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Zhao Y, Zhou L, Zheng H, Gao L, Cao H, Li X, Zheng SJ, Wang Y. Gga-miR-200a-3p suppresses avian reovirus-induced apoptosis and viral replication via targeting GRB2. Vet Microbiol 2024; 295:110149. [PMID: 38909417 DOI: 10.1016/j.vetmic.2024.110149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/25/2024]
Abstract
Avian reovirus (ARV) is a significant pathogen that causes various clinical diseases in chickens, including viral arthritis, chronic respiratory diseases, retarded growth, and malabsorption syndrome. These conditions result in substantial economic losses for the global poultry industry. MicroRNAs (miRNAs), a type of small noncoding RNAs that regulate gene expression post transcriptionally by silencing or degrading their RNA targets, play crucial roles in response to pathogenic infections. In this study, transfection of DF-1 cells with gga-miR-200a-3p, an upregulated miRNA observed in ARV-infected cells, significantly suppressed ARV-induced apoptosis by directly targeting GRB2 and impeded ARV replication. Conversely, knockdown of endogenous gga-miR-200a-3p in DF-1 cells using a specific miRNA inhibitor enhanced ARV-induced apoptosis and promoted GRB2 expression, thereby facilitating viral growth within cells. Consistently, inhibition of GRB2 activity through siRNA-mediated knockdown reduced viral titers. Therefore, gga-miR-200a-3p plays a vital antiviral role in the host response to ARV infection by suppressing apoptosis via direct targeting of GRB2 protein. This information enhances our understanding of the mechanisms by which host cells combat against ARV infection through self-encoded small RNA molecules and expands our knowledge regarding the involvement of microRNAs in the host response to pathogenic infections.
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Affiliation(s)
- Yimeng Zhao
- National Key Laboratory of Veterinary Public Health Security, China; Animal Epidemiology of the Ministry of Agriculture, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Linyi Zhou
- National Key Laboratory of Veterinary Public Health Security, China; Animal Epidemiology of the Ministry of Agriculture, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Hao Zheng
- National Key Laboratory of Veterinary Public Health Security, China; Animal Epidemiology of the Ministry of Agriculture, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Li Gao
- National Key Laboratory of Veterinary Public Health Security, China; Animal Epidemiology of the Ministry of Agriculture, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Hong Cao
- National Key Laboratory of Veterinary Public Health Security, China; Animal Epidemiology of the Ministry of Agriculture, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Xiaoqi Li
- National Key Laboratory of Veterinary Public Health Security, China; Animal Epidemiology of the Ministry of Agriculture, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Shijun J Zheng
- National Key Laboratory of Veterinary Public Health Security, China; Animal Epidemiology of the Ministry of Agriculture, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yongqiang Wang
- National Key Laboratory of Veterinary Public Health Security, China; Animal Epidemiology of the Ministry of Agriculture, China; College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
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2
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Franzo G, Tucciarone CM, Faustini G, Poletto F, Baston R, Cecchinato M, Legnardi M. Reconstruction of Avian Reovirus History and Dispersal Patterns: A Phylodynamic Study. Viruses 2024; 16:796. [PMID: 38793677 PMCID: PMC11125613 DOI: 10.3390/v16050796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/11/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024] Open
Abstract
Avian reovirus (ARV) infection can cause significant losses to the poultry industry. Disease control has traditionally been attempted mainly through vaccination. However, the increase in clinical outbreaks in the last decades demonstrated the poor effectiveness of current vaccination approaches. The present study reconstructs the evolution and molecular epidemiology of different ARV genotypes using a phylodynamic approach, benefiting from a collection of more than one thousand sigma C (σC) sequences sampled over time at a worldwide level. ARVs' origin was estimated to occur several centuries ago, largely predating the first clinical reports. The origins of all genotypes were inferred at least one century ago, and their emergence and rise reflect the intensification of the poultry industry. The introduction of vaccinations had only limited and transitory effects on viral circulation and further expansion was observed, particularly after the 1990s, likely because of the limited immunity and the suboptimal and patchy vaccination application. In parallel, strong selective pressures acted with different strengths and directionalities among genotypes, leading to the emergence of new variants. While preventing the spread of new variants with different phenotypic features would be pivotal, a phylogeographic analysis revealed an intricate network of viral migrations occurring even over long distances and reflecting well-established socio-economic relationships.
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Affiliation(s)
- Giovanni Franzo
- Department of Animal Medicine, Production and Health (MAPS), University of Padua, 35020 Legnaro, Italy; (C.M.T.); (G.F.); (F.P.); (R.B.); (M.C.); (M.L.)
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3
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Gga-miR-29a-3p suppresses avian reovirus-induced apoptosis and viral replication via targeting Caspase-3. Vet Microbiol 2021; 264:109294. [PMID: 34847454 DOI: 10.1016/j.vetmic.2021.109294] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/09/2021] [Accepted: 09/16/2021] [Indexed: 12/25/2022]
Abstract
Avian reovirus (ARV) is an important pathogen causing multiple types of clinical diseases in chickens, including viral arthritis, chronic respiratory diseases, retarded growth, and malabsorption syndrome, leading to considerable economic losses to the poultry industry across the globe. MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression post transcriptionally by silencing or degrading their targets, thus playing important roles in the host response to pathogenic infection. However, the role of miRNAs in host response to ARV infection is still not clear. Here, we show that infection of DF-1 cells (a chicken fibroblast cell line) with ARV markedly altered the expressions of 583 chicken miRNAs(gga-miR), and that transfection of DF-1 cells with gga-miR-29a-3p, an upregulated miRNA in ARV-infected cells, significantly suppressed ARV-induced apoptosis via directly targeting Caspase-3, retarding ARV growth in cells. In contrast, knockdown of endogenous gga-miR-29a-3p in DF-1 cells by specific miRNA inhibitor enhanced ARV-induced apoptosis and increased the content and activity of caspase-3, facilitating viral growth in cells. Consistently, inhibition of Caspase-3 activity by inhibitors decreased viral titers in cell cultures. Thus, gga-miR-29a-3p plays an important antiviral role in host response to ARV infection by suppression of apoptosis via targeting Caspase-3. This information will further our understandings of how host cells combat against ARV infection by self-encoded small RNA and increase our knowledge of the role of microRNAs in host response to pathogenic infection.
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4
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Zhang C, Hu J, Wang X, Wang Y, Guo M, Zhang X, Wu Y. Avian reovirus infection activate the cellular unfold protein response and induced apoptosis via ATF6-dependent mechanism. Virus Res 2021; 297:198346. [PMID: 33741393 DOI: 10.1016/j.virusres.2021.198346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 01/10/2021] [Accepted: 02/12/2021] [Indexed: 11/18/2022]
Abstract
Avian reovirus (ARV) infection induced apoptosis in vitro and vivo; nevertheless, the intracellular molecular mechanisms have not been sufficiently revealed. In the previous studies, there have been shown that cellular apoptosis caused by ARV were related with GRP78/IRE1/XBP1 pathway. Protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1) and activating transcription factor 6 (ATF6) are core molecules in unfold protein response (UPR) and play critical role in ER stress related apoptosis, as well as downstream regulation factors, as Caspase-12 and C/EBP homologous protein (CHOP). In this study, we investigated with a focus on the contribution of UPR related signal pathways in the mechanism of ARV mediated apoptosis. Our results showed that the key molecules of UPR pathways proteins, ATF6, PERK and IRE1 as well as Caspase-12 and cleaved-Caspase-3 expression significant increased both in transcript and protein level in ARV infected cultured Vero cells. In the same time, the ARV induces apoptosis was observed by flow cytometric analysis. Further study revealed that when inhibit the UPR effect by 4PBA pretreated or knockdown of ATF6 by lentivirus mediated shRNA abolished the activation effect of UPR, Caspase-12, cleaved-Caspase-3 activation, as well as the apoptosis induction by ARV infection. The present study provides mechanistic insights into that UPR particular ATF6 played critical roles and works upstream of caspase in the process of cellular apoptosis induced by ARV infection.
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Affiliation(s)
- Chengcheng Zhang
- College of Veterinary Medicine, Yangzhou University, Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, 225009, PR China
| | - Jiashu Hu
- College of Veterinary Medicine, Yangzhou University, Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, 225009, PR China
| | - Xiuling Wang
- College of Veterinary Medicine, Yangzhou University, Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, 225009, PR China
| | - Yuyang Wang
- College of Veterinary Medicine, Yangzhou University, Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, 225009, PR China
| | - Mengjiao Guo
- College of Veterinary Medicine, Yangzhou University, Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, 225009, PR China
| | - Xiaorong Zhang
- College of Veterinary Medicine, Yangzhou University, Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, 225009, PR China
| | - Yantao Wu
- College of Veterinary Medicine, Yangzhou University, Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, 225009, PR China.
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5
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Ayalew LE, Ahmed KA, Mekuria ZH, Lockerbie B, Popowich S, Tikoo SK, Ojkic D, Gomis S. The dynamics of molecular evolution of emerging avian reoviruses through accumulation of point mutations and genetic re-assortment. Virus Evol 2020; 6:veaa025. [PMID: 32411390 PMCID: PMC7211400 DOI: 10.1093/ve/veaa025] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
In the last decade, the emergence of variant strains of avian reovirus (ARV) has caused enormous economic impact in the poultry industry across Canada and USA. ARVs are non-enveloped viruses with ten segments of double-stranded RNA genome. So far, only six genotyping cluster groups are identified worldwide based on sequence analysis of the σC protein encoded by the S1 segment. In this study, we performed deep next generation whole-genome sequencing and analysis of twelve purified ARVs isolated from Saskatchewan, Canada. The viruses represent different genotyping cluster. A genome-wide sequence divergence of up to 25 per cent was observed between the virus isolates with a comparable and contrasting evolutionary history. The proportion of synonymous single-nucleotide variations (sSNVs) was higher than the non-synonymous (ns) SNVs across all the genomic segments. Genomic segment S1 was the most variable as compared with the other genes followed by segment M2. Evidence of positive episodic/diversifying selection was observed at different codon positions in the σC protein sequence, which is the genetic marker for the classification of ARV genotypes. In addition, the N-terminus of σC protein had a persuasive diversifying selection, which was not detected in other genomic segments. We identified only four ARV genotypes based on the most variable σC gene sequence. However, a different pattern of phylogenetic clustering was observed with concatenated whole-genome sequences. Together with the accumulation of point mutations, multiple re-assortment events appeared as mechanisms of ARV evolution. For the first time, we determined the mean rate of molecular evolution of ARVs, which was computed as 2.3 × 10-3 substitution/site/year. In addition, widespread geographic intermixing of ARVs was observed between Canada and USA, and between different countries of the world. In conclusion, the study provides a comprehensive analysis of the complete genome of different genotyping clusters of ARVs including their molecular rate of evolution and spatial distribution. The new findings in this study can be utilized for the development of effective vaccines and other control strategies against ARV-induced arthritis/tenosynovitis in the poultry industry worldwide.
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Affiliation(s)
- Lisanework E Ayalew
- Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Khawaja Ashfaque Ahmed
- Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Zelalem H Mekuria
- College of Veterinary Medicine and Global One Health Initiative, Infectious Disease Molecular Epidemiology Laboratory, The Ohio State University, 1900 Coffey Road, Columbus, Ohio, 43210, USA
| | - Betty Lockerbie
- Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Shelly Popowich
- Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
| | - Suresh K Tikoo
- Vaccinology & Immunotherapeutic Program, School of Public Health, University of Saskatchewan, 104 Clinic Place, Saskatoon, Saskatchewan, S7N 5E3, Canada
| | - Davor Ojkic
- Animal Health Laboratory, Laboratory Services Division, University of Guelph, 419 Gordon St., Guelph, Ontario, N1H 6R8, Canada
| | - Susantha Gomis
- Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada
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6
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Xiao R, Mi X, Sun J, Ding M, Li C, Zhu J, Liu G, Ma W, Zhou H, Chen Z. Interaction between Translocation-associated membrane protein 1 and σC protein of novel duck reovirus controls virus infectivity. Virus Genes 2020; 56:347-353. [PMID: 32180130 DOI: 10.1007/s11262-020-01750-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 03/05/2020] [Indexed: 10/24/2022]
Abstract
Novel duck reovirus (NDRV), the prototype strain of the species Avian orthoreovirus (ARV), is associated with high mortality in Pekin ducklings. σC is an outer capsid protein encoded by the S1 genome segment of NDRV which mediates attachment to host cells. Our previous studies using immunoprecipitation and mass spectrometry found that σC coprecipitated with some host proteins including Translocation-associated membrane protein 1 (TRAM1). However, the interaction between σC and TRAM1 has not been further confirmed experimentally. In this study, we utilized coimmunoprecipitation assays, glutathione S-transferase pull-down, and confocal microscopy to confirm the interaction between σC and TRAM1. In addition, knockdown of TRAM1 using siRNA and overexpression of TRAM1 gene were conducted to explore its effect on virus replication. The result showed that TRAM1 silencing benefits while overexpression inhibits viral replication. This study confirms the important role TRAM1 during NDRV infection which can help develop new approaches for NDRV disease prevention and control.
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Affiliation(s)
- Rong Xiao
- National Engineering Research Center for Poultry, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China.,Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China
| | - Xiaoyun Mi
- Institute of Veterinary Medicine (Research Center of Animal Clinical), Xinjiang Academy of Animal Sciences, Urumqi, 830000, Xinjiang Uygur Autonomous Region, China
| | - Jiahui Sun
- National Engineering Research Center for Poultry, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China
| | - Mingyang Ding
- National Engineering Research Center for Poultry, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China
| | - Chuanfeng Li
- National Engineering Research Center for Poultry, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China
| | - Jie Zhu
- National Engineering Research Center for Poultry, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China
| | - Guangqing Liu
- National Engineering Research Center for Poultry, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China
| | - Wenge Ma
- Institute of Veterinary Medicine (Research Center of Animal Clinical), Xinjiang Academy of Animal Sciences, Urumqi, 830000, Xinjiang Uygur Autonomous Region, China
| | - Hailong Zhou
- Institute of Tropical Agriculture and Forestry, Hainan University, Haikou, 570228, China.
| | - Zongyan Chen
- National Engineering Research Center for Poultry, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518 Ziyue Road, Minhang District, Shanghai, 200241, China.
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7
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Wang Q, Huang WR, Chih WY, Chuang KP, Chang CD, Wu Y, Huang Y, Liu HJ. Cdc20 and molecular chaperone CCT2 and CCT5 are required for the Muscovy duck reovirus p10.8-induced cell cycle arrest and apoptosis. Vet Microbiol 2019; 235:151-163. [PMID: 31282373 DOI: 10.1016/j.vetmic.2019.06.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/19/2019] [Accepted: 06/22/2019] [Indexed: 01/22/2023]
Abstract
This study demonstrates that the Muscovy duck reovirus (MDRV) p10.8 protein is one of many viral non-structural proteins that induces both cell cycle arrest and apoptosis. The p10.8 but not σC is a nuclear targeting protein that shuttles between the nucleus and the cytoplasm. Our results reveal that p10.8-induced apoptosis in cultured cells occurs by the nucleoporin Tpr/p53-dependent and Fas/caspase 8-mediated pathways. Furthermore, a compelling finding from this study is that the p10.8 and σC proteins of MDRV facilitate CDK2 and CDK4 degradation via the ubiquitin-proteasome pathway. We found that depletion of Cdc20 reversed the p10.8- and σC- mediated CDK4 degradation and p10.8-induced apoptosis, suggesting that Cdc20 plays a critical role in modulating p10.8-mediated cell cycle and apoptosis. Furthermore, we found that depletion of chaperonin-containing tailless complex polypeptide 1 (CCT) 2 and CCT5 reduced the level of Cdc20 and reversed the p10.8- and σC-mediated CDK4 degradation and p10.8-induced apoptosis, indicating that molecular chaperone CCT2 and CCT5 are required for stabilization of Ccd20 for mediating both cell cycle arrest and apoptosis. This study provides mechanistic insights into how p10.8 induces both cell cycle arrest and apoptosis.
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Affiliation(s)
- Quanxi Wang
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Wei-Ru Huang
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan
| | - Wan-Yi Chih
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan
| | - Kuo-Pin Chuang
- Graduate Institute of Animal Vaccine Technology, National Pingtung University of Science and Technology, Pingtung, 912, Taiwan
| | - Ching-Dong Chang
- Department of Veterinary medicine, National Pingtung University of Science and Technology, Pingtung, 912, Taiwan
| | - Yijian Wu
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Yifan Huang
- College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China
| | - Hung-Jen Liu
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan; Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan; Ph. D Program in Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan; Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.
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8
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Tsuruta Y, Shibutani S, Watanabe R, Iwata H. Apoptosis induced by Ibaraki virus does not affect virus replication and cell death in hamster lung HmLu-1 cells. J Vet Med Sci 2019; 81:197-203. [PMID: 30541980 PMCID: PMC6395211 DOI: 10.1292/jvms.18-0366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ibaraki virus (IBAV) is an arbovirus that is transmitted by biting midges and causes
Ibaraki disease in cattle. IBAV induces apoptosis in several mammalian cell lines, and
apoptosis in turn facilitates IBAV replication. In addition, virus-induced apoptosis may
contribute to mammalian-specific pathogenicity considering that some arboviruses induce
apoptosis in mammalian cells but not in insect cells. In this study, we found that when
hamster lung cells (HmLu-1) are used as a virus host, IBAV causes severe cytopathic
effects with little induction of apoptosis. Furthermore, pharmacological inhibition of
apoptosis did not affect IBAV-induced cytotoxicity. These results indicate the existence
of an apoptosis-independent pathway in which IBAV replicates and exerts cytotoxicity in
mammalian cells.
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Affiliation(s)
- Yuya Tsuruta
- Laboratory of Veterinary Hygiene, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Shusaku Shibutani
- Laboratory of Veterinary Hygiene, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Rie Watanabe
- Laboratory of Veterinary Hygiene, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan.,Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama, 36849, U.S.A
| | - Hiroyuki Iwata
- Laboratory of Veterinary Hygiene, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
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Arthropod venoms: Biochemistry, ecology and evolution. Toxicon 2018; 158:84-103. [PMID: 30529476 DOI: 10.1016/j.toxicon.2018.11.433] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 11/20/2018] [Accepted: 11/26/2018] [Indexed: 12/17/2022]
Abstract
Comprising of over a million described species of highly diverse invertebrates, Arthropoda is amongst the most successful animal lineages to have colonized aerial, terrestrial, and aquatic domains. Venom, one of the many fascinating traits to have evolved in various members of this phylum, has underpinned their adaptation to diverse habitats. Over millions of years of evolution, arthropods have evolved ingenious ways of delivering venom in their targets for self-defence and predation. The morphological diversity of venom delivery apparatus in arthropods is astounding, and includes extensively modified pedipalps, tail (telson), mouth parts (hypostome), fangs, appendages (maxillulae), proboscis, ovipositor (stinger), and hair (urticating bristles). Recent investigations have also unravelled an astonishing venom biocomplexity with molecular scaffolds being recruited from a multitude of protein families. Venoms are a remarkable bioresource for discovering lead compounds in targeted therapeutics. Several components with prospective applications in the development of advanced lifesaving drugs and environment friendly bio-insecticides have been discovered from arthropod venoms. Despite these fascinating features, the composition, bioactivity, and molecular evolution of venom in several arthropod lineages remains largely understudied. This review highlights the prevalence of venom, its mode of toxic action, and the evolutionary dynamics of venom in Arthropoda, the most speciose phylum in the animal kingdom.
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10
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The E3 Ubiquitin Ligase Siah-1 Suppresses Avian Reovirus Infection by Targeting p10 for Degradation. J Virol 2018; 92:JVI.02101-17. [PMID: 29321312 DOI: 10.1128/jvi.02101-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 12/19/2017] [Indexed: 01/08/2023] Open
Abstract
Avian reovirus (ARV) causes viral arthritis, chronic respiratory diseases, retarded growth, and malabsorption syndrome. The ARV p10 protein, a viroporin responsible for the induction of cell syncytium formation and apoptosis, is rapidly degraded in host cells. Our previous report demonstrated that cellular lysosome-associated membrane protein 1 (LAMP-1) interacted with p10 and was involved in its degradation. However, the molecular mechanism underlying LAMP-1-mediated p10 degradation remains elusive. We report here that the E3 ubiquitin ligase seven in absentia homolog 1 (Siah-1) is critical for p10 ubiquitylation. Our data show that Siah-1 ubiquitylated p10 and targeted it for proteasome degradation. Furthermore, the ubiquitylation of p10 by Siah-1 required the participation of LAMP-1 by forming a multicomponent complex. Thus, LAMP-1 promotes the proteasomal degradation of p10 via interacting with both p10 and the E3 ligase Siah-1. These data establish a novel host defense mechanism where LAMP-1 serves as a scaffold for both Siah-1 and p10 that allows the E3 ligase targeting p10 for ubiquitylation and degradation to suppress ARV infection.IMPORTANCE Avian reovirus (ARV) is an important poultry pathogen causing viral arthritis, chronic respiratory diseases, retarded growth, and malabsorption syndrome, leading to considerable economic losses to the poultry industry across the globe. The ARV p10 protein is a virulence factor responsible for the induction of cell syncytium formation and apoptosis and is rapidly degraded in host cells. We previously found that cellular lysosome-associated membrane protein 1 (LAMP-1) interacts with p10 and is involved in its degradation. Here we report that the E3 ubiquitin ligase seven in absentia homolog 1 (Siah-1) ubiquitylated p10 and targeted it for proteasomal degradation. Furthermore, the ubiquitylation of p10 by Siah-1 required the participation of LAMP-1 by forming a multicomponent complex. Thus, LAMP-1 serves as an adaptor to allow Siah-1 to target p10 for degradation, thereby suppressing ARV growth in host cells.
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11
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Xie L, Xie Z, Huang L, Fan Q, Luo S, Huang J, Deng X, Xie Z, Zeng T, Zhang Y, Wang S. Avian reovirus σA and σNS proteins activate the phosphatidylinositol 3-kinase-dependent Akt signalling pathway. Arch Virol 2016; 161:2243-8. [PMID: 27233800 DOI: 10.1007/s00705-016-2908-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/19/2016] [Indexed: 11/26/2022]
Abstract
The present study was conducted to identify avian reovirus (ARV) proteins that can activate the phosphatidylinositol 3-kinase (PI3K)-dependent Akt pathway. Based on ARV protein amino acid sequence analysis, σA, σNS, μA, μB and μNS were identified as putative proteins capable of mediating PI3K/Akt pathway activation. The recombinant plasmids σA-pcAGEN, σNS-pcAGEN, μA-pcAGEN, μB-pcAGEN and μNS-pcAGEN were constructed and used to transfect Vero cells, and the expression levels of the corresponding genes were quantified by immunofluorescence and Western blot analysis. Phosphorylated Akt (P-Akt) levels in the transfected cells were measured by flow cytometry and Western blot analysis. The results showed that the σA, σNS, μA, μB and μNS genes were expressed in Vero cells. σA-expressing and σNS-expressing cells had higher P-Akt levels than negative control cells, pcAGEN-expressing cells and cells designed to express other proteins (i.e., μA, μB and μNS). Pre-treatment with the PI3K inhibitor LY294002 inhibited Akt phosphorylation in σA- and σNS-expressing cells. These results indicate that the σA and σNS proteins can activate the PI3K/Akt pathway.
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Affiliation(s)
- Liji Xie
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
| | - Zhixun Xie
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China.
| | - Li Huang
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
| | - Qing Fan
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
| | - Sisi Luo
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
| | - Jiaoling Huang
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
| | - Xianwen Deng
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
| | - Zhiqin Xie
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
| | - Tingting Zeng
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
| | - Yanfang Zhang
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
| | - Sheng Wang
- Department of Biotechnology, Guangxi Key Laboratory of Animal Epidemic Etiology and Diagnostics, Guangxi Veterinary Research Institute, 51 Youai North Road, Nanning, 530001, China
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12
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A critical role of LAMP-1 in avian reovirus P10 degradation associated with inhibition of apoptosis and virus release. Arch Virol 2016; 161:899-911. [PMID: 26744063 DOI: 10.1007/s00705-015-2731-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 12/17/2015] [Indexed: 10/22/2022]
Abstract
Avian reovirus (ARV) causes viral arthritis, chronic respiratory diseases, retarded growth and malabsorption syndrome. The ARV p10 protein, a viroporin responsible for the induction of cell syncytium formation and apoptosis, is rapidly degraded in host cells. However, the mechanism of p10 degradation and its relevance are still unclear. We report here the identification of cellular lysosome-associated membrane protein 1 (LAMP-1) as an interaction partner of p10 by yeast two-hybrid screening, immunoprecipitation and confocal microscopy assays. We found that rapid degradation of p10 was associated with ubiquitination. Importantly, ARV p10 degradation in host cells could be completely abolished by knockdown of LAMP-1 by siRNA, indicating that LAMP-1 is required for ARV p10 degradation in host cells. In contrast, overexpression of LAMP-1 facilitated p10 degradation. Furthermore, knockdown of LAMP-1 allowed p10 accumulation, enhancing p10-induced apoptosis and viral release. Thus, LAMP-1 plays a critical role in ARV p10 degradation associated with inhibition of apoptosis and viral release.
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13
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Lin PY, Liu HJ, Chang CD, Chen YC, Chang CI, Shih WL. Avian reovirus S1133-induced apoptosis is associated with Bip/GRP79-mediated Bim translocation to the endoplasmic reticulum. Apoptosis 2016; 20:481-90. [PMID: 25576194 DOI: 10.1007/s10495-015-1085-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In this study the mechanism of avian reovirus (ARV) S1133-induced pathogenesis was investigated, with a focus on the contribution of ER stress to apoptosis. Our results showed that upregulation of the ER stress response protein, as well as caspase-3 activation, occurred in ARV S1133-infected cultured cells and in SPF White Leghorn chicks organs. Upon infection, Bim was translocated specifically to the ER, but not mitochondria, in the middle to late infectious stages. In addition, ARV S1133 induced JNK phosphorylation and promoted JNK-Bim complex formation, which correlated with the Bim translocation and apoptosis induction that was observed at the same time point. Knockdown of BiP/GRP78 by siRNA and inhibition of BiP/GRP78 using EGCG both abolished the formation of the JNK-Bim complex, caspase-3 activation, and subsequent apoptosis induction by ARV S1133 efficiently. These results suggest that BiP/GRP78 played critical roles and works upstream of JNK-Bim in response to the ARV S1133-mediated apoptosis process.
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Affiliation(s)
- Ping-Yuan Lin
- Department of Biological Science and Technology, National Pingtung University of Science and Technology, 1, Shuefu Rd., Neipu, 91201, Pingtung, Taiwan
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14
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Interferon induction by avian reovirus. Virology 2015; 487:104-11. [PMID: 26517397 DOI: 10.1016/j.virol.2015.10.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 06/30/2015] [Accepted: 10/05/2015] [Indexed: 12/17/2022]
Abstract
We have previously shown that the replication of avian reovirus (ARV) in chicken embryo fibroblasts (CEF) is more resistant to the antiviral action of interferon (IFN) than the replication of vesicular stomatitis virus (VSV) or vaccinia virus (VV). In this study we examined the capacity of these three viruses to induce the expression of IFN when infecting avian cells. Efficient expression of both type-α and type-β IFNs, as well as of the double-stranded RNA (dsRNA)-activated protein kinase (PKR), takes place in ARV-infected CEF, but not in cells infected with VSV or VV. PKR expression is not directly induced by ARV infection, but by the IFN secreted by ARV-infected cells. IFN induction in ARV-infected cells requires viral uncoating, but not viral gene expression, a situation similar to that reported for apoptosis induction by ARV-infected cells. However, our results demonstrate that IFN induction by ARV-infected CEF occurs by a caspase-independent mechanism.
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15
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Vermaak E, Theron J. Virus uncoating is required for apoptosis induction in cultured mammalian cells infected with African horse sickness virus. J Gen Virol 2015; 96:1811-20. [PMID: 25783475 DOI: 10.1099/vir.0.000124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Elaine Vermaak
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria 0002, South Africa
| | - Jacques Theron
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria 0002, South Africa
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16
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Critical role of eukaryotic elongation factor 1 alpha 1 (EEF1A1) in avian reovirus sigma-C-induced apoptosis and inhibition of viral growth. Arch Virol 2015; 160:1449-61. [PMID: 25854689 DOI: 10.1007/s00705-015-2403-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/16/2015] [Indexed: 10/23/2022]
Abstract
Avian reovirus (ARV) causes viral arthritis, chronic respiratory diseases, retarded growth and malabsorption syndrome. It is well established that the ARV sigma-C protein induces apoptosis in host cells. However, the underlying molecular mechanism of this induction is still unclear. We report here the identification of eukaryotic elongation factor 1 alpha 1 (EEF1A1) as the interacting partner of σC. We found that σC-induced apoptosis in DF-1 cells could be completely abolished by knockdown of EEF1A1 by siRNA. Furthermore, knockdown of EEF1A1 markedly reduced ARV-induced apoptosis associated with decreased caspase-9 and -3 activation and cytochrome C release, leading to increased ARV growth in host cells. Thus, EEF1A1 plays a critical role in σC-induced apoptosis and inhibition of viral growth.
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17
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Rodríguez-Grille J, Busch LK, Martínez-Costas J, Benavente J. Avian reovirus-triggered apoptosis enhances both virus spread and the processing of the viral nonstructural muNS protein. Virology 2014; 462-463:49-59. [PMID: 25092461 PMCID: PMC7112042 DOI: 10.1016/j.virol.2014.04.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 04/24/2014] [Accepted: 04/26/2014] [Indexed: 01/09/2023]
Abstract
Avian reovirus non-structural protein muNS is partially cleaved in infected chicken embryo fibroblast cells to produce a 55-kDa carboxyterminal protein, termed muNSC, and a 17-kDa aminoterminal polypeptide, designated muNSN. In this study we demonstrate that muNS processing is catalyzed by a caspase 3-like protease activated during the course of avian reovirus infection. The cleavage site was mapped by site directed mutagenesis between residues Asp-154 and Ala-155 of the muNS sequence. Although muNS and muNSC, but not muNSN, are able to form inclusions when expressed individually in transfected cells, only muNS is able to recruit specific ARV proteins to these structures. Furthermore, muNSC associates with ARV factories more weakly than muNS, sigmaNS and lambdaA. Finally, the inhibition of caspase activity in ARV-infected cells does not diminish ARV gene expression and replication, but drastically reduces muNS processing and the release and dissemination of progeny viral particles. Avian reovirus-triggered apoptosis promotes cleavage of the viral nonstructural muNS protein. muNS processing is catalyzed by a caspase 3-like protease activated during avian reovirus infection. Cleavage occurs between residues Asp-154 and Ala-155 of the muNS sequence. Avian reovirus-induced apoptosis enhances the release and dissemination of progeny viral particles.
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Affiliation(s)
- Javier Rodríguez-Grille
- Centro de Investigación en Química Biológica y Materiales Moleculares, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Lisa K Busch
- Centro de Investigación en Química Biológica y Materiales Moleculares, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - José Martínez-Costas
- Centro de Investigación en Química Biológica y Materiales Moleculares, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Javier Benavente
- Centro de Investigación en Química Biológica y Materiales Moleculares, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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18
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Epizootic hemorrhagic disease virus induces and benefits from cell stress, autophagy, and apoptosis. J Virol 2013; 87:13397-408. [PMID: 24089565 DOI: 10.1128/jvi.02116-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mode and timing of virally induced cell death hold the potential of regulating viral yield, viral transmission, and the severity of virally induced disease. Orbiviruses such as the epizootic hemorrhagic disease virus (EHDV) are nonenveloped and cytolytic. To date, the death of cells infected with EHDV, the signal transduction pathways involved in this process, and the consequence of their inhibition have yet to be characterized. Here, we report that the Ibaraki strain of EHDV2 (EHDV2-IBA) induces apoptosis, autophagy, a decrease in cellular protein synthesis, the activation of c-Jun N-terminal kinase (JNK), and the phosphorylation of the JNK substrate c-Jun. The production of infectious virions decreased upon inhibition of apoptosis with the pan-caspase inhibitor Q-VD-OPH (quinolyl-valyl-O-methylaspartyl-[-2,6-difluorophenoxy]-methyl ketone), upon inhibition of autophagy with 3-methyladenine or via the knockout of the autophagy regulator Atg5, or upon treatment of infected cells with the JNK inhibitor SP600125 or the cyclin-dependent kinase (CDK) inhibitor roscovitine, which also inhibited c-Jun phosphorylation. Moreover, Q-VD-OPH, SP600125, and roscovitine partially reduced EHDV2-IBA-induced cell death, and roscovitine diminished the induction of autophagy by EHDV2-IBA. Taken together, our results imply that EHDV induces and benefits from the activation of signaling pathways involved in cell stress and death.
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19
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Perera S, Krell P, Demirbag Z, Nalçacioğlu R, Arif B. Induction of apoptosis by the Amsacta moorei entomopoxvirus. J Gen Virol 2013; 94:1876-1887. [DOI: 10.1099/vir.0.051888-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
CF-70-B2 cells derived from the spruce budworm (Choristoneura fumiferana) undergo apoptosis when infected with Amsacta moorei entomopoxvirus (AMEV), as characterized by membrane blebbing, formation of apoptotic bodies, TdT-mediated dUTP nick-end labelling (TUNEL) staining, condensed chromatin and induction of caspase-3/7 activity. The apoptotic response was reduced when cells were infected with UV-inactivated AMEV, but not when infected in the presence of the DNA synthesis inhibitor, cytosine β-d-arabinofuranoside. Hence, only pre-DNA replication events were involved in inducing the antiviral response in CF-70-B2 cells. The virus eventually overcame the host’s antiviral response and replicated to high progeny virus titres accompanied by high levels of caspase-3/7 activity. The CF-70-B2 cells were less productive of progeny virus in comparison to LD-652, a Lymantria dispar cell line routinely used for propagation of AMEV. At late stages of infection, LD-652 cells also showed characteristics of apoptosis such as oligosomal DNA fragmentation, TUNEL staining, condensed chromatin and increased caspase-3/7 activity. Induction of apoptosis in LD-652 cells was dependent on viral DNA replication and/or late gene expression. A significantly reduced rate of infection was observed in the presence of general caspase inhibitors Q-VD-OPH and Z-VAD-FMK, indicating caspases may be involved in productive virus infection.
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Affiliation(s)
- Srini Perera
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada
- Laboratory for Molecular Virology, Great Lakes Forestry Centre, Sault Ste. Marie, Ontario, Canada
| | - Peter Krell
- Department of Molecular and Cellular Biology, University of Guelph, Ontario, Canada
| | - Zihni Demirbag
- Department of Biology, Karadeniz Technical University, Trabzon, Turkey
| | | | - Basil Arif
- Laboratory for Molecular Virology, Great Lakes Forestry Centre, Sault Ste. Marie, Ontario, Canada
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20
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Abstract
Virus-induced apoptosis is thought to be the primary mechanism of cell death following reovirus infection. Induction of cell death following reovirus infection is initiated by the incoming viral capsid proteins during cell entry and occurs via NF-κB-dependent activation of classical apoptotic pathways. Prototype reovirus strain T3D displays a higher cell-killing potential than strain T1L. To investigate how signaling pathways initiated by T3D and T1L differ, we methodically analyzed cell death pathways activated by these two viruses in L929 cells. We found that T3D activates NF-κB, initiator caspases, and effector caspases to a significantly greater extent than T1L. Surprisingly, blockade of NF-κB or caspases did not affect T3D-induced cell death. Cell death following T3D infection resulted in a reduction in cellular ATP levels and was sensitive to inhibition of the kinase activity of receptor interacting protein 1 (RIP1). Furthermore, membranes of T3D-infected cells were compromised. Based on the dispensability of caspases, a requirement for RIP1 kinase function, and the physiological status of infected cells, we conclude that reovirus can also induce an alternate, necrotic form of cell death described as necroptosis. We also found that induction of necroptosis requires synthesis of viral RNA or proteins, a step distinct from that necessary for the induction of apoptosis. Thus, our studies reveal that two different events in the reovirus replication cycle can injure host cells by distinct mechanisms. Virus-induced cell death is a determinant of pathogenesis. Mammalian reovirus is a versatile experimental model for identifying viral and host intermediaries that contribute to cell death and for examining how these factors influence viral disease. In this study, we identified that in addition to apoptosis, a regulated form of cell death, reovirus is capable of inducing an alternate form of controlled cell death known as necroptosis. Death by this pathway perturbs the integrity of host membranes and likely triggers inflammation. We also found that apoptosis and necroptosis following viral infection are activated by distinct mechanisms. Our results suggest that host cells can detect different stages of viral infection and attempt to limit viral replication through different forms of cellular suicide. While these death responses may aid in curbing viral spread, they can also exacerbate tissue injury and disease following infection.
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21
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Vacchelli E, Eggermont A, Sautès-Fridman C, Galon J, Zitvogel L, Kroemer G, Galluzzi L. Trial watch: Oncolytic viruses for cancer therapy. Oncoimmunology 2013; 2:e24612. [PMID: 23894720 PMCID: PMC3716755 DOI: 10.4161/onci.24612] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 04/08/2013] [Indexed: 12/13/2022] Open
Abstract
Oncolytic virotherapy is emerging as a promising approach for the treatment of several neoplasms. The term "oncolytic viruses" is generally employed to indicate naturally occurring or genetically engineered attenuated viral particles that cause the demise of malignant cells while sparing their non-transformed counterparts. From a conceptual standpoint, oncolytic viruses differ from so-called "oncotropic viruses" in that only the former are able to kill cancer cells, even though both display a preferential tropism for malignant tissues. Of note, such a specificity can originate at several different steps of the viral cycle, including the entry of virions (transductional specificity) as well as their intracellular survival and replication (post-transcriptional and transcriptional specificity). During the past two decades, a large array of replication-competent and replication-incompetent oncolytic viruses has been developed and engineered to express gene products that would specifically promote the death of infected (cancer) cells. However, contrarily to long-standing beliefs, the antineoplastic activity of oncolytic viruses is not a mere consequence of the cytopathic effect, i.e., the lethal outcome of an intense, productive viral infection, but rather involves the elicitation of an antitumor immune response. In line with this notion, oncolytic viruses genetically modified to drive the local production of immunostimulatory cytokines exert more robust therapeutic effects than their non-engineered counterparts. Moreover, the efficacy of oncolytic virotherapy is significantly improved by some extent of initial immunosuppression (facilitating viral replication and spread) followed by the administration of immunostimulatory molecules (boosting antitumor immune responses). In this Trial Watch, we will discuss the results of recent clinical trials that have evaluated/are evaluating the safety and antineoplastic potential of oncolytic virotherapy.
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Affiliation(s)
- Erika Vacchelli
- Institut Gustave Roussy; Villejuif, France ; Université Paris-Sud/Paris XI; Le Kremlin-Bicêtre, France ; INSERM, U848; Villejuif, France
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22
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Reversine suppresses oral squamous cell carcinoma via cell cycle arrest and concomitantly apoptosis and autophagy. J Biomed Sci 2012; 19:9. [PMID: 22283874 PMCID: PMC3299600 DOI: 10.1186/1423-0127-19-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 01/27/2012] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The effective therapies for oral cancer patients of stage III and IV are generally surgical excision and radiation combined with adjuvant chemotherapy using 5-Fu and Cisplatin. However, the five-year survival rate is still less than 30% in Taiwan. Therefore, evaluation of effective drugs for oral cancer treatment is an important issue. Many studies indicated that aurora kinases (A, B and C) were potential targets for cancer therapies. Reversine was proved to be a novel aurora kinases inhibitor with lower toxicity recently. In this study, the potentiality for reversine as an anticancer agent in oral squamous cell carcinoma (OSCC) was evaluated. METHODS Effects of reversine on cell growth, cell cycle progress, apoptosis, and autophagy were evaluated mainly by cell counting, flow cytometry, immunoblot, and immunofluorescence. RESULTS The results demonstrated that reversine significantly suppressed the proliferation of two OSCC cell lines (OC2 and OCSL) and markedly rendered cell cycle arrest at G2/M stage. Reversine also induced cell death via both caspase-dependent and -independent apoptosis. In addition, reversine could inhibit Akt/mTORC1 signaling pathway, accounting for its ability to induce autophagy. CONCLUSIONS Taken together, reversine suppresses growth of OSCC via multiple mechanisms, which may be a unique advantage for developing novel therapeutic regimens for treatment of oral cancer in the future.
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23
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Meng S, Jiang K, Zhang X, Zhang M, Zhou Z, Hu M, Yang R, Sun C, Wu Y. Avian reovirus triggers autophagy in primary chicken fibroblast cells and Vero cells to promote virus production. Arch Virol 2012; 157:661-8. [PMID: 22241622 DOI: 10.1007/s00705-012-1226-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Accepted: 12/06/2011] [Indexed: 12/14/2022]
Abstract
Avian reovirus (ARV) is an important cause of disease in poultry. Although ARV is known to induce apoptosis in infected cells, the interaction between ARV and its target cells requires further elucidation. In this report, we show that the ARV isolate strain GX/2010/1 induces autophagy in both Vero and primary chicken embryonic fibroblast (CEF) cells based on the appearance of an increased number of double-membrane vesicles, the presence of GFP-microtubule-associated protein 1 light chain 3 (GFP-LC3) dot formation, and the elevated production of LC3II. We further demonstrate that the class I phosphoinositide 3-kinase (PI3K)/Akt/mTOR pathway contributes to autophagic induction by ARV infection. Moreover, treatment of ARV-infected cells with the autophagy inducer rapamycin increased viral yields, while inhibition of the autophagosomal pathway using chloroquine led to a decrease in virus production. Altogether, our studies strongly suggest that autophagy may play a critical role in determining viral yield during ARV infection.
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Affiliation(s)
- Songshu Meng
- Ministry of Education Key Lab for Avian Preventive Medicine, College of Veterinary Medicine, Yangzhou University, Wenhuidong Road No. 48, Yangzhou, 225009, China.
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24
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Lin PY, Liu HJ, Chang CD, Chang CI, Hsu JL, Liao MH, Lee JW, Shih WL. Avian reovirus S1133-induced DNA damage signaling and subsequent apoptosis in cultured cells and in chickens. Arch Virol 2011; 156:1917-29. [PMID: 21779911 DOI: 10.1007/s00705-011-1063-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2011] [Accepted: 06/30/2011] [Indexed: 12/22/2022]
Abstract
In this study, intracellular signaling in ARV S1133-mediated apoptosis was investigated. A microarray was used to examine the gene expression profiles of cells upon ARV S1133 infection and ARV-encoded pro-apoptotic protein σC overexpression. The analysis indicated that in the set of DNA-damage-responsive genes, DDIT-3 and GADD45α were both upregulated by viral infection and σC overexpression. Further investigation demonstrated that both treatments caused DNA breaks, which increased the expression and/or phosphorylation of DNA damage response proteins. ROS and lipid peroxidation levels were increased, and ARV S1133 and σC caused apoptosis mediated by DNA damage signaling. ROS scavenger NAC, caffeine and an ATM-specific inhibitor significantly reduced ARV S1133- and σC-induced DNA breaks, DDIT-3 and GADD45α expression, H2AX phosphorylation, and apoptosis. Overexpression of DDIT-3 and GADD45α enhanced the oxidative stress and apoptosis induced by ARV S1133 and σC. In conclusion, our results demonstrate the involvement of the DNA-damage-signaling pathway in ARV S1133- and σC-induced apoptosis.
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Affiliation(s)
- Ping-Yuan Lin
- Graduate Institute and Department of Life Science, Tzu-Chi University, Hualien, Taiwan
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25
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Enter the kill zone: initiation of death signaling during virus entry. Virology 2011; 411:316-24. [PMID: 21262519 PMCID: PMC7126532 DOI: 10.1016/j.virol.2010.12.043] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 12/14/2010] [Accepted: 12/22/2010] [Indexed: 12/28/2022]
Abstract
Infection of host cells by a variety of viruses results in programmed cell death or apoptosis. In many cases, early events in virus replication that occur prior to synthesis of viral proteins and replication of viral genomes directly or indirectly activate signaling pathways that culminate in cell death. Using examples of viruses for which prodeath signaling is better defined, this review will describe how cell entry steps including virus attachment to receptors, virus uncoating in endosomes, and events that occur following membrane penetration lead to apoptosis. The relevance and physiologic consequences of early induction of prodeath signaling to viral pathogenesis also will be discussed.
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26
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Acrani GO, Gomes R, Proença-Módena JL, da Silva AF, Oliveira Carminati P, Silva ML, Santos RIM, Arruda E. Apoptosis induced by Oropouche virus infection in HeLa cells is dependent on virus protein expression. Virus Res 2010; 149:56-63. [DOI: 10.1016/j.virusres.2009.12.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 12/19/2009] [Accepted: 12/22/2009] [Indexed: 01/31/2023]
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27
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Lin PY, Liu HJ, Liao MH, Chang CD, Chang CI, Cheng HL, Lee JW, Shih WL. Activation of PI 3-kinase/Akt/NF-kappaB and Stat3 signaling by avian reovirus S1133 in the early stages of infection results in an inflammatory response and delayed apoptosis. Virology 2010; 400:104-14. [PMID: 20170934 DOI: 10.1016/j.virol.2010.01.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 01/05/2010] [Accepted: 01/20/2010] [Indexed: 01/08/2023]
Abstract
Avian reovirus (ARV) strain S1133 causes apoptosis in host cells in the middle to late stages of infection. This study investigated the early-stage biological response and intracellular signaling in ARV S1133-infected Vero and chicken cells. Treatment with conditioned medium from ARV S1133-infected cells increased the chemotactic activity of U937 cells. Neutralizing antibodies against IL-1beta and IL-6 showed that both cytokines contribute to viral-induced inflammation but neither affect cell survival. Inhibition of Akt, NF-kappaB, and Stat3 released the chemotactic activity and anti-apoptotic effect elicited by ARV S1133. ARV S1133 activated PI 3-kinase-dependent Akt/NF-kappaB and p70 S6 kinase, as well as Stat3; however, p70 S6 kinase was not involved in ARV S1133-mediated effects. DF1 cells over-expressing constitutively active PI 3-kinase and Stat3 showed association with enhancement of anti-apoptotic activity. In conclusion, in the early stages of ARV S1133 infection, activation of cell survival signals contributes to virus-induced inflammation and anti-apoptotic response.
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Affiliation(s)
- Ping-Yuan Lin
- Graduate Institute and Department of Life Science, Tzu-Chi University, Hualien, Taiwan
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28
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Vázquez-Iglesias L, Lostalé-Seijo I, Martínez-Costas J, Benavente J. Avian reovirus sigmaA localizes to the nucleolus and enters the nucleus by a nonclassical energy- and carrier-independent pathway. J Virol 2009; 83:10163-75. [PMID: 19640987 PMCID: PMC2747991 DOI: 10.1128/jvi.01080-09] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Accepted: 07/16/2009] [Indexed: 12/24/2022] Open
Abstract
Avian reovirus sigmaA is a double-stranded RNA (dsRNA)-binding protein that has been shown to stabilize viral core particles and to protect the virus against the antiviral action of interferon. To continue with the characterization of this viral protein, we have investigated its intracellular distribution in avian cells. Most sigmaA accumulates into cytoplasmic viral factories of infected cells, and yet a significant fraction was detected in the nucleolus. The protein also localizes in the nucleolus of transfected cells, suggesting that nucleolar targeting is not facilitated by the viral infection or by viral factors. Assays performed in both intact cells and digitonin-permeabilized cells demonstrate that sigmaA is able to enter the nucleus via a nucleoporin-dependent nondiffusional mechanism that does not require added cytosolic factors or energy input. These results indicate that sigmaA by itself is able to penetrate into the nucleus using a process that is mechanistically different from the classical nuclear localization signal/importin pathway. On the other hand, two sigmaA arginines that are necessary for dsRNA binding are also required for nucleolar localization, suggesting that dsRNA-binding and nucleolar targeting are intimately linked properties of the viral protein.
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Affiliation(s)
- Lorena Vázquez-Iglesias
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
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Ji WT, Wang L, Lin RC, Huang WR, Liu HJ. Avian reovirus influences phosphorylation of several factors involved in host protein translation including eukaryotic translation elongation factor 2 (eEF2) in Vero cells. Biochem Biophys Res Commun 2009; 384:301-5. [DOI: 10.1016/j.bbrc.2009.04.116] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Accepted: 04/22/2009] [Indexed: 10/20/2022]
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Modulation of p53 by mitogen-activated protein kinase pathways and protein kinase C δ during avian reovirus S1133-induced apoptosis. Virology 2009; 385:323-34. [DOI: 10.1016/j.virol.2008.12.028] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2008] [Revised: 12/12/2008] [Accepted: 12/17/2008] [Indexed: 01/08/2023]
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31
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Day JM, Spackman E, Pantin-Jackwood MJ. Turkey origin reovirus-induced immune dysfunction in specific pathogen free and commercial turkey poults. Avian Dis 2008; 52:387-91. [PMID: 18939624 DOI: 10.1637/8190-120607-reg] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recently, pathogenesis studies, using genetically distinct turkey-origin reoviruses (TRVs), revealed that poults infected with certain TRV isolates had moderate to severe bursal atrophy, suggesting virus-induced immune dysfunction. In order to characterize the effect of TRV infection on the turkey immune system, classical assays were undertaken to quantify the humoral and cell-mediated immune responses in small Beltsville and broad-breasted white poults infected with the TRV isolate NC/SEP-R44/03. A marked effect on the cutaneous basophil hypersensitivity response, and on the antibody response to Newcastle disease virus (NDV) exposure, was noted in commercial and specific pathogen free (SPF) poults inoculated with NC/SEP-R44/03 at three days of age. Moderate to severe bursal atrophy, similar to that noted previously in SPF poults, occurred in commercial poults inoculated at three days of age. This immune dysfunction and bursal atrophy was not present in commercial poults inoculated at three weeks of age.
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Affiliation(s)
- J Michael Day
- Southeast Poultry Research Laboratory, Agricultural Research Service, United States Department of Agriculture, 934 College Station Road, Athens, Georgia 30605, USA.
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32
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Wu YF, Liu HJ, Shien JH, Chiou SH, Lee LH. Characterization of interleukin-1beta mRNA expression in chicken macrophages in response to avian reovirus. J Gen Virol 2008; 89:1059-1068. [PMID: 18343850 DOI: 10.1099/vir.0.82957-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inhibitors of viral disassembly or RNA and protein synthesis, viral disassembly intermediates (infectious subviral particles, ISVP), binary ethylenimine-inactivated virions, and viral particles lacking genomic double-stranded (ds) RNA (empty particles) were used to assess the expression of interleukin-1beta (IL-1beta) mRNA in chicken (chIL-1beta) macrophages in response to avian reovirus. The results demonstrate that two distinct expression patterns of chIL-1beta mRNA mediated by different steps in viral replication were found. Viral disassembly was required for the induction of a rapid, transient expression pattern of chIL-1beta mRNA that was rapidly induced at 30 min, with maximal levels reached by 2 h, and fell to a low level within 6 h post-inoculation, while viral RNA synthesis rather than protein translation, which was subsequent to membrane penetration, was required to induce a stable, sustained expression pattern of chIL-1beta mRNA that occurred at and after 6 h post-inoculation. In addition, the induction of chIL-1beta mRNA expression by the empty particles and ISVP was extremely weak, compared with the active dsRNA(+) virions or binary ethylenimine-inactivated virions, suggesting that the presence of dsRNA, even if transcriptionally inactive, may be an important factor in this response.
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Affiliation(s)
- Yung Fu Wu
- Graduate Institute of Veterinary Microbiology, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan ROC
| | - Hung Jen Liu
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan ROC
| | - Jui Huang Shien
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan ROC
| | - Shiow Her Chiou
- Graduate Institute of Veterinary Microbiology, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan ROC
| | - Long Huw Lee
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan ROC
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33
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Lin HY, Chuang ST, Chen YT, Shih WL, Chang CD, Liu HJ. Avian reovirus-induced apoptosis related to tissue injury. Avian Pathol 2007; 36:155-9. [PMID: 17479377 DOI: 10.1080/03079450701261262] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Apoptosis plays an important role in pathogenesis of many viral infections. Infection of chicken with avian reovirus S1133 causes tissue injury related to virus-induced apoptosis. To determine whether avian reovirus (ARV) induced apoptosis in chicken tissues, six 3-week-old specific pathogen free White Leghorn chicks were inoculated with ARV S1133. Tissues were dual-labelled for the simultaneous detection of viral antigen containing and apoptotic cells. DNA laddering was detected in ARV-infected but not mock-infected chicken tissues. Dual-labelling assay revealed that the majority of antigen-expressing cells were not apoptotic. Surprisingly, some apoptotic but non-antigen-expressing cells were frequently located in the vicinity of antigen-expressing cells. Syncytium formation in ARV-infected chicken tissues undergoing apoptosis was apparent, suggesting a correlation between virus replication and apoptosis in chicken tissues.
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Affiliation(s)
- Hsin Y Lin
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
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34
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DeWitte-Orr SJ, Bols NC. Cytopathic effects of chum salmon reovirus to salmonid epithelial, fibroblast and macrophage cell lines. Virus Res 2007; 126:159-71. [PMID: 17391795 DOI: 10.1016/j.virusres.2007.02.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Revised: 01/13/2007] [Accepted: 02/15/2007] [Indexed: 10/23/2022]
Abstract
The cytopathic effect (CPE) of chum salmon reovirus (CSV), an aquareovirus, was studied in three salmonid cell lines: epithelial-like CHSE-214 from Chinook salmon embryo, fibroblast-like RTG-2, and monocyte/macrophage-like RTS11, both from rainbow trout. CHSE-214 and RTG-2 supported syncytia formation with more dramatic syncytia being observed in CHSE-214 cultures, while CSV induced homotypic aggregation (HA) in RTS11. Syncytia and HA formation were blocked by cycloheximide and ribavirin but not actinomycin D, suggesting that expression of CSV genes were required for both phenomena. Cultures with syncytia underwent a decline in cell viability, which appeared to be via apoptosis, as determined by intranucleosomal fragmentation and caspase dependence assays using the pan-caspase inhibitor, zVAD-fmk. In the presence of zVAD-fmk, CHSE-214 cultures continued to form syncytia and show diminished energy metabolism, but DNA fragmentation, the loss of membrane integrity, and the release of infectious CSV were considerably blocked. These results suggest that the formation of syncytia triggers apoptosis and a leaky plasma membrane, which enhances viral release. By contrast, RTS11 cultures undergoing HA showed no loss of cell viability. The significance of HA is unclear, but the response suggests that macrophage behaviour in rainbow trout potentially could be modulated by CSV.
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35
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Pantin-Jackwood MJ, Spackman E, Day JM. Pathology and virus tissue distribution of Turkey origin reoviruses in experimentally infected Turkey poults. Vet Pathol 2007; 44:185-95. [PMID: 17317795 DOI: 10.1354/vp.44-2-185] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The pathogenesis of 4 isolates of turkey-origin reovirus (NC/SEP-R44/03, NC/98, TX/98, and NC/85) and 1 chicken-origin reovirus (1733) was examined by infecting specific pathogen free (SPF) poults. These turkey-origin reovirus (TRV) isolates were collected from turkey flocks experiencing poult enteritis and are genetically distinct from previously reported avian reoviruses. Microscopic examination of the tissues collected from the TRV-infected poults revealed different degrees of bursal atrophy characterized by lymphoid depletion and increased fibroplasia between the bursal follicles. To understand the relationship between virus spread and replication, and the induction of lesions, immunohistochemical staining (IHC) for viral antigen, in situ hybridization (ISH) for the detection of viral RNA, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay for the detection of apoptosis in affected tissues was performed. Both IHC and ISH revealed viral antigen and RNA in the surface epithelial cells of the bursa, in macrophages in the interstitium of the bursa and, to lesser degree, in splenic red pulp macrophages and intestinal epithelial cells. Increased apoptosis of bursal lymphocytes and macrophages was observed at 2 and 5 days postinoculation. No lesions were found in tissues from poults inoculated with the virulent chicken-origin strain, however viral antigen was detected in the bursa and the intestine. Although all TRVs studied displayed similar tissue tropism, there were substantial differences in the severity of the lesions produced. Poults inoculated with NC/SEP-R44/03 or NC/98 had moderate to severe bursal atrophy, whereas poults inoculated with TX/98 or NC/85 presented a mild to moderate bursal lymphoid depletion. The lymphoid depletion observed in the bursa appears to be the effect of an indirectly induced apoptosis and would most likely result in immune dysfunction in poults infected with TRV.
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Affiliation(s)
- M J Pantin-Jackwood
- Southeast Poultry Research Laboratory, US Department of Agriculture, Agricultural Research Service, 934 College Station Road, Athens, GA 30605, USA.
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36
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Vähä-Koskela MJ, Heikkilä JE, Hinkkanen AE. Oncolytic viruses in cancer therapy. Cancer Lett 2007; 254:178-216. [PMID: 17383089 PMCID: PMC7126325 DOI: 10.1016/j.canlet.2007.02.002] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 02/01/2007] [Accepted: 02/05/2007] [Indexed: 12/26/2022]
Abstract
Oncolytic virotherapy is a promising form of gene therapy for cancer, employing nature’s own agents to find and destroy malignant cells. The purpose of this review is to provide an introduction to this very topical field of research and to point out some of the current observations, insights and ideas circulating in the literature. We have strived to acknowledge as many different oncolytic viruses as possible to give a broader picture of targeting cancer using viruses. Some of the newest additions to the panel of oncolytic viruses include the avian adenovirus, foamy virus, myxoma virus, yaba-like disease virus, echovirus type 1, bovine herpesvirus 4, Saimiri virus, feline panleukopenia virus, Sendai virus and the non-human coronaviruses. Although promising, virotherapy still faces many obstacles that need to be addressed, including the emergence of virus-resistant tumor cells.
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Affiliation(s)
- Markus J.V. Vähä-Koskela
- Åbo Akademi University, Department of Biochemistry and Pharmacy and Turku Immunology Centre, Turku, Finland
- Turku Graduate School of Biomedical Sciences, Turku, Finland
- Corresponding author. Address: Åbo Akademi University, Department of Biochemistry and Pharmacy and Turku Immunology Centre, Turku, Finland. Tel.: +358 2 215 4018; fax: +358 2 215 4745.
| | - Jari E. Heikkilä
- Åbo Akademi University, Department of Biochemistry and Pharmacy and Turku Immunology Centre, Turku, Finland
| | - Ari E. Hinkkanen
- Åbo Akademi University, Department of Biochemistry and Pharmacy and Turku Immunology Centre, Turku, Finland
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37
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Chulu JLC, Lee LH, Lee YC, Liao SH, Lin FL, Shih WL, Liu HJ. Apoptosis induction by avian reovirus through p53 and mitochondria-mediated pathway. Biochem Biophys Res Commun 2007; 356:529-35. [PMID: 17379188 DOI: 10.1016/j.bbrc.2007.02.164] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2007] [Accepted: 02/28/2007] [Indexed: 11/19/2022]
Abstract
Although induction of apoptosis by avian reovirus has been demonstrated in primary chicken embryonic fibroblast and several cell lines, to date, the potential significance of avian reovirus (ARV)-induced apoptosis and its pathways in cultured cells are still largely unknown. We now provide the first evidence of upregulation of p53 and Bax and specifically for Bax translocation from cytosol to mitochondria following infection with a cytoplasmically replicating RNA virus. Bax translocation to the mitochondria led to the release of mitochondrial proapoptic factors cytochrome c and Smac/DIABLO from mitochondria to the cytosol, but not the release of apoptosis-inducting factor. Activation of caspases-9 and -3 which cleaves the enzyme poly(ADP-ribose) polymerase in ARV-infected BHK-21 cells was also detected. Internucleosomal DNA cleavage was prevented by caspase inhibitors, further demonstrating that ARV-induced apoptosis was executed through caspase-dependent mechanisms. Stable expression of human bcl-2 in BHK-21 cells not only blocked ARV-induced apoptosis and DNA fragmentation but also reduced the level of infectious virus production and its spread in BHK-21 cells infected with ARV at a low multiplicity of infection. All our data suggest that p53 and the mitochondria-mediated pathway played an important regulatory role in ARV-induced apoptosis in BHK-21 cells. To further study the pathogenesis of ARV infection, a dual-labeling assay was used for the simultaneous detection of cells containing viral antigen and apoptotic cells. Dual-labeling assay revealed that the majority of antigen-expressing cells were not apoptotic. Remarkably, some apoptotic but non-antigen-expressing cells were frequently located in the vicinity of antigen-expressing cells. Syncytium formation in ARV-infected BHK-21 cells undergoing apoptosis, was apparent in large syncytia at late infection times, indicating a correlation between virus replication and apoptosis in cultured cells.
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Affiliation(s)
- Julius L C Chulu
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
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38
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Benavente J, Martínez-Costas J. Avian reovirus: Structure and biology. Virus Res 2007; 123:105-19. [PMID: 17018239 DOI: 10.1016/j.virusres.2006.09.005] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2006] [Revised: 09/06/2006] [Accepted: 09/07/2006] [Indexed: 11/28/2022]
Abstract
Avian reoviruses are important pathogens that cause considerable losses to the poultry industry, but they have been poorly characterized at the molecular level in the past, mostly because they have been considered to be very similar to the well-studied mammalian reoviruses. Studies performed over the last 20 years have revealed that avian reoviruses have unique properties and activities, different to those displayed by their mammalian counterparts, and of considerable interest to molecular virologists. Notably, the avian reovirus S1 gene is unique, in that it is a functional tricistronic gene that possesses three out-of-phase and partially overlapping open reading frames; the identification of the mechanisms that govern the initiation of translation of the three S1 cistrons, and the study of the properties and activities displayed by their encoded proteins, are particularly interesting areas of research. For instance, avian reoviruses are one of the few nonenveloped viruses that cause cell-cell fusion, and their fusogenic phenotype has been associated with a nonstructural 10 kDa transmembrane protein, which is expressed by the second cistron of the S1 gene; the small size of this atypical fusion protein offers an interesting model for studying the mechanisms of cell-cell fusion and for identifying fusogenic domains. Finally, avian reoviruses are highly resistant to interferon, and therefore they may be useful for investigating the mechanisms and strategies that viruses utilize to counteract the antiviral actions of interferons.
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Affiliation(s)
- Javier Benavente
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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39
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Ping-Yuan L, Hung-Jen L, Meng-Jiun L, Feng-Ling Y, Hsue-Yin H, Jeng-Woei L, Wen-Ling S. Avian Reovirus activates a novel proapoptotic signal by linking Src to p53. Apoptosis 2006; 11:2179-93. [PMID: 17051326 DOI: 10.1007/s10495-006-0291-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We have previously shown that avian reovirus (ARV) S1133 and its structural protein sigmaC cause apoptosis in cultured Vero cells through an unknown intracellular signaling pathway. This work investigates how ARV S1133 induces proapoptotic signals. Upon ARV S1133 infection and subsequent apoptosis, levels of p53 mRNA and protein, and p53 serine-46 and serine-392 phosphorylation increased. In addition, p53-driven reporter activity and levels of the p53-induced apoptotic protein bax were increased, and Src tyrosine-418 phosphorylation was elevated. UV-inactivated virus failed to activate Src, p53 or induce apoptosis. Over-expression of dominant negative p53, or treatment with tyrosine kinase inhibitor genistein protected cells from ARV S1133-induced apoptosis. Inhibition of Src by over-expression of C-terminal Src kinase (Csk) or treatment with Src family tyrosine kinase inhibitor SU-6656 diminished the ARV S1133-induced p53 expression, activation, and apoptosis. Over-expression of sigmaC resulted in the upregulation of p53, p53 serine-46 phosphorylation, p53-driven reporter activity and accumulation of bax. sigmaC expression during ARV S1133 infection was concomitant with the onset of apoptosis. These studies provide strong evidence that the viral gene expression is required for ARV S1133 to initiate a proapoptotic signal via Src to p53. In addition, sigmaC was able to utilize a p53-dependent pathway to elicit apoptosis.
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Affiliation(s)
- Lin Ping-Yuan
- Graduate Institute and Department of Life Science, Tzu-Chi University, 701, Sec. 3, Chung-Yang Rd., Hualien, Taiwan, 970
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40
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Coffey CM, Sheh A, Kim IS, Chandran K, Nibert ML, Parker JSL. Reovirus outer capsid protein micro1 induces apoptosis and associates with lipid droplets, endoplasmic reticulum, and mitochondria. J Virol 2006; 80:8422-38. [PMID: 16912293 PMCID: PMC1563861 DOI: 10.1128/jvi.02601-05] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The mechanisms by which reoviruses induce apoptosis have not been fully elucidated. Earlier studies identified the mammalian reovirus S1 and M2 genes as determinants of apoptosis induction. However, no published results have demonstrated the capacities of the proteins encoded by these genes to induce apoptosis, either independently or in combination, in the absence of reovirus infection. Here we report that the mammalian reovirus micro1 protein, encoded by the M2 gene, was sufficient to induce apoptosis in transfected cells. We also found that micro1 localized to lipid droplets, endoplasmic reticulum, and mitochondria in both transfected cells and infected cells. Two small regions encompassing amphipathic alpha-helices within a carboxyl-terminal portion of micro1 were necessary for efficient induction of apoptosis and association with lipid droplets, endoplasmic reticulum, and mitochondria in transfected cells. Induction of apoptosis by micro1 and its association with lipid droplets and intracellular membranes in transfected cells were abrogated when micro1 was coexpressed with sigma3, with which it is known to coassemble. We propose that micro1 plays a direct role in the induction of apoptosis in infected cells and that this property may relate to the capacity of micro1 to associate with intracellular membranes. Moreover, during reovirus infection, association with sigma3 may regulate apoptosis induction by micro1.
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Affiliation(s)
- Caroline M Coffey
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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41
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Abstract
Avian reoviruses are important pathogens that may cause considerable economic losses in poultry farming. Their genome expresses at least eight structural and four nonstructural proteins, three of them encoded by the S1 gene. These viruses enter cells by receptor-mediated endocytosis, and acidification of virus-containing endosomes is necessary for the virus to uncoat and release transcriptionally active cores into the cytosol. Avian reoviruses replicate within cytoplasmic inclusions of globular morphology, termed viral factories, which are not microtubule-associated, and which are formed by the nonstructural protein muNS. This protein also mediates the association of some viral proteins (but not of others) with inclusions, suggesting that the recruitment of viral proteins into avian reovirus factories has specificity. Avian reovirus morphogenesis is a complex and temporally controlled process that takes place exclusively within viral factories of infected cells. Core assembly takes place within the first 30 min after the synthesis of their protein components, and fully formed cores are then coated by outer-capsid polypeptides over the next 30 min to generate mature infectious reovirions. Based on data from avian reovirus studies and on results reported for other members of the Reoviridae family, we present a model for avian reovirus gene expression and morphogenesis.
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Affiliation(s)
- J Benavente
- Departamento de Bioquímica y Biología Molecular, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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42
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Clarke P, Debiasi RL, Goody R, Hoyt CC, Richardson-Burns S, Tyler KL. Mechanisms of reovirus-induced cell death and tissue injury: role of apoptosis and virus-induced perturbation of host-cell signaling and transcription factor activation. Viral Immunol 2005; 18:89-115. [PMID: 15802955 PMCID: PMC2366905 DOI: 10.1089/vim.2005.18.89] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Reoviruses have provided insight into the roles played by specific viral genes and the proteins they encode in virus-induced cell death and tissue injury. Apoptosis is a major mechanism of cell death induced by reoviruses. Reovirus-induced apoptosis involves both death-receptor and mitochondrial cell death pathways. Reovirus infection is associated with selective activation of mitogen activated protein kinase (MAPK) cascades including JNK/SAPK. Infection also perturbs transcription factor signaling resulting in the activation of c-Jun and initial activation followed by strain-specific inhibition of NF-kappaB. Infection results in changes in the expression of genes encoding proteins involved in cell cycle regulation, apoptosis, and DNA damage and repair processes. Apoptosis is a major mechanism of reovirus-induced injury to key target organs including the CNS and heart. Inhibition of apoptosis through the use of caspase or calpain inhibitors, minocycline, or in caspase 3(-/-) mice all reduce virus-associated tissue injury and enhance survival of infected animals. Reoviruses induce apoptotic cell death (oncolysis) in a wide variety of cancer cells and tumors. The capacity of reoviruses to grow efficiently in transformed cells is enhanced by the presence of an activated Ras signaling pathway likely through mechanisms involving inhibition of antiviral PKR signaling and activation of Ras/RalGEF/p38 pathways. The potential of reovirus-induced oncolysis in therapy of human cancers is currently being investigated in phase I/II clinical trials.
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Affiliation(s)
- P Clarke
- Department of Neurology, University of Colorado Health Sciences Center, 4200 East 9th Ave., Denver, CO 80262, USA
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43
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Pal K, Kaetzel CS, Brundage K, Cunningham CA, Cuff CF. Regulation of polymeric immunoglobulin receptor expression by reovirus. J Gen Virol 2005; 86:2347-2357. [PMID: 16033983 DOI: 10.1099/vir.0.80690-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Polymeric immunoglobulin receptor (pIgR) transcytoses dimeric IgA and IgA-coated immune complexes from the lamina propria across epithelia and into secretions. The effect of reovirus infection on regulation of pIgR expression in the human intestinal epithelial cell line HT-29 was characterized in this report. Both replication-competent and UV-inactivated reovirus at m.o.i. equivalents of 1-100 p.f.u. per cell upregulated pIgR mRNA by 24 h post-infection and intracellular pIgR protein was increased at 48 h following exposure to UV-inactivated virus. Binding of virus to HT-29 cells was required, as pre-incubating virus with specific antiserum, but not non-immune serum, inhibited reovirus-mediated pIgR upregulation. Endosomal acidification leading to uncoating of virus is a required step for pIgR upregulation, as ammonium chloride or bafilomycin A1 pre-treatment inhibited virus-induced pIgR upregulation. Inhibition experiments using the calpain inhibitor N-acetyl-leucyl-leucyl-norleucinal suggested that calpains are involved in reovirus-mediated pIgR upregulation. Upregulation of pIgR following virus infection appears to be an innate immune response against invading pathogens that could help the host clear infection effectively. Signalling induced by microbes and their products may serve to augment pIgR-mediated transcytosis of IgA, linking the innate and acquired immune responses to viruses.
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Affiliation(s)
- Kasturi Pal
- Department of Microbiology, Immunology and Cell Biology, Robert C. Byrd Health Sciences Center, West Virginia University, PO Box 9177, Morgantown, WV 26506-9177, USA
| | - Charlotte S Kaetzel
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY 40536, USA
| | - Kathleen Brundage
- Department of Microbiology, Immunology and Cell Biology, Robert C. Byrd Health Sciences Center, West Virginia University, PO Box 9177, Morgantown, WV 26506-9177, USA
| | - Cynthia A Cunningham
- Department of Microbiology, Immunology and Cell Biology, Robert C. Byrd Health Sciences Center, West Virginia University, PO Box 9177, Morgantown, WV 26506-9177, USA
| | - Christopher F Cuff
- Department of Microbiology, Immunology and Cell Biology, Robert C. Byrd Health Sciences Center, West Virginia University, PO Box 9177, Morgantown, WV 26506-9177, USA
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44
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Chaïbi C, Cotte-Laffitte J, Sandré C, Esclatine A, Servin AL, Quéro AM, Géniteau-Legendre M. Rotavirus induces apoptosis in fully differentiated human intestinal Caco-2 cells. Virology 2005; 332:480-90. [PMID: 15680413 DOI: 10.1016/j.virol.2004.11.039] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Revised: 07/07/2004] [Accepted: 11/18/2004] [Indexed: 01/06/2023]
Abstract
Rotaviruses, which are the main cause of viral gastroenteritis in young children, induce structural and functional damages in infected mature enterocytes of the small intestine. To investigate a relationship between rotavirus infection and cell death by apoptosis, we used the human intestinal Caco-2 cell line. We demonstrated by several methods including TUNEL and ELISA detection of cytoplasmic histone-associated DNA fragments that the infection of fully differentiated Caco-2 cells by the RRV rotavirus strain induces apoptosis. Rotavirus infection leads to the loss of mitochondrial membrane potential and the release of cytochrome C from mitochondria. We showed that rotavirus-induced apoptosis was dependent of the multiplicity of infection and increased with time from 4 h to 24 h of infection. Flow cytometric analysis showed that DNA fragmentation occurs in productively infected cells, suggesting that rotavirus induces apoptosis by a direct mechanism. We also demonstrated that non-replicative RRV particles are not sufficient to induce apoptosis and viral gene expression seems required. Intracellular calcium plays a role in RRV-induced apoptosis because treatment with an intracellular calcium ion chelator (BAPTA-AM) partially inhibited apoptosis.
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Affiliation(s)
- Charlotte Chaïbi
- Institut National de la Santé et de la Recherche Médicale, U 510, Pathogènes et Fonctions des Cellules Epithéliales Polarisées, Faculté de Pharmacie, 5 rue J.B. Clément, 92290 Châtenay-Malabry, France
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45
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Renault S, Stasiak K, Federici B, Bigot Y. Commensal and mutualistic relationships of reoviruses with their parasitoid wasp hosts. JOURNAL OF INSECT PHYSIOLOGY 2005; 51:137-48. [PMID: 15749099 PMCID: PMC7127831 DOI: 10.1016/j.jinsphys.2004.08.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2004] [Accepted: 08/20/2004] [Indexed: 05/16/2023]
Abstract
During evolution, certain endoparasitoid wasps have developed mechanisms to suppress the defence systems of their hosts. For this purpose, these species, all of which belong to the families Ichneumonidae and Braconidae, inject various kinds of virus-like particles. The most studied of these particles are classified as polydnaviruses (family Polydnaviridae) which are symbiotic viruses. Over the past decade, it has also been shown that several wasp species harbour reoviruses (family Reoviridae), and that two of these suppress host defence, allowing the development of the parasitoid eggs. In this paper, we summarize the key features of these viruses and their relationships with their wasp hosts. Five reoviruses are known that appear to be non-pathogenic for the wasps. Three of these, McRVLP, HeRV, OpRVLP, use their wasp hosts as vectors, and do not appear to be involved in host defence suppression. The fourth, DpRV-1, is a commensal reovirus detected in most field populations of the wasp, Diadromus pulchellus. This reovirus is always found associated with an ascovirus, DpAV-4a, which is indispensable for host immune suppression. Although DpRV-1 has not been shown to directly increase D. pulchellus parasitic success, it may contribute to this success by retarding DpAV-4a replication in the wasp. The fifth reovirus, DpRV-2, occurs in a specific population of D. pulchellus in which DpRV-1 and DpAV-4 are absent. This virus has a mutualistic relationship with its wasp host, as its injection by females during oviposition is essential for host immunosuppression. Interestingly, these viruses belong to several different reovirus genera.
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Affiliation(s)
- Sylvaine Renault
- Laboratoire d'Etude des Parasites Génétiques, Université François Rabelais, UFR Sciences et Techniques, Parc Grandmont, 37200 Tours, France.
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Miles DH, Willcox MDP, Athmanathan S. Ocular and neuronal cell apoptosis during HSV-1 infection: a review. Curr Eye Res 2005; 29:79-90. [PMID: 15512955 DOI: 10.1080/02713680490504669] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
HSV-1 may activate or suppress the apoptotic pathway in various cells. This review will discuss this apparent dichotomy and place particular emphasis on the different strategies HSV-1 uses to block or suppress the apoptotic pathway in various cell lines and tissues.
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Affiliation(s)
- David H Miles
- Cooperative Research Centre for Eye Research; Technology, School of Optometry and Vision Science, University of New South Wales, Sydney, NSW 2052, Australia
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Hermann LL, Coombs KM. Mycophenolic acid inhibits replication of Type 2 Winnipeg, a cerebrospinal fluid-derived reovirus isolate. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2004; 15:261-5. [PMID: 18159503 PMCID: PMC2094986 DOI: 10.1155/2004/387272] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Accepted: 08/09/2004] [Indexed: 12/23/2022]
Abstract
BACKGROUND The role of reoviruses in human disease is uncertain. Most identified cases are sporadic and asymptomatic or produce minor upper respiratory or gastrointestinal symptoms. In November 1997, a reovirus was isolated from the cerebrospinal fluid of a severe combined immune deficient infant in Winnipeg, Manitoba. RNA characterization and sequencing studies demonstrated this reovirus isolate to be unique. Thus, the virus was named Type 2 Winnipeg (T2W). OBJECTIVE Mycophenolic acid (MPA), a drug primarily used as an immunosuppressive agent, was assessed in the capacity to inhibit T2W viral growth. METHODS The effects of MPA on viral growth were determined by plaque reduction assays. Cells were treated with different MPA concentrations, infected with T2W and incubated at 37 degrees C for 0 h to 72 h. Virus titres were determined and compared with untreated controls. RESULTS Production of infectious T2W progeny decreased more than 99% at 3 microg/mL MPA compared with untreated controls. Inhibition was not caused by cell toxicity because there was no difference in cell viability. The 50% cell toxic dose was 30 microg/mL MPA. CONCLUSIONS MPA was able to inhibit viral growth of the novel reovirus T2W. Although MPA is usually used as an immunosuppressive agent, and despite the fact that T2W was isolated from an immunocompromised patient, these results suggest that MPA could have been used as a possible treatment at subimmunosuppressive doses. Animal studies to better define the antiviral and immunosuppressive activities of MPA (and its prodrug mycophenolate mofetil) appear warranted.
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Affiliation(s)
- Laura L Hermann
- Departments of Medical Microbiology and Infectious Diseases, and Physiology, University of Manitoba, Winnipeg, Manitoba
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Hermann LL, Coombs KM. Inhibition of reovirus by mycophenolic acid is associated with the M1 genome segment. J Virol 2004; 78:6171-9. [PMID: 15163710 PMCID: PMC416527 DOI: 10.1128/jvi.78.12.6171-6179.2004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycophenolic acid (MPA), an inhibitor of IMP dehydrogenase, inhibits reovirus replication and viral RNA and protein production. In mouse L929 cells, antiviral effects were greatest at 30 microg of MPA/ml. At this dosage, MPA inhibited replication of reovirus strain T3D more than 1,000-fold and inhibited replication of reovirus strain T1L nearly 100-fold, compared to non-drug-treated controls. Genetic reassortant analysis indicated the primary determinant of strain-specific differences in sensitivity to MPA mapped to the viral M1 genome segment, which encodes the minor core protein mu2. MPA also inhibited replication of both strains of reovirus in a variety of other cell lines, including Vero monkey kidney and U373 human astrocytoma cells. Addition of exogenous guanosine to MPA-treated reovirus-infected cells restored viral replicative capacity to nearly normal levels. These results suggest the mu2 protein is involved in the uptake and processing of GTP in viral transcription in infected cells and strengthens the evidence that the mu2 protein can function as an NTPase and is likely a transcriptase cofactor.
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Affiliation(s)
- Laura L Hermann
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, 730 William Avenue, Winnipeg, Manitoba, Canada R3E 0W3
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Shih WL, Hsu HW, Liao MH, Lee LH, Liu HJ. Avian reovirus sigmaC protein induces apoptosis in cultured cells. Virology 2004; 321:65-74. [PMID: 15033566 DOI: 10.1016/j.virol.2003.12.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Revised: 12/03/2003] [Accepted: 12/03/2003] [Indexed: 10/26/2022]
Abstract
The avian reovirus (ARV) infection is associated with various disease conditions in poultry. However, the pathogenesis mechanisms are poorly characterized. In the present study, we clearly demonstrated that the sigmaC of ARV S1133 strain induced apoptosis in both BHK-21 and Vero cells. Five kinds of assays for apoptosis were used in analyzing ARV-infected BHK-21 and Vero cells: (1) assay for DNA ladders, (2) ELISA detection of cytoplasmic histone-associated DNA fragments, (3) nuclear staining with acridine orange, (4) Western blot, Northern blot, and immunofluorescent assay (IFA), and (5) flow cytometric analysis. The sigmaC protein of ARV could elicit apoptosis occurring in a dose- and time-dependent manner. The current results further our understanding of the function of sigmaC in cultured cells and suggest that sigmaC is a viral-encoded apoptin and possesses apoptosis-inducing ability. Furthermore, deletion analysis of the ARV sigmaC protein suggests that the carboxyl-terminus of sigmaC is important in mediating sigmaC-induced apoptosis because its deletion abolished the induction of apoptosis.
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Affiliation(s)
- Wen L Shih
- Department of Life Science, Tzu-Chi University, Hualien, Taiwan
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Esfandiarei M, Luo H, Yanagawa B, Suarez A, Dabiri D, Zhang J, McManus BM. Protein kinase B/Akt regulates coxsackievirus B3 replication through a mechanism which is not caspase dependent. J Virol 2004; 78:4289-98. [PMID: 15047842 PMCID: PMC374262 DOI: 10.1128/jvi.78.8.4289-4298.2004] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The role of signaling pathways including the mitogen-activated protein kinases (MAPKs) and phosphatidylinositol 3-kinase (PI3K) during viral infection has gained much recent attention. Our laboratory reported on an important regulatory role for extracellular signal-regulated kinases (ERK1/2), subfamily members of the MAPKs, during coxsackievirus B3 (CVB3) infection. However, the role of the PI3K pathway in CVB3 infection has not been well characterized. CVB3 is the most common known viral infectant of heart muscle that directly injures and kills infected cardiac myocytes during the myocarditic process. In the present study, we investigated the role of protein kinase B (PKB) (also known as Akt), a general downstream mediator of survival signals through the PI3K cascade, in regulating CVB3 replication and virus-induced apoptosis in a well-established HeLa cell model. We have demonstrated that CVB3 infection leads to phosphorylation of PKB/Akt on both Ser-473 and Thr-308 residues through a PI3K-dependent mechanism. Transfection of HeLa cells with a dominant negative mutant of Akt1 or pretreatment of wild-type HeLa cells with the specific PI3K inhibitor LY294002 significantly suppresses viral RNA expression, as reflected in diminished viral capsid protein expression and viral release. Dominant negative Akt1 and LY294002 also increase apoptosis in infected cells, which can be reversed by addition of the general caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.fmk). Interestingly, blocking of apoptosis by zVAD.fmk does not reverse the viral RNA translation blockade, indicating that the inhibitory effect of dominant negative Akt1 on viral protein expression is not caspase dependent. In addition, we showed that the attachment of virus to its receptor-coreceptor complex is not sufficient for PKB/Akt activation and that postentry viral replication is required for Akt phosphorylation. Taken together, these data illustrate a new and imperative role for Akt in CVB3 infection in HeLa cells and show that the PI3K/Akt signaling is beneficial to CVB3 replication.
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Affiliation(s)
- Mitra Esfandiarei
- The James Hogg iCAPTURE Centre for Cardiovascular and Pulmonary Research, Department of Pathology and Laboratory Medicine, St. Paul's Hospital/Providence Health Care-University of British Columbia, Vancouver, Canada
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