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Perdrizet UG, Hill JE, Sobchishin L, Singh B, Fernando C, Bollinger TK, Misra V. Tissue and cellular tropism of Eptesicus fuscus gammaherpesvirus in big brown bats, potential role of pulmonary intravascular macrophages. Vet Pathol 2024; 61:550-561. [PMID: 38619093 PMCID: PMC11264566 DOI: 10.1177/03009858241244849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Gammaherpesviruses (γHVs) are recognized as important pathogens in humans but their relationship with other animal hosts, especially wildlife species, is less well characterized. Our objectives were to examine natural Eptesicus fuscus gammaherpesvirus (EfHV) infections in their host, the big brown bat (Eptesicus fuscus), and determine whether infection is associated with disease. In tissue samples from 132 individual big brown bats, EfHV DNA was detected by polymerase chain reaction in 41 bats. Tissues from 59 of these cases, including 17 from bats with detectable EfHV genomes, were analyzed. An EfHV isolate was obtained from one of the cases, and electron micrographs and whole genome sequencing were used to confirm that this was a unique isolate of EfHV. Although several bats exhibited various lesions, we did not establish EfHV infection as a cause. Latent infection, defined as RNAScope probe binding to viral latency-associated nuclear antigen in the absence of viral envelope glycoprotein probe binding, was found within cells of the lymphoid tissues. These cells also had colocalization of the B-cell probe targeting CD20 mRNA. Probe binding for both latency-associated nuclear antigen and a viral glycoprotein was observed in individual cells dispersed throughout the alveolar capillaries of the lung, which had characteristics of pulmonary intravascular macrophages. Cells with a similar distribution in bat lungs expressed major histocompatibility class II, a marker for antigen presenting cells, and the existence of pulmonary intravascular macrophages in bats was confirmed with transmission electron microscopy. The importance of this cell type in γHVs infections warrants further investigation.
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Affiliation(s)
| | | | | | - Baljit Singh
- University of Saskatchewan, Saskatoon, SK, Canada
| | | | | | - Vikram Misra
- University of Saskatchewan, Saskatoon, SK, Canada
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Peters-Kennedy J, Löhr CV, Cossic B, Glaser AL, Duhamel GE. Association of equine gammaherpesvirus-5 with facial lymphohistiocytic interface dermatitis in seven adult horses from the United States. Vet Pathol 2023; 60:888-897. [PMID: 37688513 DOI: 10.1177/03009858231197830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/11/2023]
Abstract
Equine herpesvirus-5 (EHV-5) is commonly found in healthy asymptomatic horses worldwide. Although a cause-and-effect relationship has not been thoroughly determined, this virus has been associated with several disease conditions including equine multinodular pulmonary fibrosis (EMPF) and 1 case of interface dermatitis. The authors searched the New York State Animal Health Diagnostic Center database for cases of equine interface dermatitis between 2007 and 2022. Ten cases were identified and scrutinized for viral inclusion bodies which were present in 5 of 10 cases. Two similar cases with interface dermatitis and viral inclusion bodies, which were not part of a retrospective search, were from the Oregon Veterinary Diagnostic Laboratory. The authors describe a total of 7 horses with dermatitis characterized by crusted, alopecic, non-pruritic, non-painful, irregular to annular areas over the face, most commonly the muzzle, for up to several years duration. Histologically, there was a CD3+ T lymphocyte-dominated lymphohistiocytic interface dermatitis with hydropic degeneration, apoptotic keratinocytes, and pigmentary incontinence. Keratinocytes within the upper stratum spinosum and stratum granulosum had glassy pale basophilic intranuclear inclusion bodies consistent with herpesvirus. The presence of EHV-5 was confirmed by quantitative polymerase chain reaction (qPCR) and in situ hybridization in 7 horses and by electron microscopy in 1 horse. One horse later developed EMPF and was euthanized. EHV-5 was not detected with qPCR from 5 control horses and 5 horses with interface dermatitis without histologic evidence of viral inclusion bodies. These are the first cases of facial interface dermatitis associated with EHV-5 reported in the United States.
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Acevedo HD, Hassebroek AM, Leventhal HR, Duhamel GE, Carvallo FR. Colonic T-cell-rich, large B-cell lymphoma associated with equid herpesvirus 5 infection and secondary trans-colonic fistula in a horse. J Vet Diagn Invest 2023; 35:272-277. [PMID: 36786313 PMCID: PMC10185988 DOI: 10.1177/10406387231155414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
A 17-y-old Rocky Mountain gelding was presented to the Virginia-Maryland Veterinary Teaching Hospital because of a 4-wk history of anorexia, weight loss, lethargy, and fever of unknown origin. Abdominal ultrasound revealed lymphadenomegaly of the abdominal and colonic lymph nodes, thickening of the wall of the large colon, and a mass associated with the large colon. The horse was euthanized given a poor prognosis. On autopsy, an ~20-cm diameter mass was found within the mesocolon between the right ventral and right dorsal colon. The mass had invaded through the colonic walls and formed a fistula between the 2 involved lumina. On histologic evaluation, the mass consisted of small numbers of large neoplastic lymphocytes, numerous small lymphocytes, and many foamy macrophages. A diagnosis of T-cell-rich, large B-cell lymphoma was made based on immunohistochemical staining for CD79a, CD3, and Iba1; concurrent infection with equid herpesvirus 5 was confirmed with in-situ hybridization (ISH). To our knowledge, neither a trans-colonic fistula resulting from alimentary lymphoma in a horse nor detection of intralesional equid herpesvirus 5 in equine alimentary lymphoma by ISH has been reported previously.
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Affiliation(s)
- Hernando D. Acevedo
- Faculty of Veterinary Medicine and Zootechnics, University of Tolima (UT), Ibagué, Tolima, Colombia
| | - Anna M. Hassebroek
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
| | | | - Gerald E. Duhamel
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA
| | - Francisco R. Carvallo
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA
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Detection of Equine Papillomaviruses and Gamma-Herpesviruses in Equine Squamous Cell Carcinoma. Pathogens 2023; 12:pathogens12020179. [PMID: 36839451 PMCID: PMC9958655 DOI: 10.3390/pathogens12020179] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/09/2023] [Accepted: 01/21/2023] [Indexed: 01/25/2023] Open
Abstract
Squamous cell carcinoma (SCC) seriously compromises the health and welfare of affected horses. Although robust evidence points to equine papillomavirus type 2 (EcPV2) causing genital lesions, the etiopathogenesis of equine SCC is still poorly understood. We screened a series of SCCs from the head-and-neck (HN), (peri-)ocular and genital region, and site-matched controls for the presence of EcPV2-5 and herpesvirus DNA using type-specific EcPV PCR, and consensus nested herpesvirus PCR followed by sequencing. EcPV2 DNA was detected in 45.5% of HN lesions, 8.3% of (peri-)ocular SCCs, and 100% of genital tumors, whilst control samples from tumor-free horses except one tested EcPV-negative. Two HNSCCs harbored EcPV5, and an ocular lesion EcPV4 DNA. Herpesvirus DNA was detected in 63.6%, 66.6%, 47.2%, and 14.2% of horses with HN, ocular, penile, and vulvar SCCs, respectively, and mainly identified as equine herpesvirus 2 (EHV2), 5 (EHV5) or asinine herpesvirus 5 (AsHV5) DNA. In the tumor-free control group, 9.6% of oral secretions, 46.6% of ocular swabs, 47% of penile samples, and 14.2% of vaginal swabs scored positive for these herpesvirus types. This work further highlights the role of EcPV2 as an oncovirus and is the first to provide information on the prevalence of (gamma-)herpesviruses in equine SCCs.
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Runft S, Färber I, Krüger J, Krüger N, Armando F, Rocha C, Pöhlmann S, Burigk L, Leitzen E, Ciurkiewicz M, Braun A, Schneider D, Baumgärtner L, Freisleben B, Baumgärtner W. Alternatives to animal models and their application in the discovery of species susceptibility to SARS-CoV-2 and other respiratory infectious pathogens: A review. Vet Pathol 2022; 59:565-577. [PMID: 35130766 DOI: 10.1177/03009858211073678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The emergence of the coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inspired rapid research efforts targeting the host range, pathogenesis and transmission mechanisms, and the development of antiviral strategies. Genetically modified mice, rhesus macaques, ferrets, and Syrian golden hamsters have been frequently used in studies of pathogenesis and efficacy of antiviral compounds and vaccines. However, alternatives to in vivo experiments, such as immortalized cell lines, primary respiratory epithelial cells cultured at an air-liquid interface, stem/progenitor cell-derived organoids, or tissue explants, have also been used for isolation of SARS-CoV-2, investigation of cytopathic effects, and pathogen-host interactions. Moreover, initial proof-of-concept studies for testing therapeutic agents can be performed with these tools, showing that animal-sparing cell culture methods could significantly reduce the need for animal models in the future, following the 3R principles of replace, reduce, and refine. So far, only few studies using animal-derived primary cells or tissues have been conducted in SARS-CoV-2 research, although natural infection has been shown to occur in several animal species. Therefore, the need for in-depth investigations on possible interspecies transmission routes and differences in susceptibility to SARS-CoV-2 is urgent. This review gives an overview of studies employing alternative culture systems like primary cell cultures, tissue explants, or organoids for investigations of the pathophysiology and reverse zoonotic potential of SARS-CoV-2 in animals. In addition, future possibilities of SARS-CoV-2 research in animals, including previously neglected methods like the use of precision-cut lung slices, will be outlined.
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Affiliation(s)
- Sandra Runft
- University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Iris Färber
- University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Johannes Krüger
- University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Nadine Krüger
- German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Federico Armando
- University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Cheila Rocha
- German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Stefan Pöhlmann
- German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany
| | - Laura Burigk
- University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Eva Leitzen
- University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | | | - Armin Braun
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany
- Hannover Medical School, Hannover, Germany
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Easton-Jones C. Recent advancements in our understanding of equid gammaherpesvirus infections. Equine Vet J 2021; 54:11-23. [PMID: 34519074 DOI: 10.1111/evj.13512] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 06/18/2021] [Accepted: 09/03/2021] [Indexed: 12/19/2022]
Abstract
Equid gammaherpesviruses are ubiquitous and widespread in the equine population. Despite their frequent detection, their contribution to immune system modulation and the pathogenesis of several diseases remains unclear. Genetic variability and the combination of equid gammaherpesvirus strains a horse is infected with might be clinically significant. Initial gammaherpesvirus infection occurs in foals peripartum with latency then established in peripheral blood mononuclear cells. A novel EHV-5 study suggests that following inhalation equid gammaherpesviruses might obtain direct access to T and B lymphocytes via the tonsillar crypts to establish latency. EHV-5 is associated with equine multinodular pulmonary fibrosis, however, unlike with EHV-2 there is currently minimal evidence for its role in milder cases of respiratory disease and poor performance. Transmission is presumed to be via the upper respiratory tract with periodic reactivation of the latent virus in adult horses. Stress of transport has been identified as a risk factor for reactivation and shedding of equine gammaherpesviruses. There is currently a lack of evidence for the effectiveness of antiviral drugs in the treatment of equine gammaherpesvirus infections.
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Scheurer L, Bachofen C, Hardmeier I, Lechmann J, Schoster A. Prevalence of Nasal Shedding of Equid Gammaherpesviruses in Healthy Swiss Horses. Viruses 2021; 13:v13091686. [PMID: 34578268 PMCID: PMC8473365 DOI: 10.3390/v13091686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/09/2021] [Accepted: 08/20/2021] [Indexed: 12/12/2022] Open
Abstract
Equid Gamma herpesvirus (eGHV) infections have been reported worldwide and may be correlated with clinical signs, e.g., affecting the respiratory tract in young horses. eGHV are shed by healthy horses as well as horses with respiratory tract disease. The prevalence in healthy Swiss horses is unknown to date but this data would provide valuable information for causal diagnosis in clinical cases and formulation of biosecurity recommendations. Nasal swabs from 68 healthy horses from 12 Swiss stables and 2 stables near the Swiss border region in Germany were analyzed by panherpes nested PCR. Positive samples were sequenced. A multivariable model was used to determine if sex, age, breed, canton, or stable had a significant effect on the shedding status of each detected eGHV. Overall, the eGHV prevalence was 59% (n = 68); the prevalence for equid herpesvirus-2 (EHV-2), equid herpesvirus-5 (EHV-5) and asinine herpesvirus-5 (AHV-5) was 38%, 12% and 9%, respectively. Co-infections with multiple eGHVs were observed in 25% of the positive samples. The odds of shedding EHV-2 decreased with age (p = 0.01) whereas the odds of shedding AHV-5 increased with age (p = 0.04). Breed, sex, canton, or stable had no significant association with eGHV shedding. As EHV-2 shedding was common in healthy horses a positive PCR result must be interpreted with caution regarding the formulation of biosecurity recommendations and causal diagnosis. As EHV-5 and AHV-5 shedding was less common than EHV-2, a positive test result is more likely to be of clinical relevance. Shedding of multiple eGHV complicates the interpretation of positive test results in a horse.
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Affiliation(s)
- Laura Scheurer
- Klinik für Pferdemedizin, Departement für Pferde, Vetsuisse Fakultät Zürich, Winterthurerstrasse 260, 8057 Zürich, Switzerland; (L.S.); (I.H.)
| | - Claudia Bachofen
- Institut für Virologie, Vetsuisse Fakultät Zürich, Winterthurerstrasse 266a, 8057 Zürich, Switzerland; (C.B.); (J.L.)
| | - Isabelle Hardmeier
- Klinik für Pferdemedizin, Departement für Pferde, Vetsuisse Fakultät Zürich, Winterthurerstrasse 260, 8057 Zürich, Switzerland; (L.S.); (I.H.)
| | - Julia Lechmann
- Institut für Virologie, Vetsuisse Fakultät Zürich, Winterthurerstrasse 266a, 8057 Zürich, Switzerland; (C.B.); (J.L.)
| | - Angelika Schoster
- Klinik für Pferdemedizin, Departement für Pferde, Vetsuisse Fakultät Zürich, Winterthurerstrasse 260, 8057 Zürich, Switzerland; (L.S.); (I.H.)
- Correspondence:
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Tsai MS, Fogarty U, Byrne AW, O’Keeffe J, Newman C, Macdonald DW, Buesching CD. Effects of Mustelid gammaherpesvirus 1 (MusGHV-1) Reactivation in European Badger ( Meles meles) Genital Tracts on Reproductive Fitness. Pathogens 2020; 9:E769. [PMID: 32962280 PMCID: PMC7559395 DOI: 10.3390/pathogens9090769] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/01/2020] [Accepted: 09/18/2020] [Indexed: 12/31/2022] Open
Abstract
Reactivation of latent Gammaherpesvirus in the genital tract can lead to reproductive failure in domestic animals. Nevertheless, this pathophysiology has not received formal study in wild mammals. High prevalence of Mustelid gammaherpesvirus 1 (MusGHV-1) DNA detected in the genital tracts of European badgers (Meles meles) implies that this common pathogen may be a sexual transmitted infection. Here we used PCR to test MusGHV-1 DNA prevalence in genital swabs collected from 144 wild badgers in Ireland (71 males, 73 females) to investigate impacts on male fertility indicators (sperm abundance and testes weight) and female fecundity (current reproductive output). MusGHV-1 reactivation had a negative effect on female reproduction, but not on male fertility; however males had a higher risk of MusGHV-1 reactivation than females, especially during the late-winter mating season, and genital MusGHV-1 reactivation differed between age classes, where 3-5 year old adults had significantly lower reactivation rates than younger or older ones. Negative results in foetal tissues from MusGHV-1 positive mothers indicated that cross-placental transmission was unlikely. This study has broader implications for how wide-spread gammaherpesvirus infections could affect reproductive performance in wild Carnivora species.
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Affiliation(s)
- Ming-shan Tsai
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Recanati-Kaplan Centre, Abingdon Road, Tubney House, Tubney, Oxfordshire OX13 5QL, UK; (C.N.); (D.W.M.); (C.D.B.)
| | - Ursula Fogarty
- Irish Equine Centre, Johnstown, Naas, Co. Kildare W91 RH93, Ireland;
| | - Andrew W. Byrne
- One-Health Scientific Support Unit, Department of Agriculture, Agriculture House, Dublin 2 DO2 WK12, Ireland;
| | - James O’Keeffe
- Department of Agriculture, Agriculture House, Dublin 2 DO2 WK1, Ireland;
- Centre for Veterinary Epidemiology and Risk Analysis, University College Dublin, Belfield, Dublin 4 D04 W6F6, Ireland
| | - Chris Newman
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Recanati-Kaplan Centre, Abingdon Road, Tubney House, Tubney, Oxfordshire OX13 5QL, UK; (C.N.); (D.W.M.); (C.D.B.)
- Cook’s Lake Farming Forestry and Wildlife Inc (Ecological Consultancy), Queens County, NS B0J 2H0, Canada
| | - David W. Macdonald
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Recanati-Kaplan Centre, Abingdon Road, Tubney House, Tubney, Oxfordshire OX13 5QL, UK; (C.N.); (D.W.M.); (C.D.B.)
| | - Christina D. Buesching
- Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, Recanati-Kaplan Centre, Abingdon Road, Tubney House, Tubney, Oxfordshire OX13 5QL, UK; (C.N.); (D.W.M.); (C.D.B.)
- Cook’s Lake Farming Forestry and Wildlife Inc (Ecological Consultancy), Queens County, NS B0J 2H0, Canada
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An Alphaherpesvirus Exploits Antimicrobial β-Defensins To Initiate Respiratory Tract Infection. J Virol 2020; 94:JVI.01676-19. [PMID: 31996426 PMCID: PMC7108845 DOI: 10.1128/jvi.01676-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/22/2020] [Indexed: 01/22/2023] Open
Abstract
How herpesviruses circumvent mucosal defenses to promote infection of new hosts through the respiratory tract remains unknown due to a lack of host-specific model systems. We used the alphaherpesvirus equine herpesvirus type 1 (EHV1) and equine respiratory tissues to decipher this key event in general alphaherpesvirus pathogenesis. In contrast to several respiratory viruses and bacteria, EHV1 resisted potent antimicrobial equine β-defensins (eBDs) eBD2 and eBD3 by the action of glycoprotein M. Instead, eBD2 and -3 facilitated EHV1 particle aggregation and infection of rabbit kidney (RK13) cells. In addition, virion binding to and subsequent infection of respiratory epithelial cells were increased upon preincubation of these cells with eBD1, -2, and -3. Infected cells synthesized eBD2 and -3, promoting further host cell invasion by EHV1. Finally, eBD1, -2, and -3 recruited leukocytes, which are well-known EHV1 dissemination and latency vessels. The exploitation of host innate defenses by herpesviruses during the early phase of host colonization indicates that highly specialized strategies have developed during host-pathogen coevolution. β-Defensins protect the respiratory tract against the myriad of microbial pathogens entering the airways with each breath. However, this potentially hostile environment is known to serve as a portal of entry for herpesviruses. The lack of suitable respiratory model systems has precluded understanding of how herpesvirus virions overcome the abundant mucosal β-defensins during host invasion. We demonstrate how a central alphaherpesvirus, equine herpesvirus type 1 (EHV1), actually exploits β-defensins to invade its host and initiate viral spread. The equine β-defensins (eBDs) eBD1, -2, and -3 were produced and secreted along the upper respiratory tract. Despite the marked antimicrobial action of eBD2 and -3 against many bacterial and viral pathogens, EHV1 virions were resistant to eBDs through the action of the viral glycoprotein M envelope protein. Pretreatment of EHV1 virions with eBD2 and -3 increased the subsequent infection of rabbit kidney (RK13) cells, which was dependent on viral N-linked glycans. eBD2 and -3 also caused the aggregation of EHV1 virions on the cell surface of RK13 cells. Pretreatment of primary equine respiratory epithelial cells (EREC) with eBD1, -2, and -3 resulted in increased EHV1 virion binding to and infection of these cells. EHV1-infected EREC, in turn, showed an increased production of eBD2 and -3 compared to that seen in mock- and influenza virus-infected EREC. In addition, these eBDs attracted leukocytes, which are essential for EHV1 dissemination and which serve as latent infection reservoirs. These novel mechanisms provide new insights into herpesvirus respiratory tract infection and pathogenesis. IMPORTANCE How herpesviruses circumvent mucosal defenses to promote infection of new hosts through the respiratory tract remains unknown due to a lack of host-specific model systems. We used the alphaherpesvirus equine herpesvirus type 1 (EHV1) and equine respiratory tissues to decipher this key event in general alphaherpesvirus pathogenesis. In contrast to several respiratory viruses and bacteria, EHV1 resisted potent antimicrobial equine β-defensins (eBDs) eBD2 and eBD3 by the action of glycoprotein M. Instead, eBD2 and -3 facilitated EHV1 particle aggregation and infection of rabbit kidney (RK13) cells. In addition, virion binding to and subsequent infection of respiratory epithelial cells were increased upon preincubation of these cells with eBD1, -2, and -3. Infected cells synthesized eBD2 and -3, promoting further host cell invasion by EHV1. Finally, eBD1, -2, and -3 recruited leukocytes, which are well-known EHV1 dissemination and latency vessels. The exploitation of host innate defenses by herpesviruses during the early phase of host colonization indicates that highly specialized strategies have developed during host-pathogen coevolution.
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Thorsteinsdóttir L, Jónsdóttir S, Stefánsdóttir SB, Andrésdóttir V, Wagner B, Marti E, Torsteinsdóttir S, Svansson V. The effect of maternal immunity on the equine gammaherpesvirus type 2 and 5 viral load and antibody response. PLoS One 2019; 14:e0218576. [PMID: 31226153 PMCID: PMC6588279 DOI: 10.1371/journal.pone.0218576] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/04/2019] [Indexed: 12/27/2022] Open
Abstract
Two types of gammaherpesviruses (γEHV) are known to infect horses, EHV-2 and EHV-5. Foals become infected early in life, probably via the upper respiratory tract, despite maternal antibodies. In this study, we analyzed samples from a herd of mares and their foals. The foals were followed from birth to 22 months of age and the dams during the first 6 months postpartum. Blood and nasal swab samples were taken regularly for evaluation of antibody responses, virus isolation and viral load by qPCR. EHV-2 was isolated on day 5, and EHV-5 on day 12, earlier than previously reported. γEHV specific antibodies were not detectable in serum of foals before colostrum intake but peaked a few days after colostrum. Overall, EHV-2 viral load peaked in nasal swab at three to four months of age, paralleled with decline in maternal antibodies, but EHV-5 viral load did not peak until month 12. Maternal antibodies had a notable effect on the viral load and induction of endogenous antibody production. Foals were grouped in two groups depending on the mare’s γEHV specific total IgG levels in serum at birth, group-high and group-low. Group-high had higher levels of maternal γEHV specific total IgG and IgG4/7 for the first 3 months, but when the endogenous production had superseded maternal antibodies, group-low was higher. The maternal antibodies had an effect on the γEHV viral load. Group-low peaked in EHV-2 viral load one month earlier than group-high. These effects were more evident for EHV-5, as there were seven months between the viral load peaks for the groups. The study provides information on how maternal antibody transfer affects γEHV shedding and antibody production in offspring. It also extends our knowledge on the occurrence of EHV-2 and EHV-5 infection in foals during the first two years of life.
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Affiliation(s)
- Lilja Thorsteinsdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
- * E-mail:
| | - Sigríður Jónsdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
- Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Sara Björk Stefánsdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
| | - Valgerður Andrésdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
| | - Bettina Wagner
- Department of Population Medicine & Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States of America
| | - Eliane Marti
- Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Sigurbjörg Torsteinsdóttir
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
| | - Vilhjálmur Svansson
- Institute for Experimental Pathology, Biomedical Center, University of Iceland, Keldur, Reykjavík, Iceland
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