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Geng XM, Xi YM, Huang XM, Wang YL, Wang XY, Ouyang K, Chen Y, Wei ZZ, Qin YF, Huang WJ. Construction of and evaluation of the immune response to two recombinant pseudorabies viruses expressing the B119L and EP364R proteins of African swine fever virus. Arch Virol 2024; 169:22. [PMID: 38193974 DOI: 10.1007/s00705-023-05935-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/31/2023] [Indexed: 01/10/2024]
Abstract
African swine fever (ASF) is an infectious disease caused by ASF virus (ASFV), which is characterized by high infectivity, rapid onset of disease, and a high mortality rate. Outbreaks of ASFV have caused great economic losses to the global pig industry, and there is a need to develop safe and effective vaccines. In this study, two recombinant pseudorabies virus (PRV) strains, rGXGG-2016-ΔgI/ΔgE-EP364R and rGXGG-2016-ΔgI/ΔgE-B119L, expressing the EP364R and B119L protein, respectively, of ASFV, were constructed by homologous recombination technology. Western blotting and immunofluorescence analysis showed that these foreign proteins were expressed in cells infected with the recombinant strains. The strains showed good genetic stability and proliferative characteristics for 20 passages in BHK-21 cells. Both of these strains were immunogenic in mice, inducing the production of specific antibodies against the expressed ASFV proteins while providing protection against lethal challenge with PRV. Thus, the recombinant strains rGXGG-2016-ΔgI/ΔgE-EP364R and rGXGG-2016-ΔgI/ΔgE-B119L could be used as candidate vaccines for both ASFV and PRV. In addition, our study identifies two potential target genes for the development of safe and efficient ASFV vaccines, provides a reference for the construction of bivalent ASFV and PRV vaccines, and demonstrates the feasibility of developing a live ASFV vector vaccine.
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Affiliation(s)
- Xin-Mei Geng
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China
| | - Ying-Mu Xi
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China
| | - Xiang-Mei Huang
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China
| | - Yang-Lin Wang
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China
| | - Xu-Ying Wang
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China
| | - Kang Ouyang
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China
| | - Ying Chen
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China
| | - Zu-Zhang Wei
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China
| | - Yi-Feng Qin
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China.
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China.
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China.
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China.
| | - Wei-Jian Huang
- Laboratory of Animal Infectious Diseases and Molecular Immunology, College of Animal Science and Technology, Guangxi University, Nanning, 530004, China.
- Guangxi Zhuang Autonomous Region Engineering Research Center of Veterinary Biologics, Nanning, 530004, China.
- Guangxi Key Laboratory of Animal Breeding, Disease Control and Prevention, Nanning, 530004, China.
- Guangxi Colleges and Universities Key Laboratory of Prevention and Control for Animal Disease, Nanning, 530004, China.
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Salazar S, Luong KTY, Nua T, Koyuncu OO. Interferon-λ Activates a Differential Response in Peripheral Neurons That Is Effective against Alpha Herpesvirus Infections. Pathogens 2023; 12:1142. [PMID: 37764950 PMCID: PMC10536099 DOI: 10.3390/pathogens12091142] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 09/01/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Alpha herpesviruses (α-HV) infect host mucosal epithelial cells prior to establishing a life-long latent infection in the peripheral nervous system. The initial spread of viral particles from mucosa to the nervous system and the role of intrinsic immune responses at this barrier is not well understood. Using primary neurons cultured in compartmentalized chambers, prior studies performed on Pseudorabies virus (PRV) have demonstrated that type I and type II interferons (IFNs) induce a local antiviral response in axons via distinct mechanisms leading to a reduction in viral particle transport to the neuronal nucleus. A new class of interferons known as type III IFNs has been shown to play an immediate role against viral infection in mucosal epithelial cells. However, the antiviral effects of type III IFNs within neurons during α-HV infection are largely unknown. In this study, we focused on elucidating the antiviral activity of type III IFN against PRV neuronal infection, and we compared the interferon-stimulated gene (ISGs) induction pattern in neurons to non-neuronal cells. We found that IFN pre-exposure of both primary neurons and fibroblast cells significantly reduces PRV virus yield, albeit by differential STAT activation and ISG induction patterns. Notably, we observed that type III IFNs trigger the expression of a subset of ISGs mainly through STAT1 activation to induce an antiviral state in primary peripheral neurons.
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Affiliation(s)
| | | | | | - Orkide O. Koyuncu
- Department of Microbiology and Molecular Genetics, School of Medicine and Center for Virus Research, University of California, Irvine, CA 92697, USA; (S.S.); (K.T.Y.L.); (T.N.)
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3
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A Comparison of Pseudorabies Virus Latency to Other A-Herpesvirinae Subfamily Members. Viruses 2022; 14:v14071386. [PMID: 35891367 PMCID: PMC9316381 DOI: 10.3390/v14071386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/12/2022] [Accepted: 06/22/2022] [Indexed: 12/04/2022] Open
Abstract
Pseudorabies virus (PRV), the causative agent of Aujeszky’s disease, is one of the most important infectious pathogens threatening the global pig industry. Like other members of alphaherpesviruses, PRV establishes a lifelong latent infection and occasionally reactivates from latency after stress stimulus in infected pigs. Latent infected pigs can then serve as the source of recurrent infection, which is one of the difficulties for PRV eradication. Virus latency refers to the retention of viral complete genomes without production of infectious progeny virus; however, following stress stimulus, the virus can be reactivated into lytic infection, which is known as the latency-reactivation cycle. Recently, several research have indicated that alphaherpesvirus latency and reactivation is regulated by a complex interplay between virus, neurons, and the immune system. However, with those limited reports, the relevant advances in PRV latency are lagging behind. Therefore, in this review we focus on the regulatory mechanisms in PRV latency via summarizing the progress of PRV itself and that of other alphaherpesviruses, which will improve our understanding in the underlying mechanism of PRV latency and help design novel therapeutic strategies to control PRV latency.
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Deng J, Wu Z, Liu J, Ji Q, Ju C. The Role of Latency-Associated Transcripts in the Latent Infection of Pseudorabies Virus. Viruses 2022; 14:v14071379. [PMID: 35891360 PMCID: PMC9320458 DOI: 10.3390/v14071379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 11/16/2022] Open
Abstract
Pseudorabies virus (PRV) can cause neurological, respiratory, and reproductive diseases in pigs and establish lifelong latent infection in the peripheral nervous system (PNS). Latent infection is a typical feature of PRV, which brings great difficulties to the prevention, control, and eradication of pseudorabies. The integral mechanism of latent infection is still unclear. Latency-associated transcripts (LAT) gene is the only transcriptional region during latent infection of PRV which plays the key role in regulating viral latent infection and inhibiting apoptosis. Here, we review the characteristics of PRV latent infection and the transcriptional characteristics of the LAT gene. We also analyzed the function of non-coding RNA (ncRNA) produced by the LAT gene and its importance in latent infection. Furthermore, we provided possible strategies to solve the problem of latent infection of virulent PRV strains in the host. In short, the detailed mechanism of PRV latent infection needs to be further studied and elucidated.
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Lu JJ, Yuan WZ, Zhu YP, Hou SH, Wang XJ. Latent pseudorabies virus infection in medulla oblongata from quarantined pigs. Transbound Emerg Dis 2020; 68:543-551. [PMID: 32615031 DOI: 10.1111/tbed.13712] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/09/2020] [Accepted: 06/27/2020] [Indexed: 12/15/2022]
Abstract
Pseudorabies virus (PRV) is a major pathogen in pig husbandry and is also a risk to human well-being. Pigs with latent PRV infection carry the virus lifelong, and it can be activated under conducive conditions. This poses a very important challenge to the control of the virus and may even prevent its elimination. To investigate latent infection with wild-type (wt) PRV, and also infection due to the use of live attenuated vaccines on farms, 80 pigs from two large-scale swine operations were traced. At 6 months old, the quarantined pigs were slaughtered and brain samples were collected. A PCR assay targeting the gB and gE genes was developed to detect PRV DNA fragments in medulla oblongata. Five of the samples (6.3%) were gB and gE gene fragment double-positive, 60 of the samples (75%) were gB single-positive, and 15 samples (18.7%) showed double-negative. A portion of latency-associated transcripts (LATs), EP0 mRNA, were found to be present in the gB gene fragment positive samples. Furthermore, the five double-positive samples were transmitted blindly, and apparent cytopathic effects were found in three of the five samples in the fourth generation. By means of Western blotting, PCR and sequencing, two of the isolated viruses were found to be related to vaccine strain Bartha-K61. Another was closely related to domestic epidemic strains HN1201 and LA and relatively unrelated to other Asian isolates. These results suggest that the live vaccines are latently present in brains, in a manner similar to wt PRV, and this poses potential safety issues in the pig husbandry industry. Wt PRV and live vaccine viruses were found to co-exist in pigs, demonstrating that the live vaccines were unable to confer complete sterilizing immunity, which may explain outbreaks of pseudorabies on vaccinated farms.
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Affiliation(s)
- Jin-Jin Lu
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Wan-Zhe Yuan
- College of Veterinary Medicine, Hebei Agricultural University, Baoding, China
| | - Yong-Ping Zhu
- Agricultural Bureau of Wuzhong District, Suzhou, China
| | - Shao-Hua Hou
- Beijing Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiao-Jia Wang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
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6
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Maturana CJ, Verpeut JL, Pisano TJ, Dhanerawala ZM, Esteves A, Enquist LW, Engel EA. Small Alphaherpesvirus Latency-Associated Promoters Drive Efficient and Long-Term Transgene Expression in the CNS. Mol Ther Methods Clin Dev 2020; 17:843-857. [PMID: 32368565 PMCID: PMC7191541 DOI: 10.1016/j.omtm.2020.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/06/2020] [Indexed: 02/06/2023]
Abstract
Recombinant adeno-associated viruses (rAAVs) are used as gene therapy vectors to treat central nervous system (CNS) diseases. Despite their safety and broad tropism, important issues need to be corrected such as the limited payload capacity and the lack of small gene promoters providing long-term, pan-neuronal transgene expression in the CNS. Commonly used gene promoters are relatively large and can be repressed a few months after CNS transduction, risking the long-term performance of single-dose gene therapy applications. We used a whole-CNS screening approach based on systemic delivery of AAV-PHP.eB, iDisco+ tissue-clearing and light-sheet microscopy to identify three small latency-associated promoters (LAPs) from the herpesvirus pseudorabies virus (PRV). These promoters are LAP1 (404 bp), LAP2 (498 bp), and LAP1_2 (880 bp). They drive chronic transcription of the virus-encoded latency-associated transcript (LAT) during productive and latent phases of PRV infection. We observed stable, pan-neuronal transgene transcription and translation from AAV-LAPs in the CNS for 6 months post AAV transduction. In several CNS areas, the number of cells expressing the transgene was higher for LAP2 than the large conventional EF1α promoter (1,264 bp). Our data suggest that the LAPs are suitable candidates for viral vector-based CNS gene therapies requiring chronic transgene expression after one-time viral-vector administration.
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Affiliation(s)
- Carola J. Maturana
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Jessica L. Verpeut
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Thomas J. Pisano
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Zahra M. Dhanerawala
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Andrew Esteves
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Lynn W. Enquist
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Esteban A. Engel
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
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Guan X, Liu J, Jiang H, Wu CX, Chen HC, Liu ZF. Expression of pseudorabies virus-encoded long noncoding RNAs in epithelial cells and neurons. J Neurovirol 2018; 24:597-605. [PMID: 29987580 DOI: 10.1007/s13365-018-0651-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 05/18/2018] [Accepted: 05/23/2018] [Indexed: 11/30/2022]
Abstract
Long noncoding RNAs (lncRNAs) play important roles in regulating eukaryotic genome replication and gene expression in diverse biological systems. Here, we identified lncRNAs transcribed from pseudorabies virus (PRV)-infected PK-15 cells. Based on high-throughput sequencing data, we obtained 87,263,926 and 93,947,628 clean reads from mock-infected and PRV-infected PK-15 cells, respectively. Through a normalized analytic protocol, we identified three novel viral lncRNAs. According to an analysis of differential expression between the mock-infected and PRV-infected cells, 4151 host lncRNAs were significantly upregulated and 2327 host lncRNAs were significantly downregulated in the latter group. Viral lncRNAs and several host lncRNAs were verified by northern blotting and real-time PCR. The findings showed that the viral lncRNA LDI might regulate the expression of IE180, a potent transcriptional activator of viral genes. Furthermore, we characterized the expression of viral lncRNAs in a culture of infected primary chicken dorsal root ganglia (DRG). Collectively, the obtained data suggest that PRV generates lncRNAs in both epithelial cells and chick DRG neurons.
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Affiliation(s)
- Xiang Guan
- State Key Laboratory of Agricultural Microbiology and Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jie Liu
- State Key Laboratory of Agricultural Microbiology and Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hui Jiang
- State Key Laboratory of Agricultural Microbiology and Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chang-Xian Wu
- State Key Laboratory of Agricultural Microbiology and Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Huan-Chun Chen
- State Key Laboratory of Agricultural Microbiology and Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zheng-Fei Liu
- State Key Laboratory of Agricultural Microbiology and Key Laboratory of Preventive Veterinary Medicine in Hubei Province, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.
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8
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Koyuncu OO, MacGibeny MA, Enquist LW. Latent versus productive infection: the alpha herpesvirus switch. Future Virol 2018; 13:431-443. [PMID: 29967651 DOI: 10.2217/fvl-2018-0023] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 03/27/2018] [Indexed: 12/19/2022]
Abstract
Alpha herpesviruses are common pathogens of mammals. They establish a productive infection in many cell types, but a life-long latent infection occurs in PNS neurons. A vast majority of the human population has latent HSV-1 infections. Currently, there is no cure to clear latent infections. Even though HSV-1 is among the best studied viral pathogens, regulation of latency and reactivation is not well understood due to several challenges including a lack of animal models that precisely recapitulate latency/reactivation episodes; a difficulty in modeling in vitro latency; and a limited understanding of neuronal biology. In this review, we discuss insights gained from in vitro latency models with a focus on the neuronal and viral factors that determine the mode of infection.
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Affiliation(s)
- Orkide O Koyuncu
- Department of Molecular Biology and Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Margaret A MacGibeny
- Department of Molecular Biology and Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Lynn W Enquist
- Department of Molecular Biology and Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
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Feldman ER, Tibbetts SA. Emerging Roles of Herpesvirus microRNAs During In Vivo Infection and Pathogenesis. CURRENT PATHOBIOLOGY REPORTS 2015; 3:209-217. [PMID: 26246961 PMCID: PMC4522463 DOI: 10.1007/s40139-015-0085-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herpesviridae constitutes a large family of double-stranded DNA viruses that are associated with a wide range of diseases, including herpetic lesions, birth defects, and cancer. Herpesviruses establish lifelong latent infections in part because they are exceptionally adept at modulating the virus/host interface. New insights into the numerous roles of microRNAs (miRNAs) in cell biology, along with the recent appreciation that nearly every host transcript is targeted by at least one miRNA, has fundamentally changed our conceptualization of the virus/host relationship. The identification of miRNAs expressed from nearly all human herpesvirus genomes has led to the speculation that these short non-coding transcripts play essential roles in herpesvirus biology. Because the activity of miRNAs depends upon the transcriptome of the cell in which they are expressed, in vivo systems will be essential for defining the true biological relevance of herpesvirus miRNAs. This review will specifically focus on experimental systems which have investigated the functional role of herpesvirus-encoded miRNAs in viral biology and pathogenesis in vivo.
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Affiliation(s)
- Emily R. Feldman
- Department of Molecular Genetics & Microbiology, College of Medicine, UF Health Cancer Center, University of Florida, 1200 Newell Dr., R2-291, Gainesville, FL 32610 USA
| | - Scott A. Tibbetts
- Department of Molecular Genetics & Microbiology, College of Medicine, UF Health Cancer Center, University of Florida, 1200 Newell Dr., R2-291, Gainesville, FL 32610 USA
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Tombácz D, Csabai Z, Oláh P, Havelda Z, Sharon D, Snyder M, Boldogkői Z. Characterization of novel transcripts in pseudorabies virus. Viruses 2015; 7:2727-44. [PMID: 26008709 PMCID: PMC4452928 DOI: 10.3390/v7052727] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/14/2015] [Accepted: 05/18/2015] [Indexed: 01/20/2023] Open
Abstract
In this study we identified two 3'-coterminal RNA molecules in the pseudorabies virus. The highly abundant short transcript (CTO-S) proved to be encoded between the ul21 and ul22 genes in close vicinity of the replication origin (OriL) of the virus. The less abundant long RNA molecule (CTO-L) is a transcriptional readthrough product of the ul21 gene and overlaps OriL. These polyadenylated RNAs were characterized by ascertaining their nucleotide sequences with the Illumina HiScanSQ and Pacific Biosciences Real-Time (PacBio RSII) sequencing platforms and by analyzing their transcription kinetics through use of multi-time-point Real-Time RT-PCR and the PacBio RSII system. It emerged that transcription of the CTOs is fully dependent on the viral transactivator protein IE180 and CTO-S is not a microRNA precursor. We propose an interaction between the transcription and replication machineries at this genomic location, which might play an important role in the regulation of DNA synthesis.
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Affiliation(s)
- Dóra Tombácz
- These authors contributed equally to this work..
| | - Zsolt Csabai
- These authors contributed equally to this work..
| | - Péter Oláh
- These authors contributed equally to this work..
| | - Zoltán Havelda
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Somogyi B. u. 4., Szeged H-6720, Hungary.
| | - Donald Sharon
- Agricultural Biotechnology Center, Institute for Plant Biotechnology, Plant Developmental Biology Group, Szent-Györgyi A. u. 4, Gödöllő H-2100, Hungary.
| | - Michael Snyder
- Agricultural Biotechnology Center, Institute for Plant Biotechnology, Plant Developmental Biology Group, Szent-Györgyi A. u. 4, Gödöllő H-2100, Hungary.
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The number of alphaherpesvirus particles infecting axons and the axonal protein repertoire determines the outcome of neuronal infection. mBio 2015; 6:mBio.00276-15. [PMID: 25805728 PMCID: PMC4453538 DOI: 10.1128/mbio.00276-15] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Infection by alphaherpesviruses invariably results in invasion of the peripheral nervous system (PNS) and establishment of either a latent or productive infection. Infection begins with long-distance retrograde transport of viral capsids and tegument proteins in axons toward the neuronal nuclei. Initial steps of axonal entry, retrograde transport, and replication in neuronal nuclei are poorly understood. To better understand how the mode of infection in the PNS is determined, we utilized a compartmented neuron culturing system where distal axons of PNS neurons are physically separated from cell bodies. We infected isolated axons with fluorescent-protein-tagged pseudorabies virus (PRV) particles and monitored viral entry and transport in axons and replication in cell bodies during low and high multiplicities of infection (MOIs of 0.01 to 100). We found a threshold for efficient retrograde transport in axons between MOIs of 1 and 10 and a threshold for productive infection in the neuronal cell bodies between MOIs of 1 and 0.1. Below an MOI of 0.1, the viral genomes that moved to neuronal nuclei were silenced. These genomes can be reactivated after superinfection by a nonreplicating virus, but not by a replicating virus. We further showed that viral particles at high-MOI infections compete for axonal proteins and that this competition determines the number of viral particles reaching the nuclei. Using mass spectrometry, we identified axonal proteins that are differentially regulated by PRV infection. Our results demonstrate the impact of the multiplicity of infection and the axonal milieu on the establishment of neuronal infection initiated from axons. Alphaherpesvirus genomes may remain silent in peripheral nervous system (PNS) neurons for the lives of their hosts. These genomes occasionally reactivate to produce infectious virus that can reinfect peripheral tissues and spread to other hosts. Here, we use a neuronal culture system to investigate the outcome of axonal infection using different numbers of viral particles and coinfection assays. We found that the dynamics of viral entry, transport, and replication change dramatically depending on the number of virus particles that infect axons. We demonstrate that viral genomes are silenced when the infecting particle number is low and that these genomes can be reactivated by superinfection with UV-inactivated virus, but not with replicating virus. We further show that viral invasion rapidly changes the profiles of axonal proteins and that some of these axonal proteins are rate limiting for efficient infection. Our study provides new insights into the establishment of silent versus productive alphaherpesvirus infections in the PNS.
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A 2.5-kilobase deletion containing a cluster of nine microRNAs in the latency-associated-transcript locus of the pseudorabies virus affects the host response of porcine trigeminal ganglia during established latency. J Virol 2014; 89:428-42. [PMID: 25320324 DOI: 10.1128/jvi.02181-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED The alphaherpesvirus pseudorabies virus (PrV) establishes latency primarily in neurons of trigeminal ganglia when only the transcription of the latency-associated transcript (LAT) locus is detected. Eleven microRNAs (miRNAs) cluster within the LAT, suggesting a role in establishment and/or maintenance of latency. We generated a mutant (M) PrV deleted of nine miRNA genes which displayed properties that were almost identical to those of the parental PrV wild type (WT) during propagation in vitro. Fifteen pigs were experimentally infected with either WT or M virus or were mock infected. Similar levels of virus excretion and host antibody response were observed in all infected animals. At 62 days postinfection, trigeminal ganglia were excised and profiled by deep sequencing and quantitative RT-PCR. Latency was established in all infected animals without evidence of viral reactivation, demonstrating that miRNAs are not essential for this process. Lower levels of the large latency transcript (LLT) were found in ganglia infected by M PrV than in those infected by WT PrV. All PrV miRNAs were expressed, with highest expression observed for prv-miR-LLT1, prv-miR-LLT2 (in WT ganglia), and prv-miR-LLT10 (in both WT and M ganglia). No evidence of differentially expressed porcine miRNAs was found. Fifty-four porcine genes were differentially expressed between WT, M, and control ganglia. Both viruses triggered a strong host immune response, but in M ganglia gene upregulation was prevalent. Pathway analyses indicated that several biofunctions, including those related to cell-mediated immune response and the migration of dendritic cells, were impaired in M ganglia. These findings are consistent with a function of the LAT locus in the modulation of host response for maintaining a latent state. IMPORTANCE This study provides a thorough reference on the establishment of latency by PrV in its natural host, the pig. Our results corroborate the evidence obtained from the study of several LAT mutants of other alphaherpesviruses encoding miRNAs from their LAT regions. Neither PrV miRNA expression nor high LLT expression levels are essential to achieve latency in trigeminal ganglia. Once latency is established by PrV, the only remarkable differences are found in the pattern of host response. This indicates that, as in herpes simplex virus, LAT functions as an immune evasion locus.
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Tanaka S, Mannen K. Analysis of the mechanism of reactivation of latently infecting pseudorabies virus by acetylcholine. J Vet Med Sci 2014; 76:719-22. [PMID: 24419873 PMCID: PMC4073341 DOI: 10.1292/jvms.13-0425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
In this study, the effect of cholinergic or adrenergic inhibitors on the
reactivation of latent Pseudorabies virus (PRV) was analyzed to clarify the mechanism of
the reactivation of latent PRV by acetylcholine. For acetylcholine inhibition, latently
infected mice were injected with scopolamine or succynilcholine before acetylcholine
stimulation. For sympathetic blocking, mice were preinjected intraperitoneally with
phenoxybenzamine or propranolol. The signals to both acetylcholine receptors had no
relationship to the reactivation of latent PRV, and both sympathetic blockers showed
inhibition of PRV reactivation by acetylcholine. In our reactivation model, a large amount
of acetylcholine may stimulate the sympathetic nerve system in some way to reactivate the
virus.
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Affiliation(s)
- Seiichi Tanaka
- Center for Experimental Animals, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
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14
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Boldogköi Z. Transcriptional interference networks coordinate the expression of functionally related genes clustered in the same genomic loci. Front Genet 2012; 3:122. [PMID: 22783276 PMCID: PMC3389743 DOI: 10.3389/fgene.2012.00122] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 06/15/2012] [Indexed: 11/25/2022] Open
Abstract
The regulation of gene expression is essential for normal functioning of biological systems in every form of life. Gene expression is primarily controlled at the level of transcription, especially at the phase of initiation. Non-coding RNAs are one of the major players at every level of genetic regulation, including the control of chromatin organization, transcription, various post-transcriptional processes, and translation. In this study, the Transcriptional Interference Network (TIN) hypothesis was put forward in an attempt to explain the global expression of antisense RNAs and the overall occurrence of tandem gene clusters in the genomes of various biological systems ranging from viruses to mammalian cells. The TIN hypothesis suggests the existence of a novel layer of genetic regulation, based on the interactions between the transcriptional machineries of neighboring genes at their overlapping regions, which are assumed to play a fundamental role in coordinating gene expression within a cluster of functionally linked genes. It is claimed that the transcriptional overlaps between adjacent genes are much more widespread in genomes than is thought today. The Waterfall model of the TIN hypothesis postulates a unidirectional effect of upstream genes on the transcription of downstream genes within a cluster of tandemly arrayed genes, while the Seesaw model proposes a mutual interdependence of gene expression between the oppositely oriented genes. The TIN represents an auto-regulatory system with an exquisitely timed and highly synchronized cascade of gene expression in functionally linked genes located in close physical proximity to each other. In this study, we focused on herpesviruses. The reason for this lies in the compressed nature of viral genes, which allows a tight regulation and an easier investigation of the transcriptional interactions between genes. However, I believe that the same or similar principles can be applied to cellular organisms too.
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Affiliation(s)
- Zsolt Boldogköi
- Department of Medical Biology, Faculty of Medicine, University of Szeged, Szeged, Hungary
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Pseudorabies virus infected porcine epithelial cell line generates a diverse set of host microRNAs and a special cluster of viral microRNAs. PLoS One 2012; 7:e30988. [PMID: 22292087 PMCID: PMC3264653 DOI: 10.1371/journal.pone.0030988] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 12/29/2011] [Indexed: 12/29/2022] Open
Abstract
Pseudorabies virus (PRV) belongs to Alphaherpesvirinae subfamily that causes huge economic loss in pig industry worldwide. It has been recently demonstrated that many herpesviruses encode microRNAs (miRNAs), which play crucial roles in viral life cycle. However, the knowledge about PRV-encoded miRNAs is still limited. Here, we report a comprehensive analysis of both viral and host miRNA expression profiles in PRV-infected porcine epithelial cell line (PK-15). Deep sequencing data showed that the ∼4.6 kb intron of the large latency transcript (LLT) functions as a primary microRNA precursor (pri-miRNA) that encodes a cluster of 11 distinct miRNAs in the PRV genome, and 209 known and 39 novel porcine miRNAs were detected. Viral miRNAs were further confirmed by stem-loop RT-PCR and northern blot analysis. Intriguingly, all of these viral miRNAs exhibited terminal heterogeneity both at the 5′ and 3′ ends. Seven miRNA genes produced mature miRNAs from both arms and two of the viral miRNA genes showed partially overlapped in their precursor regions. Unexpectedly, a terminal loop-derived small RNA with high abundance and one special miRNA offset RNA (moRNA) were processed from a same viral miRNA precursor. The polymorphisms of viral miRNAs shed light on the complexity of host miRNA-processing machinery and viral miRNA-regulatory mechanism. The swine genes and PRV genes were collected for target prediction of the viral miRNAs, revealing a complex network formed by both host and viral genes. GO enrichment analysis of host target genes suggests that PRV miRNAs are involved in complex cellular pathways including cell death, immune system process, metabolic pathway, indicating that these miRNAs play significant roles in virus-cells interaction of PRV and its hosts. Collectively, these data suggest that PRV infected epithelial cell line generates a diverse set of host miRNAs and a special cluster of viral miRNAs, which might facilitate PRV replication in cells.
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Tanaka S, Mannen K. Usage of analgesic in a murine model infected latently with pseudorabies virus. J Vet Med Sci 2010; 73:351-4. [PMID: 20953125 DOI: 10.1292/jvms.10-0332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Butorphanol tartrate (BT) was injected into mice before injection with acetylcholine in a murine model infected latently with pseudorabies virus. The analgesic effect and its influence on virus reactivation were observed. Mice preinjected with BT showed suppression of screaming, moving and excitation and the same level of movement after excitation as mice injected with PBS. In the group injected with BT i.p., one mouse died and another developed diarrhea with increased virus excretion. These results showed that BT has analgesic effects by both injection routes, s.c. and i.p.; however, BT induced death as a side effect, especially with i.p. injection. The injection route for BT should therefore be investigated further.
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Affiliation(s)
- Seiichi Tanaka
- Division of Laboratory Animal Sciences, Research Promotion Project, Oita University, Hasama, Yufu, Oita.
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17
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De Regge N, Van Opdenbosch N, Nauwynck HJ, Efstathiou S, Favoreel HW. Interferon alpha induces establishment of alphaherpesvirus latency in sensory neurons in vitro. PLoS One 2010; 5. [PMID: 20927329 PMCID: PMC2947521 DOI: 10.1371/journal.pone.0013076] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 09/07/2010] [Indexed: 11/19/2022] Open
Abstract
Background Several alphaherpesviruses, including herpes simplex virus 1 (HSV-1) and pseudorabies virus (PRV), establish lifelong latency in neurons of the trigeminal ganglion (TG). Although it is thought that efficient establishment of alphaherpesvirus latency is based on a subtle interplay between virus, neurons and the immune system, it is not clear which immune components are of major importance for the establishment of latency. Methodology/Principal Findings Here, using an in vitro model that enables a natural route of infection, we show that interferon alpha (IFNalpha) has the previously uncharacterized capacity to induce a quiescent HSV-1 and PRV infection in porcine TG neurons that shows strong similarity to in vivo latency. IFNalpha induced a stably suppressed HSV-1 and PRV infection in TG neurons in vitro. Subsequent treatment of neurons containing stably suppressed virus with forskolin resulted in reactivation of both viruses. HSV and PRV latency in vivo is often accompanied by the expression of latency associated transcripts (LATs). Infection of TG neurons with an HSV-1 mutant expressing LacZ under control of the LAT promoter showed activation of the LAT promoter and RT-PCR analysis confirmed that both HSV-1 and PRV express LATs during latency in vitro. Conclusions/Significance These data represent a unique in vitro model of alphaherpesvirus latency and indicate that IFNalpha may be a driving force in promoting efficient latency establishment.
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Affiliation(s)
- Nick De Regge
- Department of Virology, Parasitology, and Immunology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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18
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Regulation of the ORF61 promoter and ORF61 functions in varicella-zoster virus replication and pathogenesis. J Virol 2009; 83:7560-72. [PMID: 19457996 DOI: 10.1128/jvi.00118-09] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Varicella-zoster virus (VZV) open reading frame 61 (ORF61) encodes a protein that transactivates viral and cellular promoters in transient-transfection assays and is the ortholog of herpes simplex virus ICP0. In this report, we mapped the ORF61 promoter and investigated its regulation by viral and cellular proteins in transient-expression experiments and by mutagenesis of the VZV genome (parent Oka strain). The 5' boundary of the minimal ORF61 promoter required for IE62 transactivation was mapped to position -95 relative to the mRNA start site, and three noncanonical GT-rich Sp1-binding sites were documented to occur within the region comprising positions -95 to -45. Contributions of the three Sp1-binding-site motifs, designated Sp1a, Sp1b, and Sp1c, to ORF61 expression and viral replication were varied despite their similar sequences. Two sites, Sp1a and Sp1c, functioned synergistically. When both sites were mutated in the pOka genome to produce pOka-61proDeltaSp1ac, the mutant virus expressed significantly less ORF61 protein. Using this mutant to investigate ORF61 functions resulted in reductions in the expression levels of IE proteins, viral kinases ORF47 and ORF66, and the major glycoprotein gE, with the most impact on gE. Virion morphogenesis appeared to be intact despite minimal ORF61 expression. Pretreating melanoma cells with sodium butyrate enhanced titers of pOka-61proDeltaSp1ac but not pOka, suggesting that ORF61 has a role in histone deacetylase inhibition. Growth of pOka-61proDeltaSp1ac was impaired in SCIDhu skin xenografts, indicating that the regulation of the ORF61 promoter by Sp1 family proteins is important for ORF61 expression in vivo and that ORF61 contributes to VZV virulence at skin sites of replication.
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Ma W, Lager KM, Richt JA, Stoffregen WC, Zhou F, Yoon KJ. Development of real-time polymerase chain reaction assays for rapid detection and differentiation of wild-type pseudorabies and gene-deleted vaccine viruses. J Vet Diagn Invest 2008; 20:440-7. [PMID: 18599848 DOI: 10.1177/104063870802000405] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The successful eradication of pseudorabies in U.S. domestic swine was accomplished through the use of glycoprotein E (gE) deleted modified live virus vaccines and an accompanying gE differential enzyme-linked immunosorbent assay (ELISA). Yet, pseudorabies virus (PRV) was established in feral swine in the United States, becoming a potential reservoir of PRV for infection of domestic swine and other native wildlife. A critical need for the current PRV surveillance program in the United States is the rapid detection of PRV infection. For this reason, a set of 2 real-time polymerase chain reaction (PCR) assays by using TaqMan chemistry was developed and evaluated for their capability in the detection and differentiation of field and vaccine strains of PRV. PCR primers and probes were designed for gB and gE genes of PRV, respectively. The newly developed PRV-specific real-time PCR assays could detect all wild-type PRV isolates from diagnostic submissions and differentiate them from vaccine strains. The analytical sensitivity of the assays was approximately 0.1 plaque-forming units per reaction. The assays were highly specific for PRV, because no positive results were obtained from testing other common swine viral pathogens and other animal herpesviruses. The results of testing samples from domestic and feral swine and from bovine showed that the real-time PCR assays are more sensitive than gel-based PCR. These results demonstrated the potential application of the developed real-time PCR assays as a differential test for rapid and specific detection of PRV in domestic and feral swine, as well as nonporcine species that can be infected with PRV and serve as carriers.
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Affiliation(s)
- Wenjun Ma
- Department of Veterinary Diagonostic and Production Animal Services, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
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TANAKA S, MANNEN K. Pregnancy and Parturition of Mice Latently Infected with Pseudorabies Virus. Exp Anim 2008; 57:149-52. [DOI: 10.1538/expanim.57.149] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Affiliation(s)
- Seiichi TANAKA
- Division of Laboratory Animal Sciences, Department of Life Science, Institute of Scientific Research, Oita University
| | - Kazuaki MANNEN
- Division of Laboratory Animal Sciences, Department of Life Science, Institute of Scientific Research, Oita University
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21
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Carpintero R, Alonso C, Piñeiro M, Iturralde M, Andrés M, Le Potier MF, Madec F, Alava MA, Piñeiro A, Lampreave F. Pig major acute-phase protein and apolipoprotein A-I responses correlate with the clinical course of experimentally induced African Swine Fever and Aujeszky's disease. Vet Res 2007; 38:741-53. [PMID: 17637332 DOI: 10.1051/vetres:2007030] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Accepted: 04/17/2007] [Indexed: 11/14/2022] Open
Abstract
In the present work, we studied the acute phase protein response after experimental virus infection in pigs. The animals were experimentally infected with African Swine Fever (ASF) or Aujeszky's disease (AD) viruses. The clinical course of ASF infection correlated with increasingly high levels of pig Major Acute-phase Protein (pig-MAP) (mean value of 6 mg/mL on day 6 post infection (p.i.), from 6 to 9 times higher than day 0) and sharp apolipoprotein A-I (apo A-I) decrease (mean value of 0.5 mg/mL, from 4 to 10 times lower than day 0 on day 4 p.i.). AD-clinical signs appeared at day 3 p.i., both in vaccinated (moderate clinical signs) and non-vaccinated pigs (severe outcome within 48 h p.i.). Pig-MAP and apo A-I profiles also followed clinical signs (changing from 0.70 mg/mL to around 3 mg/mL and from around 3 mg/mL to 0.96 mg/mL, respectively in non-vaccinated animals), with minor changes in concentration in the vaccinated group. Haptoglobin levels significantly increased in ASF and AD infected animals (mean maximum values of 2.77 and 3.96 mg/mL, respectively). Minor differences for the C-Reactive Protein in the case of ASF were observed, whereas its concentration increased more than 7 times in AD-infection. The albumin level was not modified in either case. The correlation of clinical signs to our data suggests the potential use of pig-MAP and apo A-I in monitoring infections in swine.
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Affiliation(s)
- Rakel Carpintero
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza, Spain
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Pomeranz LE, Reynolds AE, Hengartner CJ. Molecular biology of pseudorabies virus: impact on neurovirology and veterinary medicine. Microbiol Mol Biol Rev 2005; 69:462-500. [PMID: 16148307 PMCID: PMC1197806 DOI: 10.1128/mmbr.69.3.462-500.2005] [Citation(s) in RCA: 580] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Pseudorabies virus (PRV) is a herpesvirus of swine, a member of the Alphaherpesvirinae subfamily, and the etiological agent of Aujeszky's disease. This review describes the contributions of PRV research to herpesvirus biology, neurobiology, and viral pathogenesis by focusing on (i) the molecular biology of PRV, (ii) model systems to study PRV pathogenesis and neurovirulence, (iii) PRV transsynaptic tracing of neuronal circuits, and (iv) veterinary aspects of pseudorabies disease. The structure of the enveloped infectious particle, the content of the viral DNA genome, and a step-by-step overview of the viral replication cycle are presented. PRV infection is initiated by binding to cellular receptors to allow penetration into the cell. After reaching the nucleus, the viral genome directs a regulated gene expression cascade that culminates with viral DNA replication and production of new virion constituents. Finally, progeny virions self-assemble and exit the host cells. Animal models and neuronal culture systems developed for the study of PRV pathogenesis and neurovirulence are discussed. PRV serves asa self-perpetuating transsynaptic tracer of neuronal circuitry, and we detail the original studies of PRV circuitry mapping, the biology underlying this application, and the development of the next generation of tracer viruses. The basic veterinary aspects of pseudorabies management and disease in swine are discussed. PRV infection progresses from acute infection of the respiratory epithelium to latent infection in the peripheral nervous system. Sporadic reactivation from latency can transmit PRV to new hosts. The successful management of PRV disease has relied on vaccination, prevention, and testing.
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Affiliation(s)
- Lisa E Pomeranz
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08540, USA.
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23
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Tanaka S, Mannen K. Role of IL-6 and IL-1beta in reactivation by acetylcholine of latently infecting pseudorabies virus. Exp Anim 2005; 53:457-61. [PMID: 15516795 DOI: 10.1538/expanim.53.457] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
We previously reported that the latently infecting Pseudorabies virus (PrV) could be reactivated by injection of swine or mice with acetylcholine. However, the mechanism of the reactivation was not clear yet. In this study, we analyzed the kinetics of cytokines related to stress to clarify the relationship between virus reactivation by acetylcholine and the immune system. IL-6 and IL-1beta were detected in mice after stimulation with acetylcholine. This shows that acetylcholine induced physiological stress conditions. However, there seemed to be no relationship between the kinetics of the cytokine levels and PrV excretion. Moreover, neither IL-6 nor IL-1beta alone could reactivate latently infecting PrV. Thus, acetylcholine causes the reactivation of latent PrV via a mechanism not involving these immunological factors.
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Affiliation(s)
- Seiichi Tanaka
- Division of Laboratory Animal Sciences, Department of Life Science, Institute of Scientific Research, Oita University, Japan
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Abstract
Stress is one of the important factors that induces reactivation of pseudorabies virus (PrV) in latently infected pigs. We established a murine model of latent PrV infection and examined the effects of mild stress treatment in order to demonstrate that this model simulates natural infection in the pig. Latently infected mice excreted PrV from the nasal cavity under stress treatments consisting of restraint, exposure to cold or transport. Similar reactions have been observed upon treatment with acetylcholine and dexamethasone. The present findings demonstrate that these kinds of mild stress reactivate the virus in murine latent infection models in a manner similar to the induction of latent infection in pigs in the field.
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Affiliation(s)
- Seiichi Tanaka
- Institute of Scientific Research, Oita Medical University, Hasama-machi, Oita, Japan
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25
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Gilden DH, Cohrs RJ, Mahalingam R. Clinical and molecular pathogenesis of varicella virus infection. Viral Immunol 2004; 16:243-58. [PMID: 14583142 DOI: 10.1089/088282403322396073] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Varicella zoster virus (VZV) is a neurotropic human herpesvirus that infects nearly all humans and causes chickenpox (varicella). After chickenpox, VZV becomes latent in cranial nerve, dorsal root, and autonomic nervous system ganglia along the entire neuraxis. Virus reactivation produces shingles (zoster), characterized by pain and rash usually restricted to 1-3 dermatomes. Zoster is often complicated by postherpetic neuralgia (PHN), pain that persists for months to years after rash resolves. Virus may also spread to the spinal cord and blood vessels of the brain, producing a unifocal or multifocal vasculopathy, particularly in immunocompromised individuals. The increased incidence of zoster in elderly and immunocompromised individuals appears to be due to a VZV-specific host immunodeficiency. PHN may reflect a chronic VZV ganglionitis, and VZV vasculopathy is due to productive virus infection in cerebral arteries. Strategies that might boost host cell-mediated immunity to VZV are discussed, as well as the physical state of viral nucleic acid during latency and the possible mechanisms by which herpesvirus latency is maintained and virus is reactivated. A current summary of varicella latency and pathogenesis produced by simian varicella virus (SVV), the counterpart of human VZV, points to the usefulness of a primate model of natural infection to study varicella latency, as well as the experimental model of intratracheal inoculation to study the effectiveness of antiviral agents in driving persistent varicella virus into a latent state.
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Affiliation(s)
- Donald H Gilden
- Department of Neurology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
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Taharaguchi S, Yoshino S, Amagai K, Ono E. The latency-associated transcript promoter of pseudorabies virus directs neuron-specific expression in trigeminal ganglia of transgenic mice. J Gen Virol 2003; 84:2015-2022. [PMID: 12867631 DOI: 10.1099/vir.0.19080-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The latency-associated transcript (LAT) promoter of pseudorabies virus (PRV) is unique among viral promoters in that it remains active in trigeminal ganglia during the latent state. It is not known which the viral or host proteins regulate expression of the PRV LAT gene in latently infected neurons. To determine whether host transcriptional proteins in neurons can regulate the PRV LAT promoter in vivo, three transgenic mouse lines containing the PRV LAT promoter (LAP; LAP1 and LAP2) linked to the chloramphenicol acetyltransferase (CAT) gene were generated. All of the transgenic mouse lines, in the absence of the viral proteins, displayed strong expression of the transgene in trigeminal ganglia in addition to other neuronal tissues such as cerebral cortex, cerebellum, hippocampus and olfactory bulb. Expression of the transgene in neurons of trigeminal ganglia was demonstrated by in situ hybridization. These data provide direct evidence that neuronal transcription factors are sufficient to activate the PRV LAP in vivo and that the promoter is neuron-specific.
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Affiliation(s)
- Satoshi Taharaguchi
- Laboratory of Animal Experiment for Disease Model, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan
| | - Saori Yoshino
- G-in Techno Science, Sapporo 001-0015, Japan
- Laboratory of Animal Experiment for Disease Model, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan
| | - Keiko Amagai
- Sankyo Labo Service Corporation, Tokyo 132-0023, Japan
- Laboratory of Animal Experiment for Disease Model, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan
| | - Etsuro Ono
- Laboratory of Animal Experiment for Disease Model, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan
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Tanaka S, Mannen K. Activation of latent pseudorabies virus infection in mice treated with acetylcholine. Exp Anim 2002; 51:407-9. [PMID: 12221936 DOI: 10.1538/expanim.51.407] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Pseudorabies virus (PrV) YS-81 strain latently infected in 6-week-old BALB/c mice was detectable by nasal swabbing, and serum antibody was shown to increase in titer after intraperitoneal injection for 3 days with acetylcholine or dexamethasone.
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Affiliation(s)
- Seiichi Tanaka
- Animal Laboratory Center, Oita Medical University, Hasama-machi, Oita 879-5593, Japan
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28
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Taharaguchi S, Kobayashi T, Yoshino S, Ono E. Analysis of regulatory functions for the region located upstream from the latency-associated transcript (LAT) promoter of pseudorabies virus in cultured cells. Vet Microbiol 2002; 85:197-208. [PMID: 11852187 DOI: 10.1016/s0378-1135(01)00513-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The latency-associated transcript (LAT) promoter of pseudorabies virus (PrV) is unique among the many promoters of the viral genome in that it remains active during the latent state. The regulatory mechanism of PrV LAT gene expression is complex and different between latency and lytic infection of cultured cells. Although two different sequences, LAP1 and LAP2, are thought to be involved in LAT gene expression, the function of the upstream region of the LAT promoter (LAP1 and LAP2) remains an enigma, even in cultured cells. To analyze the function of the upstream region, it is necessary to examine the effects of the upstream sequence on LAT gene expression in the absence of other viral proteins. Transient expression assays were performed by employing a series of reporter plasmids in which various sequences upstream of the LAT promoter (from nucleotide positions -592 to +423 relative to the transcriptional start site of the large latency transcript (LLT)) were linked to the chloramphenicol acetyltransferase (CAT) gene in cells of neuronal and non-neuronal origin. We identified a region (from nucleotide positions -3606 to -1386) that was capable of repressing the LAT promoter activity in Vero cells by analyzing CAT gene expression of the series of reporter plasmids. This effect was not observed in Neuro-2a cells. We have also shown that the LAT promoter activity of the reporter plasmid containing the upstream region was repressed by the immediate-early gene product IE180 in Vero cells, but not in Neuro-2a cells. These results suggest that the upstream region of the LAT promoter may have a role in repressing LAT gene expression in cultured non-neuronal cells.
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Affiliation(s)
- Satoshi Taharaguchi
- Laboratory of Animal Experiment for Disease Model, Institute for Genetic, Medicine, Hokkaido University, 060-0815, Sapporo, Japan
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Borchers K, Field HJ. Neuronal latency in human and animal herpesvirus infections. Curr Top Microbiol Immunol 2001; 253:61-94. [PMID: 11417140 DOI: 10.1007/978-3-662-10356-2_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- K Borchers
- Institut für Virologie, Freie Universität Berlin, Königin-Luise-Strasse 49, 14195 Berlin, Germany.
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30
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Jin L, Schnitzlein WM, Scherba G. Identification of the pseudorabies virus promoter required for latency-associated transcript gene expression in the natural host. J Virol 2000; 74:6333-8. [PMID: 10864643 PMCID: PMC112139 DOI: 10.1128/jvi.74.14.6333-6338.2000] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Expression of the latency-associated transcript (LAT) gene is a hallmark of alphaherpesvirus latency, and yet its control and function remain an enigma. Resolution of this problem will require verification and subsequent elimination or disabling of elements regulating LAT gene transcription so that the influence of the resultant RNA can be evaluated. Toward this end, we generated a novel pseudorabies virus (PrV) recombinant in which a 282-bp region containing the LAP1 (first latency-active promoter) consensus sequence was replaced by a reporter cassette. Despite this substitution, replication of the recombinant was comparable to that of the parental and rescuant viruses both in cultured mammalian cells and in the natural host, swine. Furthermore, production of the LAT gene-associated 2.0- and 8.0-kb RNAs during an in vitro lytic infection of cultured neuronal cells was unaffected. However, the otherwise constitutively produced and processed 8.4-kb LAT was not detected in porcine trigeminal ganglia latently infected with this novel recombinant, although the viral genome was shown to be present. Therefore, LAP1 is apparently the basal promoter for PrV LAT gene expression during viral latency but is not required for such activity during an in vitro lytic infection of neuronal cells. More importantly, the ability of PrV to persist in a latent state in the absence of LAT suggests that other factors are responsible for this event in the natural host.
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Affiliation(s)
- L Jin
- Department of Veterinary Pathobiology, University of Illinois, Urbana, Illinois 61802, USA
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31
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Jin L, Scherba G. Expression of the pseudorabies virus latency-associated transcript gene during productive infection of cultured cells. J Virol 1999; 73:9781-8. [PMID: 10559288 PMCID: PMC113025 DOI: 10.1128/jvi.73.12.9781-9788.1999] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Like other alphaherpesviruses, pseudorabies virus (PrV) exhibits restricted gene expression during latency. These latency-associated transcripts (LATs) are derived from the region located within 0.69 to 0.77 map units of the viral genome. However, the presence of such viral RNAs during a productive infection has not been described. Although several transcripts originating between 0.706 to 0.737 map units have been detected in PrV-infected cultured cells, their relationship to the LATs has not been examined. Therefore, to determine if any correlation exists between PrV LAT gene expression in the natural and laboratory systems, transcription from the LAT gene region during lytic infection of cultured neuronal and nonneuronal cells was evaluated. A Northern blot assay using single-stranded RNA probes complementary to the spliced in vivo 8. 4-kb largest latency transcript (LLT) detected 1.0-, 2.0-, and 8. 0-kb poly(A) RNAs in all PrV-infected cells lines. The 1.0- and 8. 0-kb transcripts partially overlapped the first and second exons of the LLT, respectively. In contrast, portions of both LLT exons comprised the 2.0-kb RNA sequence, which lacked the same intron as the LLT. Generation of this transcript began about 243 bp downstream of the LLT initiation site and terminated near the junction of BamHI fragments 8' and 8. Its synthesis was inhibited by cycloheximide but not by cytosine beta-D-arabinofuranoside, which suggests that the 2. 0-kb RNA is not an immediate-early gene product. Thus, although the PrV LAT gene is transcriptionally active during a productive infection of cultured cells, the resulting RNAs are distinctive from the LLT.
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Affiliation(s)
- L Jin
- Department of Veterinary Pathobiology, University of Illinois, Urbana, Illinois 61802, USA
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32
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Borchers K, Wolfinger U, Ludwig H. Latency-associated transcripts of equine herpesvirus type 4 in trigeminal ganglia of naturally infected horses. J Gen Virol 1999; 80 ( Pt 8):2165-2171. [PMID: 10466816 DOI: 10.1099/0022-1317-80-8-2165] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Equine herpesvirus type 4 (EHV-4) is a major respiratory pathogen of horses. Unlike most other members of the Alphaherpesvirinae, EHV-4 was regarded as non-neurotropic. Here, neural and lymphoid tissues of 17 horses have been analysed post-mortem. EHV-4 DNA was detected in 11 cases (65%) by PCR, exclusively in the trigeminal ganglia. In order to define the transcriptional activity, RNA preparations of 10 EHV-4 DNA-positive ganglia were investigated by nested RT-PCR. EHV-4-specific transcripts derived from genes 63 [herpes simplex virus type 1 (HSV-1) ICPO gene homologue] and 64 (HSV-1 ICP4 gene homologue) were detected in six trigeminal ganglia. In one other case, only gene 64-specific transcripts were present. All of the transcripts proved to be antisense orientated when a strand-specific RT-PCR was applied. Type-specific primers for gene 33 (encoding glycoprotein B) served to detect transcripts of an acute EHV-4-infection, which were found in only one of the six ganglia positive for gene 63- and gene 64-specific transcripts. Overall, these studies clearly demonstrate that EHV-4 is latent in trigeminal ganglia.
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Affiliation(s)
- Kerstin Borchers
- Institut für Virologie, Freie Universität Berlin, Königin-Luise-Straße 49, 14195 Berlin, Germany1
| | - Uta Wolfinger
- Institut für Veterinärpathologie, FU Berlin, Str. 518, Nr. 15, 14163 Berlin, Germany2
| | - Hanns Ludwig
- Institut für Virologie, Freie Universität Berlin, Königin-Luise-Straße 49, 14195 Berlin, Germany1
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33
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Tanaka S, Imamura T, Sakaguchi M, Mannen K. Acetylcholine reactivates latent pseudorabies virus in mice. J Virol Methods 1998; 70:103-6. [PMID: 9506818 DOI: 10.1016/s0166-0934(97)00174-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The latency model of pseudorabies virus (PrV) wild strain, YS-81, in mice was established and latent PrV reactivated with acetylcholine. The latent PrV was reactivated from the trigeminal ganglia with acetylcholine. It was found that this model is useful in investigating the mechanism of latent PrV reactivation by acetylcholine.
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Affiliation(s)
- S Tanaka
- Animal Laboratory Center, Oita Medical University, Japan
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34
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Huang C, Lin YS, Cheng JW, Chang TJ. Immunolocalization of the pseudorabies virus immediate-early protein IE180 by immunoperoxidase staining. J Virol Methods 1997; 66:219-26. [PMID: 9255733 DOI: 10.1016/s0166-0934(97)00069-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The immediate-early (1E) gene of pseudorabies virus (PRV) expresses immediately upon infection, a phosphorylated protein (immediate-early protein, IE180) that can transactivate viral other genes and plays an essential role in regulating viral gene expression. In order to detect and localize IE180 in infected cells early on, this gene was cloned for overexpression, and the expressed products were applied to generate specific antibodies against IE180 protein. Two recombinant expression plasmids pN and pNB were constructed by cloning the IE gene onto pET 30a(+) expression vector via NcoI and BamHI sites. Plasmid pN contains the 1.8-kb NcoI-NcoI fragment of IE gene coding for the N-terminus of 616 amino acid residues, while pNB contains the 2.8-kb NcoI-Bam HI fragment coding for the rest of the IE180 protein. Both pN and pNB were transformed, respectively, into E. coli cells and produced large amounts of IE protein products during induction with 1 mM IPTG. The expressed IE proteins for pN and pNB were 60 kDa and 100 kDa in size, respectively. These expression products were purified and then used as antigens to immunize mice for preparing specific antibodies against PRV IE180 protein. The specificities of the mice immune sera were confirmed by their abilities to react with IE180 protein present in the PRV infected cells in the Western immunoblotting assay. Furthermore, immunoperoxidase staining of PRV infected cells undertaken with these antisera revealed the subcellular distribution of the IE proteins in the infected cells and also demonstrated their transportation from the cytoplasm to the nucleus during infection.
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Affiliation(s)
- C Huang
- Graduate Institute of Veterinary Microbiology, National Chung Hsing University, Taichung, Taiwan, ROC
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35
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Abstract
The clinical manifestations of herpes simplex virus infection generally involve a mild and localized primary infection followed by asymptomatic (latent) infection interrupted sporadically by periods of recrudescence (reactivation) where virus replication and associated cytopathologic findings are manifest at the site of initial infection. During the latent phase of infection, viral genomes, but not infectious virus itself, can be detected in sensory and autonomic neurons. The process of latent infection and reactivation has been subject to continuing investigation in animal models and, more recently, in cultured cells. The initiation and maintenance of latent infection in neurons are apparently passive phenomena in that no virus gene products need be expressed or are required. Despite this, a single latency-associated transcript (LAT) encoded by DNA encompassing about 6% of the viral genome is expressed during latent infection in a minority of neurons containing viral DNA. This transcript is spliced, and the intron derived from this splicing is stably maintained in the nucleus of neurons expressing it. Reactivation, which can be induced by stress and assayed in several animal models, is facilitated by the expression of LAT. Although the mechanism of action of LAT-mediated facilitation of reactivation is not clear, all available evidence argues against its involving the expression of a protein. Rather, the most consistent models of action involve LAT expression playing a cis-acting role in a very early stage of the reactivation process.
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Affiliation(s)
- E K Wagner
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92697-3900, USA.
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36
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Wesley RD, Cheung AK. A pseudorabies virus mutant with deletions in the latency and early protein O genes: replication, virulence, and immunity in neonatal piglets. J Vet Diagn Invest 1996; 8:21-4. [PMID: 9026076 DOI: 10.1177/104063879600800104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The pathogenicity of a double mutant of pseudorabies virus (PRV) with deletions in the latency gene and the early protein O gene was examined. In comparison to the parent Indiana-Funkhauser virus, the ability of this mutant to replicate and to cause disease in piglets is greatly reduced. At an infection dose that caused no clinical signs in 5-day-old neonatal piglets, this mutant was capable of eliciting solid protective immunity against a lethal PRV challenge. Thus, the double-gene deletion attenuates PRV but does not affect its immunogenicity. These features may be desirable for inclusion into future PRV vaccines.
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Affiliation(s)
- R D Wesley
- Virology Swine Research Unit, National Animal Disease Center, USDA, Ames, IA 50010, USA
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37
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Tanaka S, Imamura T, Sakaguchi M, Mannen K, Matsuo K. Acetylcholine activates latent pseudorabies virus in pigs. Arch Virol 1996; 141:161-6. [PMID: 8629944 DOI: 10.1007/bf01718597] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Pseudorabies virus (PrV) was isolated from the nasal swabs and the cultured trigeminal ganglia of latently infected pigs after they were treated with acetylcholine (ACH). These results indicate that ACH activates latent infections of PrV.
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Affiliation(s)
- S Tanaka
- The Chemo-Sero Therapeutic Research Institute, Kikuchi Research Center, Kumamoto, Japan
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38
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Affiliation(s)
- A K Cheung
- Virology Swine Research Unit, National Animal Disease Center, USDA, Ames, IA 50010, USA
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39
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Johnson MA, Tyack SG, Prideaux C, Kongsuwan K, Sheppard M. Nucleotide sequence of infectious laryngotracheitis virus (gallid herpesvirus 1) ICP4 gene. Virus Res 1995; 35:193-204. [PMID: 7762292 DOI: 10.1016/0168-1702(94)00096-u] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The infectious laryngotracheitis virus (ILTV) gene encoding a homologue to the ICP4 protein of herpes simplex virus (HSV) has been mapped to the inverted repeat region. The complete nucleotide sequence of ILTV ICP4 has been determined. The ILTV ORF encoding ICP4 is 4386 nucleotides long, calculated from the first of four ATG codons, and has an overall G+C content of 59%. The ILTV ICP4 contains two domains of high homology which have been reported in other studies to be conserved in the ICP4 homologues of alphaherpesviruses, and to be functionally important. Several regulatory features were identified including a serine-rich domain in region one. A more extensive serine-rich domain was located in region five which is also found in varicella-zoster virus (VZV) and bovine herpesvirus 1. A 5.4 kb immediate early transcript was identified in infected primary kidney cells.
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Affiliation(s)
- M A Johnson
- CSIRO Division of Animal Health, Animal Health Research Laboratory, Victoria, Australia
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40
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Abstract
A recombinant pseudorabies virus (PRV), designated LLT beta delta 2, which contains a 3-kbp deletion spanning the junction of the unique long and internal repeat sequences was constructed. Compared with the parental strain and a virus rescued for the deleted sequences, LLT beta delta 2 exhibited similar replication characteristics in tissue culture. When inoculated intranasally in swine, LLT beta delta 2 was significantly reduced in virulence and did not produce neurological signs characteristic of PRV infection. LLT beta delta 2 replicated efficiently at the site of inoculation and in peripheral nervous tissues, but replication was restricted in the central nervous system. These results indicate the presence of a PRV neurovirulence determinant in the vicinity of the junction.
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Affiliation(s)
- H J Dean
- Virology Swine Research Unit, National Animal Disease Center, USDA Agricultural Research Service, Ames, Iowa 50010
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41
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Pfeffer M, Wiedmann M, Batt CA. Applications of DNA amplification techniques in veterinary diagnostics. Vet Res Commun 1995; 19:375-407. [PMID: 8560754 PMCID: PMC7089009 DOI: 10.1007/bf01839319] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/1995] [Indexed: 01/31/2023]
Abstract
An overview of the principles of the polymerase chain reaction, ligase chain reaction, self-sustained sequence replication and Q beta replicase is given. The application of these methods for the diagnosis of veterinary infectious and hereditary diseases as well as for other diagnostic purposes is discussed and comprehensive tables of reported assays are provided. Specific areas where these DNA-based amplification methods provide substantial advantages over traditional approaches are also highlighted. With regard to PCR-based assays for the detection of viral pathogens, this article is an update of a previous review by Belák and Ballagi-Pordány (1993).
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Affiliation(s)
- M Pfeffer
- Institute for Medical Microbiology, Infectious and Epidemic Diseases, Ludwig-Maximilians University, Munich, Germany
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42
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Cantello JL, Anderson AS, Morgan RW. Identification of latency-associated transcripts that map antisense to the ICP4 homolog gene of Marek's disease virus. J Virol 1994; 68:6280-90. [PMID: 8083968 PMCID: PMC237048 DOI: 10.1128/jvi.68.10.6280-6290.1994] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Two small RNAs (0.9 and 0.75 kb), named Marek's disease virus (MDV) small RNAs (MSRs) and a 10-kb RNA, all of which map antisense to the MDV ICP4 homolog gene, have been readily detected in MDCC-MSB1 MDV-transformed T-lymphoblastoid cells. These RNAs were not detectable in reticuloendotheliosis virus-transformed T cells. When MDV was reactivated by treatment of lymphoblastoid cells with 25 micrograms of iododeoxyuridine per ml, the relative levels of the transcripts decreased. These RNAs were not detected by Northern (RNA) hybridization in productively infected chicken embryo fibroblasts 48 h postinfection; however, they were apparent 140 h postinfection. By using Northern hybridization, RNase protection assays, and primer extension analysis, the MSRs were determined to map antisense to the predicted translational start site of the ICP4 homolog gene. The conclusion most consistent with the data is that the two MSRs are overlapping, spliced RNAs. Both small RNAs contain a latency promoter binding factor consensus recognition sequence located toward their 5' ends as well as two potential ICP4 recognition consensus sequences, one in each orientation. The region contains a number of small open reading frames on each side and within the MSRs. Although the exact endpoints are unknown, the large 10-kb species spans the entire ICP4 homolog region. We believe that this group of RNAs, which map antisense to the ICP4 homolog gene, are latency-associated transcripts of MDV.
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MESH Headings
- Animals
- Base Sequence
- Blotting, Northern
- Cell Line, Transformed
- Cell Transformation, Viral
- Cells, Cultured
- Chick Embryo
- Cloning, Molecular
- DNA Primers
- Fibroblasts
- Genes, Viral
- Herpesvirus 2, Gallid/genetics
- Immediate-Early Proteins/genetics
- Molecular Sequence Data
- Plasmids
- Polymerase Chain Reaction
- RNA, Antisense/metabolism
- RNA, Viral/biosynthesis
- Restriction Mapping
- Sequence Homology, Nucleic Acid
- T-Lymphocytes
- Transcription, Genetic
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Affiliation(s)
- J L Cantello
- Delaware Agricultural Experiment Station, Department of Animal Science and Agricultural Biochemistry, College of Agricultural Sciences, University of Delaware, Newark 19717-1303
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43
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Cheung AK. Detection of the large latency transcript of pseudorabies virus by RNA-PCR and its potential in diagnosis. J Vet Diagn Invest 1994; 6:483-6. [PMID: 7858029 DOI: 10.1177/104063879400600414] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- A K Cheung
- Virology Swine Research Unit, USDA, Agricultural Research Service, Ames, IA 50010
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44
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Huang CJ, Rice MK, Devi-Rao GB, Wagner EK. The activity of the pseudorabies virus latency-associated transcript promoter is dependent on its genomic location in herpes simplex virus recombinants as well as on the type of cell infected. J Virol 1994; 68:1972-6. [PMID: 8107257 PMCID: PMC236661 DOI: 10.1128/jvi.68.3.1972-1976.1994] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
As do many other alphaherpesviruses, pseudorabies virus (PRV) transcribes a limited portion of its viral genome in latently infected neurons during latency. The sequence of the PRV latency-associated transcript (LAT) is bounded on its 5' end by a putative promoter region which contains sequence elements similar to those characterized for the herpes simplex virus (HSV) LAT promoter. Using the bacterial beta-galactosidase gene as a reporter, we have assayed PRV LAT promoter activity in the genomic environment in recombinant HSVs. The PRV LAT promoter-beta-galactosidase reporter gene was recombined into the terminal and internal long repeat regions (RL regions), replacing the normal HSV LAT promoter, the cap site, and the first 60 bases of the primary transcript. When recombined into the RL region, appreciable reporter gene expression was observed following infection of two cell lines of neuronal origin; little or no activity was seen with these recombinants following infection of rabbit skin or mouse embryo fibroblasts. No significant expression was seen when the promoter was recombined into the gC locus in the long unique region in any of the cell types utilized. Such results suggest that the PRV latency promoter contains neuronal cell-specific elements and that the HSV RL region provides an appropriate genomic environment for the manifestation of that specificity.
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Affiliation(s)
- C J Huang
- Department of Molecular Biology and Biochemistry, University of California, Irvine 92717
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45
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Register KB, Wesley RD. Molecular characterization of attenuated vaccine strains of transmissible gastroenteritis virus. J Vet Diagn Invest 1994; 6:16-22. [PMID: 8011775 DOI: 10.1177/104063879400600104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Previous studies in our laboratory demonstrated that 2 attenuated strains of transmissible gastroenteritis virus (TGEV) contain deletions affecting messenger (m) RNAs 2, 3, or 4. In this report, we have compared mRNAs of four modified-live virus vaccines for TGEV with the virulent Miller PP3 isolate to determine whether any transcriptional patterns are shared among attenuated strains. Using northern blot analysis, all vaccine viruses expressed mRNAs indistinguishable in size from those of Miller PP3. However, using S1 nuclease protection experiments, alterations in the regions of the genome from which mRNAs 2 and 3 are transcribed were detected in 2 of the vaccine strains. When genomic cDNA fragments derived from the coding region for mRNA 2 were sequenced, a 6-nucleotide deletion, also found in the attenuated strain Purdue-115, was discovered. The product of mRNA 2, a spike glycoprotein, was visualized by western blotting for each vaccine strain, and no profound differences in mobility were detected relative to Miller PP3. Alterations in the region of the genome from which mRNA 3 is transcribed appear to be identical or very similar to sequence alterations already described in this region for Purdue-115, one of which is likely to alter the polypeptide product of mRNA 3. Insertions or deletions in mRNAs 2 or 3 may contribute to attenuation but are not a prerequisite for this phenotype. The S1 nuclease protection analysis is a sensitive tool for differentiating particular strains of TGEV.
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Affiliation(s)
- K B Register
- USDA, Agricultural Research Service, Swine Virology Research Unit, Ames, IA 50010
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46
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Dean HJ, Cheung AK. A 3' coterminal gene cluster in pseudorabies virus contains herpes simplex virus UL1, UL2, and UL3 gene homologs and a unique UL3.5 open reading frame. J Virol 1993; 67:5955-61. [PMID: 8396663 PMCID: PMC238016 DOI: 10.1128/jvi.67.10.5955-5961.1993] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We have determined the nucleotide sequence and transcription pattern of a group of open reading frames of pseudorabies virus (PRV), which are located at the right end of the BamHI-G fragment from 0.664 to 0.695 map units in the unique long region of the genome. Nucleotide sequence analysis revealed four open reading frames. The first three correspond in genome location to the herpes simplex virus type 1 (HSV-1) open reading frames UL1, which codes for glycoprotein L (gL); UL2, which codes for a uracil-DNA glycosylase; and UL3, which codes for a polypeptide of unknown function. The fourth open reading frame, UL3.5, is not present in the HSV-1 genome. Northern (RNA) blot analysis with oligonucleotide and cDNA probes revealed four abundant mRNA species of 3.3, 2.7, 1.8, and 0.9 kb, which are likely to yield polypeptides encoded by the UL1, -2, -3, and -3.5 open reading frames, respectively. All four transcripts were of the early-late kinetic class, transcribed in the same direction, and 3' coterminal. The UL2 and UL3 genes of PRV and HSV-1 have significant amino acid sequence homology, while the UL1 genes are positional homologs and the UL3.5 gene is unique to PRV.
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Affiliation(s)
- H J Dean
- Virology Swine Research Unit, U.S. Department of Agriculture, Ames, Iowa 50010
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47
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Saalmüller A, Mettenleiter TC. Rapid identification and quantitation of cells infected by recombinant herpesvirus (pseudorabies virus) using a fluorescence-based beta-galactosidase assay and flow cytometry. J Virol Methods 1993; 44:99-108. [PMID: 8227283 DOI: 10.1016/0166-0934(93)90012-g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We recently described construction and use of a beta-galactosidase expression cassette in isolating recombinant pseudorabies virus (PrV) mutants (Mettenleiter and Rauh, 1990). We report here the identification and exact quantitation of cells infected by these mutants using an assay based on the reaction of intracellular beta-galactosidase expressed during infection by the recombinant viruses with the fluorogenic substrate fluorescein di-beta-D-galactopyranoside (FDG) followed by detection of positive cells in flow cytometry (FACS-Gal assay; Nolan et al., 1988). The detection method is fast, sensitive, and reliable, and yields quantitative results on single cell basis.
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Affiliation(s)
- A Saalmüller
- Federal Research Centre for Virus Diseases of Animals, Tübingen, Germany
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48
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Steiner I, Kennedy PG. Molecular biology of herpes simplex virus type 1 latency in the nervous system. Mol Neurobiol 1993; 7:137-59. [PMID: 8396944 DOI: 10.1007/bf02935640] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Herpes simplex virus (HSV) is one of the best studied examples of viral ability to remain latent in the human nervous system and to cause recurrent disease by reactivation. Intensive effort was directed in recent years to unveil the molecular viral mechanisms and the virus-host interactions associated with latent HSV infection. The discovery of the state of the latent viral DNA in nervous tissues and of the presence of latency-associated gene expression during latent infection, both differing from the situation during viral replication, provided important clues relevant to the pathogenesis of latent HSV infection. This review summarizes the current state of knowledge on the site of latent infection, the molecular phenomena of latency, and the mechanisms of the various stages of latency: acute infection, establishment and maintenance of latency, and reactivation. This information paved the way to recent trials aiming to use herpes viruses as vectors to deliver genes into the nervous system, an issue that is also addressed in this review.
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Affiliation(s)
- I Steiner
- Department of Neurology, Hadassah University Hospital, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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49
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Puentes E, Eiras A, Cancio E, Nores MV, Aguilera A, Seoane R, Regueiro BJ. Comparison of the protective efficacy of Aujeszky's disease (pseudorabies) virus glycoproteins obtained from different sources. Vet Microbiol 1993; 35:45-59. [PMID: 8395745 DOI: 10.1016/0378-1135(93)90115-n] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The immunogenic properties of a series of glycoprotein preparations are compared using inactivated conventional vaccines as reference. Serological response and protective efficacy of vaccination of mice and pigs are evaluated for glycoprotein immunogens obtained from various sources. BHK-21 cell cultures were infected with Aujeszky's disease virus and used as antigenic source. Glycoproteins were obtained from (i) the whole culture (ii) the cell sediment and (iii) the clarified supernatant. Both in pigs and in mice, protection was greater with glycoproteins purified from infected-cell membranes than with viral mature particle glycoproteins. The specific profiles of humoral responses were basically identical regardless of the source of glycoprotein. Bartha strain, one of the gI- strains most commonly used as an attenuated vaccine, was also used as a glycoprotein source. Immunogens obtained from this strain were protective in challenge trials with the virulent E-974 strain of the Aujeszky's disease virus. Glycoproteins did not induce detectable delayed type hypersensitivity in mice but conferred greater protection than particulate antigens (which, conversely, did induce a detectable delayed type hypersensitivity reaction). Until the recent proposal of the potency criterion delta 7, no objective method was available to evaluate the degree of protection conferred by Aujeszky's disease vaccines. In this study, we thus used the protection index, a quantitative parameter designed to evaluate potency of vaccines against Aujeszky's disease virus.
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Affiliation(s)
- E Puentes
- Dpto. Microbiología y Parasitología, Fac. Medicina, Università Santiago, Spain
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Ohmura Y, Ono E, Matsuura T, Kida H, Shimizu Y. Detection of feline herpesvirus 1 transcripts in trigeminal ganglia of latently infected cats. Arch Virol 1993; 129:341-7. [PMID: 8385921 DOI: 10.1007/bf01316910] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Y Ohmura
- Department of Veterinary Hygiene and Microbiology, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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