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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.
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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.
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2
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Lei Z, Lian L, Zhang L, Liu C, Zhai S, Yuan X, Wei J, Liu H, Liu Y, Du Z, Gul I, Zhang H, Qin Z, Zeng S, Jia P, Du K, Deng L, Yu D, He Q, Qin P. Detection of Frog Virus 3 by Integrating RPA-CRISPR/Cas12a-SPM with Deep Learning. ACS OMEGA 2023; 8:32555-32564. [PMID: 37720737 PMCID: PMC10500685 DOI: 10.1021/acsomega.3c02929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/03/2023] [Indexed: 09/19/2023]
Abstract
A fast, easy-to-implement, highly sensitive, and point-of-care (POC) detection system for frog virus 3 (FV3) is proposed. Combining recombinase polymerase amplification (RPA) and CRISPR/Cas12a, a limit of detection (LoD) of 100 aM (60.2 copies/μL) is achieved by optimizing RPA primers and CRISPR RNAs (crRNAs). For POC detection, smartphone microscopy is implemented, and an LoD of 10 aM is achieved in 40 min. The proposed system detects four positive animal-derived samples with a quantitation cycle (Cq) value of quantitative PCR (qPCR) in the range of 13 to 32. In addition, deep learning models are deployed for binary classification (positive or negative samples) and multiclass classification (different concentrations of FV3 and negative samples), achieving 100 and 98.75% accuracy, respectively. Without temperature regulation and expensive equipment, the proposed RPA-CRISPR/Cas12a combined with smartphone readouts and artificial-intelligence-assisted classification showcases the great potential for FV3 detection, specifically POC detection of DNA virus.
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Affiliation(s)
- Zhengyang Lei
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Lijin Lian
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Likun Zhang
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Changyue Liu
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Shiyao Zhai
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Xi Yuan
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Jiazhang Wei
- Department
of Otolaryngology & Head and Neck, The
People’s Hospital of Guangxi Zhuang Autonomous Region, Guangxi
Academy of Medical Sciences, 6 Taoyuan Road, Nanning, 530021, China
| | - Hong Liu
- Animal
and Plant Inspection and Quarantine Technical Centre, Shenzhen Exit and Entry Inspection and Quarantine Bureau, Shenzhen, Guangdong Province 518045, China
| | - Ying Liu
- Animal
and Plant Inspection and Quarantine Technical Centre, Shenzhen Exit and Entry Inspection and Quarantine Bureau, Shenzhen, Guangdong Province 518045, China
| | - Zhicheng Du
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Ijaz Gul
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Haihui Zhang
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Zhifeng Qin
- Animal
and Plant Inspection and Quarantine Technology Center, Shenzhen Customs, Shenzhen, Guangdong Province 518033, China
| | - Shaoling Zeng
- Animal
and Plant Inspection and Quarantine Technology Center, Shenzhen Customs, Shenzhen, Guangdong Province 518033, China
| | - Peng Jia
- Quality and
Standards Academy, Shenzhen Technology University, Shenzhen 518118, China
| | - Ke Du
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Lin Deng
- Shenzhen
Bay Laboratory, Shenzhen 518132, China
| | - Dongmei Yu
- School
of Mechanical, Electrical & Information Engineering, Shandong University, Weihai, Shandong 264209, China
| | - Qian He
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
| | - Peiwu Qin
- Center
of Precision Medicine and Healthcare, Tsinghua-Berkeley
Shenzhen Institute, Shenzhen, Guangdong Province 518055, China
- Tsinghua
Shenzhen International Graduate School, Institute of Biopharmaceutics and Health Engineering, Shenzhen, Guangdong Province 518055, China
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3
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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.
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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
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4
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Yuan JM, Chen YS, He J, Weng SP, Guo CJ, He JG. Identification and differential expression analysis of MicroRNAs encoded by Tiger Frog Virus in cross-species infection in vitro. Virol J 2016; 13:73. [PMID: 27129448 PMCID: PMC4851794 DOI: 10.1186/s12985-016-0530-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 04/19/2016] [Indexed: 01/20/2023] Open
Abstract
Background Tiger frog virus (TFV), dsDNA virus of the genus Ranavirus and family Iridoviridae, causes a high mortality of tiger frog tadpoles cultured in Southern China. MicroRNAs (miRNAs) have been identified in many viruses especially DNA viruses such as Singapore Grouper Iridoviruses (SGIV). MicroRNAs play important roles in regulating gene expression for virus subsistence in host. Considering that TFV infects cells of different species under laboratory conditions, we aim to identify the specific and essential miRNAs expressed in ZF4 and HepG2 cells. Methods We identified and predicted novel viral miRNAs in TFV-infected ZF4 and HepG2 cells by deep sequencing and software prediction. Then, we verified and described the expression patterns of TFV-encoded miRNAs by using qRT-PCR and Northern blot. Results Deep sequencing predicted 24 novel TFV-encoded miRNAs, and qRT-PCR verified 19 and 23 miRNAs in TFV-infected ZF4 (Group Z) and HepG2 (Group H) cells, respectively. Northern blot was performed to validate eight and five TFV-encoded miRNAs in Groups H and Z, respectively. We compared the expression of TFV-encoded miRNAs from two groups and defined TFV-miR-11 as the essential viral miRNA and TFV-miR-13 and TFV-miR-14 as the specific miRNAs that contribute to HepG2 cell infection. Conclusions We identified novel viral miRNAs and compared their expression in two host cells. The results of this study provide novel insights into the role of viral miRNAs in cross-species infection in vitro. Electronic supplementary material The online version of this article (doi:10.1186/s12985-016-0530-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ji-Min Yuan
- 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.,State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, PR China
| | - Yong-Shun Chen
- 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
| | - Jian He
- 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
| | - Shao-Ping Weng
- 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. .,State Key Laboratory for Biocontrol, School of Life Sciences, 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.,State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou, 510275, PR China
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5
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De Jesús Andino F, Jones L, Maggirwar SB, Robert J. Frog Virus 3 dissemination in the brain of tadpoles, but not in adult Xenopus, involves blood brain barrier dysfunction. Sci Rep 2016; 6:22508. [PMID: 26931458 PMCID: PMC4773881 DOI: 10.1038/srep22508] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/16/2016] [Indexed: 12/28/2022] Open
Abstract
While increasing evidence points to a key role of monocytes in amphibian host defenses, monocytes are also thought to be important in the dissemination and persistent infection caused by ranavirus. However, little is known about the fate of infected macrophages or if ranavirus exploits immune privileged organs, such as the brain, in order to establish a reservoir. The amphibian Xenopus laevis and Frog Virus 3 (FV3) were established as an experimental platform for investigating in vivo whether ranavirus could disseminate to the brain. Our data show that the FV3 infection alters the BBB integrity, possibly mediated by an inflammatory response, which leads to viral dissemination into the central nervous system in X. laevis tadpole but not adult. Furthermore, our data suggest that the macrophages play a major role in viral dissemination by carrying the virus into the neural tissues.
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Affiliation(s)
- Francisco De Jesús Andino
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Letitia Jones
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Sanjay B Maggirwar
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA
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6
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Warne RW, LaBumbard B, LaGrange S, Vredenburg VT, Catenazzi A. Co-Infection by Chytrid Fungus and Ranaviruses in Wild and Harvested Frogs in the Tropical Andes. PLoS One 2016; 11:e0145864. [PMID: 26726999 PMCID: PMC4701007 DOI: 10.1371/journal.pone.0145864] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 12/09/2015] [Indexed: 11/18/2022] Open
Abstract
While global amphibian declines are associated with the spread of Batrachochytrium dendrobatidis (Bd), undetected concurrent co-infection by other pathogens may be little recognized threats to amphibians. Emerging viruses in the genus Ranavirus (Rv) also cause die-offs of amphibians and other ectotherms, but the extent of their distribution globally, or how co-infections with Bd impact amphibians are poorly understood. We provide the first report of Bd and Rv co-infection in South America, and the first report of Rv infections in the amphibian biodiversity hotspot of the Peruvian Andes, where Bd is associated with extinctions. Using these data, we tested the hypothesis that Bd or Rv parasites facilitate co-infection, as assessed by parasite abundance or infection intensity within individual adult frogs. Co-infection occurred in 30% of stream-dwelling frogs; 65% were infected by Bd and 40% by Rv. Among terrestrial, direct-developing Pristimantis frogs 40% were infected by Bd, 35% by Rv, and 20% co-infected. In Telmatobius frogs harvested for the live-trade 49% were co-infected, 92% were infected by Bd, and 53% by Rv. Median Bd and Rv loads were similar in both wild (Bd = 101.2 Ze, Rv = 102.3 viral copies) and harvested frogs (Bd = 103.1 Ze, Rv = 102.7 viral copies). While neither parasite abundance nor infection intensity were associated with co-infection patterns in adults, these data did not include the most susceptible larval and metamorphic life stages. These findings suggest Rv distribution is global and that co-infection among these parasites may be common. These results raise conservation concerns, but greater testing is necessary to determine if parasite interactions increase amphibian vulnerability to secondary infections across differing life stages, and constitute a previously undetected threat to declining populations. Greater surveillance of parasite interactions may increase our capacity to contain and mitigate the impacts of these and other wildlife diseases.
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Affiliation(s)
- Robin W. Warne
- Southern Illinois University, Department of Zoology, 1125 Lincoln Dr., MC6501, Carbondale, IL, 62901, United States of America
- * E-mail:
| | - Brandon LaBumbard
- Southern Illinois University, Department of Zoology, 1125 Lincoln Dr., MC6501, Carbondale, IL, 62901, United States of America
| | - Seth LaGrange
- Southern Illinois University, Department of Zoology, 1125 Lincoln Dr., MC6501, Carbondale, IL, 62901, United States of America
| | - Vance T. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, 94132, United States of America
| | - Alessandro Catenazzi
- Southern Illinois University, Department of Zoology, 1125 Lincoln Dr., MC6501, Carbondale, IL, 62901, United States of America
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7
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Robert J, Grayfer L, Edholm ES, Ward B, De Jesús Andino F. Inflammation-induced reactivation of the ranavirus Frog Virus 3 in asymptomatic Xenopus laevis. PLoS One 2014; 9:e112904. [PMID: 25390636 PMCID: PMC4229299 DOI: 10.1371/journal.pone.0112904] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 10/17/2014] [Indexed: 12/16/2022] Open
Abstract
Natural infections of ectothermic vertebrates by ranaviruses (RV, family Iridoviridae) are rapidly increasing, with an alarming expansion of RV tropism and resulting die-offs of numerous animal populations. Notably, infection studies of the amphibian Xenopus laevis with the ranavirus Frog Virus 3 (FV3) have revealed that although the adult frog immune system is efficient at controlling RV infections, residual quiescent virus can be detected in mononuclear phagocytes of otherwise asymptomatic animals following the resolution of RV infections. It is noteworthy that macrophage-lineage cells are now believed to be a critical element in the RV infection strategy. In the present work, we report that inflammation induced by peritoneal injection of heat-killed bacteria in asymptomatic frogs one month after infection with FV3 resulted in viral reactivation including detectable viral DNA and viral gene expression in otherwise asymptomatic frogs. FV3 reactivation was most prominently detected in kidneys and in peritoneal HAM56+ mononuclear phagocytes. Notably, unlike adult frogs that typically clear primary FV3 infections, a proportion of the animals succumbed to the reactivated FV3 infection, indicating that previous exposure does not provide protection against subsequent reactivation in these animals.
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Affiliation(s)
- Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, United States of America
- * E-mail:
| | - Leon Grayfer
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, United States of America
| | - Eva-Stina Edholm
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, United States of America
| | - Brian Ward
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, United States of America
| | - Francisco De Jesús Andino
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, United States of America
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8
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Robert J, Edholm ES. A prominent role for invariant T cells in the amphibian Xenopus laevis tadpoles. Immunogenetics 2014; 66:513-23. [PMID: 24898512 DOI: 10.1007/s00251-014-0781-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2014] [Accepted: 05/12/2014] [Indexed: 12/20/2022]
Abstract
Invariant T (iT) cells expressing an invariant or semi-invariant T cell receptor (TCR) repertoire have gained attention in recent years because of their potential as specialized regulators of immune function. These iT cells are typically restricted by nonclassical MHC class I molecules (e.g., CD1d and MR1) and undergo differentiation pathways distinct from conventional T cells. While the benefit of a limited TCR repertoire may appear counterintuitive in regard to the advantage of the diversified repertoire of conventional T cells allowing for exquisite specificity to antigens, the full biological importance and evolutionary conservation of iT cells are just starting to emerge. It is generally considered that iT cells are specialized to recognize conserved antigens equivalent to pathogen-associated molecular pattern. Until recently, little was known about the evolution of iT cells. The identification of class Ib and class I-like genes in nonmammalian vertebrates, despite the heterogeneity and variable numbers of these genes among species, suggests that iT cells are also present in ectothermic vertebrates. Indeed, recent studies in the amphibian Xenopus have revealed a drastic overrepresentation of several invariant TCRs in tadpoles and identified a prominent nonclassical MHC class I-restricted iT cell subset critical for tadpole antiviral immunity. This suggests an important and perhaps even dominant role of multiple nonclassical MHC class I-restricted iT cell populations in tadpoles and, by extension, other aquatic vertebrates with rapid external development that are under pressure to produce a functional lymphocyte repertoire with small numbers of cells.
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Affiliation(s)
- Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, 14642, USA,
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9
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Brenes R, Miller DL, Waltzek TB, Wilkes RP, Tucker JL, Chaney JC, Hardman RH, Brand MD, Huether RR, Gray MJ. Susceptibility of fish and turtles to three ranaviruses isolated from different ectothermic vertebrate classes. JOURNAL OF AQUATIC ANIMAL HEALTH 2014; 26:118-126. [PMID: 24895866 DOI: 10.1080/08997659.2014.886637] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Ranaviruses have been associated with mortality of lower vertebrates around the world. Frog virus 3 (FV3)-like ranaviruses have been isolated from different ectothermic vertebrate classes; however, few studies have demonstrated whether this pathogen can be transmitted among classes. Using FV3-like ranaviruses isolated from the American bullfrog Lithobates catesbeianus, eastern box turtle Terrapene carolina carolina, and Pallid Sturgeon Scaphirhynchus albus, we tested for the occurrence of interclass transmission (i.e., infection) and host susceptibility (i.e., percent mortality) for five juvenile fish and three juvenile turtle species exposed to each of these isolates. Exposure was administered via water bath (10(3) PFU/mL) for 3 d and survival was monitored for 28 d. Florida softshell turtles Apalone ferox experienced no mortality, but 10% and 20% of individuals became infected by the turtle and fish isolate, respectively. Similarly, 5% of Mississippi map turtles Graptemys pseudogeographica kohni were subclinically infected with the turtle isolate at the end of the experiment. Channel Catfish Ictalurus punctatus experienced 5% mortality when exposed to the turtle isolate, while Western Mosquitofish Gambusia affinis experienced 10% mortality when exposed to the turtle and amphibian isolates and 5% mortality when exposed to the fish isolate. Our results demonstrated that interclass transmission of FV3-like ranaviruses is possible. Although substantial mortality did not occur in our experiments, the occurrence of low mortality and subclinical infections suggest that fish and aquatic turtles may function as reservoirs for FV3-like ranaviruses. Additionally, our study is the first to report transmission of FV3-like ranaviruses between fish and chelonians.
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Affiliation(s)
- Roberto Brenes
- a Department of Biology , Carroll University , 100 North East Avenue, Waukesha , Wisconsin 53186 , USA
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10
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Ecopathology of ranaviruses infecting amphibians. Viruses 2011; 3:2351-2373. [PMID: 22163349 PMCID: PMC3230856 DOI: 10.3390/v3112351] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 11/03/2011] [Accepted: 11/10/2011] [Indexed: 12/19/2022] Open
Abstract
Ranaviruses are capable of infecting amphibians from at least 14 families and over 70 individual species. Ranaviruses infect multiple cell types, often culminating in organ necrosis and massive hemorrhaging. Subclinical infections have been documented, although their role in ranavirus persistence and emergence remains unclear. Water is an effective transmission medium for ranaviruses, and survival outside the host may be for significant duration. In aquatic communities, amphibians, reptiles and fish may serve as reservoirs. Controlled studies have shown that susceptibility to ranavirus infection and disease varies among amphibian species and developmental stages, and likely is impacted by host-pathogen coevolution, as well as, exogenous environmental factors. Field studies have demonstrated that the likelihood of epizootics is increased in areas of cattle grazing, where aquatic vegetation is sparse and water quality is poor. Translocation of infected amphibians through commercial trade (e.g., food, fish bait, pet industry) contributes to the spread of ranaviruses. Such introductions may be of particular concern, as several studies report that ranaviruses isolated from ranaculture, aquaculture, and bait facilities have greater virulence (i.e., ability to cause disease) than wild-type isolates. Future investigations should focus on the genetic basis for pathogen virulence and host susceptibility, ecological and anthropogenic mechanisms contributing to emergence, and vaccine development for use in captive populations and species reintroduction programs.
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11
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Antiviral immunity in amphibians. Viruses 2011; 3:2065-2086. [PMID: 22163335 PMCID: PMC3230842 DOI: 10.3390/v3112065] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 10/20/2011] [Accepted: 10/22/2011] [Indexed: 01/27/2023] Open
Abstract
Although a variety of virus species can infect amphibians, diseases caused by ranaviruses ([RVs]; Iridoviridae) have become prominent, and are a major concern for biodiversity, agriculture and international trade. The relatively recent and rapid increase in prevalence of RV infections, the wide range of host species infected by RVs, the variability in host resistance among population of the same species and among different developmental stages, all suggest an important involvement of the amphibian immune system. Nevertheless, the roles of the immune system in the etiology of viral diseases in amphibians are still poorly investigated. We review here the current knowledge of antiviral immunity in amphibians, focusing on model species such as the frog Xenopus and the salamander (Ambystoma tigrinum), and on recent progress in generating tools to better understand how host immune defenses control RV infections, pathogenicity, and transmission.
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