1
|
Steel R, Hamed M, Haugom JT, Ho T, Kenner N, Malfavon-Borja J, Morgans S, Salek SA, Seylani A, Jancovich JK. Age- and dose-dependent susceptibility of axolotls (Ambystoma mexicanum) by bath exposure to Ambystoma tigrinum virus (ATV). Virology 2023; 588:109909. [PMID: 37879268 DOI: 10.1016/j.virol.2023.109909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/04/2023] [Accepted: 10/09/2023] [Indexed: 10/27/2023]
Abstract
Ranaviruses are large, dsDNA viruses that have significant ecological and economic impact on cold-blooded vertebrates. However, our understanding of the viral proteins and subsequent host immune response(s) that impact susceptibility to infection and disease is not clear. The ranavirus Ambystoma tigrinum virus (ATV), originally isolated from the Sonoran tiger salamander (Ambystoma mavortium stebbinsi), is highly pathogenic at low doses of ATV at all tiger salamander life stages and this model has been used to explore the host-pathogen interactions of ATV infection. However, inconsistencies in the availability of laboratory reared larval tiger salamanders required us to look at the well characterized axolotl (A. mexicanum) as a model for ATV infection. Data obtained from five infection experiments over different developmental timepoints suggest that axolotls are susceptible to ATV in an age- and dose-dependent manner. These data support the use of the ATV-axolotl model to further explore the host-pathogen interactions of ranavirus infections.
Collapse
Affiliation(s)
- Riley Steel
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA
| | - Michelle Hamed
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA
| | - Josefine T Haugom
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA
| | - Trang Ho
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA
| | - Nathaniel Kenner
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA
| | - Joanna Malfavon-Borja
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA
| | - Scott Morgans
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA
| | - Savannah A Salek
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA
| | - Allen Seylani
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA
| | - James K Jancovich
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA, 92078, USA.
| |
Collapse
|
2
|
Peñafiel-Ricaurte A, Price SJ, Leung WTM, Alvarado-Rybak M, Espinoza-Zambrano A, Valdivia C, Cunningham AA, Azat C. Is Xenopus laevis introduction linked with Ranavirus incursion, persistence and spread in Chile? PeerJ 2023; 11:e14497. [PMID: 36874973 PMCID: PMC9979829 DOI: 10.7717/peerj.14497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 11/10/2022] [Indexed: 03/03/2023] Open
Abstract
Ranaviruses have been associated with amphibian, fish and reptile mortality events worldwide and with amphibian population declines in parts of Europe. Xenopus laevis is a widespread invasive amphibian species in Chile. Recently, Frog virus 3 (FV3), the type species of the Ranavirus genus, was detected in two wild populations of this frog near Santiago in Chile, however, the extent of ranavirus infection in this country remains unknown. To obtain more information about the origin of ranavirus in Chile, its distribution, species affected, and the role of invasive amphibians and freshwater fish in the epidemiology of ranavirus, a surveillance study comprising wild and farmed amphibians and wild fish over a large latitudinal gradient (2,500 km) was carried out in 2015-2017. In total, 1,752 amphibians and 496 fish were tested using a ranavirus-specific qPCR assay, and positive samples were analyzed for virus characterization through whole genome sequencing of viral DNA obtained from infected tissue. Ranavirus was detected at low viral loads in nine of 1,011 X. laevis from four populations in central Chile. No other amphibian or fish species tested were positive for ranavirus, suggesting ranavirus is not threatening native Chilean species yet. Phylogenetic analysis of partial ranavirus sequences showed 100% similarity with FV3. Our results show a restricted range of ranavirus infection in central Chile, coinciding with X. laevis presence, and suggest that FV3 may have entered the country through infected X. laevis, which appears to act as a competent reservoir host, and may contribute to the spread the virus locally as it invades new areas, and globally through the pet trade.
Collapse
Affiliation(s)
- Alexandra Peñafiel-Ricaurte
- Sustainability Research Centre & PhD in Conservation Medicine Program, Life Sciences Faculty, Universidad Andres Bello, Santiago, Chile.,Institute of Zoology, Zoological Society of London, London, United Kingdom
| | | | - William T M Leung
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - Mario Alvarado-Rybak
- Sustainability Research Centre & PhD in Conservation Medicine Program, Life Sciences Faculty, Universidad Andres Bello, Santiago, Chile.,Institute of Zoology, Zoological Society of London, London, United Kingdom.,Núcleo de Ciencias Aplicadas en Ciencias Veterinarias y Agronómicas, Facultad de Medicina Veterinaria y Agronomía, Universidad de las Américas, Santiago, Chile
| | - Andrés Espinoza-Zambrano
- Escuela de Medicina Veterinaria, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Catalina Valdivia
- Sustainability Research Centre & PhD in Conservation Medicine Program, Life Sciences Faculty, Universidad Andres Bello, Santiago, Chile
| | | | - Claudio Azat
- Sustainability Research Centre & PhD in Conservation Medicine Program, Life Sciences Faculty, Universidad Andres Bello, Santiago, Chile
| |
Collapse
|
3
|
Endogenous Retroviruses Augment Amphibian (Xenopus laevis) Tadpole Antiviral Protection. J Virol 2022; 96:e0063422. [PMID: 35575553 PMCID: PMC9175618 DOI: 10.1128/jvi.00634-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The global amphibian declines are compounded by infections with members of the Ranavirus genus such as Frog Virus 3 (FV3). Premetamorphic anuran amphibians are believed to be significantly more susceptible to FV3 while this pathogen targets the kidneys of both pre- and postmetamorphic animals. Paradoxically, FV3-challenged Xenopus laevis tadpoles exhibit lower kidney viral loads than adult frogs. Presently, we demonstrate that X. laevis tadpoles are intrinsically more resistant to FV3 kidney infections than cohort-matched metamorphic and postmetamorphic froglets and that this resistance appears to be epigenetically conferred by endogenous retroviruses (ERVs). Using a X. laevis kidney-derived cell line, we show that enhancing ERV gene expression activates cellular double-stranded RNA-sensing pathways, resulting in elevated mRNA levels of antiviral interferon (IFN) cytokines and thus greater anti-FV3 protection. Finally, our results indicate that large esterase-positive myeloid-lineage cells, rather than renal cells, are responsible for the elevated ERV/IFN axis seen in the tadpole kidneys. This conclusion is supported by our observation that CRISPR-Cas9 ablation of colony-stimulating factor-3 results in abolished homing of these myeloid cells to tadpole kidneys, concurrent with significantly abolished tadpole kidney expression of both ERVs and IFNs. We believe that the manuscript marks an important step forward in understanding the mechanisms controlling amphibian antiviral defenses and thus susceptibility and resistance to pathogens like FV3. IMPORTANCE Global amphibian biodiversity is being challenged by pathogens like the Frog Virus 3 (FV3) ranavirus, underlining the need to gain a greater understanding of amphibian antiviral defenses. While it was previously believed that anuran (frog/toad) amphibian tadpoles are more susceptible to FV3, we demonstrated that tadpoles are in fact more resistant to this virus than metamorphic and postmetamorphic froglets. We showed that this resistance is conferred by large myeloid cells within the tadpole kidneys (central FV3 target), which possess an elevated expression of endogenous retroviruses (ERVs). In turn, these ERVs activate cellular double-stranded RNA-sensing pathways, resulting in a greater expression of antiviral interferon cytokines, thereby offering the observed anti-FV3 protection.
Collapse
|
4
|
Jiang N, Fan Y, Zhou Y, Meng Y, Liu W, Li Y, Xue M, Robert J, Zeng L. The Immune System and the Antiviral Responses in Chinese Giant Salamander, Andrias davidianus. Front Immunol 2021; 12:718627. [PMID: 34675918 PMCID: PMC8524050 DOI: 10.3389/fimmu.2021.718627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 09/16/2021] [Indexed: 12/25/2022] Open
Abstract
The Chinese giant salamander, belonging to an ancient amphibian lineage, is the largest amphibian existing in the world, and is also an important animal for artificial cultivation in China. However, some aspects of the innate and adaptive immune system of the Chinese giant salamander are still unknown. The Chinese giant salamander iridovirus (GSIV), a member of the Ranavirus genus (family Iridoviridae), is a prominent pathogen causing high mortality and severe economic losses in Chinese giant salamander aquaculture. As a serious threat to amphibians worldwide, the etiology of ranaviruses has been mainly studied in model organisms, such as the Ambystoma tigrinum and Xenopus. Nevertheless, the immunity to ranavirus in Chinese giant salamander is distinct from other amphibians and less known. We review the unique immune system and antiviral responses of the Chinese giant salamander, in order to establish effective management of virus disease in Chinese giant salamander artificial cultivation.
Collapse
Affiliation(s)
- Nan Jiang
- Division of Fish Disease, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
- Department of Microbiology and Immunology, University of Rochester Medical Center, New York, NY, United States
| | - Yuding Fan
- Division of Fish Disease, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Yong Zhou
- Division of Fish Disease, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Yan Meng
- Division of Fish Disease, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Wenzhi Liu
- Division of Fish Disease, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Yiqun Li
- Division of Fish Disease, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Mingyang Xue
- Division of Fish Disease, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, New York, NY, United States
| | - Lingbing Zeng
- Division of Fish Disease, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| |
Collapse
|
5
|
Hauser KA, Singer JC, Hossainey MRH, Moore TE, Wendel ES, Yaparla A, Kalia N, Grayfer L. Amphibian ( Xenopus laevis) Tadpoles and Adult Frogs Differ in Their Antiviral Responses to Intestinal Frog Virus 3 Infections. Front Immunol 2021; 12:737403. [PMID: 34489981 PMCID: PMC8418544 DOI: 10.3389/fimmu.2021.737403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 08/05/2021] [Indexed: 11/19/2022] Open
Abstract
The global amphibian declines are compounded by ranavirus infections such as Frog Virus 3 (FV3), and amphibian tadpoles more frequently succumb to these pathogens than adult animals. Amphibian gastrointestinal tracts represent a major route of ranavirus entry, and viral pathogenesis often leads to hemorrhaging and necrosis within this tissue. Alas, the differences between tadpole and adult amphibian immune responses to intestinal ranavirus infections remain poorly defined. As interferon (IFN) cytokine responses represent a cornerstone of vertebrate antiviral immunity, it is pertinent that the tadpoles and adults of the anuran Xenopus laevis frog mount disparate IFN responses to FV3 infections. Presently, we compared the tadpole and adult X. laevis responses to intestinal FV3 infections. Our results indicate that FV3-challenged tadpoles mount more robust intestinal type I and III IFN responses than adult frogs. These tadpole antiviral responses appear to be mediated by myeloid cells, which are recruited into tadpole intestines in response to FV3 infections. Conversely, myeloid cells bearing similar cytology already reside within the intestines of healthy (uninfected) adult frogs, possibly accounting for some of the anti-FV3 resistance of these animals. Further insight into the differences between tadpole and adult frog responses to ranaviral infections is critical to understanding the facets of susceptibility and resistance to these pathogens.
Collapse
Affiliation(s)
- Kelsey A Hauser
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - Julia C Singer
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| | | | - Tyler E Moore
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - Emily S Wendel
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - Amulya Yaparla
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - Namarta Kalia
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - Leon Grayfer
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| |
Collapse
|
6
|
TLR5-Mediated Reactivation of Quiescent Ranavirus FV3 in Xenopus Peritoneal Macrophages. J Virol 2021; 95:JVI.00215-21. [PMID: 33827949 DOI: 10.1128/jvi.00215-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 03/28/2021] [Indexed: 12/25/2022] Open
Abstract
Ranaviruses such as frog virus 3 (FV3) are large double-stranded DNA (dsDNA) viruses causing emerging infectious diseases leading to extensive morbidity and mortality of amphibians and other ectothermic vertebrates worldwide. Among the hosts of FV3, some are highly susceptible, whereas others are resistant and asymptomatic carriers that can take part in disseminating the infectious virus. To date, the mechanisms involved in the processes of FV3 viral persistence associated with subclinical infection transitioning to lethal outbreaks remain unknown. Investigation in Xenopus laevis has revealed that in asymptomatic FV3 carrier animals, inflammation induced by heat-killed (HK) Escherichia coli stimulation can provoke the relapse of active infection. Since Toll-like receptors (TLRs) are critical for recognizing microbial molecular patterns, we investigated their possible involvement in inflammation-induced FV3 reactivation. Among the 10 different TLRs screened for changes in expression levels following FV3 infection and HK E. coli stimulation, only TLR5 and TLR22, both of which recognize bacterial products, showed differential expression, and only the TLR5 ligand flagellin was able to induce FV3 reactivation similarly to HK E. coli Furthermore, only the TLR5 ligand flagellin induced FV3 reactivation in peritoneal macrophages both in vitro and in vivo These data indicate that the TLR5 signaling pathway can trigger FV3 reactivation and suggest a role of secondary bacterial infections or microbiome alterations (stress or pollution) in initiating sudden deadly disease outbreaks in amphibian populations with detectable persistent asymptomatic ranavirus.IMPORTANCE This study in the amphibian Xenopus laevis provides new evidence of the critical role of macrophages in the persistence of ranaviruses in a quiescent state as well as in the reactivation of these pathogens into a virulent infection. Among the multiple microbial sensors expressed by macrophages, our data underscore the preponderant involvement of TLR5 stimulation in triggering the reactivation of quiescent FV3 in resident peritoneal macrophages, unveiling a mechanistic connection between the reactivation of persisting ranavirus infection and bacterial coinfection. This suggests a role for secondary bacterial infections or microbiome alterations (stress or pollution) in initiating sudden deadly disease outbreaks in amphibian populations with detectable persistent asymptomatic ranavirus.
Collapse
|
7
|
Development and comparison of qPCR and qLAMP for rapid detection of the decapod iridescent virus 1 (DIV1). J Invertebr Pathol 2021; 182:107567. [PMID: 33711317 DOI: 10.1016/j.jip.2021.107567] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 02/18/2021] [Accepted: 03/03/2021] [Indexed: 12/26/2022]
Abstract
Decapod iridescent virus 1 (DIV1) is a new virus discovered in recent years that infects farmed shrimp. DIV1 is highly infectious and causes substantial economic loss to the aquaculture industry of China. To prevent and control the spread and outbreak of DIV1 in a timely manner, it is necessary to establish an efficient method for DIV1 diagnosis. In this study, quantitative real-time polymerase chain reaction (qPCR) and quantitative real-time loop-mediated isothermal amplification (qLAMP) detection methods were established based on the specific sequence of the viral ATPase gene. The results indicated that the minimum detection limits of qPCR and qLAMP were 1.9 × 101 copies/μL and 1.9 × 102 copies/μL, respectively; the designed primer had good specificity for DIV1 and did not react with 13 other viruses, including white spot syndrome virus (WSSV), Enterocytozoon hepatopenaei (EHP), acute hepatopancreatic necrosis disease (AHPND), infectious hypodermal and haematopoietic necrosis virus (IHHNV), etc. A total of 43 clinical samples suspected of DIV1 infection were diagnosed by qPCR and qLAMP. Our qPCR demonstrated results consistent with a qPCR assay published previously, and the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of qLAMP were 85.71% and 100%, respectively. This result indicates that qPCR and qLAMP have good accuracy in the detection of DIVI in clinical samples. As established in this study, qPCR and qLAMP combined with a comprehensive comparative analysis can provide effective new solutions for the detection of DIV1.
Collapse
|
8
|
Johan CAC, Zainathan SC. Megalocytiviruses in ornamental fish: A review. Vet World 2020; 13:2565-2577. [PMID: 33363355 PMCID: PMC7750215 DOI: 10.14202/vetworld.2020.2565-2577] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/19/2020] [Indexed: 12/13/2022] Open
Abstract
Iridoviruses, especially megalocytiviruses, are related to severe disease resulting in high economic losses in the aquaculture industry worldwide. The ornamental fish industry has been affected severely due to Megalocytivirus infections. Megalocytivirus is a DNA virus that has three genera; including red sea bream iridovirus, infectious spleen and kidney necrosis virus, and turbot reddish body iridovirus. Megalocytivirus causes non-specific clinical signs in ornamental fish. Cell culture, histology, immunofluorescence test, polymerase chain reaction (PCR) assay, and loop-mediated isothermal amplification assay have been used to diagnose megalocytiviruses. Risk factors such as temperature, transportation (export and import), and life stages of ornamental fish have been reported for the previous cases due to Megalocytivirus infections. In addition, other prevention and control methods also have been practiced in farms to prevent Megalocytivirus outbreaks. This is the first review of megalocytiviruses in ornamental fish since its first detection in 1989. This review discusses the occurrences of Megalocytivirus in ornamental fish, including the history, clinical signs, detection method, risk factors, and prevention measures.
Collapse
Affiliation(s)
- Che Azarulzaman Che Johan
- Department of Fisheries and Aquaculture, Faculty of Fisheries and Food Science, University Malaysia Terengganu, Terengganu, Malaysia
| | - Sandra Catherine Zainathan
- Department of Fisheries and Aquaculture, Faculty of Fisheries and Food Science, University Malaysia Terengganu, Terengganu, Malaysia
| |
Collapse
|
9
|
He JH, Huang L, Guo Z, Weng S, He J, Xu X. Transcriptional programs of infectious spleen and kidney necrosis virus (ISKNV) in vitro and in vivo. Virus Genes 2020; 56:749-755. [PMID: 33033883 DOI: 10.1007/s11262-020-01800-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/26/2020] [Indexed: 11/26/2022]
Abstract
Infectious spleen and kidney necrosis virus (ISKNV), causing serious infectious diseases to marine and freshwater fishes, is the type species of the genus Megalocytivirus, family Iridoviridae. In this study, the transcriptional programs of ISKNV in vitro (MFF-1 cells) and in vivo (spleens from mandarin fish) were investigated using real-time PCR. Transcription of all the putative open reading frames (ORFs) of ISKNV was verified. The temporal expression patterns of ISKNV ORFs in vitro and in vivo, including peak expression times (PETs) and relative maximal expression levels, were determined and compared. The K-means clustering with Spearman rank correlation was generated in heat maps constructed based on ISKNV ORF expression profiles in vivo and in vitro. The current study may provide a global picture of ISKNV infection at the transcription level and help better understand the molecular pathogenic mechanism of megalocytiviruses.
Collapse
Affiliation(s)
- Jian-Hui He
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - Lichao Huang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
| | - Zhixun Guo
- South China Sea Fisheries Research Institute (CAFS), Guangzhou, PR China
| | - Shaoping Weng
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, P. R. China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, P. R. China
- Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Jianguo He
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, P. R. China.
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, P. R. China.
- Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou, P. R. China.
| | - Xiaopeng Xu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, P. R. China.
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou, P. R. China.
- Institute of Aquatic Economic Animals and Guangdong Provice Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou, P. R. China.
| |
Collapse
|
10
|
Tsai JM, Huang SL, Yang CD. PCR Detection and Phylogenetic Analysis of Megalocytivirus Isolates in Farmed Giant Sea Perch Lates calcarifer in Southern Taiwan. Viruses 2020; 12:v12060681. [PMID: 32599850 PMCID: PMC7354458 DOI: 10.3390/v12060681] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/20/2020] [Accepted: 06/22/2020] [Indexed: 01/12/2023] Open
Abstract
The Megalocytivirus genus includes three genotypes, red sea bream iridovirus (RSIV), infectious spleen and kidney necrosis virus (ISKNV), and turbot reddish body iridovirus (TRBIV), and has caused mass mortalities in various marine and freshwater fish species in East and Southeast Asia. Of the three genotypes, TRBIV-like megalocytivirus is not included in the World Organization for Animal Health (OIE)-reportable virus list because of its geographic restriction and narrow host range. In 2017, 39 cases of suspected iridovirus infection were isolated from fingerlings of giant sea perch (Lates calcarifer) cultured in southern Taiwan during megalocytivirus epizootics. Polymerase chain reaction (PCR) with different specific primer sets was undertaken to identify the causative agent. Our results revealed that 35 out of the 39 giant sea perch iridovirus (GSPIV) isolates were TRBIV-like megalocytiviruses. To further evaluate the genetic variation, the nucleotide sequences of major capsid protein (MCP) gene (1348 bp) from 12 of the 35 TRBIV-like megalocytivirus isolates were compared to those of other known. High nucleotide sequence identity showed that these 12 TRBIV-like GSPIV isolates are the same species. Phylogenetic analysis based on the MCP gene demonstrated that these 12 isolates belong to the clade II of TRBIV megalocytiviruses, and are distinct from RSIV and ISKNV. In conclusion, the GSPIV isolates belonging to TRBIV clade II megalocytiviruses have been introduced into Taiwan and caused a severe impact on the giant sea perch aquaculture industry.
Collapse
Affiliation(s)
- Jia-Ming Tsai
- Graduate Institute of Animal Vaccine Technology, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
| | - Song-Lang Huang
- Pingtung County Animal Disease Control Center, Pingtung 90001, Taiwan;
| | - Chung-Da Yang
- Graduate Institute of Animal Vaccine Technology, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan;
- International Degree Program of Animal Vaccine Technology, International College, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Correspondence: ; Tel.: +886-8-7703-202 (ext. 5334)
| |
Collapse
|
11
|
Yu Q, Liu M, Wu S, Wei X, Xiao H, Yi Y, Cheng H, Wang S, Zhang Q, Qin Q, Li P. Specific Aptamer-Based Probe for Analyzing Biomarker MCP Entry Into Singapore Grouper Iridovirus-Infected Host Cells via Clathrin-Mediated Endocytosis. Front Microbiol 2020; 11:1206. [PMID: 32636813 PMCID: PMC7318552 DOI: 10.3389/fmicb.2020.01206] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/12/2020] [Indexed: 01/16/2023] Open
Abstract
Biomarkers have important roles in various physiological functions and disease pathogenesis. As a nucleocytoplasmic DNA virus, Singapore grouper iridovirus (SGIV) causes high economic losses in the mariculture industry. Aptamer-Q5-complexed major capsid protein (MCP) in the membrane of SGIV-infected cells can be used as a specific molecular probe to investigate the crucial events of MCP endocytosis into SGIV-infected host cells during viral infection. Chlorpromazine blocks clathrin-mediated endocytosis, and MCP endocytosis into SGIV-infected cells decreased significantly when the cells were pretreated with chlorpromazine. The disruption of cellular cholesterol by methyl-β-cyclodextrin also significantly reduced MCP endocytosis. In contrast, inhibitors of key regulators of caveolae/raft-dependent endocytosis and macropinocytosis, including genistein, Na+/H+ exchanger, p21-activated kinase 1 (PAK1), myosin II, Rac1 GTPase, and protein kinase C (PKC), had no effect on MCP endocytosis. The endocytosis of the biomarker MCP is dependent on low pH and cytoskeletal actin filaments, as shown with various inhibitors (chloroquine, ammonia chloride, cytochalasin D). Therefore, MCP enters SGIV-infected host cells via clathrin-mediated endocytosis, which is dependent on dynamin, cholesterol, low pH, and cytoskeletal actin filaments. This is the first report of a specific aptamer-based probe used to analyze MCP endocytosis into SGIV-infected host cells during viral infection. This method provides a convenient strategy for exploring viral pathogenesis and facilitates the development of diagnostic tools for and therapeutic approaches to viral infection.
Collapse
Affiliation(s)
- Qing Yu
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Guangxi Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning, China
| | - Mingzhu Liu
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Guangxi Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning, China
| | - Siting Wu
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Science, South China Agricultural University, Guangzhou, China.,Guangxi Key Laboratory for Polysaccharide Materials and Modifications, Guangxi Colleges and Universities Key Laboratory of Utilization of Microbial and Botanical Resources, School of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning, China
| | - Xinxian Wei
- Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Academy of Fishery Sciences, Nanning, China
| | - Hehe Xiao
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Guangxi Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning, China
| | - Yi Yi
- Guangxi Key Laboratory of Green Processing of Sugar Resources, College of Biological and Chemical Engineering, Guangxi University of Science and Technology, Liuzhou, China
| | - Hao Cheng
- Guangxi Key Laboratory of Green Processing of Sugar Resources, College of Biological and Chemical Engineering, Guangxi University of Science and Technology, Liuzhou, China
| | - Shaowen Wang
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Science, South China Agricultural University, Guangzhou, China
| | - Qin Zhang
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, Guangxi Colleges and Universities Key Laboratory of Utilization of Microbial and Botanical Resources, School of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning, China
| | - Qiwei Qin
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Science, South China Agricultural University, Guangzhou, China
| | - Pengfei Li
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Guangxi Beibu Gulf Marine Research Center, Guangxi Academy of Sciences, Nanning, China
| |
Collapse
|
12
|
Pound HL, Gann ER, Tang X, Krausfeldt LE, Huff M, Staton ME, Talmy D, Wilhelm SW. The "Neglected Viruses" of Taihu: Abundant Transcripts for Viruses Infecting Eukaryotes and Their Potential Role in Phytoplankton Succession. Front Microbiol 2020; 11:338. [PMID: 32210938 PMCID: PMC7067694 DOI: 10.3389/fmicb.2020.00338] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 02/17/2020] [Indexed: 01/18/2023] Open
Abstract
Drivers of algal bloom dynamics remain poorly understood, but viruses have been implicated as important players. Research addressing bloom dynamics has generally been restricted to the virus-infection of the numerically dominant (i.e. bloom forming) taxa. Yet this approach neglects a broad diversity of viral groups, limiting our knowledge of viral interactions and constraints within these systems. We examined hallmark virus marker genes in metatranscriptomic libraries from a seasonal and spatial survey of a Microcystis aeruginosa bloom in Lake Tai (Taihu) China to identify active infections by nucleocytoplasmic large DNA viruses (NCLDVs), RNA viruses, ssDNA viruses, bacteriophage, and virophage. Phylogenetic analyses revealed a diverse virus population with seasonal and spatial variability. We observed disproportionately high expression of markers associated with NCLDVs and ssRNA viruses (consistent with viruses that infect photosynthetic protists) relative to bacteriophage infecting heterotrophic bacteria or cyanobacteria during the height of the Microcystis bloom event. Under a modified kill-the-winner scheme, we hypothesize viruses infecting protists help suppress the photosynthetic eukaryotic community and allow for the proliferation of cyanobacteria such as Microcystis. Our observations provide a foundation for a little considered factor promoting algal blooms.
Collapse
Affiliation(s)
- Helena L Pound
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Eric R Gann
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Xiangming Tang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China
| | - Lauren E Krausfeldt
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Matthew Huff
- Department of Entomology and Plant Pathology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Margaret E Staton
- Department of Entomology and Plant Pathology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - David Talmy
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Steven W Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| |
Collapse
|
13
|
Kim A, Yoon D, Lim Y, Roh HJ, Kim S, Park CI, Kim HS, Cha HJ, Choi YH, Kim DH. Co-Expression Network Analysis of Spleen Transcriptome in Rock Bream ( Oplegnathus fasciatus) Naturally Infected with Rock Bream Iridovirus (RBIV). Int J Mol Sci 2020; 21:ijms21051707. [PMID: 32131541 PMCID: PMC7084886 DOI: 10.3390/ijms21051707] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 02/28/2020] [Accepted: 02/29/2020] [Indexed: 12/12/2022] Open
Abstract
Rock bream iridovirus (RBIV) is a notorious agent that causes high mortality in aquaculture of rock bream (Oplegnathus fasciatus). Despite severity of this virus, no transcriptomic studies on RBIV-infected rock bream that can provide fundamental information on protective mechanism against the virus have been reported so far. This study aimed to investigate physiological mechanisms between host and RBIV through transcriptomic changes in the spleen based on RNA-seq. Depending on infection intensity and sampling time point, fish were divided into five groups: uninfected healthy fish at week 0 as control (0C), heavy infected fish at week 0 (0H), heavy mixed RBIV and bacterial infected fish at week 0 (0MH), uninfected healthy fish at week 3 (3C), and light infected fish at week 3 (3L). We explored clusters from 35,861 genes with Fragments Per Kilo-base of exon per Million mapped fragments (FPKM) values of 0.01 or more through signed co-expression network analysis using WGCNA package. Nine of 22 modules were highly correlated with viral infection (|gene significance (GS) vs. module membership (MM) |> 0.5, p-value < 0.05). Expression patterns in selected modules were divided into two: heavy infected (0H and 0MH) and control and light-infected groups (0C, 3C, and 3L). In functional analysis, genes in two positive modules (5448 unigenes) were enriched in cell cycle, DNA replication, transcription, and translation, and increased glycolysis activity. Seven negative modules (3517 unigenes) built in this study showed significant decreases in the expression of genes in lymphocyte-mediated immune system, antigen presentation, and platelet activation, whereas there was significant increased expression of endogenous apoptosis-related genes. These changes lead to RBIV proliferation and failure of host defense, and suggests the importance of blood cells such as thrombocytes and B cells in rock bream in RBIV infection. Interestingly, a hub gene, pre-mRNA processing factor 19 (PRPF19) showing high connectivity (kME), and expression of this gene using qRT-PCR was increased in rock bream blood cells shortly after RBIV was added. It might be a potential biomarker for diagnosis and vaccine studies in rock bream against RBIV. This transcriptome approach and our findings provide new insight into the understanding of global rock bream-RBIV interactions including immune and pathogenesis mechanisms.
Collapse
Affiliation(s)
- Ahran Kim
- Department of Chemistry, Center for Proteome Biophysics, and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea; (A.K.); (D.Y.); (S.K.)
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, Busan 48513, Korea; (Y.L.); (H.J.R.)
| | - Dahye Yoon
- Department of Chemistry, Center for Proteome Biophysics, and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea; (A.K.); (D.Y.); (S.K.)
- Department of Herbal Crop Research, National Institute of Horticultural and Herbal Science, RDA, Eumseong 27709, Korea
| | - Yunjin Lim
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, Busan 48513, Korea; (Y.L.); (H.J.R.)
- Hazardous Substances Analysis Division, Gwangju Regional Office of Food and Drug Safety, Gwangju 61012, Korea
| | - Heyong Jin Roh
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, Busan 48513, Korea; (Y.L.); (H.J.R.)
| | - Suhkmann Kim
- Department of Chemistry, Center for Proteome Biophysics, and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Korea; (A.K.); (D.Y.); (S.K.)
| | - Chan-Il Park
- Department of Marine Biology and Aquaculture, College of Marine Science, Gyeongsang National University, Tongyeong 53064, Korea;
| | - Heui-Soo Kim
- Department of Biological Sciences, College of Natural Sciences, Pusan National University, Busan 46241, Korea;
| | - Hee-Jae Cha
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan 49267, Korea;
| | - Yung Hyun Choi
- Department of Biochemistry, College of Oriental Medicine, Dongeui University, Busan 47227, Korea;
| | - Do-Hyung Kim
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, Busan 48513, Korea; (Y.L.); (H.J.R.)
- Correspondence: ; Tel.: +82-51-629-5945
| |
Collapse
|
14
|
Bienentreu JF, Grayfer L, Schock DM, Guerreiro M, Mehes-Smith M, DeWitte-Orr SJ, Robert J, Brunetti CR, Lesbarrères D. Sublethal effects of wild-type and a vIF-2α-knockout Frog virus 3 on postmetamorphic wood frogs (Rana sylvatica): potential for a stage-specific reservoir. Facets (Ott) 2020. [DOI: 10.1139/facets-2020-0001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Ranaviruses have been associated with rising numbers of mass die-offs in amphibian populations around the globe. However, most studies on ranaviruses to date focused on larval amphibians. To assess the role of postmetamorphic amphibians in the epidemiology of ranaviruses and to determine the role of viral immune-suppression genes, we performed a bath-exposure study on post-metamorphic wood frogs ( Rana sylvatica) using environmentally relevant concentrations of wild-type Frog virus 3 (WT FV3), and a gene-knockout mutant (KO FV3), deficient for the putative immune-suppression gene vIF-2α. We observed a 42% infection rate and 5% mortality across the virus challenges, with infection rates and viral loads following a dose-dependent pattern. Individuals exposed to the knockout variant exhibited significantly decreased growth and increased lethargy compared with wild-type treatments. Although 85% of exposed individuals exhibited common signs of ranavirosis throughout the experiment, most of these individuals did not exhibit signs of infection by 40 d post-exposure. Overall, we showed that even a single short time exposure to environmentally relevant concentrations of ranavirus may cause sublethal infections in postmetamorphic amphibians, highlighting the importance of this life stage in the epidemiology of ranaviruses. Our study also supports the importance of the vIF-2α gene in immune-suppression in infected individuals.
Collapse
Affiliation(s)
| | - Leon Grayfer
- Department of Biological Sciences, George Washington University, Washington, DC 20052, USA
| | - Danna M. Schock
- University Studies and Environmental Technology, Keyano College, Fort McMurray, AB T9H 2H7, Canada
| | - Matthew Guerreiro
- Department of Health Sciences, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
| | | | | | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester, Rochester, NY 14642, USA
| | - Craig R. Brunetti
- Department of Biology, Trent University, Peterborough, ON K9J 7B8, Canada
| | - David Lesbarrères
- Department of Biology, Laurentian University, Sudbury, ON P3E 2C6, Canada
| |
Collapse
|
15
|
Wirth W, Ariel E. Temperature-dependent infection of freshwater turtle hatchlings, Emydura macquarii krefftii, inoculated with a ranavirus isolate (Bohle iridovirus, Iridoviridae). Facets (Ott) 2020. [DOI: 10.1139/facets-2020-0012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Fish, amphibians, and reptiles exhibit temperature-dependent ranaviral disease. We performed an experimental infection at four different environmental temperatures (16, 22, 28, and 34 °C) to investigate the effect of temperature on ranaviral infection in Krefft’s turtle ( Emydura macquarii krefftii). Infection rates and viral loads were determined by quantitative polymerase chain reaction to detect ranaviral DNA in liver samples at 21 d postexposure. The rate of infection differed across the temperature treatment groups. Infection rates were 44%, 90%, 60%, and 10% for the 16, 22, 28, and 34 °C temperature groups, respectively. Highest viral load was observed in the 28 °C temperature group, and there was a statistically significant difference in viral load between the 16 and 28 °C temperature groups ( p = 0.027). Based on the results of this study, the temperature of maximal infection rate for ranaviral infection in Krefft’s river turtles is estimated to be 23.2 °C (SD = 4.5). The findings of this study can inform management decisions in terms of disease control and treatment and form a platform for modelling disease outbreaks.
Collapse
Affiliation(s)
- Wytamma Wirth
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Douglas, QLD 4814, Australia
| | - Ellen Ariel
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Douglas, QLD 4814, Australia
| |
Collapse
|
16
|
Rosa GM, Bosch J, Martel A, Pasmans F, Rebelo R, Griffiths RA, Garner TWJ. Sex‐biased disease dynamics increase extinction risk by impairing population recovery. Anim Conserv 2019. [DOI: 10.1111/acv.12502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- G. M. Rosa
- Durrell Institute of Conservation and Ecology School of Anthropology and Conservation University of Kent CanterburyKent UK
- Institute of Zoology Zoological Society of London Regent's ParkLondon UK
- Centre for Ecology, Evolution and Environmental Changes (CE3C)Faculdade de Ciências da Universidade de LisboaLisboa Portugal
| | - J. Bosch
- Museo Nacional de Ciencias NaturalesCSIC Madrid Spain
| | - A. Martel
- Department of Pathology, Bacteriology and Avian Diseases Faculty of Veterinary Medicine Ghent University Merelbeke Belgium
| | - F. Pasmans
- Department of Pathology, Bacteriology and Avian Diseases Faculty of Veterinary Medicine Ghent University Merelbeke Belgium
| | - R. Rebelo
- Centre for Ecology, Evolution and Environmental Changes (CE3C)Faculdade de Ciências da Universidade de LisboaLisboa Portugal
| | - R. A. Griffiths
- Durrell Institute of Conservation and Ecology School of Anthropology and Conservation University of Kent CanterburyKent UK
| | - T. W. J. Garner
- Institute of Zoology Zoological Society of London Regent's ParkLondon UK
| |
Collapse
|
17
|
Xiao H, Liu M, Li S, Shi D, Zhu D, Ke K, Xu Y, Dong D, Zhu L, Yu Q, Li P. Isolation and Characterization of a Ranavirus Associated with Disease Outbreaks in Cultured Hybrid Grouper (♀ Tiger Grouper Epinephelus fuscoguttatus × ♂ Giant Grouper E. lanceolatus) in Guangxi, China. JOURNAL OF AQUATIC ANIMAL HEALTH 2019; 31:364-370. [PMID: 31519049 DOI: 10.1002/aah.10090] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
An outbreak of suspected iridovirus disease in cultured hybrid grouper (♀Tiger Grouper Epinephelus fuscoguttatus × ♂ Giant Grouper Epinephelus lanceolatus) occurred in the Guangxi Province in July, 2018. In this study, grouper iridovirus Guangxi (SGIV-Gx) was isolated from diseased hybrid grouper that were collected from Guangxi. Cytopathic effects were observed and identified in grouper spleen cells that were incubated with diseased tissue homogenates after 24 h, and the effects increased at 48 h postinfection. The transmission electron microscopy results showed that viral particles that were about 200 nm in diameter with hexagonal profiles were present in the cell cytoplasm of suspected virus-infected cells. The presence of SGIV-Gx (accession number: MK107821) was identified by polymerase chain reaction (PCR) and amplicon sequencing, which showed that this strain was most closely related to Singapore grouper iridovirus (AY521625.1). The detection of SGIV-Gx infection was further supported by novel aptamer (Q2c)-based detection technology. The effects of temperature and pH on viral infectivity were analyzed by using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and cell culture. The results indicated that SGIV-Gx was resistant to exposure to pH levels 5, 7, and 7.5 for 1 h, but its infectivity was remarkably lower at pH levels 3 and 10 after 1 h. The analyses showed that SGIV-Gx was stable for 1 h at 4°C and 25°C but was inactivated after 1 h at 40, 50, and 60°C.
Collapse
Affiliation(s)
- Hehe Xiao
- College of Life Science, Henan Normal University, Xinxiang, China
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Sciences, Nanning, China
| | - Mingzhu Liu
- Guangxi Key Laboratory for Marine Biotechnology, Guangxi Institute of Oceanography, Guangxi Academy of Sciences, Beihai, China
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, College of Marine Sciences, Beibu Gulf University, Qinzhou, China
| | - Siqiao Li
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Sciences, Nanning, China
| | - Deqiang Shi
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Sciences, Nanning, China
| | - Donglin Zhu
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Sciences, Nanning, China
| | - Ke Ke
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Sciences, Nanning, China
| | - Youhou Xu
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, College of Marine Sciences, Beibu Gulf University, Qinzhou, China
| | - Dexin Dong
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Sciences, Nanning, China
| | - Libo Zhu
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Sciences, Nanning, China
| | - Qing Yu
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Sciences, Nanning, China
| | - Pengfei Li
- Guangxi Key Laboratory for Marine Biotechnology, Guangxi Institute of Oceanography, Guangxi Academy of Sciences, Beihai, China
| |
Collapse
|
18
|
Ma L, Zhang N, Qu Z, Liang R, Zhang L, Zhang B, Meng G, Dijkstra JM, Li S, Xia MC. A Glimpse of the Peptide Profile Presentation by Xenopus laevis MHC Class I: Crystal Structure of p Xela-UAA Reveals a Distinct Peptide-Binding Groove. THE JOURNAL OF IMMUNOLOGY 2019; 204:147-158. [PMID: 31776204 DOI: 10.4049/jimmunol.1900865] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/27/2019] [Indexed: 12/15/2022]
Abstract
The African clawed frog, Xenopus laevis, is a model species for amphibians. Before metamorphosis, tadpoles do not efficiently express the single classical MHC class I (MHC-I) molecule Xela-UAA, but after metamorphosis, adults express this molecule in abundance. To elucidate the Ag-presenting mechanism of Xela-UAA, in this study, the Xela-UAA structure complex (pXela-UAAg) bound with a peptide from a synthetic random peptide library was determined. The amino acid homology between the Xela-UAA and MHC-I sequences of different species is <45%, and these differences are fully reflected in the three-dimensional structure of pXela-UAAg. Because of polymorphisms and interspecific differences in amino acid sequences, pXela-UAAg forms a distinct peptide-binding groove and presents a unique peptide profile. The most important feature of pXela-UAAg is the two-amino acid insertion in the α2-helical region, which forms a protrusion of ∼3.8 Å that is involved in TCR docking. Comparison of peptide-MHC-I complex (pMHC-I) structures showed that only four amino acids in β2-microglobulin that were bound to MHC-I are conserved in almost all jawed vertebrates, and the most unique feature in nonmammalian pMHC-I molecules is that the AB loop bound β2-microglobulin. Additionally, the binding distance between pMHC-I and CD8 molecules in nonmammals is different from that in mammals. These unique features of pXela-UAAg provide enhanced knowledge of T cell immunity and bridge the knowledge gap regarding the coevolutionary progression of the MHC-I complex from aquatic to terrestrial species.
Collapse
Affiliation(s)
- Lizhen Ma
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Nianzhi Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zehui Qu
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Ruiying Liang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Lijie Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Bing Zhang
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Geng Meng
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China; and
| | - Johannes M Dijkstra
- Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Japan
| | - Shen Li
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Max Chun Xia
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China;
| |
Collapse
|
19
|
Robert J, McGuire CC, Kim F, Nagel SC, Price SJ, Lawrence BP, De Jesús Andino F. Water Contaminants Associated With Unconventional Oil and Gas Extraction Cause Immunotoxicity to Amphibian Tadpoles. Toxicol Sci 2019; 166:39-50. [PMID: 30011011 DOI: 10.1093/toxsci/kfy179] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Chemicals associated with unconventional oil and gas (UOG) operations have been shown to contaminate surface and ground water with a variety of endocrine disrupting compounds (EDCs) inducing multiple developmental alteration in mice. However, little is known about the impacts of UOG-associated contaminants on amphibian health and resistance to an emerging ranavirus infectious disease caused by viruses in the genus Ranavirus, especially at the vulnerable tadpole stage. Here we used tadpoles of the amphibian Xenopus laevis and the ranavirus Frog virus 3 (FV3) as a model relevant to aquatic environment conservation research for investigating the immunotoxic effects of exposure to a mixture of 23 UOG-associated chemicals with EDC activity. Xenopus tadpoles were exposed to an equimass mixture of 23 UOG-associated chemicals (range from 0.1 to 10 µg/l) for 3 weeks prior to infection with FV3. Our data show that exposure to the UOG chemical mixture is toxic for tadpoles at ecological doses of 5 to 10 µg/l. Lower doses significantly altered homeostatic expression of myeloid lineage genes and compromised tadpole responses to FV3 through expression of TNF-α, IL-1β, and Type I IFN genes, correlating with an increase in viral load. Exposure to a subset of 6 UOG chemicals was still sufficient to perturb the antiviral gene expression response. These findings suggest that UOG-associated water pollutants at low but environmentally relevant doses have the potential to induce acute alterations of immune function and antiviral immunity.
Collapse
Affiliation(s)
- Jacques Robert
- Department of Microbiology and Immunology.,Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642
| | - Connor C McGuire
- Department of Microbiology and Immunology.,Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642
| | - Fayth Kim
- Department of Microbiology and Immunology
| | - Susan C Nagel
- Department of Obstetrics & Gynecology, University of Missouri, Missouri, Columbia, MO 65212
| | - Stephen J Price
- UCL Genetics Institute, London WC1E 6BT, UK.,Institute of Zoology, Zoological Society of London, Regents Park, London NW1 4RY, UK
| | - B Paige Lawrence
- Department of Microbiology and Immunology.,Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642
| | | |
Collapse
|
20
|
Pintilie G, Chen DH, Tran BN, Jakana J, Wu J, Hew CL, Chiu W. Segmentation and Comparative Modeling in an 8.6-Å Cryo-EM Map of the Singapore Grouper Iridovirus. Structure 2019; 27:1561-1569.e4. [PMID: 31447288 PMCID: PMC6853598 DOI: 10.1016/j.str.2019.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/19/2019] [Accepted: 08/02/2019] [Indexed: 10/26/2022]
Abstract
SGIV, or Singapore grouper iridovirus, is a large double-stranded DNA virus, reaching a diameter of 220 nm and packaging a genome of 140 kb. We present a 3D cryoelectron microscopy (cryo-EM) icosahedral reconstruction of SGIV determined at 8.6-Å resolution. It reveals several layers including a T = 247 icosahedral outer coat, anchor proteins, a lipid bilayer, and the encapsidated DNA. A new segmentation tool, iSeg, was applied to extract these layers from the reconstructed map. The outer coat was further segmented into major and minor capsid proteins. None of the proteins extracted by segmentation have known atomic structures. We generated models for the major coat protein using three comparative modeling tools, and evaluated each model using the cryo-EM map. Our analysis reveals a new architecture in the Iridoviridae family of viruses. It shares similarities with others in the same family, e.g., Chilo iridescent virus, but also shows new features of the major and minor capsid proteins.
Collapse
Affiliation(s)
- Grigore Pintilie
- Department of Bioengineering, and of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA.
| | - Dong-Hua Chen
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA
| | - Bich Ngoc Tran
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117558, Singapore
| | - Joanita Jakana
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jinlu Wu
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117558, Singapore
| | - Choy Leong Hew
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117558, Singapore
| | - Wah Chiu
- Department of Bioengineering, and of Microbiology and Immunology, Stanford University, Stanford, CA 94305, USA; Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| |
Collapse
|
21
|
Xia LQ, Chen JL, Zhang HL, Cai J, Zhou S, Lu YS. Identification of virion-associated transcriptional transactivator (VATT) of SGIV ICP46 promoter and their binding site on promoter. Virol J 2019; 16:110. [PMID: 31481132 PMCID: PMC6724233 DOI: 10.1186/s12985-019-1210-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 08/05/2019] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Iridoviruses are large DNA viruses that cause diseases in fish, amphibians and insects. Singapore grouper iridovirus (SGIV) is isolated from cultured grouper and characterized as a ranavirus. ICP46 is defined to be a core gene of the family Iridoviridae and SGIV ICP46 was demonstrated to be an immediate-early (IE) gene associated with cell growth control and could contribute to virus replication in previous research. METHODS The transcription start site (TSS) and 5'-untranslated region (5'-UTR) of SGIV ICP46 were determined using 5' RACE. The core promoter elements of ICP46s were analyzed by bioinformatics analysis. The core promoter region and the regulation model of SGIV ICP46 promoter were revealed by the construction of serially deleted promoter plasmids, transfections, drug treat and luciferase reporter assays. The identification of virion-associated transcriptional transactivator (VATT) that interact with SGIV ICP46 promoter and their binding site on promoter were performed by electrophoretic mobility shift assays (EMSA), DNA pull-down assays and mass spectrometry (MS). RESULTS SGIV ICP46 was found to have short 5'-UTR and a presumptive downstream promoter element (DPE), AGACA, which locates at + 36 to + 39 nt downstream of the TSS. The core promoter region of SGIV ICP46 located from - 22 to + 42 nt relative to the TSS. VATTs were involved in the promoter activation of SGIV ICP46 and further identified to be VP12, VP39, VP57 and MCP. A 10-base DNA sequence "ATGGCTTTCG" between the TSS and presumptive DPE was determined to be the binding site of the VATTs. CONCLUSION Our study showed that four VAATs (VP12, VP39, VP57 and MCP) might bind with the SGIV ICP46 promoter and be involved in the promoter activation. Further, the binding site of the VATTs on promoter was a 10-base DNA sequence between the TSS and presumptive DPE.
Collapse
Affiliation(s)
- Li-Qun Xia
- Shenzhen Institute of Guangdong Ocean University, Shenzhen City, Guangdong, China
- College of Fisheries, Guangdong Ocean University, Zhanjiang City, Guangdong, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen City, Guangdong, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Guangdong Ocean University, Zhanjiang City, Guangdong, China
| | - Jian-Lin Chen
- Shenzhen Institute of Guangdong Ocean University, Shenzhen City, Guangdong, China
- College of Fisheries, Guangdong Ocean University, Zhanjiang City, Guangdong, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen City, Guangdong, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Guangdong Ocean University, Zhanjiang City, Guangdong, China
| | - Hong-Lian Zhang
- Shenzhen Institute of Guangdong Ocean University, Shenzhen City, Guangdong, China
- College of Fisheries, Guangdong Ocean University, Zhanjiang City, Guangdong, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen City, Guangdong, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Guangdong Ocean University, Zhanjiang City, Guangdong, China
| | - Jia Cai
- Shenzhen Institute of Guangdong Ocean University, Shenzhen City, Guangdong, China
- College of Fisheries, Guangdong Ocean University, Zhanjiang City, Guangdong, China
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen City, Guangdong, China
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Guangdong Ocean University, Zhanjiang City, Guangdong, China
| | - Sheng Zhou
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Guangdong Ocean University, Zhanjiang City, Guangdong, China
- College of Marine Sciences, South China Agricultural University, Guangzhou City, Guangdong, China
| | - Yi-Shan Lu
- Shenzhen Institute of Guangdong Ocean University, Shenzhen City, Guangdong, China.
- College of Fisheries, Guangdong Ocean University, Zhanjiang City, Guangdong, China.
- Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedings, Shenzhen City, Guangdong, China.
- Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal, Guangdong Ocean University, Zhanjiang City, Guangdong, China.
| |
Collapse
|
22
|
Chinchar VG, Duffus ALJ. Molecular and Ecological Studies of a Virus Family ( Iridoviridae) Infecting Invertebrates and Ectothermic Vertebrates. Viruses 2019; 11:v11060538. [PMID: 31181817 PMCID: PMC6630830 DOI: 10.3390/v11060538] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 05/31/2019] [Indexed: 12/18/2022] Open
Affiliation(s)
- V Gregory Chinchar
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS 39216, USA.
| | - Amanda L J Duffus
- Department of Mathematics and Natural Sciences, Gordon State College, Barnesville, GA 30204, USA.
| |
Collapse
|
23
|
Halaly MA, Subramaniam K, Koda SA, Popov VL, Stone D, Way K, Waltzek TB. Characterization of a Novel Megalocytivirus Isolated from European Chub ( Squalius cephalus). Viruses 2019; 11:v11050440. [PMID: 31096590 PMCID: PMC6563503 DOI: 10.3390/v11050440] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 12/29/2022] Open
Abstract
A novel virus from moribund European chub (Squalius cephalus) was isolated on epithelioma papulosum cyprini (EPC) cells. Transmission electron microscopic examination revealed abundant non-enveloped, hexagonal virus particles in the cytoplasm of infected EPC cells consistent with an iridovirus. Illumina MiSeq sequence data enabled the assembly and annotation of the full genome (128,216 bp encoding 108 open reading frames) of the suspected iridovirus. Maximum Likelihood phylogenetic analyses based on 25 iridovirus core genes supported the European chub iridovirus (ECIV) as being the sister species to the recently-discovered scale drop disease virus (SDDV), which together form the most basal megalocytivirus clade. Genetic analyses of the ECIV major capsid protein and ATPase genes revealed the greatest nucleotide identity to members of the genus Megalocytivirus including SDDV. These data support ECIV as a novel member within the genus Megalocytivirus. Experimental challenge studies are needed to fulfill River’s postulates and determine whether ECIV induces the pathognomonic microscopic lesions (i.e., megalocytes with basophilic cytoplasmic inclusions) observed in megalocytivirus infections.
Collapse
Affiliation(s)
- Maya A Halaly
- Department of Animal Sciences, College of Agricultural and Life Sciences, University of Florida, Gainesville, FL 32611, USA.
| | - Kuttichantran Subramaniam
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA.
| | - Samantha A Koda
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA.
| | - Vsevolod L Popov
- Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - David Stone
- Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Weymouth DT4 8UB, UK.
| | - Keith Way
- Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Weymouth DT4 8UB, UK.
| | - Thomas B Waltzek
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA.
| |
Collapse
|
24
|
Shih TC, Ho LP, Wu JL, Chou HY, Pai TW. A voting mechanism-based linear epitope prediction system for the host-specific Iridoviridae family. BMC Bioinformatics 2019; 20:192. [PMID: 31074372 PMCID: PMC6509842 DOI: 10.1186/s12859-019-2736-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background The Iridoviridae family is categorized into five genera and clustered into two subfamilies: Alphairidovirinae includes Lymphocystivirus, Ranavirus (GIV), and Megalocystivirus (TGIV), which infect vertebrate hosts and Betairidovirinae includes Iridovirus and Chloriridovirus, which infect invertebrate hosts. Clustered Iridoviridae subfamilies possess host-specific characteristics, which can be considered as exclusive features for in-silico prediction of effective epitopes for vaccine development. A voting mechanism-based linear epitope (LE) prediction system was applied to identify and endorse LE candidates with a minimum length requirement for each clustered subfamily Results The experimental results showed that four conserved epitopes among the Iridovirideae family, one exclusive epitope for invertebrate subfamily and two exclusive epitopes for vertebrate family were predicted. These predicted LE candidates were further validated by ELISA assays for evaluating the strength of antigenicity and cross antigenicity. The conserved LEs for Iridoviridae family reflected high antigenicity responses for the two subfamilies, while exclusive LEs reflected high antigenicity responses only for the host-specific subfamily Conclusions Host-specific characteristics are important features and constraints for effective epitope prediction. Our proposed voting mechanism based system provides a novel approach for in silico LE prediction prior to vaccine development, and it is especially powerful for analyzing antigen sequences with exclusive features between two clustered groups.
Collapse
Affiliation(s)
- Tao-Chuan Shih
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan
| | - Li-Ping Ho
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Jen-Leih Wu
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.,Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Hsin-Yiu Chou
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan. .,Department of Aquaculture, College of Life Science, National Taiwan Ocean University, Keelung, Taiwan.
| | - Tun-Wen Pai
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan. .,Department of Computer Science and Information Engineering, National Taipei University of Technology, Taipei, Taiwan.
| |
Collapse
|
25
|
Qiu L, Chen X, Zhao RH, Li C, Gao W, Zhang QL, Huang J. Description of a Natural Infection with Decapod Iridescent Virus 1 in Farmed Giant Freshwater Prawn, Macrobrachium rosenbergii. Viruses 2019; 11:E354. [PMID: 30999644 PMCID: PMC6521035 DOI: 10.3390/v11040354] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/05/2019] [Accepted: 04/16/2019] [Indexed: 12/26/2022] Open
Abstract
Macrobrachium rosenbergii is a valuable freshwater prawn in Asian aquaculture. In recent years, a new symptom that was generally called "white head" has caused high mortality in M. rosenbergii farms in China. Samples of M. rosenbergii, M. nipponense, Procambarus clarkii, M. superbum, Penaeus vannamei, and Cladocera from a farm suffering from white head in Jiangsu Province were collected and analyzed in this study. Pathogen detection showed that all samples were positive for Decapod iridescent virus 1 (DIV1). Histopathological examination revealed dark eosinophilic inclusions and pyknosis in hematopoietic tissue, hepatopancreas, and gills of M. rosenbergii and M. nipponense. Blue signals of in situ digoxigenin-labeled loop-mediated isothermal amplification appeared in hematopoietic tissue, hemocytes, hepatopancreatic sinus, and antennal gland. Transmission electron microscopy of ultrathin sections showed a large number of DIV1 particles with a mean diameter about 157.9 nm. The virogenic stromata and budding virions were observed in hematopoietic cells. Quantitative detection with TaqMan probe based real-time PCR of different tissues in naturally infected M. rosenbergii showed that hematopoietic tissue contained the highest DIV1 load with a relative abundance of 25.4 ± 16.9%. Hepatopancreas and muscle contained the lowest DIV1 loads with relative abundances of 2.44 ± 1.24% and 2.44 ± 2.16%, respectively. The above results verified that DIV1 is the pathogen causing white head in M. rosenbergii. M. nipponense and Pr. clarkii are also species susceptible to DIV1.
Collapse
Affiliation(s)
- Liang Qiu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology (Qingdao); Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs; Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Qingdao 266071, China.
| | - Xing Chen
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology (Qingdao); Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs; Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Qingdao 266071, China.
- Shanghai Ocean University, Shanghai 201306, China.
| | - Ruo-Heng Zhao
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology (Qingdao); Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs; Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Qingdao 266071, China.
- Dalian Ocean University, Dalian 116023, China.
| | - Chen Li
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology (Qingdao); Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs; Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Qingdao 266071, China.
| | - Wen Gao
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology (Qingdao); Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs; Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Qingdao 266071, China.
- Shanghai Ocean University, Shanghai 201306, China.
| | - Qing-Li Zhang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology (Qingdao); Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs; Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Qingdao 266071, China.
- Shanghai Ocean University, Shanghai 201306, China.
| | - Jie Huang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Laboratory for Marine Fisheries Science and Food Production Processes, National Laboratory for Marine Science and Technology (Qingdao); Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture and Rural Affairs; Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Qingdao 266071, China.
- Shanghai Ocean University, Shanghai 201306, China.
- Dalian Ocean University, Dalian 116023, China.
| |
Collapse
|
26
|
Mihaljevic JR, Hoverman JT, Johnson PTJ. Co-exposure to multiple ranavirus types enhances viral infectivity and replication in a larval amphibian system. DISEASES OF AQUATIC ORGANISMS 2018; 132:23-35. [PMID: 30530928 DOI: 10.3354/dao03300] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Multiple pathogens commonly co-occur in animal populations, yet few studies demonstrate how co-exposure of individual hosts scales up to affect transmission. Although viruses in the genus Ranavirus are globally widespread, and multiple virus species or strains likely co-occur in nature, no studies have examined how co-exposure affects infection dynamics in larval amphibians. We exposed individual northern red-legged frog Rana aurora larvae to 2 species of ranavirus, namely Ambystoma tigrinum virus (ATV), frog virus 3 (FV3), or an FV3-like strain isolated from a frog-culturing facility in Georgia, USA (RCV-Z2). We compared single-virus to pairwise co-exposures while experimentally accounting for dosage. Co-exposure to ATV and FV3-like strains resulted in almost twice as many infected individuals compared to single-virus exposures, suggesting an effect of co-exposure on viral infectivity. The viral load in infected individuals exposed to ATV and FV3 was also higher than the single-dose FV3 treatment, suggesting an effect of co-exposure on viral replication. In a follow-up experiment, we examined how the co-occurrence of ATV and FV3 affected epizootics in mesocosm populations of larval western chorus frogs Pseudacris triseriata. Although ATV did not generally establish within host populations (<4% prevalence), when ATV and FV3 were both present, this co-exposure resulted in a larger epizootic of FV3. Our results emphasize the importance of multi-pathogen interactions in epizootic dynamics and have management implications for natural and commercial amphibian populations.
Collapse
Affiliation(s)
- Joseph R Mihaljevic
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | | | | |
Collapse
|
27
|
Lopez-Porras A, Morales JA, Alvarado G, Koda SA, Camus A, Subramaniam K, Waltzek TB, Soto E. Red seabream iridovirus associated with cultured Florida pompano Trachinotus carolinus mortality in Central America. DISEASES OF AQUATIC ORGANISMS 2018; 130:109-115. [PMID: 30198486 DOI: 10.3354/dao03267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Mariculture of Florida pompano Trachinotus carolinus in Central America has increased over the last few decades and it is now a highly valued food fish. High feed costs and infectious diseases are significant impediments to the expansion of mariculture. Members of the genus Megalocytivirus (MCV), subfamily Alphairidovirinae, within the family Iridoviridae, are emerging pathogens that negatively impact Asian mariculture. A significant mortality event in Florida pompano fingerlings cultured in Central America occurred in October 2014. Affected fish presented with abdominal distension, darkening of the skin, and periocular hemorrhages. Microscopic lesions included cytomegalic 'inclusion body-bearing cells' characterized by basophilic granular cytoplasmic inclusions in multiple organs. Transmission electron microscopy revealed arrays of hexagonal virions (155-180 nm in diameter) with electron-dense cores within the cytoplasm of cytomegalic cells. Pathological findings were suggestive of an MCV infection, and the diagnosis was later confirmed by partial PCR amplification and sequencing of the viral gene encoding the myristylated membrane protein. The viral sequence revealed that the fingerlings were infected with an MCV genotype, red seabream iridovirus (RSIV), previously reported only from epizootics in Asian mariculture. This case underscores the threat RSIV poses to global mariculture, including the production of Florida pompano in Central America.
Collapse
Affiliation(s)
- Adrian Lopez-Porras
- Servicio de Patologia Veterinaria, Universidad Nacional de Costa Rica, Heredia, Costa Rica
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Koda SA, Subramaniam K, Francis-Floyd R, Yanong RP, Frasca S, Groff JM, Popov VL, Fraser WA, Yan A, Mohan S, Waltzek TB. Phylogenomic characterization of two novel members of the genus Megalocytivirus from archived ornamental fish samples. DISEASES OF AQUATIC ORGANISMS 2018; 130:11-24. [PMID: 30154268 DOI: 10.3354/dao03250] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The genus Megalocytivirus is the most recently described member of the family Iridoviridae; as such, little is known about the genetic diversity of this genus of globally emerging viral fish pathogens. We sequenced the genomes of 2 megalocytiviruses (MCVs) isolated from epizootics involving South American cichlids (oscar Astronotus ocellatus and keyhole cichlid Cleithracara maronii) and three spot gourami Trichopodus trichopterus sourced through the ornamental fish trade during the early 1990s. Phylogenomic analyses revealed the South American cichlid iridovirus (SACIV) and three spot gourami iridovirus (TSGIV) possess 116 open reading frames each, and form a novel clade within the turbot reddish body iridovirus genotype (TRBIV Clade 2). Both genomes displayed a unique truncated paralog of the major capsid protein gene located immediately upstream of the full-length parent gene. Histopathological examination of archived oscar tissue sections that were PCR-positive for SACIV revealed numerous cytomegalic cells characterized by basophilic intracytoplasmic inclusions within various organs, particularly the anterior kidney, spleen, intestinal lamina propria and submucosa. TSGIV-infected grunt fin (GF) cells grown in vitro displayed cytopathic effects (e.g. cytomegaly, rounding, and refractility) as early as 96 h post-infection. Ultrastructural examination of infected GF cells revealed unenveloped viral particles possessing hexagonal nucleocapsids (120 to 144 nm in diameter) and electron-dense cores within the cytoplasm, consistent with the ultrastructural morphology of a MCV. Sequencing of SACIV and TSGIV provides the first complete TRBIV Clade 2 genome sequences and expands the known host and geographic range of the TRBIV genotype to include freshwater ornamental fishes traded in North America.
Collapse
Affiliation(s)
- Samantha A Koda
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32611, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Amphibian ( Xenopus laevis) Tadpoles and Adult Frogs Differ in Their Use of Expanded Repertoires of Type I and Type III Interferon Cytokines. Viruses 2018; 10:v10070372. [PMID: 30018186 PMCID: PMC6070924 DOI: 10.3390/v10070372] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 06/30/2018] [Accepted: 07/07/2018] [Indexed: 12/19/2022] Open
Abstract
While amphibians around the globe are facing catastrophic declines, in part because of infections with pathogens such as the Frog Virus 3 (FV3) ranavirus; the mechanisms governing amphibian susceptibility and resistance to such pathogens remain poorly understood. The type I and type III interferon (IFN) cytokines represent a cornerstone of vertebrate antiviral immunity, while our recent work indicates that tadpoles and adult frogs of the amphibian Xenopus laevis may differ in their IFN responses to FV3. In this respect, it is notable that anuran (frogs and toads) tadpoles are significantly more susceptible to FV3 than adult frogs, and thus, gaining greater insight into the differences in the tadpole and adult frog antiviral immunity would be invaluable. Accordingly, we examined the FV3-elicited expression of a panel of type I and type III IFN genes in the skin (site of FV3 infection) and kidney (principal FV3 target) tissues and isolated cells of X. laevis tadpoles and adult frogs. We also examined the consequence of tadpole and adult frog skin and kidney cell stimulation with hallmark pathogen-associated molecular patterns (PAMPs) on the IFN responses of these cells. Together, our findings indicate that tadpoles and adult frogs mount drastically distinct IFN responses to FV3 as well as to viral and non-viral PAMPs, while these expression differences do not appear to be the result of a distinct pattern recognition receptor expression by tadpoles and adults.
Collapse
|
30
|
Xu T, Chu Q, Cui J. Rhabdovirus-Inducible MicroRNA-210 Modulates Antiviral Innate Immune Response via Targeting STING/MITA in Fish. THE JOURNAL OF IMMUNOLOGY 2018; 201:982-994. [DOI: 10.4049/jimmunol.1800377] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 06/05/2018] [Indexed: 01/10/2023]
|
31
|
Standish I, Leis E, Schmitz N, Credico J, Erickson S, Bailey J, Kerby J, Phillips K, Lewis T. Optimizing, validating, and field testing a multiplex qPCR for the detection of amphibian pathogens. DISEASES OF AQUATIC ORGANISMS 2018; 129:1-13. [PMID: 29916388 DOI: 10.3354/dao03230] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Amphibian populations worldwide are facing numerous threats, including the emergence and spread of infectious diseases. In the past 2 decades, Batrachochytrium dendrobatidis (Bd), a parasitic fungus, and a group of viruses comprising the genus Ranavirus have become widespread and resulted in mass mortality events and extirpations worldwide. In 2013, another novel fungus, B. salamandrivorans (Bsal), was attributed to dramatic declines in populations of fire salamander Salamandra salamandra in the Netherlands. Experimental infections demonstrated that Bsal is highly pathogenic to numerous salamander genera. In an effort to prevent the introduction of Bsal to North America, the US Fish and Wildlife Service (USFWS) listed 201 salamander species as injurious wildlife under the Lacey Act. To determine infection status and accurately assess amphibian health, the development of a sensitive and specific diagnostic assay was needed. We describe the optimization and validation of a multiplex quantitative polymerase chain reaction (qPCR) protocol for the simultaneous detection of Bd, Bsal, and frog virus 3-like ranaviruses. A synthetic genome template (gBlock®) containing the target genes from all 3 pathogens served as the positive control and allowed accurate quantification of pathogen genes. The assay was validated in the field using an established non-lethal swabbing technique to survey local amphibian populations throughout a range of habitats. This multiplex qPCR demonstrates high reproducibility, sensitivity, and was capable of detecting both Bd and ranavirus in numerous locations, species, and life stages. Bsal was not detected at any point during these sampling efforts.
Collapse
Affiliation(s)
- Isaac Standish
- US Fish and Wildlife Service, Midwest Fisheries Center, La Crosse Fish Health Center, Onalaska, WI 54650, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Bermúdez R, Losada AP, de Azevedo AM, Guerra-Varela J, Pérez-Fernández D, Sánchez L, Padrós F, Nowak B, Quiroga MI. First description of a natural infection with spleen and kidney necrosis virus in zebrafish. JOURNAL OF FISH DISEASES 2018; 41:1283-1294. [PMID: 29882280 DOI: 10.1111/jfd.12822] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 05/04/2023]
Abstract
Zebrafish has become a popular research model in the last years, and several diseases affecting zebrafish research facilities have been reported. However, only one case of naturally occurring viral infections was described for this species. In 2015, infectious spleen and kidney necrosis virus (ISKNV) was detected in zebrafish from a research facility in Spain. Affected fish showed lethargy, loss of appetite, abnormal swimming, distention of the coelomic cavity and, in the most severe cases, respiratory distress, pale gills and petechial haemorrhages at the base of fins. Cytomegaly was the most relevant histopathological finding in organs and tissues, sometimes associated to degenerative and necrotic changes. ISKNV belongs to the relatively newly defined genus Megalocytivirus, family Iridoviridae, comprising large, icosahedral cytoplasmic DNA viruses. This is the first case of naturally occurring Megalocytivirus infection in zebrafish research facilities, associated with morbidity. The virus has been identified based on both pathologic and genetic evidence, to better understand the pathogenesis of the infection in zebrafish and the phylogenetic relationship with other iridoviruses. Given the ability of megalocytiviruses to cross-species boundaries, it seems necessary to implement stringent biosecurity practices as these infections may invalidate experimental data and have major impact on laboratory and cultured fish.
Collapse
Affiliation(s)
- Roberto Bermúdez
- Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
| | - Ana Paula Losada
- Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
| | - Ana Manuela de Azevedo
- Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
| | - Jorge Guerra-Varela
- Department of Zoology, Genetics and Physical Anthropology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
| | - David Pérez-Fernández
- Department of Zoology, Genetics and Physical Anthropology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
| | - Laura Sánchez
- Department of Zoology, Genetics and Physical Anthropology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
| | - Francesc Padrós
- Department of Animal Biology, Vegetal Biology and Ecology, Autonomous University of Barcelona, Barcelona, Spain
| | - Barbara Nowak
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania
| | - María Isabel Quiroga
- Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
| |
Collapse
|
33
|
Qiu L, Chen MM, Wang RY, Wan XY, Li C, Zhang QL, Dong X, Yang B, Xiang JH, Huang J. Complete genome sequence of shrimp hemocyte iridescent virus (SHIV) isolated from white leg shrimp, Litopenaeus vannamei. Arch Virol 2018; 163:781-785. [PMID: 29181623 PMCID: PMC5814465 DOI: 10.1007/s00705-017-3642-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 11/02/2017] [Indexed: 12/13/2022]
Abstract
Infection with shrimp hemocyte iridescent virus (SHIV), a new virus of the family Iridoviridae isolated in China, results in a high mortality rate in white leg shrimp (Litopenaeus vannamei). The complete genome sequence of SHIV was determined and analyzed in this study. The genomic DNA was 165,809 bp long with 34.6% G+C content and 170 open reading frames (ORFs). Dotplot analysis showed that the longest repetitive region was 320 bp in length, including 11 repetitions of an 18-bp sequence and 3.1 repetitions of a 39-bp sequence. Two phylogenetic trees were constructed based on 27 or 16 concatenated sequences of proteins encoded by genes that are conserved between SHIV homologous and other iridescent viruses. The results of this study, suggest that SHIV should be considered a member of the proposed new genus "Xiairidovirus".
Collapse
Affiliation(s)
- Liang Qiu
- Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Shanghai Ocean University, Shanghai, 201306, China
| | - Meng-Meng Chen
- Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Shanghai Ocean University, Shanghai, 201306, China
| | - Ruo-Yu Wang
- Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Dalian Ocean University, Dalian, 116023, China
| | - Xiao-Yuan Wan
- Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
| | - Chen Li
- Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
| | - Qing-Li Zhang
- Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
- Shanghai Ocean University, Shanghai, 201306, China
| | - Xuan Dong
- Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
| | - Bing Yang
- Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
| | - Jian-Hai Xiang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Jie Huang
- Qingdao Key Laboratory of Mariculture Epidemiology and Biosecurity, Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China.
- Shanghai Ocean University, Shanghai, 201306, China.
- Dalian Ocean University, Dalian, 116023, China.
| |
Collapse
|
34
|
Huynh TP, Jancovich JK, Tripuraneni L, Heck MC, Langland JO, Jacobs BL. Characterization of a PKR inhibitor from the pathogenic ranavirus, Ambystoma tigrinum virus, using a heterologous vaccinia virus system. Virology 2017; 511:290-299. [PMID: 28919326 PMCID: PMC6192022 DOI: 10.1016/j.virol.2017.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/03/2017] [Accepted: 08/09/2017] [Indexed: 02/07/2023]
Abstract
Ambystoma tigrinum virus (ATV) (family Iridoviridae, genus Ranavirus) was isolated from diseased tiger salamanders (Ambystoma tigrinum stebbinsi) from the San Rafael Valley in southern Arizona, USA in 1996. Genomic sequencing of ATV, as well as other members of the genus, identified an open reading frame that has homology to the eukaryotic translation initiation factor, eIF2α (ATV eIF2α homologue, vIF2αH). Therefore, we asked if the ATV vIF2αH could also inhibit PKR. To test this hypothesis, the ATV vIF2αH was cloned into vaccinia virus (VACV) in place of the well-characterized VACV PKR inhibitor, E3L. Recombinant VACV expressing ATV vIF2αH partially rescued deletion of the VACV E3L gene. Rescue coincided with rapid degradation of PKR in infected cells. These data suggest that the salamander virus, ATV, contains a novel gene that may counteract host defenses, and this gene product may be involved in the presentation of disease caused by this environmentally important pathogen.
Collapse
Affiliation(s)
- Trung P Huynh
- School of Life Sciences, and The Biodesign Institute, Center for Infectious Diseases and Vaccinology Arizona State University, Tempe, AZ 85287-5001, USA
| | - James K Jancovich
- School of Life Sciences, and The Biodesign Institute, Center for Infectious Diseases and Vaccinology Arizona State University, Tempe, AZ 85287-5001, USA
| | - Latha Tripuraneni
- School of Life Sciences, and The Biodesign Institute, Center for Infectious Diseases and Vaccinology Arizona State University, Tempe, AZ 85287-5001, USA
| | - Michael C Heck
- School of Life Sciences, and The Biodesign Institute, Center for Infectious Diseases and Vaccinology Arizona State University, Tempe, AZ 85287-5001, USA
| | - Jeffrey O Langland
- School of Life Sciences, and The Biodesign Institute, Center for Infectious Diseases and Vaccinology Arizona State University, Tempe, AZ 85287-5001, USA; Southwest College of Naturopathic Medicine, Tempe, AZ 85282, USA
| | - Bertram L Jacobs
- School of Life Sciences, and The Biodesign Institute, Center for Infectious Diseases and Vaccinology Arizona State University, Tempe, AZ 85287-5001, USA.
| |
Collapse
|
35
|
Multisubunit DNA-Dependent RNA Polymerases from Vaccinia Virus and Other Nucleocytoplasmic Large-DNA Viruses: Impressions from the Age of Structure. Microbiol Mol Biol Rev 2017; 81:81/3/e00010-17. [PMID: 28701329 DOI: 10.1128/mmbr.00010-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The past 17 years have been marked by a revolution in our understanding of cellular multisubunit DNA-dependent RNA polymerases (MSDDRPs) at the structural level. A parallel development over the past 15 years has been the emerging story of the giant viruses, which encode MSDDRPs. Here we link the two in an attempt to understand the specialization of multisubunit RNA polymerases in the domain of life encompassing the large nucleocytoplasmic DNA viruses (NCLDV), a superclade that includes the giant viruses and the biochemically well-characterized poxvirus vaccinia virus. The first half of this review surveys the recently determined structural biology of cellular RNA polymerases for a microbiology readership. The second half discusses a reannotation of MSDDRP subunits from NCLDV families and the apparent specialization of these enzymes by virus family and by subunit with regard to subunit or domain loss, subunit dissociability, endogenous control of polymerase arrest, and the elimination/customization of regulatory interactions that would confer higher-order cellular control. Some themes are apparent in linking subunit function to structure in the viral world: as with cellular RNA polymerases I and III and unlike cellular RNA polymerase II, the viral enzymes seem to opt for speed and processivity and seem to have eliminated domains associated with higher-order regulation. The adoption/loss of viral RNA polymerase proofreading functions may have played a part in matching intrinsic mutability to genome size.
Collapse
|
36
|
Nikolic J, Le Bars R, Lama Z, Scrima N, Lagaudrière-Gesbert C, Gaudin Y, Blondel D. Negri bodies are viral factories with properties of liquid organelles. Nat Commun 2017; 8:58. [PMID: 28680096 PMCID: PMC5498545 DOI: 10.1038/s41467-017-00102-9] [Citation(s) in RCA: 186] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 05/31/2017] [Indexed: 11/23/2022] Open
Abstract
Replication of Mononegavirales occurs in viral factories which form inclusions in the host-cell cytoplasm. For rabies virus, those inclusions are called Negri bodies (NBs). We report that NBs have characteristics similar to those of liquid organelles: they are spherical, they fuse to form larger structures, and they disappear upon hypotonic shock. Their liquid phase is confirmed by FRAP experiments. Live-cell imaging indicates that viral nucleocapsids are ejected from NBs and transported along microtubules to form either new virions or secondary viral factories. Coexpression of rabies virus N and P proteins results in cytoplasmic inclusions recapitulating NBs properties. This minimal system reveals that an intrinsically disordered domain and the dimerization domain of P are essential for Negri bodies-like structures formation. We suggest that formation of liquid viral factories by phase separation is common among Mononegavirales and allows specific recruitment and concentration of viral proteins but also the escape to cellular antiviral response. Negative strand RNA viruses, such as rabies virus, induce formation of cytoplasmic inclusions for genome replication. Here, Nikolic et al. show that these so-called Negri bodies (NBs) have characteristics of liquid organelles and they identify the minimal protein domains required for NB formation.
Collapse
Affiliation(s)
- Jovan Nikolic
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Romain Le Bars
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Zoé Lama
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Nathalie Scrima
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Cécile Lagaudrière-Gesbert
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Yves Gaudin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
| | - Danielle Blondel
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
| |
Collapse
|
37
|
Hua J, Wuerthner VP, Jones DK, Mattes B, Cothran RD, Relyea RA, Hoverman JT. Evolved pesticide tolerance influences susceptibility to parasites in amphibians. Evol Appl 2017; 10:802-812. [PMID: 29151872 PMCID: PMC5680434 DOI: 10.1111/eva.12500] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 05/26/2017] [Indexed: 01/08/2023] Open
Abstract
Because ecosystems throughout the globe are contaminated with pesticides, there is a need to understand how natural populations cope with pesticides and the implications for ecological interactions. From an evolutionary perspective, there is evidence that pesticide tolerance can be achieved via two mechanisms: selection for constitutive tolerance over multiple generations or by inducing tolerance within a single generation via phenotypic plasticity. While both mechanisms can allow organisms to persist in contaminated environments, they might result in different performance trade-offs including population susceptibility to parasites. We have identified 15 wood frog populations that exist along a gradient from close to agriculture and high, constitutive pesticide tolerance to far from agriculture and inducible pesticide tolerance. Using these populations, we investigated the relationship between evolutionary responses to the common insecticide carbaryl and host susceptibility to the trematode Echinoparyphium lineage 3 and ranavirus using laboratory exposure assays. For Echinoparyphium, we discovered that wood frog populations living closer to agriculture with high, constitutive tolerance experienced lower loads than populations living far from agriculture with inducible pesticide tolerance. For ranavirus, we found no relationship between the mechanism of evolved pesticide tolerance and survival, but populations living closer to agriculture with high, constitutive tolerance experienced higher viral loads than populations far from agriculture with inducible tolerance. Land use and mechanisms of evolved pesticide tolerance were associated with susceptibility to parasites, but the direction of the relationship is dependent on the type of parasite, underscoring the complexity between land use and disease outcomes. Collectively, our results demonstrate that evolved pesticide tolerance can indirectly influence host-parasite interactions and underscores the importance of including evolutionary processes in ecotoxicological studies.
Collapse
Affiliation(s)
- Jessica Hua
- Biological Sciences Department Binghamton University (SUNY) Binghamton NY USA
| | - Vanessa P Wuerthner
- Biological Sciences Department Binghamton University (SUNY) Binghamton NY USA
| | - Devin K Jones
- Department of Biological Sciences Rensselaer Polytechnic Institute Troy NY USA
| | - Brian Mattes
- Department of Biological Sciences Rensselaer Polytechnic Institute Troy NY USA
| | - Rickey D Cothran
- Biological Sciences Department Southwestern Oklahoma State University Weatherford OK USA
| | - Rick A Relyea
- Department of Biological Sciences Rensselaer Polytechnic Institute Troy NY USA
| | - Jason T Hoverman
- Department of Forestry and Natural Resources Purdue University West Lafayette IN USA
| |
Collapse
|
38
|
Abstract
We first review fundamental insights into anti-ranavirus immunity learned with the Xenopus laevis/ranavirus FV3 model that are generally applicable to ectothermic vertebrates. We then further investigate FV3 genes involved in immune evasion. Focusing on FV3 knockout (KO) mutants defective for a putative viral caspase activation and recruitment domain-containing (CARD)-like protein (Δ64R-FV3), a β-hydroxysteroid dehydrogenase homolog (Δ52L-FV3), and an immediate-early18kDa protein (FV3-Δ18K), we assessed the involvement of these viral genes in replication, dissemination and interaction with peritoneal macrophages in tadpole and adult frogs. Our results substantiate the role of 64R and 52L as critical immune evasion genes, promoting persistence and dissemination in the host by counteracting type III IFN in tadpoles and type I IFN in adult frogs. Comparably, the substantial accumulation of genome copy numbers and exacerbation of type I and III IFN gene expression responses but deficient release of infectious virus suggests that 18K is a viral regulatory gene.
Collapse
Affiliation(s)
- Robert Jacques
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, United States.
| | - Eva-Stina Edholm
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, United States
| | - Sanchez Jazz
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, United States
| | - Torres-Luquis Odalys
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, United States
| | - De Jesús Andino Francisco
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, United States
| |
Collapse
|
39
|
Chinchar VG, Hick P, Ince IA, Jancovich JK, Marschang R, Qin Q, Subramaniam K, Waltzek TB, Whittington R, Williams T, Zhang QY, Ictv Report Consortium. ICTV Virus Taxonomy Profile: Iridoviridae. J Gen Virol 2017; 98:890-891. [PMID: 28555546 PMCID: PMC5656800 DOI: 10.1099/jgv.0.000818] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The Iridoviridae is a family of large, icosahedral viruses with double-stranded DNA genomes ranging in size from 103 to 220 kbp. Members of the subfamily Alphairidovirinae infect ectothermic vertebrates (bony fish, amphibians and reptiles), whereas members of the subfamily Betairidovirinae mainly infect insects and crustaceans. Infections can be either covert or patent, and in vertebrates they can lead to high levels of mortality among commercially and ecologically important fish and amphibians. This is a summary of the current International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Iridoviridae, which is available at www.ictv.global/report/iridoviridae.
Collapse
Affiliation(s)
- V Gregory Chinchar
- Department of Microbiology, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Paul Hick
- Faculty of Veterinary Science, University of Sydney, Sydney NSW, Australia
| | - Ikbal Agah Ince
- Department of Medical Microbiology, Acibadem Medical School, Istanbul, Turkey
| | - James K Jancovich
- Department of Biological Sciences, California State University, San Marcos, CA 92096, USA
| | | | - Qiwei Qin
- Key Laboratory of Tropical Marine BioResources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, PR China
| | - Kuttichantran Subramaniam
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
| | - Thomas B Waltzek
- Department of Infectious Diseases and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA
| | | | | | - Qi-Ya Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, PR China
| | | |
Collapse
|
40
|
Oliveira GP, Andrade ACDSP, Rodrigues RAL, Arantes TS, Boratto PVM, Silva LKDS, Dornas FP, Trindade GDS, Drumond BP, La Scola B, Kroon EG, Abrahão JS. Promoter Motifs in NCLDVs: An Evolutionary Perspective. Viruses 2017; 9:v9010016. [PMID: 28117683 PMCID: PMC5294985 DOI: 10.3390/v9010016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/30/2016] [Accepted: 01/05/2017] [Indexed: 01/18/2023] Open
Abstract
For many years, gene expression in the three cellular domains has been studied in an attempt to discover sequences associated with the regulation of the transcription process. Some specific transcriptional features were described in viruses, although few studies have been devoted to understanding the evolutionary aspects related to the spread of promoter motifs through related viral families. The discovery of giant viruses and the proposition of the new viral order Megavirales that comprise a monophyletic group, named nucleo-cytoplasmic large DNA viruses (NCLDV), raised new questions in the field. Some putative promoter sequences have already been described for some NCLDV members, bringing new insights into the evolutionary history of these complex microorganisms. In this review, we summarize the main aspects of the transcription regulation process in the three domains of life, followed by a systematic description of what is currently known about promoter regions in several NCLDVs. We also discuss how the analysis of the promoter sequences could bring new ideas about the giant viruses’ evolution. Finally, considering a possible common ancestor for the NCLDV group, we discussed possible promoters’ evolutionary scenarios and propose the term “MEGA-box” to designate an ancestor promoter motif (‘TATATAAAATTGA’) that could be evolved gradually by nucleotides’ gain and loss and point mutations.
Collapse
Affiliation(s)
- Graziele Pereira Oliveira
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Ana Cláudia Dos Santos Pereira Andrade
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Rodrigo Araújo Lima Rodrigues
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Thalita Souza Arantes
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Paulo Victor Miranda Boratto
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Ludmila Karen Dos Santos Silva
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Fábio Pio Dornas
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Giliane de Souza Trindade
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Betânia Paiva Drumond
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Bernard La Scola
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE) UM63 CNRS 7278 IRD 198 INSERM U1095, Aix-Marseille Université., 27 Boulevard Jean Moulin, Faculté de Médecine, 13385 Marseille Cedex 05, France.
| | - Erna Geessien Kroon
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| | - Jônatas Santos Abrahão
- Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Minas Gerais, Brazil.
| |
Collapse
|
41
|
Forzán MJ, Jones KM, Ariel E, Whittington RJ, Wood J, Markham RJF, Daoust PY. Pathogenesis of Frog Virus 3 (Ranavirus, Iridoviridae) Infection in Wood Frogs (Rana sylvatica). Vet Pathol 2017; 54:531-548. [DOI: 10.1177/0300985816684929] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Wood frogs ( Rana sylvatica) are highly susceptible to infection with Frog virus 3 (FV3, Ranavirus, Iridoviridae), a cause of mass mortality in wild populations. To elucidate the pathogenesis of FV3 infection in wood frogs, 40 wild-caught adults were acclimated to captivity, inoculated orally with a fatal dose of 104.43 pfu/frog, and euthanized at 0.25, 0.5, 1, 2, 4, 9, and 14 days postinfection (dpi). Mild lesions occurred sporadically in the skin (petechiae) and bone marrow (necrosis) during the first 2 dpi. Severe lesions occurred 1 to 2 weeks postinfection and consisted of necrosis of medullary and extramedullary hematopoietic tissue, lymphoid tissue in spleen and throughout the body, and epithelium of skin, mucosae, and renal tubules. Viral DNA was first detected (polymerase chain reaction) in liver at 4 dpi; by dpi 9 and 14, all viscera tested (liver, kidney, and spleen), skin, and feces were positive. Immunohistochemistry (IHC) first detected viral antigen in small areas devoid of histologic lesions in the oral mucosa, lung, and colon at 4 dpi; by 9 and 14 dpi, IHC labeling of viral antigen associated with necrosis was found in multiple tissues. Based on IHC staining intensity and lesion severity, the skin, oral, and gastrointestinal epithelium and renal tubular epithelium were important sites of viral replication and shedding, suggesting that direct contact (skin) and fecal-oral contamination are effective routes of transmission and that skin tissue, oral, and cloacal swabs may be appropriate antemortem diagnostic samples in late stages of disease (>1 week postinfection) but poor samples to detect infection in clinically healthy frogs.
Collapse
Affiliation(s)
- M. J. Forzán
- Canadian Wildlife Health Cooperative, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
- Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - K. M. Jones
- Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - E. Ariel
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia
| | - R. J. Whittington
- School of Life and Environmental Sciences, Faculty of Veterinary Science, University of Sydney, Camden, New South Wales, Australia
| | - J. Wood
- Pisces Molecular LLC, Boulder, CO, USA
| | - R. J. Frederick Markham
- Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| | - P.-Y. Daoust
- Canadian Wildlife Health Cooperative, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
- Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada
| |
Collapse
|
42
|
Price SJ. Comparative Genomics of Amphibian-like Ranaviruses, Nucleocytoplasmic Large DNA Viruses of Poikilotherms. Evol Bioinform Online 2016; 11:71-82. [PMID: 27812275 PMCID: PMC5081246 DOI: 10.4137/ebo.s33490] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/12/2016] [Accepted: 09/15/2016] [Indexed: 12/15/2022] Open
Abstract
Recent research on genome evolution of large DNA viruses has highlighted a number of incredibly dynamic processes that can facilitate rapid adaptation. The genomes of amphibian-like ranaviruses – double-stranded DNA viruses infecting amphibians, reptiles, and fish (family Iridoviridae) – were examined to assess variation in genome content and evolutionary processes. The viruses studied were closely related, but their genome content varied considerably, with 29 genes identified that were not present in all of the major clades. Twenty-one genes had evidence of recombination, while a virus isolated from a captive reptile appeared to be a mosaic of two divergent parents. Positive selection was also found to be acting on more than a quarter of Ranavirus genes and was found most frequently in the Spanish common midwife toad virus, which has had a severe impact on amphibian host communities. Efforts to resolve the root of this group by inclusion of an outgroup were inconclusive, but a set of core genes were identified, which recovered a well-supported species tree.
Collapse
Affiliation(s)
- Stephen J Price
- Genetics, Evolution and Environment department, UCL Genetics Institute, London, UK.; Institute of Zoology, Zoological Society of London (ZSL), London, UK
| |
Collapse
|
43
|
Hine PM, Wakefield SJ, Mackereth G, Morrison R. Ultrastructural morphogenesis of a virus associated with lymphocystis-like lesions in parore Girella tricuspidata (Kyphosidae: Perciformes). DISEASES OF AQUATIC ORGANISMS 2016; 121:129-139. [PMID: 27667810 DOI: 10.3354/dao03050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The morphogenesis of large icosahedral viruses associated with lymphocystis-like lesions in the skin of parore Girella tricuspidata is described. The electron-lucent perinuclear viromatrix comprised putative DNA with open capsids at the periphery, very large arrays of smooth endoplasmic reticulum (sER), much of it with a reticulated appearance (rsER) or occurring as rows of vesicles. Lysosomes, degenerating mitochondria and virions in various stages of assembly, and paracrystalline arrays were also present. Long electron-dense inclusions (EDIs) with 15 nm repeating units split terminally and curled to form tubular structures internalising the 15 nm repeating structures. These tubular structures appeared to form the virion capsids. Large parallel arrays of sER sometimes alternated with aligned arrays of crinkled cisternae along which passed a uniformly wide (20 nm) thread-like structure. Strings of small vesicles near open capsids may also have been involved in formation of an inner lipid layer. Granules with a fine fibrillar appearance also occurred in the viromatrix, and from the presence of a halo around mature virions it appeared that the fibrils may form a layer around the capsid. The general features of virogenesis of large icosahedral dsDNA viruses, the large amount of ER, particularly rsER and the EDIs, are features of nucleo-cytoplasmic large DNA viruses, rather than features of 1 genus or family.
Collapse
Affiliation(s)
- P M Hine
- National Centre for Disease Investigation, MAF Operations, Ministry of Agriculture and Forestry, PO Box 40-742, Upper Hutt, New Zealand
| | | | | | | |
Collapse
|
44
|
Robert J, Jancovich JK. Recombinant Ranaviruses for Studying Evolution of Host-Pathogen Interactions in Ectothermic Vertebrates. Viruses 2016; 8:E187. [PMID: 27399758 PMCID: PMC4974522 DOI: 10.3390/v8070187] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 06/16/2016] [Accepted: 06/23/2016] [Indexed: 12/14/2022] Open
Abstract
Ranaviruses (Iridoviridae) are large DNA viruses that are causing emerging infectious diseases at an alarming rate in both wild and captive cold blood vertebrate species all over the world. Although the general biology of these viruses that presents some similarities with poxvirus is characterized, many aspects of their replication cycles, host cell interactions and evolution still remain largely unclear, especially in vivo. Over several years, strategies to generate site-specific ranavirus recombinant, either expressing fluorescent reporter genes or deficient for particular viral genes, have been developed. We review here these strategies, the main ranavirus recombinants characterized and their usefulness for in vitro and in vivo studies.
Collapse
Affiliation(s)
- Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - James K Jancovich
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Rd., San Marcos, CA 92096, USA.
| |
Collapse
|
45
|
pol-miR-731, a teleost miRNA upregulated by megalocytivirus, negatively regulates virus-induced type I interferon response, apoptosis, and cell cycle arrest. Sci Rep 2016; 6:28354. [PMID: 27311682 PMCID: PMC4911600 DOI: 10.1038/srep28354] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 06/02/2016] [Indexed: 02/07/2023] Open
Abstract
Megalocytivirus is a DNA virus that is highly infectious in a wide variety of marine and freshwater fish, including Japanese flounder (Paralichthys olivaceus), a flatfish that is farmed worldwide. However, the infection mechanism of megalocytivirus remains largely unknown. In this study, we investigated the function of a flounder microRNA, pol-miR-731, in virus-host interaction. We found that pol-miR-731 was induced in expression by megalocytivirus and promoted viral replication at the early infection stage. In vivo and in vitro studies revealed that pol-miR-731 (i) specifically suppresses the expression of interferon regulatory factor 7 (IRF7) and cellular tumor antigen p53 in a manner that depended on the integrity of the pol-miR-731 complementary sequences in the 3′ untranslated regions of IRF7 and p53, (ii) disrupts megalocytivirus-induced Type I interferon response through IRF7, (iii) inhibits megalocytivirus-induced splenocyte apoptosis and cell cycle arrest through p53. Furthermore, overexpression of IRF7 and p53 abolished both the inhibitory effects of pol-miR-731 on these biological processes and its stimulatory effect on viral replication. These results disclosed a novel evasion mechanism of megalocytivirus mediated by a host miRNA. This study also provides the first evidence that a virus-induced host miRNA can facilitate viral infection by simultaneously suppressing several antiviral pathways.
Collapse
|
46
|
Xu L, Wang T, Li F, Yang F. Isolation and preliminary characterization of a new pathogenic iridovirus from redclaw crayfish Cherax quadricarinatus. DISEASES OF AQUATIC ORGANISMS 2016; 120:17-26. [PMID: 27304867 DOI: 10.3354/dao03007] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report the preliminary characterization of a new iridovirus detected in diseased Cherax quadricarinatus collected from a farm in Fujian, China. Transmission electron microscopy identified numerous icosahedral particles (~150 nm in diameter) in the cytoplasm and budding from the plasma membrane of hematopoietic tissue cells. SDS-PAGE of virions semi-purified from the hemolymph of moribund C. quadricarinatus identified 24 proteins including a 50 kDa major capsid protein (MCP). By summing the sizes of DNA restriction endonuclease fragments, the viral genome was estimated to be ~150 kb in length. A 34 amino acid sequence deduced from a 103 bp MCP gene region amplified by PCR using degenerate primers targeted to MCP gene regions conserved among iridoviruses and chloriridoviruses was most similar (55% identity) to Sergestid iridovirus. Based on virion morphology, protein composition, DNA genome length, and MCP sequence relatedness, the virus identified has tentatively been named Cherax quadricarinatus iridovirus (CQIV). In addition, experimental infection of healthy C. quadricarinatus, Procambarus clarkii, and Litopenaeus vannamei with CQIV caused the same disease and high mortality, suggesting that CQIV poses a potential threat to cultured and wild crayfish and shrimp.
Collapse
Affiliation(s)
- Limei Xu
- Key Laboratory of Marine Genetic Resources, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, PR China
| | | | | | | |
Collapse
|
47
|
Grayfer L, Edholm ES, Robert J. Mechanisms of amphibian macrophage development: characterization of the Xenopus laevis colony-stimulating factor-1 receptor. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2016; 58:757-66. [PMID: 26154317 DOI: 10.1387/ijdb.140271jr] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Macrophage-lineage cells are indispensable to vertebrate homeostasis and immunity. In turn, macrophage development is largely regulated through colony-stimulating factor-1 (CSF1) binding to its cognate receptor (CSF1R). To study amphibian monopoiesis, we identified and characterized the X. laevis CSF1R cDNA transcript. Quantitative analysis revealed that CSF1R tissue gene expression increased with X. laevis development, with greatest transcript levels detected in the adult lung, spleen and liver tissues. Notably, considerable levels of CSF1R mRNA were also detected in the regressing tails of metamorphosing animals, suggesting macrophage involvement in this process, and in the adult bone marrow; corroborating the roles for this organ in Xenopus monopoiesis. Following animal infections with the ranavirus Frog Virus 3 (FV3), both tadpole and adult X. laevis exhibited increased kidney CSF1R gene expression. Conversely, while FV3-infected tadpoles increased their spleen and liver CSF1R mRNA levels, the FV3-challenged adults did not. Notably, FV3 induced elevated bone marrow CSF1R expression, and while stimulation of tadpoles with heat-killed E. coli had no transcriptional effects, bacterial stimulation of adult frogs resulted in significantly increased spleen, liver and bone marrow CSF1R expression. We produced the X. laevis CSF1R in recombinant form (rXlCSF1R) and determined, via in vitro cross-linking studies, that two molecules of rXlCSF1R bound the dimeric rXlCSF1. Finally, administration of rXlCSF1R abrogated the rXlCSF1-induced tadpole macrophage recruitment and differentiation as well as bacterial and FV3-elicited peritoneal leukocyte accumulation. This work marks a step towards garnering greater understanding of the unique mechanisms governing amphibian macrophage biology.
Collapse
Affiliation(s)
- Leon Grayfer
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, USA
| | | | | |
Collapse
|
48
|
Aron MM, Allen AG, Kromer M, Galvez H, Vigil B, Jancovich JK. Identification of essential and non-essential genes in Ambystoma tigrinum virus. Virus Res 2016; 217:107-14. [PMID: 27025572 DOI: 10.1016/j.virusres.2016.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 02/19/2016] [Accepted: 02/26/2016] [Indexed: 10/22/2022]
Abstract
Members of the genus Ranavirus (family Iridoviridae) are large double-stranded (ds) DNA viruses that are found world-wide infecting fish, amphibian and reptile ectothermic hosts. Ranavirus genomes range from 105 to 155kbp in length and they are predicted to encode around 90-125 genes. Currently, our knowledge of the function of ∼50% of these genes is known or inferred based on homology to orthologous genes characterized in other systems; however, the function of the remaining open reading frames (ORFS) is unknown. Therefore, in order to begin to uncover the function of unknown ORFs in ranaviruses we developed a standardized approach to generate a recombination cassette for any ORF in Ambystoma tigrinum virus (ATV). Our standardized approach quickly and efficiently assembles recombination cassettes and recombinant ATV. We have used this approach to identify two essential, one semi-essential and two non-essential genes in ATV.
Collapse
Affiliation(s)
- Mariah M Aron
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Rd., San Marcos, CA 92096, United States
| | - Alexander G Allen
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Rd., San Marcos, CA 92096, United States
| | - Mathew Kromer
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Rd., San Marcos, CA 92096, United States
| | - Hector Galvez
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Rd., San Marcos, CA 92096, United States
| | - Brianna Vigil
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Rd., San Marcos, CA 92096, United States
| | - James K Jancovich
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Rd., San Marcos, CA 92096, United States.
| |
Collapse
|
49
|
He J, Zheng YW, Lin YF, Mi S, Qin XW, Weng SP, He JG, Guo CJ. Caveolae Restrict Tiger Frog Virus Release in HepG2 cells and Caveolae-Associated Proteins Incorporated into Virus Particles. Sci Rep 2016; 6:21663. [PMID: 26887868 PMCID: PMC4757878 DOI: 10.1038/srep21663] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/21/2016] [Indexed: 12/26/2022] Open
Abstract
Caveolae are flask-shaped invaginations of the plasma membrane. Caveolae play important roles in the process of viruses entry into host cells, but the roles of caveolae at the late stage of virus infection were not completely understood. Tiger frog virus (TFV) has been isolated from the diseased tadpoles of the frog, Rana tigrina rugulosa, and causes high mortality of tiger frog tadpoles cultured in Southern China. In the present study, the roles of caveolae at the late stage of TFV infection were investigated. We showed that TFV virions were localized with the caveolae at the late stage of infection in HepG2 cells. Disruption of caveolae by methyl-β-cyclodextrin/nystatin or knockdown of caveolin-1 significantly increase the release of TFV. Moreover, the interaction between caveolin-1 and TFV major capsid protein was detected by co-immunoprecipitation. Those results suggested that caveolae restricted TFV release from the HepG2 cells. Caveolae-associated proteins (caveolin-1, caveolin-2, cavin-1, and cavin-2) were selectively incorporated into TFV virions. Different combinations of proteolytic and/or detergent treatments with virions showed that caveolae-associated proteins were located in viral capsid of TFV virons. Taken together, caveolae might be a restriction factor that affects virus release and caveolae-associated proteins were incorporated in TFV virions.
Collapse
Affiliation(s)
- Jian He
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering/South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.,MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Yi-Wen Zheng
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering/South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Yi-Fan Lin
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Shu Mi
- MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Xiao-Wei Qin
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Shao-Ping Weng
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Jian-Guo He
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering/South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.,MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Chang-Jun Guo
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering/South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, School of Marine, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.,MOE Key Laboratory of Aquatic Product Safety/State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.,Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| |
Collapse
|
50
|
Visualization of Assembly Intermediates and Budding Vacuoles of Singapore Grouper Iridovirus in Grouper Embryonic Cells. Sci Rep 2016; 6:18696. [PMID: 26727547 PMCID: PMC4698634 DOI: 10.1038/srep18696] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/23/2015] [Indexed: 02/05/2023] Open
Abstract
Iridovirid infection is associated with the catastrophic loss in aquaculture industry and the population decline of wild amphibians and reptiles, but none of the iridovirid life cycles have been well explored. Here, we report the detailed visualization of the life cycle of Singapore grouper iridovirus (SGIV) in grouper cells by cryo-electron microscopy (cryoEM) and tomography (ET). EM imaging revealed that SGIV viral particles have an outer capsid layer, and the interaction of this layer with cellular plasma membrane initiates viral entry. Subsequent viral replication leads to formation of a viral assembly site (VAS), where membranous structures emerge as precursors to recruit capsid proteins to form an intermediate, double-shell, crescent-shaped structure, which curves to form icosahedral capsids. Knockdown of the major capsid protein eliminates the formation of viral capsids. As capsid formation progresses, electron-dense materials known to be involved in DNA encapsidation accumulate within the capsid until it is fully occupied. Besides the well-known budding mechanism through the cell periphery, we demonstrate a novel budding process in which viral particles bud into a tubular-like structure within vacuoles. This budding process may denote a new strategy used by SGIV to disseminate viral particles into neighbor cells while evading host immune response.
Collapse
|