhuang
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China
| | - Yue Lu
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China
| | - Han Wang
- Department of Neurosurgery, Nanjing Drum Tower Hospital, Clinical Medical College of Southern Medical University (Guangzhou), 210008, Nanjing, Jiangsu, People's Republic of China
| | - Wei Li
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China
| | - Lingyun Wu
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China
| | - Dingding Zhang
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China.
| | - Chunhua Hang
- Department of Neurosurgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Zhongshan Road 321, 210008, Nanjing, Jiangsu, People's Republic of China.
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Inhibition of TRAF3 expression alleviates cardiac ischemia reperfusion (IR) injury: A mechanism involving in apoptosis, inflammation and oxidative stress. Biochem Biophys Res Commun 2018; 506:298-305. [PMID: 30348527 DOI: 10.1016/j.bbrc.2018.10.058] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 10/08/2018] [Indexed: 12/28/2022]
Abstract
Ischemia reperfusion (IR) injury is known as a major issue in cardiac transplantation and various pathogenesis are involved in myocardial IR injury. Here, we show that tumor necrosis factor receptor-associated factor 3 (TRAF3) was increased in hearts of mice with cardiac IR injury and in cardiomyocytes incubated with lipopolysaccharide (LPS) and H2O2. Reducing TRAF3 expression in vivo markedly reduced the infacrted area, attenuated the histological changes, improved cardiac dysfunction and injury in mice subjected to IR injury. Functional study further indicated that TRAF3 knockdown inhibited apoptosis in murine hearts of mice with cardiac IR injury and in LPS and H2O2-cotreated cardiomyocytes, as evidenced by the decreased expression of cleaved Caspase-3 and poly (ADP-ribose) polymerases (PARP). In addition, inflammatory response and oxidative stress observed in hearts of mice with IR operation were significantly alleviated by TRAF3 knockdown through inhibiting nuclear factor-κB (NF-κB) and xanthine oxidase (XO) signaling pathways, and similar results were detected in LPS and H2O2-cotreated cardiomyocytes in vitro. Moreover, the loss of TRAF3 also restrained the phosphorylated c-Jun N-terminal protein kinase (JNK) activation following cardiac IR injury. Importantly, blocking JNK activation, as TRAF3 knockdown, greatly reduced apoptosis, inflammation and reactive oxygen species (ROS) production in LPS and H2O2-cotreated cardiomyocytes. In contrast, TRAF3 knockdown-reduced apoptosis, inflammatory response and oxidative stress were significantly rescued by promoting JNK activity in LPS and H2O2-cotreated cardiomyocytes. In summary, the results of our study indicated that repressing TRAF3 expression could be served as essential therapeutic target for protection against cardiac IR injury through restraining JNK-meditated apoptosis, inflammation and the production of ROS.
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Bishop GA, Stunz LL, Hostager BS. TRAF3 as a Multifaceted Regulator of B Lymphocyte Survival and Activation. Front Immunol 2018; 9:2161. [PMID: 30319624 PMCID: PMC6165887 DOI: 10.3389/fimmu.2018.02161] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 09/03/2018] [Indexed: 12/20/2022] Open
Abstract
The adaptor protein TNF receptor-associated factor 3 (TRAF3) serves as a powerful negative regulator in multiple aspects of B cell biology. Early in vitro studies in transformed cell lines suggested the potential of TRAF3 to inhibit signaling by its first identified binding receptor, CD40. However, because the canonical TRAF3 binding site on many receptors also mediates binding of other TRAFs, and whole-mouse TRAF3 deficiency is neonatally lethal, an accurate understanding of TRAF3's specific functions was delayed until conditional TRAF3-deficient mice were produced. Studies of B cell-specific TRAF3-deficient mice, complemented by investigations in normal and malignant mouse and human B cells, reveal that TRAF3 has powerful regulatory roles that are unique to this TRAF, as well as functions context-specific to the B cell. This review summarizes the current state of knowledge of these roles and functions. These include inhibition of signaling by plasma membrane receptors, negative regulation of intracellular receptors, and restraint of cytoplasmic NF- κB pathways. TRAF3 is also now known to function as a resident nuclear protein, and to impact B cell metabolism. Through these and additional mechanisms TRAF3 exerts powerful restraint upon B cell survival and activation. It is thus perhaps not surprising that TRAF3 has been revealed as an important tumor suppressor in B cells. The many and varied functions of TRAF3 in B cells, and new directions to pursue in future studies, are summarized and discussed here.
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Affiliation(s)
- Gail A. Bishop
- Department of Microbiology & Immunology, University of Iowa, Iowa City, IA, United States
- Department of Internal Medicine, University of Iowa, Iowa City, IA, United States
- Iowa City VA Health Care System, Iowa City, Iowa City, IA, United States
| | - Laura L. Stunz
- Department of Microbiology & Immunology, University of Iowa, Iowa City, IA, United States
| | - Bruce S. Hostager
- Department of Microbiology & Immunology, University of Iowa, Iowa City, IA, United States
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Cullell N, Muiño E, Carrera C, Torres N, Krupinski J, Fernandez-Cadenas I. Role of TRAF3 in neurological and cardiovascular diseases: an overview of recent studies. Biomol Concepts 2018; 8:197-202. [PMID: 28753533 DOI: 10.1515/bmc-2017-0008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/10/2017] [Indexed: 12/17/2022] Open
Abstract
Tumour necrosis factor receptor-associated factor 3 (TRAF3) is a member of the TRAF adaptor protein family, which exerts different effects on the cell depending on the receptor to which it binds and the cell type in which it is expressed. TRAF3 is a major regulator of the innate immune response. To perform its functions properly, TRAF3 is transcriptionally and epigenetically regulated. At the transcriptional level, TRAF3 expression has been associated with neurological and cardiovascular diseases including stroke, among other pathologies. Epigenetic modifications of TRAF3 have been observed at the histone and DNA levels. It has been observed that acetylation of TRAF3, as well as other NF-κβ target genes, is associated with cardiac hypertrophy. Furthermore, TRAF3 methylation has been associated with vascular recurrence after ischemic stroke in patients treated with clopidogrel. In this overview, we summarise the most interesting studies related to transcriptional and epigenetic regulation of TRAF3 focusing on those studies performed in neurological and cardiovascular diseases.
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Bishop GA. TRAF3 as a powerful and multitalented regulator of lymphocyte functions. J Leukoc Biol 2016; 100:919-926. [PMID: 27154354 PMCID: PMC6608063 DOI: 10.1189/jlb.2mr0216-063r] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/31/2016] [Accepted: 04/07/2016] [Indexed: 12/12/2022] Open
Abstract
This review summarizes the current state of knowledge regarding the roles of the signaling adapter protein tumor necrosis factor receptor (TNFR)-associated factor 3 in regulating the functions of B and T lymphocytes. In B lymphocytes, TNFR-associated factor 3 inhibits signaling by TNFR superfamily receptors, Toll-like receptors, and interleukin-6R. In contrast, signaling to B cells by the virally encoded oncogenic protein latent membrane protein 1 is promoted by TNFR-associated factor 3. An important B cell-specific role for TNFR-associated factor 3 is the inhibition of homeostatic survival, directly relevant to the common occurrence of TNFR-associated factor 3 mutations in human B cell malignancies. TNFR-associated factor 3 was recently found to be a resident nuclear protein in B cells, where it interacts with and inhibits gene expression mediated by the cAMP response element-binding protein transcription complex, including expression of the prosurvival protein myeloid leukemia cell differentiation protein 1. In T lymphocytes, TNFR-associated factor 3 is required for normal signaling by the T cell antigen receptor, while inhibiting signaling by the interleukin-2 receptor. Cytoplasmic TNFR -associated factor 3 restrains nuclear factor-κB2 activation in both T and B cells. Clinical implications and future directions for the study of this context-dependent signaling regulator are discussed.
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Affiliation(s)
- Gail A Bishop
- Department of Microbiology, The University of Iowa, Iowa City, Iowa, USA;
- Department of Internal Medicine, The University of Iowa, Iowa City, Iowa, USA; and
- Department of Veterans Affairs Medical Center, Iowa City, Iowa, USA
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Abstract
The adaptor protein TNF receptor-associated factor 3 (TRAF3) regulates signaling through B-lymphocyte receptors, including CD40, BAFF receptor, and Toll-like receptors, and also plays a critical role inhibiting B-cell homoeostatic survival. Consistent with these findings, loss-of-function human TRAF3 mutations are common in B-cell cancers, particularly multiple myeloma and B-cell lymphoma. B cells of B-cell-specific TRAF3(-/-) mice (B-Traf3(-/-)) display remarkably enhanced survival compared with littermate control (WT) B cells. The mechanism for this abnormal homeostatic survival is poorly understood, a key knowledge gap in selecting optimal treatments for human B-cell cancers with TRAF3 deficiency. We show here for the first time to our knowledge that TRAF3 is a resident nuclear protein that associates with the transcriptional regulator cAMP response element binding protein (CREB) in both mouse and human B cells. The TRAF-C domain of TRAF3 was necessary and sufficient to localize TRAF3 to the nucleus via a functional nuclear localization signal. CREB protein was elevated in TRAF3(-/-) B cells, without change in mRNA, but with a decrease in CREB ubiquitination. CREB-mediated transcriptional activity was increased in TRAF3-deficient B cells. Consistent with these findings, Mcl-1, an antiapoptotic target of CREB-mediated transcription, was increased in the absence of TRAF3 and enhanced Mcl-1 was suppressed with CREB inhibition. TRAF3-deficient B cells were also preferentially sensitive to survival inhibition with pharmacologic CREB inhibitor. Our results identify a new mechanism by which nuclear TRAF3 regulates B-cell survival via inhibition of CREB stability, information highly relevant to the role of TRAF3 in B-cell malignancies.
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Hu J, Zhu XH, Zhang XJ, Wang PX, Zhang R, Zhang P, Zhao GN, Gao L, Zhang XF, Tian S, Li H. Targeting TRAF3 signaling protects against hepatic ischemia/reperfusions injury. J Hepatol 2016; 64:146-59. [PMID: 26334576 DOI: 10.1016/j.jhep.2015.08.021] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 08/01/2015] [Accepted: 08/24/2015] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS The hallmarks of hepatic ischemia/reperfusion (I/R) injury, a common clinical problem that occurs during liver surgical procedures, include severe cell death and inflammatory responses that contribute to early graft failure and a higher incidence of organ rejection. Unfortunately, effective therapeutic strategies are limited. Tumor necrosis factor receptor (TNFR)-associated factor (TRAF) 3 transduces apoptosis and/or inflammation-related signaling pathways to regulate cell survival and cytokine production. However, the role of TRAF3 in hepatic I/R-induced liver damage remains unknown. METHODS Hepatocyte- or myeloid cell-specific TRAF3 knockdown or transgenic mice were subjected to an I/R model in vivo, and in vitro experiments were performed by treating primary hepatocytes from these mice with hypoxia/reoxygenation stimulation. The function of TRAF3 in I/R-induced liver damage and the potential underlying mechanisms were investigated through various phenotypic analyses and biological approaches. RESULTS Hepatocyte-specific, but not myeloid cell-specific, TRAF3 deficiency reduced cell death, inflammatory cell infiltration, and cytokine production in both in vivo and in vitro hepatic I/R models, whereas hepatic TRAF3 overexpression resulted in the opposite effects. Mechanistically, TRAF3 directly binds to TAK1, which enhances the activation of the downstream NF-κB and JNK pathways. Importantly, inhibition of TAK1 almost completely reversed the TRAF3 overexpression-mediated exacerbation of I/R injury. CONCLUSIONS TRAF3 is a novel hepatic I/R mediator that promotes liver damage and inflammation via TAK1-dependent activation of the JNK and NF-κB pathways. Inhibition of hepatic TRAF3 may represent a promising approach to protect the liver against I/R injury-related diseases.
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Affiliation(s)
- Junfei Hu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China; Animal Experiment Center/Animal Biosafety Level-III Laboratory, Wuhan University, Wuhan, China
| | - Xue-Hai Zhu
- Department of Thoracic and Cardiovascular Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Jing Zhang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Pi-Xiao Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China; Animal Experiment Center/Animal Biosafety Level-III Laboratory, Wuhan University, Wuhan, China
| | - Ran Zhang
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Peng Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China; Animal Experiment Center/Animal Biosafety Level-III Laboratory, Wuhan University, Wuhan, China
| | - Guang-Nian Zhao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China; Animal Experiment Center/Animal Biosafety Level-III Laboratory, Wuhan University, Wuhan, China
| | - Lu Gao
- Department of Cardiology, Institute of Cardiovascular Disease, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Fei Zhang
- College of Life Sciences, Wuhan University, Wuhan, China
| | - Song Tian
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China; Animal Experiment Center/Animal Biosafety Level-III Laboratory, Wuhan University, Wuhan, China
| | - Hongliang Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China; Animal Experiment Center/Animal Biosafety Level-III Laboratory, Wuhan University, Wuhan, China.
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