1
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Orosco FL. African swine fever virus proteins against host antiviral innate immunity and their implications for vaccine development. Open Vet J 2024; 14:941-951. [PMID: 38808296 PMCID: PMC11128636 DOI: 10.5455/ovj.2024.v14.i4.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 03/13/2024] [Indexed: 05/30/2024] Open
Abstract
African swine fever virus (ASFV) poses a significant threat to global swine populations, necessitating a profound understanding of viral strategies against host antiviral innate immunity. This review synthesizes current knowledge regarding ASFV proteins and their intricate interactions with host defenses. Noteworthy findings encompass the modulation of interferon signaling, manipulation of inflammatory pathways, and the impact on cellular apoptosis. The implications of these findings provide a foundation for advancing vaccine strategies against ASFV. In conclusion, this review consolidates current knowledge, emphasizing the adaptability of ASFV in subverting host immunity. Identified research gaps underscore the need for continued exploration, presenting opportunities for developing targeted vaccines. This synthesis provides a roadmap for future investigations, aiming to enhance our preparedness against the devastating impact of ASFV on global swine populations.
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Affiliation(s)
- Fredmoore L. Orosco
- Virology and Vaccine Institute of the Philippines Program, Industrial Technology Development Institute, Department of Science and Technology, Taguig, Philippines
- Department of Biology, College of Arts and Sciences, University of the Philippines Manila, Metro Manila, Philippines
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2
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Reis AL, Rathakrishnan A, Goulding LV, Barber C, Goatley LC, Dixon LK. Deletion of the gene for the African swine fever virus BCL-2 family member A179L increases virus uptake and apoptosis but decreases virus spread in macrophages and reduces virulence in pigs. J Virol 2023; 97:e0110623. [PMID: 37796125 PMCID: PMC10617521 DOI: 10.1128/jvi.01106-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 08/23/2023] [Indexed: 10/06/2023] Open
Abstract
IMPORTANCE African swine fever virus (ASFV) causes a lethal disease of pigs with high economic impact in affected countries in Africa, Europe, and Asia. The virus encodes proteins that inhibit host antiviral defenses, including the type I interferon response. Host cells also activate cell death through a process called apoptosis to limit virus replication. We showed that the ASFV A179L protein, a BCL-2 family apoptosis inhibitor, is important in reducing apoptosis in infected cells since deletion of this gene increased cell death and reduced virus replication in cells infected with the A179L gene-deleted virus. Pigs immunized with the BeninΔA179L virus showed no clinical signs and a weak immune response but were not protected from infection with the deadly parental virus. The results show an important role for the A179L protein in virus replication in macrophages and virulence in pigs and suggest manipulation of apoptosis as a possible route to control infection.
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Affiliation(s)
| | | | | | - Claire Barber
- The Pirbright Institute, Woking, Surrey, United Kingdom
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3
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Moniruzzaman M, Erazo Garcia MP, Farzad R, Ha AD, Jivaji A, Karki S, Sheyn U, Stanton J, Minch B, Stephens D, Hancks DC, Rodrigues RAL, Abrahao JS, Vardi A, Aylward FO. Virologs, viral mimicry, and virocell metabolism: the expanding scale of cellular functions encoded in the complex genomes of giant viruses. FEMS Microbiol Rev 2023; 47:fuad053. [PMID: 37740576 PMCID: PMC10583209 DOI: 10.1093/femsre/fuad053] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/29/2023] [Accepted: 09/21/2023] [Indexed: 09/24/2023] Open
Abstract
The phylum Nucleocytoviricota includes the largest and most complex viruses known. These "giant viruses" have a long evolutionary history that dates back to the early diversification of eukaryotes, and over time they have evolved elaborate strategies for manipulating the physiology of their hosts during infection. One of the most captivating of these mechanisms involves the use of genes acquired from the host-referred to here as viral homologs or "virologs"-as a means of promoting viral propagation. The best-known examples of these are involved in mimicry, in which viral machinery "imitates" immunomodulatory elements in the vertebrate defense system. But recent findings have highlighted a vast and rapidly expanding array of other virologs that include many genes not typically found in viruses, such as those involved in translation, central carbon metabolism, cytoskeletal structure, nutrient transport, vesicular trafficking, and light harvesting. Unraveling the roles of virologs during infection as well as the evolutionary pathways through which complex functional repertoires are acquired by viruses are important frontiers at the forefront of giant virus research.
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Affiliation(s)
- Mohammad Moniruzzaman
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables, FL 33149, United States
| | - Maria Paula Erazo Garcia
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Roxanna Farzad
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Anh D Ha
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Abdeali Jivaji
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Sangita Karki
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Uri Sheyn
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Joshua Stanton
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Benjamin Minch
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables, FL 33149, United States
| | - Danae Stephens
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables, FL 33149, United States
| | - Dustin C Hancks
- Department of Immunology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, United States
| | - Rodrigo A L Rodrigues
- Laboratório de Vírus, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Jonatas S Abrahao
- Laboratório de Vírus, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Frank O Aylward
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
- Center for Emerging, Zoonotic, and Arthropod-Borne Infectious Disease, Virginia Tech, Blacksburg, VA 24061, United States
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4
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Franzoni G, Pedrera M, Sánchez-Cordón PJ. African Swine Fever Virus Infection and Cytokine Response In Vivo: An Update. Viruses 2023; 15:233. [PMID: 36680273 PMCID: PMC9864779 DOI: 10.3390/v15010233] [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: 11/24/2022] [Revised: 01/03/2023] [Accepted: 01/10/2023] [Indexed: 01/17/2023] Open
Abstract
African swine fever (ASF) is a hemorrhagic viral disease of domestic pigs and wild suids (all Sus scrofa) caused by the ASF virus (ASFV). The disease is spreading worldwide without control, threatening pig production due to the absence of licensed vaccine or commercially available treatments. A thorough understanding of the immunopathogenic mechanisms behind ASFV infection is required to better fight the disease. Cytokines are small, non-structural proteins, which play a crucial role in many aspects of the immune responses to viruses, including ASFV. Infection with virulent ASFV isolates often results in exacerbated immune responses, with increased levels of serum pro-inflammatory interleukins (IL-1α, IL-1β, IL-6), TNF and chemokines (CCL2, CCL5, CXCL10). Increased levels of IL-1, IL-6 and TNF are often detected in several tissues during acute ASFV infections and associated with lymphoid depletion, hemorrhages and oedemas. IL-1Ra is frequently released during ASFV infection to block further IL-1 activity, with its implication in ASFV immunopathology having been suggested. Increased levels of IFN-α and of the anti-inflammatory IL-10 seem to be negatively correlated with animal survival, whereas some correlation between virus-specific IFN-γ-producing cells and protection has been suggested in different studies where different vaccine candidates were tested, although future works should elucidate whether IFN-γ release by specific cell types is related to protection or disease development.
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Affiliation(s)
- Giulia Franzoni
- Department of Animal Health, Istituto Zooprofilattico Sperimentale della Sardegna, 07100 Sassari, Italy
| | - Miriam Pedrera
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Valdeolmos, 28130 Madrid, Spain
| | - Pedro J. Sánchez-Cordón
- Centro de Investigación en Sanidad Animal (CISA), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Consejo Superior de Investigaciones Científicas (CSIC), Valdeolmos, 28130 Madrid, Spain
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5
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Netherton CL, Shimmon GL, Hui JYK, Connell S, Reis AL. African Swine Fever Virus Host-Pathogen Interactions. Subcell Biochem 2023; 106:283-331. [PMID: 38159232 DOI: 10.1007/978-3-031-40086-5_11] [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] [Indexed: 01/03/2024]
Abstract
African swine fever virus is a complex double-stranded DNA virus that exhibits tropism for cells of the mononuclear phagocytic system. Virus replication is a multi-step process that involves the nucleus of the host cell as well the formation of large perinuclear sites where progeny virions are assembled prior to transport to, and budding through, the plasma membrane. Like many viruses, African swine fever virus reorganises the cellular architecture to facilitate its replication and has evolved multiple mechanisms to avoid the potential deleterious effects of host cell stress response pathways. However, how viral proteins and virus-induced structures trigger cellular stress pathways and manipulate the subsequent responses is still relatively poorly understood. African swine fever virus alters nuclear substructures, modulates autophagy, apoptosis and the endoplasmic reticulum stress response pathways. The viral genome encodes for at least 150 genes, of which approximately 70 are incorporated into the virion. Many of the non-structural genes have not been fully characterised and likely play a role in host range and modifying immune responses. As the field moves towards approaches that take a broader view of the effect of expression of individual African swine fever genes, we summarise how the different steps in virus replication interact with the host cell and the current state of knowledge on how it modulates the resulting stress responses.
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Zheng X, Nie S, Feng WH. Regulation of antiviral immune response by African swine fever virus (ASFV). Virol Sin 2022; 37:157-167. [PMID: 35278697 PMCID: PMC9170969 DOI: 10.1016/j.virs.2022.03.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/07/2022] [Indexed: 12/13/2022] Open
Abstract
African swine fever (ASF) is a highly contagious and acute hemorrhagic viral disease with a high mortality approaching 100% in domestic pigs. ASF is an endemic in countries in sub-Saharan Africa. Now, it has been spreading to many countries, especially in Asia and Europe. Due to the fact that there is no commercial vaccine available for ASF to provide sustainable prevention, the disease has spread rapidly worldwide and caused great economic losses in swine industry. The knowledge gap of ASF virus (ASFV) pathogenesis and immune evasion is the main factor to limit the development of safe and effective ASF vaccines. Here, we will summarize the molecular mechanisms of how ASFV interferes with the host innate and adaptive immune responses. An in-depth understanding of ASFV immune evasion strategies will provide us with rational design of ASF vaccines.
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Affiliation(s)
- Xiaojie Zheng
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Shengming Nie
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Wen-Hai Feng
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
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Schäfer A, Franzoni G, Netherton CL, Hartmann L, Blome S, Blohm U. Adaptive Cellular Immunity against African Swine Fever Virus Infections. Pathogens 2022; 11:pathogens11020274. [PMID: 35215216 PMCID: PMC8878497 DOI: 10.3390/pathogens11020274] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/14/2022] [Accepted: 02/17/2022] [Indexed: 11/16/2022] Open
Abstract
African swine fever virus (ASFV) remains a threat to global pig populations. Infections with ASFV lead to a hemorrhagic disease with up to 100% lethality in Eurasian domestic and wild pigs. Although myeloid cells are the main target cells for ASFV, T cell responses are impacted by the infection as well. The complex responses remain not well understood, and, consequently, there is no commercially available vaccine. Here, we review the current knowledge about the induction of antiviral T cell responses by cells of the myeloid lineage, as well as T cell responses in infected animals, recent efforts in vaccine research, and T cell epitopes present in ASFV.
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Affiliation(s)
- Alexander Schäfer
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (A.S.); (L.H.); (S.B.)
| | - Giulia Franzoni
- Department of Animal Health, Istituto Zooprofilattico Sperimentale della Sardegna, 07100 Sassari, Italy;
| | | | - Luise Hartmann
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (A.S.); (L.H.); (S.B.)
| | - Sandra Blome
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (A.S.); (L.H.); (S.B.)
| | - Ulrike Blohm
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald-Insel Riems, Germany; (A.S.); (L.H.); (S.B.)
- Correspondence: ; Tel.: +49-38351-7-1543; +49-38351-7-1236
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8
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Schäfer A, Zani L, Pikalo J, Hühr J, Sehl J, Mettenleiter TC, Breithaupt A, Blome S, Blohm U. T-cell responses in domestic pigs and wild boar upon infection with the moderately virulent African swine fever virus strain 'Estonia2014'. Transbound Emerg Dis 2021; 68:2733-2749. [PMID: 33630409 DOI: 10.1111/tbed.14048] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 02/22/2021] [Accepted: 02/22/2021] [Indexed: 11/30/2022]
Abstract
Infection with African swine fever virus (ASFV) causes a highly lethal haemorrhagic disease in domestic and Eurasian wild pigs. Thus, it is a major threat to pig populations worldwide and a cause of substantial economic losses. Recently, less virulent ASFV strains emerged naturally, which showed higher experimental virulence in wild boar than in domestic pigs. The reason for this difference in disease progression and outcome is unclear but likely involves different immunological responses. Unfortunately, besides the importance of CD8α+ lymphocytes, little is known about the immune responses against ASFV in suids. Against this background, we used a multicolour flow cytometry platform to investigate the T-cell responses in wild boar and domestic pigs after infection with the moderately virulent ASFV strain 'Estonia2014' in two independent trials. CD4- /CD8α+ and CD4+ /CD8α+ αβ T-cell frequencies increased in both subspecies in various tissues, but CD8α+ γδ T cells differentiated and responded in wild boar only. Proliferation in CD8α+ T cells was found 10 days post infectionem only. Frequencies of T-bet+ T cells increased in wild boar but not in domestic pigs. Of note, we found a considerable loss of perforin expression in cytotoxic T cells, 5 and 7 dpi. Both subspecies established a regulatory T-cell response 10 dpi. In domestic pigs, we show increasing levels of ICOS+ and CD8α+ invariant Natural Killer T cells. These disparities in T-cell responses might explain some of the differences in disease progression in wild boar and domestic pigs and should pave the way for future studies.
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Affiliation(s)
| | - Laura Zani
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Jutta Pikalo
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Jane Hühr
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Julia Sehl
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | | | | | - Sandra Blome
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
| | - Ulrike Blohm
- Friedrich-Loeffler-Institut, Greifswald - Insel Riems, Germany
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9
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Liu J, Lu G, Cui Y, Wei S, An T, Shen G, Chen Z. An insight into the transmission role of insect vectors based on the examination of gene characteristics of African swine fever virus originated from non-blood sucking flies in pig farm environments. BMC Vet Res 2020; 16:227. [PMID: 32615970 PMCID: PMC7331130 DOI: 10.1186/s12917-020-02420-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 06/08/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Insect vector transmitted pathogens from contaminated environments are a key potential risk for public health. Meanwhile, transmission by non-blood sucking flies needs to be considered. Sequencing and phylogenetic tree analyses were used to study African swine fever virus (ASFV) genes derived from flies collected from pig farms that were infected with ASFV. The major differential genes were analyzed the encoded proteins, particularly their conformation, physico-chemical features, and interactions identified by immunophenotyping. RESULTS Results showed that the ASFV p72 and D117L genes from these non-blood sucking flies identified by morphology have high sequence similarity from ASFV genotype II strains, however, A179L is found in an independent cluster, with five amino acid substitutions; four of which are in a continuous sequence. Moreover, the binding of a BH3 peptide into a surface groove formed by α-helices of ASFV A179L from the non-blood sucking flies is consistent with that of representative ASFV genotype II strains, Georgia/2007.They only differ in the direction of spatial interaction of six conserved amino residues. Many hydrophilic amino residues are located at the canonical ligand-binding groove of A179L from flies, with hydrophobic amino residues located at the corresponding positions in A179L of the Georgia/2007.Furthermore, analysis of protein interactions by immunophenotyping revealed that both A179Ls have similar roles in regulating autophagy and apoptosis. CONCLUSIONS In conclusion, the main genes that differ between ASFV from flies and Georgia/2007 were similar in structure and protein interaction, while exhibiting differences in physico-chemical features and amino acid variations. Understanding the mechanical transmission characteristics of non-blood sucking flies is important.
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Affiliation(s)
- Jinling Liu
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, No.120, Dongling Road, Shenhe District, Shenyang, 110866, PR China
| | - Gen Lu
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, No.120, Dongling Road, Shenhe District, Shenyang, 110866, PR China
| | - Yuesong Cui
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, No.120, Dongling Road, Shenhe District, Shenyang, 110866, PR China
| | - Shu Wei
- The Preventive Center of Animal Disease of Liaoning Province, No.95, Renhe Road, Shenbei District, Shenyang, 110164, PR China
| | - Tongqing An
- Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, No. 678, Haping road, Xiangfang district, Harbin, 150069, PR China
| | - Guoshun Shen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, No.120, Dongling Road, Shenhe District, Shenyang, 110866, PR China.
| | - Zeliang Chen
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science & Veterinary Medicine, Shenyang Agricultural University, No.120, Dongling Road, Shenhe District, Shenyang, 110866, PR China.
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, PR China.
- Brucellosis Prevention and Treatment Engineering Technology Research Center of Inner Mongolia Autonomous region, Inner Mongolia University for Nationalities, Tongliao, 028000, PR China.
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Salguero FJ. Comparative Pathology and Pathogenesis of African Swine Fever Infection in Swine. Front Vet Sci 2020; 7:282. [PMID: 32509811 PMCID: PMC7248413 DOI: 10.3389/fvets.2020.00282] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 04/27/2020] [Indexed: 01/23/2023] Open
Abstract
African Swine Fever (ASF) is a viral disease that affects animals of the Suidae family, and soft ticks from the genus Ornithodoros can also be infected by the ASF virus (ASFV). The disease was first described in Africa at the beginning of the twentieth century as an acute disease characterized by high mortality and fatal hemorrhages. ASF has caused outbreaks in numerous countries and it continues to be devastating nowadays for the porcine sector in those countries affected, and a massive threat for those free of the disease. ASF can follow clinical courses from peracute to chronic in domestic pigs (Sus scrofa) depending on a variety of factors, including the immune status of the animals and the virulence of the ASFV strain. The key features of the pathogenesis of the disease in domestic swine are a) a severe lymphoid depletion including lymphopenia and a state of immunodeficiency, and b) hemorrhages. However, African wild swine like bushpigs (Potamochoerus larvatus), red river hogs (Potamochoerus porcus), and warthogs (Phacochoerus africanus) can be infected by ASFV showing no clinical signs of disease and acting as natural reservoir hosts. In this article we review the key features of the gross and microscopic pathology together with a description of the pathogenesis of ASFV infection in domestic pigs following the different clinical courses. The pathogenesis of ASF in wild and domestic swine is also described, what can provide important information for the design of control strategies, such as vaccines.
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11
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Dixon LK, Islam M, Nash R, Reis AL. African swine fever virus evasion of host defences. Virus Res 2019; 266:25-33. [PMID: 30959069 PMCID: PMC6505686 DOI: 10.1016/j.virusres.2019.04.002] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/29/2019] [Accepted: 04/04/2019] [Indexed: 12/24/2022]
Abstract
African swine fever virus causes a haemorrhagic fever in domestic pigs and wild boar. The continuing spread in Africa, Europe and Asia threatens the global pig industry. The lack of a vaccine limits disease control. To underpin rational strategies for vaccine development improved knowledge is needed of how the virus interacts with and modulates the host's responses to infection. The virus long double-stranded DNA genome codes for more than 160 proteins of which many are non-essential for replication in cells but can have important roles in evading the host's defences. Here we review knowledge of the pathways targeted by ASFV and the mechanisms by which these are inhibited. The impact of deleting single or multiple ASFV genes on virus replication in cells and infection in pigs is summarised providing information on strategies for rational development of modified live vaccines.
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Affiliation(s)
- L K Dixon
- The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey, GU24 0NF, UK.
| | - M Islam
- The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey, GU24 0NF, UK
| | - R Nash
- The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey, GU24 0NF, UK
| | - A L Reis
- The Pirbright Institute, Ash Road, Pirbright, Woking, Surrey, GU24 0NF, UK
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12
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Qian G, Lv H, Lin J, Li X, Lv Q, Wang T, Zhang J, Dong W, Guo K, Zhang Y. FHC, an NS4B-interacting Protein, Enhances Classical Swine Fever Virus Propagation and Acts Positively in Viral Anti-apoptosis. Sci Rep 2018; 8:8318. [PMID: 29844394 PMCID: PMC5974352 DOI: 10.1038/s41598-018-26777-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 05/02/2018] [Indexed: 01/10/2023] Open
Abstract
Classical swine fever virus (CSFV), the etiological agent of classical swine fever, causes enormous economic loss to the pig industry. Ferritin heavy chain (FHC) is a notable anti-apoptotic protein, and existing evidence suggests that CSFV cannot induce apoptosis of host cells, however, the role of FHC in CSFV replication remains unclear. In the present study, we found that recombinant lentivirus-mediated knockdown or overexpression of FHC inhibited or enhanced CSFV replication, respectively, indicating a positive role for FHC in CSFV proliferation. Furthermore, interaction between the CSFV NS4B protein and FHC was confirmed by glutathione S-transferase (GST) pull-down, co-immunoprecipitation (co-IP) and confocal imaging assays. In addition, both CSFV replication and NS4B expression upregulated expression of FHC, which counteracts apoptosis by modulating cellular reactive oxygen species (ROS). These results suggest that FHC, an NS4B-interacting protein, enhances CSFV replication and has a positive role in viral anti-apoptosis by regulating ROS accumulation. This work may provide a new perspective for understanding the mechanism of CSFV pathogenesis.
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Affiliation(s)
- Gui Qian
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Huifang Lv
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Jihui Lin
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Xiaomeng Li
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Qizhuang Lv
- College of Biology & Pharmacy, Yulin Normal University, No. 1303 Jiaoyu East Road, Yulin, 537000, Guangxi, China
| | - Tao Wang
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Jing Zhang
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Wang Dong
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Kangkang Guo
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, No. 22 Xinong Road, Yangling, 712100, Shaanxi, China.
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Investigations of Pro- and Anti-Apoptotic Factors Affecting African Swine Fever Virus Replication and Pathogenesis. Viruses 2017; 9:v9090241. [PMID: 28841179 PMCID: PMC5618007 DOI: 10.3390/v9090241] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 08/18/2017] [Accepted: 08/21/2017] [Indexed: 02/07/2023] Open
Abstract
African swine fever virus (ASFV) is a large DNA virus that replicates predominantly in the cell cytoplasm and is the only member of the Asfarviridae family. The virus causes an acute haemorrhagic fever, African swine fever (ASF), in domestic pigs and wild boar resulting in the death of most infected animals. Apoptosis is induced at an early stage during virus entry or uncoating. However, ASFV encodes anti-apoptotic proteins which facilitate production of progeny virions. These anti-apoptotic proteins include A179L, a Bcl-2 family member; A224L, an inhibitor of apoptosis proteins (IAP) family member; EP153R a C-type lectin; and DP71L. The latter acts by inhibiting activation of the stress activated pro-apoptotic pathways pro-apoptotic pathways. The mechanisms by which these proteins act is summarised. ASF disease is characterised by massive apoptosis of uninfected lymphocytes which reduces the effectiveness of the immune response, contributing to virus pathogenesis. Mechanisms by which this apoptosis is induced are discussed.
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14
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Alonso C, Galindo I, Cuesta-Geijo MA, Cabezas M, Hernaez B, Muñoz-Moreno R. African swine fever virus-cell interactions: from virus entry to cell survival. Virus Res 2012; 173:42-57. [PMID: 23262167 PMCID: PMC7114420 DOI: 10.1016/j.virusres.2012.12.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 12/01/2012] [Accepted: 12/04/2012] [Indexed: 11/28/2022]
Abstract
Viruses have adapted to evolve complex and dynamic interactions with their host cell. The viral entry mechanism determines viral tropism and pathogenesis. The entry of African swine fever virus (ASFV) is dynamin-dependent and clathrin-mediated, but other pathways have been described such as macropinocytosis. During endocytosis, ASFV viral particles undergo disassembly in various compartments that the virus passes through en route to the site of replication. This disassembly relies on the acid pH of late endosomes and on microtubule cytoskeleton transport. ASFV interacts with several regulatory pathways to establish an optimal environment for replication. Examples of these pathways include small GTPases, actin-related signaling, and lipid signaling. Cellular cholesterol, the entire cholesterol biosynthesis pathway, and phosphoinositides are central molecular networks required for successful infection. Here we report new data on the conformation of the viral replication site or viral factory and the remodeling of the subcellular structures. We review the virus-induced regulation of ER stress, apoptosis and autophagy as key mechanisms of cell survival and determinants of infection outcome. Finally, future challenges for the development of new preventive strategies against this virus are proposed on the basis of current knowledge about ASFV-host interactions.
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Affiliation(s)
- Covadonga Alonso
- Dpto. de Biotecnología, INIA, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Ctra. de Coruña Km 7.5, 28040 Madrid, Spain.
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15
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Pathogenesis of African swine fever in domestic pigs and European wild boar. Virus Res 2012; 173:122-30. [PMID: 23137735 DOI: 10.1016/j.virusres.2012.10.026] [Citation(s) in RCA: 210] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 10/20/2012] [Accepted: 10/22/2012] [Indexed: 11/21/2022]
Abstract
African swine fever (ASF) is among the most important viral diseases that can affect domestic and feral pigs. Both clinical signs and pathomorphological changes vary considerably depending on strain virulence and host factors. Acute infections with highly virulent virus strains lead to a clinical course that resembles a viral haemorrhagic fever that is characterized by pronounced depletion of lymphoid tissues, apoptosis of lymphocyte subsets, and impairment of haemostasis and immune functions. It is generally accepted that most lesions can be attributed to cytokine-mediated interactions triggered by infected and activated monocytes and macrophages, rather than by virus-induced direct cell damage. Nevertheless, most pathogenetic mechanisms are far from being understood. This review summarizes the current knowledge and discusses implications and research gaps.
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Singh PK, Doley J, Kumar GR, Sahoo A, Tiwari AK. Oncolytic viruses & their specific targeting to tumour cells. Indian J Med Res 2012; 136:571-84. [PMID: 23168697 PMCID: PMC3516024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Indexed: 10/25/2022] Open
Abstract
Cancer is one of the major causes of death worldwide. In spite of achieving significant successes in medical sciences in the past few decades, the number of deaths due to cancer remains unchecked. The conventional chemotherapy and radiotherapy have limited therapeutic index and a plethora of treatment related side effects. This situation has provided an impetus for search of novel therapeutic strategies that can selectively destroy the tumour cells, leaving the normal cells unharmed. Viral oncotherapy is such a promising treatment modality that offers unique opportunity for tumour targeting. Numerous viruses with inherent anti-cancer activity have been identified and are in different phases of clinical trials. In the era of modern biotechnology and with better understanding of cancer biology and virology, it has become feasible to engineer the oncolytic viruses (OVs) to increase their tumour selectivity and enhance their oncolytic activity. In this review, the mechanisms by which oncolytic viruses kill the tumour cells have been discussed as also the development made in virotherapy for cancer treatment with emphasis on their tumour specific targeting.
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Affiliation(s)
- Prafull K. Singh
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute (ICAR), Bareilly, India
| | - Juwar Doley
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute (ICAR), Bareilly, India
| | - G. Ravi Kumar
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute (ICAR), Bareilly, India
| | - A.P. Sahoo
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute (ICAR), Bareilly, India
| | - Ashok K. Tiwari
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute (ICAR), Bareilly, India
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17
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van Domselaar R, Bovenschen N. Cell death-independent functions of granzymes: hit viruses where it hurts. Rev Med Virol 2011; 21:301-14. [PMID: 21714121 DOI: 10.1002/rmv.697] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 05/03/2011] [Accepted: 05/06/2011] [Indexed: 12/24/2022]
Abstract
Granule exocytosis by cytotoxic lymphocytes is the key mechanism of our immune response to eliminate virus-infected cells. These lytic granules contain the pore-forming protein perforin and a set of five serine proteases called granzymes (GrA, GrB, GrH, GrK, GrM) that display distinct substrate specificities. Granzymes have mostly been studied for their ability to induce cell death. However, viruses have evolved many inhibitors to effectively block apoptosis. Evidence is emerging that granzymes also use noncytotoxic strategies to inhibit viral replication and potential viral reactivation from latency. Granzymes directly cleave viral or host cell proteins that are required in the viral life cycle. Furthermore, granzymes induce a pro-inflammatory cytokine response to create an antiviral environment. In this review, we summarize and discuss these novel strategies by which the immune system counteracts viral infections, and we will address the potential therapeutic applications that could emerge from this intriguing mechanism.
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Affiliation(s)
- Robert van Domselaar
- Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
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18
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Species-specific variation in RELA underlies differences in NF-κB activity: a potential role in African swine fever pathogenesis. J Virol 2011; 85:6008-14. [PMID: 21450812 DOI: 10.1128/jvi.00331-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
African swine fever virus (ASFV) is a highly infectious disease of domestic pigs, with virulent isolates causing a rapidly fatal hemorrhagic fever. In contrast, the porcine species endogenous to Africa tolerate infection. The ability of the virus to persist in one host while killing another genetically related host implies that disease severity may be, in part, modulated by host genetic variation. To complement transcription profiling approaches to identify the underlying genetic variation in the host response to ASFV, we have taken a candidate gene approach based on known signaling pathways that interact with the virus-encoded immunomodulatory protein A238L. We report the sequencing of these genes from different pig species and the identification and initial in vitro characterization of polymorphic variation in RELA (p65; v-rel reticuloendotheliosis viral oncogene homolog A), the major component of the NF-κB transcription factor. Warthog RELA and domestic pig RELA differ at three amino acids. Transient cell transfection assays indicate that this variation is reflected in reduced NF-κB activity in vitro for warthog RELA but not for domestic pig RELA. Induction assays indicate that warthog RELA and domestic pig RELA are elevated essentially to the same extent. Finally, mutational studies indicate that the S531P site conveys the majority of the functional variation between warthog RELA and domestic pig RELA. We propose that the variation in RELA identified between the warthog and domestic pig has the potential to underlie the difference between tolerance and rapid death upon ASFV infection.
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19
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Castanier C, Arnoult D. Mitochondrial localization of viral proteins as a means to subvert host defense. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1813:575-83. [PMID: 20807553 DOI: 10.1016/j.bbamcr.2010.08.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 08/18/2010] [Accepted: 08/20/2010] [Indexed: 12/29/2022]
Abstract
Viruses have developed a battery of distinct strategies to overcome the very sophisticated defense mechanisms of the infected host. Throughout the process of pathogen-host co-evolution, viruses have therefore acquired the capability to prevent host cell apoptosis because elimination of infected cells via apoptosis is one of the most ancestral defense mechanism against infection. Conversely, induction of apoptosis may favor viral dissemination as a result of the dismantlement of the infected cells. Mitochondria have been long recognized for their key role in the modulation of apoptosis but more recently, mitochondria have been shown to serve as a crucial platform for innate immune signaling as illustrated by the identification of MAVS. Thus, it is therefore not surprising that this organelle represents a recurrent target for viruses, aiming to manipulate the fate of the infected host cell or to inhibit innate immune response. In this review, we highlight the viral proteins that are specifically targeted to the mitochondria to subvert host defense. This article is part of a Special Issue entitled Mitochondria: the deadly organelle.
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Affiliation(s)
- Céline Castanier
- INSERM U1014, Hopital Paul Brousse, Batiment Lavoisier, 14 avenue Paul Vaillant Couturier, 94807 Villejuif cedex, France
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20
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Galluzzi L, Kepp O, Morselli E, Vitale I, Senovilla L, Pinti M, Zitvogel L, Kroemer G. Viral strategies for the evasion of immunogenic cell death. J Intern Med 2010; 267:526-42. [PMID: 20433579 DOI: 10.1111/j.1365-2796.2010.02223.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Viral strategies for the evasion of immunogenic cell death (Symposium). J Intern Med 2010; 267: 526-542. Driven by co-evolutionary forces, viruses have refined a wide arsenal of strategies to interfere with the host defences. On one hand, viruses can block/retard programmed cell death in infected cells, thereby suppressing one of the most ancient mechanisms against viral dissemination. On the other hand, multiple viral factors can efficiently trigger the death of infected cells and uninfected cells from the immune system, which favours viral spreading and prevents/limits an active antiviral response, respectively. Moreover, several viruses are able to inhibit the molecular machinery that drives the translocation of calreticulin to the surface of dying cells. Thereby, viruses block the exposure of an engulfment signal that is required for the efficient uptake of dying cells by dendritic cells and for the induction of the immune response. In this review, we discuss a variety of mechanisms by which viruses interfere with the cell death machinery and, in particular, by which they subvert immunogenic cell death.
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21
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Sánchez‐Vizcaíno JM, Martínez‐López B, Martínez‐Avilés M, Martins C, Boinas F, Vialc L, Michaud V, Jori F, Etter E, Albina E, Roger F. Scientific review on African Swine Fever. ACTA ACUST UNITED AC 2009. [DOI: 10.2903/sp.efsa.2009.en-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
| | | | | | - Carlos Martins
- Faculdade de Medicina Veterinaria, Universidade Técnica de Lisboa, (FMV‐UTL)
| | - Fernando Boinas
- Faculdade de Medicina Veterinaria, Universidade Técnica de Lisboa, (FMV‐UTL)
| | - Laurence Vialc
- Centre de Cooperation Internationale en Recherche Agronomique pour le Développement (CIRAD)
| | - Vincent Michaud
- Centre de Cooperation Internationale en Recherche Agronomique pour le Développement (CIRAD)
| | - Ferran Jori
- Centre de Cooperation Internationale en Recherche Agronomique pour le Développement (CIRAD)
| | - Eric Etter
- Centre de Cooperation Internationale en Recherche Agronomique pour le Développement (CIRAD)
| | - Emmanuel Albina
- Centre de Cooperation Internationale en Recherche Agronomique pour le Développement (CIRAD)
| | - François Roger
- Centre de Cooperation Internationale en Recherche Agronomique pour le Développement (CIRAD)
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22
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Characterization of African swine fever virus IAP homologue expression in porcine macrophages infected with different virulence isolates. Vet Microbiol 2009; 139:140-6. [DOI: 10.1016/j.vetmic.2009.04.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Revised: 04/16/2009] [Accepted: 04/28/2009] [Indexed: 01/16/2023]
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23
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Apoptosis in porcine macrophages infected in vitro with African swine fever virus (ASFV) strains with different virulence. Arch Virol 2009; 154:1441-50. [DOI: 10.1007/s00705-009-0466-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2009] [Accepted: 07/08/2009] [Indexed: 10/20/2022]
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24
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Abstract
African swine fever virus (ASFV) is a large, intracytoplasmically-replicating DNA arbovirus and the sole member of the family Asfarviridae. It is the etiologic agent of a highly lethal hemorrhagic disease of domestic swine and therefore extensively studied to elucidate the structures, genes, and mechanisms affecting viral replication in the host, virus-host interactions, and viral virulence. Increasingly apparent is the complexity with which ASFV replicates and interacts with the host cell during infection. ASFV encodes novel genes involved in host immune response modulation, viral virulence for domestic swine, and in the ability of ASFV to replicate and spread in its tick vector. The unique nature of ASFV has contributed to a broader understanding of DNA virus/host interactions.
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Affiliation(s)
- E R Tulman
- Department of Pathobiology and Veterinary Science, Center of Excellence for Vaccine Research, University of Connecticut, Storrs 06269, USA.
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25
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Chapman DAG, Tcherepanov V, Upton C, Dixon LK. Comparison of the genome sequences of non-pathogenic and pathogenic African swine fever virus isolates. J Gen Virol 2008; 89:397-408. [PMID: 18198370 DOI: 10.1099/vir.0.83343-0] [Citation(s) in RCA: 199] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The genomic coding sequences, apart from the inverted terminal repeats and cross-links, have been determined for two African swine fever virus (ASFV) isolates from the same virus genotype, a non-pathogenic isolate from Portugal, OURT88/3, and a highly pathogenic isolate from West Africa, Benin 97/1. These genome sequences were annotated and compared with that of a tissue culture-adapted isolate, BA71V. The genomes range in length between 170 and 182 kbp and encode between 151 and 157 open reading frames (ORFs). Compared to the Benin 97/1 isolate, the OURT88/3 and BA71V isolates have deletions of 8-10 kbp that encode six copies of the multigene family (MGF) 360 and either one MGF 505/530 copy in the BA71V or two copies in the OURT88/3 isolate. The BA71V isolate has a deletion, close to the right end of the genome, of 3 kbp compared with the other isolates. The five ORFs in this region include an additional copy of an ORF similar to that encoding the p22 virus structural protein. The OURT88/3 isolate has interruptions in ORFs that encode a CD2-like and a C-type lectin protein. Variation between the genomes is observed in the number of copies of five different MGFs. The 109 non-duplicated ORFs conserved in the three genomes encode proteins involved in virus replication, virus assembly and modulation of the host's defences. These results provide information concerning the genetic variability of African swine fever virus isolates that differ in pathogenicity.
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Affiliation(s)
- David A G Chapman
- Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK
| | - Vasily Tcherepanov
- Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
| | - Chris Upton
- Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 3P6, Canada
| | - Linda K Dixon
- Institute for Animal Health, Pirbright Laboratory, Ash Road, Pirbright, Woking, Surrey GU24 0NF, UK
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26
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Galindo I, Hernaez B, Díaz-Gil G, Escribano JM, Alonso C. A179L, a viral Bcl-2 homologue, targets the core Bcl-2 apoptotic machinery and its upstream BH3 activators with selective binding restrictions for Bid and Noxa. Virology 2008; 375:561-72. [PMID: 18329683 PMCID: PMC2572728 DOI: 10.1016/j.virol.2008.01.050] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 01/07/2008] [Accepted: 01/24/2008] [Indexed: 01/07/2023]
Abstract
Several large DNA viruses encode Bcl-2 protein homologues involved in the regulation of the cellular apoptosis cascade. This regulation often involves the interaction of these viral proteins with diverse cellular Bcl-2 family members. We have identified the specific interactions of A179L, an African swine fever virus (ASFV) Bcl-2 homologue, with the active forms of the porcine BH3-only Bid protein (truncated Bid p13 and p15). Transient expression of ASFV A179L gene in Vero cells prevented apoptosis induced by these active forms of Bid protein. Interestingly, A179L protein was able to interact, also with the main core Bcl-2 proapoptotic proteins Bax and Bak, and with several BH3-only proteins with selective binding restrictions for full length Bid and Noxa. These results suggest a fine regulation for A179L action in the suppression of apoptosis in infected cells which is essential for efficient virus replication.
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Affiliation(s)
- Inmaculada Galindo
- Departamento de Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
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27
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Kasuya H, Nishiyama Y, Nomoto S, Goshima F, Takeda S, Watanabe I, Nomura N, Shikano T, Fujii T, Kanazumi N, Nakao A. Suitability of a US3-inactivated HSV mutant (L1BR1) as an oncolytic virus for pancreatic cancer therapy. Cancer Gene Ther 2007; 14:533-42. [PMID: 17415379 DOI: 10.1038/sj.cgt.7701049] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Recently, the use of oncolytic viruses against cancer has attracted considerable attention. We studied the potential of the US3 locus-deficient herpes simplex virus (HSV), L1BR1, for oncolytic virus therapy. Its high specificity and potency indicate that L1BR1 is a promising candidate as a new oncolytic virus against pancreatic cancer. Moreover, the virus exhibited the unique characteristic of increasing apoptosis when used in combination with anticancer drugs. We assessed the feasibility of using the US3 locus-deficient HSV named L1BR1 as a new replication-competent oncolytic virus for the treatment of pancreatic cancer. The US3 locus of HSV has been shown to be a key gene in producing a multifunctional protein kinase that inhibits apoptosis induced by viral infections, chemicals and ultraviolet (UV) light. L1BR1 has been reported to be more than 10 000-fold less virulent than the parental virus in mice. In this study, we examined the tumor specificity and oncolytic effect of this attenuated replication-competent virus, L1BR1, in pancreatic cancers derived from SW1990, Capan2 and Bxpc-3cells compared with the parent virus and other well-known oncolytic herpes viruses (R3616 and hrR3). We also studied the efficacy of L1BR1 for the induction of apoptosis as an attribute of this virus in combination with the anticancer drugs 5FU and cisplatin. The combined treatment of the pancreatic cancer cells with L1BR1 and these anticancer drugs enhanced apoptosis significantly. More importantly, L1BR1 showed the lowest replication capacity in normal human hepatocytes, but the highest tumor-reducing effect in vivo among the oncolytic herpes viruses tested. In addition, L1BR1 significantly increased the induction of apoptosis of cancer cells when treated in combination with anticancer drugs although the parental virus inhibited the induction of apoptosis. These results suggest that L1BR1 is promising as a new anticancer oncolytic virus.
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Affiliation(s)
- H Kasuya
- Department of Surgery II, Nagoya University School of Medicine, Nagoya, Japan.
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28
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Fischer SF, Ludwig H, Holzapfel J, Kvansakul M, Chen L, Huang DCS, Sutter G, Knese M, Häcker G. Modified vaccinia virus Ankara protein F1L is a novel BH3-domain-binding protein and acts together with the early viral protein E3L to block virus-associated apoptosis. Cell Death Differ 2005; 13:109-18. [PMID: 16003387 DOI: 10.1038/sj.cdd.4401718] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Infection with viruses often protects the infected cell against external stimuli to apoptosis. Here we explore the balance of apoptosis induction and inhibition for infection with the modified vaccinia virus Ankara (MVA), using two MVA mutants with experimentally introduced deletions. Deletion of the E3L-gene from MVA transformed the virus from an inhibitor to an inducer of apoptosis. Noxa-deficient mouse embryonic fibroblasts (MEF) were resistant to MVA-DeltaE3L-induced apoptosis. When the gene encoding F1L was deleted from MVA, apoptosis resulted that required Bak or Bax. MVA-DeltaF1L-induced apoptosis was blocked by Bcl-2. When expressed in HeLa cells, F1L blocked apoptosis induced by forced expression of the BH3-only proteins, Bim, Puma and Noxa. Finally, biosensor analysis confirmed direct binding of F1L to BH3 domains. These data describe a molecular framework of how a cell responds to MVA infection by undergoing apoptosis, and how the virus blocks apoptosis by interfering with critical steps of its signal transduction.
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Affiliation(s)
- S F Fischer
- Institute for Medical Microbiology, Technical University Munich, Germany
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29
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Salguero FJ, Sánchez-Cordón PJ, Núñez A, Fernández de Marco M, Gómez-Villamandos JC. Proinflammatory Cytokines Induce Lymphocyte Apoptosis in Acute African Swine Fever Infection. J Comp Pathol 2005; 132:289-302. [PMID: 15893987 DOI: 10.1016/j.jcpa.2004.11.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2004] [Accepted: 11/16/2004] [Indexed: 10/25/2022]
Abstract
Twenty-one pigs inoculated with a highly virulent isolate (E70) of African swine fever (ASF) virus were killed 1-7 days later; a further three animals served as uninfected controls. An early increase in TNF-alpha, IL-1alpha, IL-1beta and IL-6 expression was detected in lymphoid organs from infected animals, together with an increase in the serum concentrations of TNF-alpha and IL-1beta. These changes were accompanied by increased apoptosis of lymphocytes, and the presence of infected and uninfected macrophages showing changes indicative of secretory and phagocytic activation. The present study demonstrated an increase in the number of macrophages expressing TNF-alpha, IL-1 and IL-6 in proximity to lymphocytes undergoing apoptosis, supporting previous suggestions that in acute ASF proinflammatory cytokines induce lymphocyte apoptosis.
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Affiliation(s)
- F J Salguero
- Departamento de Anatomía y Anatomía Patológica Comparadas, Edificio de Sanidad Animal, Campus Universitario de Rabanales, Universidad de Córdoba, 14014 Córdoba, Spain
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30
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Gimeno IM, Witter RL, Hunt HD, Reddy SM, Lee LF, Silva RF. The pp38 gene of Marek's disease virus (MDV) is necessary for cytolytic infection of B cells and maintenance of the transformed state but not for cytolytic infection of the feather follicle epithelium and horizontal spread of MDV. J Virol 2005; 79:4545-9. [PMID: 15767457 PMCID: PMC1061578 DOI: 10.1128/jvi.79.7.4545-4549.2005] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Marek's disease virus has a unique phosphoprotein, pp38, which is suspected to play an important role in Marek's disease pathogenesis. The objective of the present study was to utilize a mutant virus lacking the pp38 gene (rMd5Deltapp38) to better characterize the biological function of pp38. This work shows that the pp38 gene is necessary to establish cytolytic infection in B cells but not in feather follicle epithelium, to produce an adequate level of latently infected T cells, and to maintain the transformed status in vivo.
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Affiliation(s)
- I M Gimeno
- USDA-Agriculture Research Service, Avian Disease and Oncology Laboratory, East Lansing, MI 48823, USA
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31
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Gillet L, Vanderplasschen A. Viral Subversion of the Immune System. APPLICATIONS OF GENE-BASED TECHNOLOGIES FOR IMPROVING ANIMAL PRODUCTION AND HEALTH IN DEVELOPING COUNTRIES 2005. [PMCID: PMC7121541 DOI: 10.1007/1-4020-3312-5_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The continuous interactions between host and viruses during their co-evolution have shaped not only the immune system but also the countermeasures used by viruses. Studies in the last decade have described the diverse arrays of pathways and molecular targets that are used by viruses to elude immune detection or destruction, or both. These include targeting of pathways for major histocompatibility complex class I and class II antigen presentation, natural killer cell recognition, apoptosis, cytokine signalling, and complement activation. This paper provides an overview of the viral immune-evasion mechanisms described to date. It highlights the contribution of this field to our understanding of the immune system, and the importance of understanding this aspect of the biology of viral infection to develop efficacious and safe vaccines.
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32
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Abstract
Despite numerous studies examining the possible induction of apoptosis in porcine reproductive and respiratory syndrome virus (PRRSV)-infected cells, it remains unclear if PRRSV infection results in direct apoptotic induction. There is clear evidence that apoptotic cells are present in tissues from PRRSV-infected pigs. However, many of these studies have failed to show that the apoptotic cells are infected with PRRSV. This has led some investigators to propose that "bystander" cells, not infected cells, become apoptotic during PRRSV infection by a yet undetermined mechanism. Studies examining the induction of the apoptotic gene expression response to PRRSV infection are needed to determine if PRRSV replication triggers an apoptotic response. We have utilized microarray and semi-quantitative reverse-transcription polymerase chain reaction (sqRT-PCR) to evaluate apoptotic gene expression in PRRSV-infected MARC-145 cells. Twenty-six apoptosis-related genes were examined during the first 24 h of infection and found to be unaltered, indicating that apoptotic induction was not occurring in PRRSV-infected cells. Additionally, using detection of free nucleosomal complexes, we examined cells for both apoptotic and necrotic death resulting from PRRSV infection at varying multiplicities of infection. This study indicates that PRRSV-infected MARC-145 cells undergo necrosis at a much higher level than apoptosis, and increases with virus levels used to infect the cells.
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Affiliation(s)
- Laura C Miller
- Roman L. Hruska U.S. Meat Animal Research Center (MARC), ARS, USDA, State Spur 18D, P.O. Box 166, Clay Center, NE 68933-0166, USA
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Dixon LK, Abrams CC, Bowick G, Goatley LC, Kay-Jackson PC, Chapman D, Liverani E, Nix R, Silk R, Zhang F. African swine fever virus proteins involved in evading host defence systems. Vet Immunol Immunopathol 2004; 100:117-34. [PMID: 15207450 DOI: 10.1016/j.vetimm.2004.04.002] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
African swine fever virus (ASFV) can cause an acutely fatal haemorrhagic fever in domestic pigs although in its natural hosts, warthogs, bushpigs and the soft tick vector, Ornithodoros moubata, ASFV causes inapparent persistent infections. The virus is a large, cytoplasmic, double-stranded DNA virus which has a tropism for macrophages. As it is the only member of the Asfarviridae family, ASFV encodes many novel genes not encoded by other virus families. The ability of the virus to persist in its natural hosts and in domestic pigs, which recover from infection with less virulent isolates, shows that the virus has effective mechanisms to evade host defence systems. This review focuses on recent progress made in understanding the function of ASFV-encoded proteins, which are involved in modulating the host response to infection. Growing evidence suggests that a major strategy used by the virus is to modulate signalling pathways in infected macrophages, thus interfering with the expression of a large number of immunomodulatory genes. One potent immunomodulatory protein, A238L, inhibits both activation of the host NFkappaB transcription factor and inhibits calcineurin phosphatase activity. Calcineurin-dependent pathways, including activation of the NFAT transcription factor, are therefore inhibited. Another ASFV-encoded protein, CD2v, resembles the host CD2 protein, which is expressed on T cells and NK cells. This virus protein causes the adsorption of red blood cells around virus-infected cells and extracellular virus particles. Expression of the CD2v protein aids virus dissemination in pigs and the protein also has a role in impairing bystander lymphocyte function. This may be mediated either by a direct interaction of CD2v extracellular domain with ligands on lymphocytes or by an indirect mechanism involving interaction of the CD2v cytoplasmic tail with host proteins involved in signalling or trafficking pathways. Two ASFV proteins, an IAP and a Bcl2 homologue, inhibit apoptosis in infected cells and thus facilitate production of progeny virions. The prediction is that half to two-thirds of the approximately 150 genes encoded by ASFV are not essential for replication in cells but have an important role for virus survival and transmission in its hosts. These genes provide an untapped repository, and will be valuable tools for deciphering not only how the virus manipulates the host response to infection to avoid elimination, but also useful for understanding important host anti-viral mechanisms. In addition, they may provide leads for discovery of novel immunomodulatory drugs.
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Affiliation(s)
- Linda K Dixon
- Institute for Animal Health Pirbright Lab., Ash Road, Pirbright, Woking, Surrey GU24 ONF, UK.
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Hurtado C, Granja AG, Bustos MJ, Nogal ML, González de Buitrago G, de Yébenes VG, Salas ML, Revilla Y, Carrascosa AL. The C-type lectin homologue gene (EP153R) of African swine fever virus inhibits apoptosis both in virus infection and in heterologous expression. Virology 2004; 326:160-70. [PMID: 15262504 DOI: 10.1016/j.virol.2004.05.019] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Accepted: 05/24/2004] [Indexed: 10/26/2022]
Abstract
The open reading frame EP153R of African swine fever virus (ASFV) encodes a nonessential protein that has been involved in the hemadsorption process induced in virus-infected cells. By the use of a virus deletion mutant lacking the EP153R gene, we have detected, in several virus-sensitive cells, increased levels of caspase-3 and cell death as compared with those obtained after infection with the parental BA71V strain. Both transient and stable expression of the EP153R gene in Vero or COS cells resulted in a partial protection of the transfected lines from the apoptosis induced in response to virus infection or external stimuli. The presence of gene EP153R resulted in a reduction of the transactivating activity of the cellular protein p53 in Vero cell cultures in which apoptosis was induced by virus infection or staurosporine treatment. This is to our knowledge the first description of a viral C-type lectin with anti-apoptotic properties.
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Affiliation(s)
- Carolina Hurtado
- Centro de Biología Molecular Severo Ochoa (C.S.I.C.-U.A.M.), Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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35
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Granja AG, Nogal ML, Hurtado C, Salas J, Salas ML, Carrascosa AL, Revilla Y. Modulation of p53 cellular function and cell death by African swine fever virus. J Virol 2004; 78:7165-74. [PMID: 15194793 PMCID: PMC421689 DOI: 10.1128/jvi.78.13.7165-7174.2004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Modulation of the activity of tumor suppressor p53 is a key event in the replication of many viruses. We have studied the function of p53 in African swine fever virus (ASFV) infection by determining the expression and activity of this transcription factor in infected cells. p53 levels are increased at early times of infection and are maintained throughout the infectious cycle. The protein is transcriptionally active, stabilized by phosphorylation, and localized in the nucleus. p53 induces the expression of p21 and Mdm2. Strikingly, these two proteins are located at the cytoplasmic virus factories. The retention of Mdm2 at the factory may represent a viral mechanism to prevent p53 inactivation by the protein. The expression of apoptotic proteins, such as Bax or active caspase-3, is also increased following ASFV infection, although the increase in caspase-3 does not appear to be, at least exclusively, p53 dependent. Bax probably plays a role in the induction of apoptosis in the infected cells, as suggested by the release of cytochrome c from the mitochondria. The significance of p21 induction and localization is discussed in relation to the shutoff of cellular DNA synthesis that is observed in ASFV-infected cells.
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Affiliation(s)
- Aitor G Granja
- Centro de Biología Molecular Severo Ochoa, Universidad Autonoma, Cantoblanco, 28049 Madrid, Spain
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36
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Verrier F, Mignotte B, Jan G, Brenner C. Study of PTPC composition during apoptosis for identification of viral protein target. Ann N Y Acad Sci 2004; 1010:126-42. [PMID: 15033708 DOI: 10.1196/annals.1299.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The permeability transition pore complex (PTPC), a mitochondrial polyprotein complex, has been previously described to be involved in the control of mitochondrial membrane permeabilization (MMP) during chemotherapy-induced apoptosis. PTPC may contain proteins from both mitochondrial membranes [e.g., voltage-dependent anion channel (VDAC), PRAX-1, peripheral benzodiazepine receptor (PBR), adenine nucleotide translocator (ANT)], from cytosol (e.g., hexokinase II, glycerol kinase), from matrix [e.g., cyclophilin D (CypD)], and from intermembrane space (e.g., creatine kinase). PTPC may also interact with tumor suppressor proteins (i.e., Bax and Bid), oncoprotein homologues of Bcl-2 and some viral proteins, which can regulate apoptosis induced by pore opening. ANT and VDAC are the target of numerous pro-apoptotic MMP inducers. However, the precise composition of PTPC as well as the respective role of each PTPC component represent major issues in the understanding MMP process. Using several experimental strategies that combine co-immunoprecipitation, proteomics, and functional tests with proteoliposomes, we and others have been able to characterize some of the intra/inter-PTPC protein interactions leading to a better understanding of the process of MMP. In addition, this approach could identify new putative members and regulators of PTPC pro-apoptotic function and new targets of viral protein involved in the modulation of apoptosis during infection.
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Affiliation(s)
- Florence Verrier
- CNRS FRE 2445, Université de Versailles/St. Quentin, 45, avenue des Etats-Unis, 78035 Versailles, France
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37
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Netherton C, Rouiller I, Wileman T. The subcellular distribution of multigene family 110 proteins of African swine fever virus is determined by differences in C-terminal KDEL endoplasmic reticulum retention motifs. J Virol 2004; 78:3710-21. [PMID: 15016891 PMCID: PMC371041 DOI: 10.1128/jvi.78.7.3710-3721.2004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
African swine fever virus (ASFV) is a large double-stranded DNA virus that replicates in discrete areas in the cytosol of infected cells called viral factories. Recent studies have shown that assembling virions acquire their internal envelopes through enwrapment by membranes derived from the endoplasmic reticulum (ER). However, the mechanisms that underlie the formation of viral factories and progenitor viral membranes are as yet unclear. Analysis of the published genome of the virus revealed a conserved multigene family that encodes proteins with hydrophobic signal sequences, indicating possible translocation into the ER lumen. Strikingly, two of these genes, XP124L and Y118L, encoded proteins with KDEL-like ER retention motifs. Analysis of XP124L and Y118L gene product by biochemical and immunofluorescence techniques showed that the proteins were localized to pre-Golgi compartments and that the KEDL motif at the C terminus of pXP124L was functional. XP124L expression, in the absence of other ASFV genes, had a dramatic effect on the contents of the ER that was dependent precisely on the C-terminal sequence KEDL. The normal subcellular distribution of a number of proteins resident to this important, cellular organelle was drastically altered in cells expressing wild-type XP124L gene product. PXP124L formed unusual perinuclear structures that contained resident ER proteins, as well as proteins of the ER-Golgi intermediate compartment. The data presented here hint at a role for MGF110 gene product in preparing the ER for its role in viral morphogenesis; this and other potential functions are discussed.
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Affiliation(s)
- Christopher Netherton
- Division of Immunology, Pirbright Laboratory, Institute for Animal Health, Pirbright, Surrey GU24 0NF, United Kingdom
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38
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Kim J, Kwon YJ, Park ES, Sung B, Kim JH, Park CG, Hwang ES, Cha CY. Human cytomegalovirus (HCMV) IE1 plays role in resistance to apoptosis with etoposide in cancer cell line by Cdk2 accumulation. Microbiol Immunol 2004; 47:959-67. [PMID: 14695446 DOI: 10.1111/j.1348-0421.2003.tb03470.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Human cytomegalovirus (HCMV) has many strategies to survive the attack of the host. HCMV infection of host cells induces cellular activation and disturbance of the cell cycle. It is possible that HCMV modulates the behavior of certain cancer cells that are susceptible to HCMV infection. This study was performed to identify the possible mechanism of resistance to apoptotic stimuli in some cancer cell lines by HCMV infection. HCMV-infected cancer cells showed resistance to apoptosis induced by the topoisomerase II inhibitor etoposide. UMG1-2, which constitutively expresses HCMV immediate-early protein-1 (IE1), had resistance to apoptosis induced by etoposide as compared with the parental cell line U373MG. Measurement of caspases activity with fluorogenic substrates in etoposide-treated U373MG and UMG1-2 cells and the direct activation of caspase-3 with peptides containing arginine-glycine-aspartate in U373MG and UMG1-2 cells revealed that the inhibition level of apoptosis by HCMV IE1 would be upstream of caspase-3 in the caspase cascade pathway. Cellular expression of Cdk2 was increased in UMG1- 2 after etoposide treatment while the expression of E2F-1 in UMG1-2 was decreased as compared with that in U373MG. The Cdk2 inhibitor, roscovitine, decreased the resistance to apoptosis on etoposide-treated UMG1-2. These results suggest that aberrant HCMV infection confers resistance to anticancer drugs on some cancer cells and protects cells from apoptosis, possibly due to the deregulation of cyclin-dependent kinase by HCMV immediate-early protein.
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Affiliation(s)
- Jinhee Kim
- Department of Microbiology and Immunology, Seoul National University College of Medicine and Institute of Endemic Disease, Seoul National University Medical Research Center, Seoul, Republic of Korea
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Hernáez B, Escribano JM, Alonso C. Switching on and Off the Cell Death Cascade: African Swine Fever Virus Apoptosis Regulation. VIRUSES AND APOPTOSIS 2004; 36:57-69. [PMID: 15171607 DOI: 10.1007/978-3-540-74264-7_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- B Hernáez
- Dpt. Biotecnología, INIA, Ctra. de la Coruña Km7, 28040 Madrid, Spain
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40
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Hardwick JM, Bellows DS. Viral versus cellular BCL-2 proteins. Cell Death Differ 2003; 10 Suppl 1:S68-76. [PMID: 12655348 DOI: 10.1038/sj.cdd.4401133] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2002] [Revised: 07/15/2002] [Accepted: 07/29/2002] [Indexed: 11/08/2022] Open
Abstract
All gamma herpesviruses and a few other viruses encode at least one homologue of the mammalian cell death inhibitor BCL-2. Gamma herpesviruses are associated with human and animal lymphoid and epithelial tumours. However, the role of these viral BCL-2 homologues in the virus replication cycle or in human disease is not known, though recent developments show progress in this area. The structure of viral BCL-2 family protein, KSBcl-2, is similar to that of cellular family members, but viral BCL-2 proteins differ functionally from the cellular proteins, apparently escaping the regulatory mechanisms to which their cellular counterparts are subjected. Thus, exploring the biochemical and biological functions of the viral BCL-2 family proteins will increase our understanding of their role in virus infections and will undoubtedly teach us something about their cellular kin.
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Affiliation(s)
- J M Hardwick
- Department of Molecular Microbiology and Immunology, Johns Hopkins University School of Public Health, Baltimore, Maryland 21205, USA.
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41
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Cuconati A, White E. Viral homologs of BCL-2: role of apoptosis in the regulation of virus infection. Genes Dev 2002; 16:2465-78. [PMID: 12368257 DOI: 10.1101/gad.1012702] [Citation(s) in RCA: 225] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Andrea Cuconati
- Howard Hughes Medical Institute, Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, New Jersey 08854, USA
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42
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Abstract
Many viruses have as part of their arsenal the ability to modulate the apoptotic pathways of the host. It is counter-intuitive that such simple organisms would be efficient at regulating this the most crucial pathway within the host, given the relative complexity of the host cells. Yet, viruses have the potential to initiate or stay the onset of programmed cell death through the manipulation of a variety of key apoptotic proteins. It is the intention of this review to provide an overview of viral gene products that are able to promote or inhibit apoptotic death of the host cell and to discuss their mechanisms of action. It is not until recently that the depth at which viruses exploit the apoptotic pathways of their host has been seen. This understanding may provide a great opportunity for future therapeutic ventures.
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Affiliation(s)
- Stewart Hay
- The Fiona Elsey Cancer Research Laboratory, Cancer Research Centre, School of Science, University of Ballarat, St John of God Hospital, 1002 Mair Street, Ballarat, Victoria 3350, Australia1
| | - George Kannourakis
- The Fiona Elsey Cancer Research Laboratory, Cancer Research Centre, School of Science, University of Ballarat, St John of God Hospital, 1002 Mair Street, Ballarat, Victoria 3350, Australia1
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43
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Neilan JG, Zsak L, Lu Z, Kutish GF, Afonso CL, Rock DL. Novel swine virulence determinant in the left variable region of the African swine fever virus genome. J Virol 2002; 76:3095-104. [PMID: 11884534 PMCID: PMC136047 DOI: 10.1128/jvi.76.7.3095-3104.2002] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2001] [Accepted: 12/18/2001] [Indexed: 02/06/2023] Open
Abstract
Previously we have shown that the African swine fever virus (ASFV) NL gene deletion mutant E70DeltaNL is attenuated in pigs. Our recent observations that NL gene deletion mutants of two additional pathogenic ASFV isolates, Malawi Lil-20/1 and Pr4, remained highly virulent in swine (100% mortality) suggested that these isolates encoded an additional virulence determinant(s) that was absent from E70. To map this putative virulence determinant, in vivo marker rescue experiments were performed by inoculating swine with infection-transfection lysates containing E70 NL deletion mutant virus (E70DeltaNL) and cosmid DNA clones from the Malawi NL gene deletion mutant (MalDeltaNL). A cosmid clone representing the left-hand 38-kb region (map units 0.05 to 0.26) of the MalDeltaNL genome was capable of restoring full virulence to E70DeltaNL. Southern blot analysis of recovered virulent viruses confirmed that they were recombinant E70DeltaNL genomes containing a 23- to 28-kb DNA fragment of the Malawi genome. These recombinants exhibited an unaltered MalDeltaNL disease and virulence phenotype when inoculated into swine. Additional in vivo marker rescue experiments identified a 20-kb fragment, encoding members of multigene families (MGF) 360 and 530, as being capable of fully restoring virulence to E70DeltaNL. Comparative nucleotide sequence analysis of the left variable region of the E70DeltaNL and Malawi Lil-20/1 genomes identified an 8-kb deletion in the E70DeltaNL isolate which resulted in the deletion and/or truncation of three MGF 360 genes and four MGF 530 genes. A recombinant MalDeltaNL deletion mutant lacking three members of each MGF gene family was constructed and evaluated for virulence in swine. The mutant virus replicated normally in macrophage cell culture but was avirulent in swine. Together, these results indicate that a region within the left variable region of the ASFV genome containing the MGF 360 and 530 genes represents a previously unrecognized virulence determinant for domestic swine.
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Affiliation(s)
- J G Neilan
- Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Greenport, New York 11944-0848, USA.
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44
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Carrascosa AL, Bustos MJ, Nogal ML, González de Buitrago G, Revilla Y. Apoptosis induced in an early step of African swine fever virus entry into vero cells does not require virus replication. Virology 2002; 294:372-82. [PMID: 12009879 DOI: 10.1006/viro.2001.1348] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Permissive Vero cells develop apoptosis, as characterized by DNA fragmentation, caspases activation, cytosolic release of mitochondrial cytochrome c, and flow cytometric analysis of DNA content, upon infection with African swine fever virus (ASFV). To determine the step in virus replication that triggers apoptosis, we used UV-inactivated virus, inhibitors of protein and nucleic acid synthesis, and lysosomotropic drugs that block virus uncoating. ASFV-induced apoptosis was accompanied by caspase-3 activation, which was detected even in the presence of either cytosine arabinoside or cycloheximide, indicating that viral DNA replication and protein synthesis were not required to activate the apoptotic process. The activation of caspase-3 was released from chloroquine inhibition 2 h after virus absorption, while the infection with UV-inactivated ASFV did not induce the activation of the caspase cascade. We conclude that ASFV induces apoptosis in the infected cell by an intracellular pathway probably triggered during the process of virus uncoating.
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Affiliation(s)
- Angel L Carrascosa
- Centro de Biología Molecular "Severo Ochoa", Universidad Autónoma de Madrid, Madrid, 28049, Spain.
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45
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Moise AR, Grant JR, Vitalis TZ, Jefferies WA. Adenovirus E3-6.7K maintains calcium homeostasis and prevents apoptosis and arachidonic acid release. J Virol 2002; 76:1578-87. [PMID: 11799152 PMCID: PMC135875 DOI: 10.1128/jvi.76.4.1578-1587.2002] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
E3-6.7K is a small and hydrophobic membrane glycoprotein encoded by the E3 region of subgroup C adenovirus. Recently, E3-6.7K has been shown to be required for the downregulation of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) receptors by the adenovirus E3/10.4K and E3/14.5K complex of proteins. We demonstrate here that E3-6.7K has additional protective roles, independent of other virus proteins. In transfected Jurkat T-cell lymphoma cells, E3-6.7K was found to maintain endoplasmic reticulum-Ca(2+) homeostasis and inhibit the induction of apoptosis by thapsigargin. The presence of E3-6.7K also lead to a reduction in the TNF-induced release of arachidonic acid from transfected U937 human histiocytic lymphoma cells. In addition, E3-6.7K protected cells against apoptosis induced through Fas, TNF receptor, and TRAIL receptors. Therefore, E3-6.7K confers a wide range of protective effects against both Ca(2+) flux-induced and death receptor-mediated apoptosis.
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Affiliation(s)
- Alexander R Moise
- Biotechnology Laboratory, Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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46
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Ahmed M, Lock M, Miller CG, Fraser NW. Regions of the herpes simplex virus type 1 latency-associated transcript that protect cells from apoptosis in vitro and protect neuronal cells in vivo. J Virol 2002; 76:717-29. [PMID: 11752162 PMCID: PMC136840 DOI: 10.1128/jvi.76.2.717-729.2002] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent studies have suggested that the latency-associated transcript (LAT) region of herpes simplex virus type 1 (HSV-1) is effective at blocking virus-induced apoptosis both in vitro and in the trigeminal ganglia of acutely infected rabbits (Inman et al., J. Virol. 75:3636-3646, 2001; Perng et al., Science 287:1500-1503, 2000). By transfecting cells with a construct expressing the Pst-Mlu segment of the LAT, encompassing the LAT exon 1, the stable 2.0-kb intron, and 5' part of exon 2, we confirmed that this region was able to diminish the onset of programmed cell death initiated by anti-Fas and camptothecin treatment. In addition, caspase 8-induced apoptosis was specifically inhibited in cells expressing the Pst-Mlu LAT fragment. To further delineate the minimal region of LAT that is necessary for this antiapoptotic function, LAT mutants were used in our cotransfection assays. In HeLa cells, the plasmids lacking exon sequences were the least effective at blocking apoptosis. However, similar to previous work (Inman et al., op. cit.), our data also indicated that the 5' end of the stable 2.0-kb LAT intron appeared to contribute to the promotion of cell survival. Furthermore, cells productively infected with the 17N/H LAT mutant virus, a virus deleted in the LAT promoter, exon 1, and about half of the intron, exhibited a greater degree of DNA fragmentation than cells infected with wild-type HSV-1. These data support the finding that the exon 1 and 2.0-kb intron region of the LAT transcription unit display an antiapoptotic function both in transfected cells and in the context of the virus infection in vitro. In trigeminal ganglia of mice acutely infected with the wild-type virus, 17, and 17DeltaSty, a virus lacking most of exon 1, apoptosis was not detected in cells that were positive for virus particles. However, dual staining was observed in cells from mice infected with 17N/H virus, indicating that the LAT antiapoptotic function demonstrated in cells transfected by LAT-expressing constructs may also play a role in protecting cells from virus-induced apoptosis during acute viral infection in vivo.
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Affiliation(s)
- Maryam Ahmed
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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47
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Wasilenko ST, Meyers AF, Vander Helm K, Barry M. Vaccinia virus infection disarms the mitochondrion-mediated pathway of the apoptotic cascade by modulating the permeability transition pore. J Virol 2001; 75:11437-48. [PMID: 11689625 PMCID: PMC114730 DOI: 10.1128/jvi.75.23.11437-11448.2001] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Many viruses have evolved strategies that target crucial components within the apoptotic cascade. One of the best studied is the caspase 8 inhibitor, crmA/Spi-2, encoded by members of the poxvirus family. Since many proapoptotic stimuli induce apoptosis through a mitochondrion-dependent, caspase 8-independent pathway, we hypothesized that vaccinia virus would encode a mechanism to directly modulate the mitochondrial apoptotic pathway. In support of this, we observed that Jurkat cells, which undergo Fas-mediated apoptosis exclusively through the mitochondrial route, were resistant to Fas-induced death following infection with a crmA/Spi-2-deficient strain of vaccinia virus. In addition, vaccinia virus-infected cells subjected to the proapoptotic stimulus staurosporine exhibited decreased levels of both cytochrome c released from the mitochondria and caspase 3 activation. In all cases we found that the loss of the mitochondrial membrane potential, which occurs as a result of opening the multimeric permeability transition pore complex, was prevented in vaccinia virus-infected cells. Moreover, vaccinia virus infection specifically inhibited opening of the permeability transition pore following treatment with the permeability transition pore ligand atractyloside and t-butylhydroperoxide. These studies indicate that vaccinia virus infection directly impacts the mitochondrial apoptotic cascade by influencing the permeability transition pore.
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Affiliation(s)
- S T Wasilenko
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2S2
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48
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Vallée I, Tait SW, Powell PP. African swine fever virus infection of porcine aortic endothelial cells leads to inhibition of inflammatory responses, activation of the thrombotic state, and apoptosis. J Virol 2001; 75:10372-82. [PMID: 11581405 PMCID: PMC114611 DOI: 10.1128/jvi.75.21.10372-10382.2001] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
African swine fever (ASF) is an asymptomatic infection of warthogs and bushpigs, which has become an emergent disease of domestic pigs, characterized by hemorrhage, lymphopenia, and disseminated intravascular coagulation. It is caused by a large icosohedral double-stranded DNA virus, African swine fever virus (ASFV), with infection of macrophages well characterized in vitro and in vivo. This study shows that virulent isolates of ASFV also infect primary cultures of porcine aortic endothelial cells and bushpig endothelial cells (BPECs) in vitro. Kinetics of early and late gene expression, viral factory formation, replication, and secretion were similar in endothelial cells and macrophages. However, ASFV-infected endothelial cells died by apoptosis, detected morphologically by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling and nuclear condensation and biochemically by poly(ADP-ribose) polymerase (PARP) cleavage at 4 h postinfection (hpi). Immediate-early proinflammatory responses were inhibited, characterized by a lack of E-selectin surface expression and interleukin 6 (IL-6) and IL-8 mRNA synthesis. Moreover, ASFV actively downregulated interferon-induced major histocompatibility complex class I surface expression, a strategy by which viruses evade the immune system. Significantly, Western blot analysis showed that the 65-kDa subunit of the transcription factor NF-kappaB, a central regulator of the early response to viral infection, decreased by 8 hpi and disappeared by 18 hpi. Both disappearance of NF-kappaB p65 and cleavage of PARP were reversed by the caspase inhibitor z-VAD-fmk. Interestingly, surface expression and mRNA transcription of tissue factor, an important initiator of the coagulation cascade, increased 4 h after ASFV infection. These data suggest a central role for vascular endothelial cells in the hemorrhagic pathogenesis of the disease. Since BPECs infected with ASFV also undergo apoptosis, resistance of the natural host must involve complex pathological factors other than viral tropism.
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Affiliation(s)
- I Vallée
- Department of Immunology and Pathology, Institute for Animal Health, Pirbright, Surrey GU24 ONF, United Kingdom
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Liu JL, Kung HJ. Marek's disease herpesvirus transforming protein MEQ: a c-Jun analogue with an alternative life style. Virus Genes 2001; 21:51-64. [PMID: 11022789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
In order to adapt to and to cope with an often hostile host environment, many viruses have evolved to encode products that are homologous to cellular proteins. These proteins exploit the existing host machinery and allow viruses to readily integrate into the host functional network. As a result, viruses are able to maneuver their journey seemingly effortlessly inside the host cell to achieve ultimate survival. Such molecular mimicries sometime go overboard, allowing viruses to overtake the cellular pathways or evade the immune system as do many of the retroviral oncogenes. Retroviral oncogenes are derived directly from host genes, and they are virtually identical to host genes in sequences except those mutations that make them unregulatable by host. Oncogenic herpesviruses also encode oncogenes, or transforming genes, which have independently evolved and are distantly related to host genes. However, these genes do share consensus structural motifs with cellular genes involved in cell growth and apoptosis and are functional analogues to host genes. The Marek's disease virus oncoprotein, MEQ, is one such example. MEQ is a basic region-leucine zipper (bZIP) transactivator which shares extensive homology with the Jun/Fos family of transcription factors within the bZIP domain, but not in other regions. Like all other bZIP proteins, MEQ is capable of dimerizing with itself and with a variety of bZIP partners including c-Jun, B-Jun, c-Fos, CREB, ATF-1, ATF-2, and SNF. MEQ-Jun heterodimers bind to a TRE/CRE-like sequence in the meq promoter region and have been shown to up-regulate MEQ expression in both chicken embryo fibroblasts and F9 cells. In addition, the bZIP and transactivation domains are interchangeable between MEQ and c-Jun in terms of transforming potential; i.e. MEQ can functionally substitute for c-Jun. These properties enable MEQ to engage in host cell processes by disguising itself as c-Jun. On the other hand, there are properties of MEQ notably different from c-Jun, which include its capability to bind RNA, to bind a CACAC-bent DNA structure as a homodimer, to inhibit apoptosis, and to interact with CDK2. MEQ's subcellular localization in the nucleolus and coiled body, is also different from Jun/Fos family of transactivators. These unique features may provide the MEQ with additional facility in regulating MDV replication, establishing latency, and cellular transformation. In this review, we will attempt to summarize the past research progress on MDV meq, with a focused on the similarities and differences between MEQ and cellular proteins, and between MEQ and other viral oncoproteins.
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Affiliation(s)
- J L Liu
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4960, USA
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Abstract
During the co-evolution of viruses with their vertebrate hosts, the DNA viruses have acquired an impressive array of immunomodulatory genes to combat host immune responses and their hosts have developed a sophisticated immune system to contain virus infections. In order to replicate, the viruses have evolved mechanisms to inhibit key host anti-virus responses that include apoptosis, interferon production, chemokine production, inflammatory cytokine production, and the activity of cytotoxic T-cells, natural killer cells and antibody. In addition, some of the viruses encode cytokine or chemokine homologues that recruit or expand cell numbers for infection or that subvert the host cellular response from a protective response to a benign one. The specificity of the viral immunomodulatory molecules reflects the life cycle and the pathogenesis of the viruses. Herpesviruses achieve latency in host cells by inducing cell survival and protecting infected cells from immune recognition. This involves interference with cell signal transduction pathways. Many of the viral immunomodulatory proteins are homologues of host proteins that appear to have been pirated from the host and reassorted in the virus genomes. Some of these have unique functions and indicate novel or important aspects of both viral pathogenesis and host immunity to viruses. The specific example of orf virus infection of sheep is described.
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Affiliation(s)
- D M Haig
- Moredun Research Institute, Pentlands Science Park, Penicuik, Scotland, UK.
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