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Unique Evolution of Antiviral Tetherin in Bats. J Virol 2022; 96:e0115222. [PMID: 36173189 PMCID: PMC9599465 DOI: 10.1128/jvi.01152-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Bats are recognized as important reservoirs of viruses deadly to other mammals, including humans. These infections are typically nonpathogenic in bats, raising questions about host response differences that might exist between bats and other mammals. Tetherin is a restriction factor which inhibits the release of a diverse range of viruses from host cells, including retroviruses, coronaviruses, filoviruses, and paramyxoviruses, some of which are deadly to humans and transmitted by bats. Here, we characterize the tetherin genes from 27 bat species, revealing that they have evolved under strong selective pressure, and that fruit bats and vesper bats express unique structural variants of the tetherin protein. Tetherin was widely and variably expressed across fruit bat tissue types and upregulated in spleen tissue when stimulated with Toll-like receptor agonists. The expression of two computationally predicted splice isoforms of fruit bat tetherin was verified. We identified an additional third unique splice isoform which includes a C-terminal region that is not homologous to known mammalian tetherin variants but was functionally capable of restricting the release of filoviral virus-like particles. We also report that vesper bats possess and express at least five tetherin genes, including structural variants, more than any other mammal reported to date. These findings support the hypothesis of differential antiviral gene evolution in bats relative to other mammals. IMPORTANCE Bats are an important host of various viruses which are deadly to humans and other mammals but do not cause outward signs of illness in bats. Furthering our understanding of the unique features of the immune system of bats will shed light on how they tolerate viral infections, potentially informing novel antiviral strategies in humans and other animals. This study examines the antiviral protein tetherin, which prevents viral particles from escaping their host cell. Analysis of tetherin from 27 bat species reveals that it is under strong evolutionary pressure, and we show that multiple bat species have evolved to possess more tetherin genes than other mammals, some of which encode structurally unique tetherins capable of activity against different viral particles. These data suggest that bat tetherin plays a potentially broad and important role in the management of viral infections in bats.
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Sia WR, Hey YY, Foo R, Wang LF, Leeansyah E. Culture, expansion, and flow-cytometry-based functional analysis of pteropid bat MR1-restricted unconventional T cells. STAR Protoc 2021; 2:100487. [PMID: 34041501 PMCID: PMC8141941 DOI: 10.1016/j.xpro.2021.100487] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Bats harbor viruses of global public health significance. Understanding bat immune systems may provide intervention strategies to prevent zoonotic disease transmission and identify therapeutic targets. This protocol describes how to culture and expand pteropid bat unconventional T cells, restricted by the MHC-I-related protein 1 (MR1), an MHC-I-like protein. Using multicolor flow-cytometry-based techniques, we examine pteropid MR1T cell functionality, including proliferative capacity, cytotoxicity, and cytokine production. This protocol can be adapted to aid immunological research in other bat species. For complete details on the use and execution of this protocol, please refer to Leeansyah et al. (2020b) Studies into bat immune systems are hampered by the lack of specific protocols Protocol describes culture and expansion of pteropid bat MR1-restricted T cells Performs antigen-specific stimulations of pteropid bat MR1-restricted T cells Flow-cytometry-based analyses of proliferation, cytotoxicity, and cytokine production
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Affiliation(s)
- Wan Rong Sia
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore 169857, Singapore.,Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
| | - Ying Ying Hey
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
| | - Randy Foo
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore 169857, Singapore
| | - Lin-Fa Wang
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore 169857, Singapore.,SingHealth Duke-NUS Global Health Institute, Singapore 169857, Singapore
| | - Edwin Leeansyah
- Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, People's Republic of China.,Precision Medicine and Healthcare Research Center, Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, People's Republic of China.,Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore 169857, Singapore.,Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, 14183 Stockholm, Sweden
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Irving AT, Zhang Q, Kong PS, Luko K, Rozario P, Wen M, Zhu F, Zhou P, Ng JHJ, Sobota RM, Wang LF. Interferon Regulatory Factors IRF1 and IRF7 Directly Regulate Gene Expression in Bats in Response to Viral Infection. Cell Rep 2020; 33:108345. [PMID: 33147460 PMCID: PMC8755441 DOI: 10.1016/j.celrep.2020.108345] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 08/23/2020] [Accepted: 10/13/2020] [Indexed: 12/15/2022] Open
Abstract
Bat cells and tissue have elevated basal expression levels of antiviral genes commonly associated with interferon alpha (IFNα) signaling. Here, we show Interferon Regulatory Factor 1 (IRF1), 3, and 7 levels are elevated in most bat tissues and that, basally, IRFs contribute to the expression of type I IFN ligands and high expression of interferon regulated genes (IRGs). CRISPR knockout (KO) of IRF 1/3/7 in cells reveals distinct subsets of genes affected by each IRF in an IFN-ligand signaling-dependent and largely independent manner. As the master regulators of innate immunity, the IRFs control the kinetics and maintenance of the IRG response and play essential roles in response to influenza A virus (IAV), herpes simplex virus 1 (HSV-1), Melaka virus/Pteropine orthoreovirus 3 Melaka (PRV3M), and Middle East respiratory syndrome-related coronavirus (MERS-CoV) infection. With its differential expression in bats compared to that in humans, this highlights a critical role for basal IRF expression in viral responses and potentially immune cell development in bats with relevance for IRF function in human biology.
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Affiliation(s)
- Aaron T Irving
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore; Zhejiang University-University of Edinburgh Institute, Zhejiang University School of Medicine, Zhejiang University International Campus, Haining, China; Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
| | - Qian Zhang
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore; University of Chinese Academy of Sciences, Beijing, China; Key Laboratory of Special Pathogens, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Pui-San Kong
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
| | - Katarina Luko
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
| | - Pritisha Rozario
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
| | - Ming Wen
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
| | - Feng Zhu
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
| | - Peng Zhou
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore; Key Laboratory of Special Pathogens, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Justin H J Ng
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
| | - Radoslaw M Sobota
- Functional Proteomics Laboratory, Institute of Molecular and Cell Biology (A(∗)STAR), Singapore, Singapore; Institute of Medical Biology (IMB), Agency for Science, Technology and Research (A(∗)STAR), Singapore, Singapore
| | - Lin-Fa Wang
- Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore.
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