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Mammarenaviral Infection Is Dependent on Directional Exposure to and Release from Polarized Intestinal Epithelia. Viruses 2018; 10:v10020075. [PMID: 29439402 PMCID: PMC5850382 DOI: 10.3390/v10020075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 02/02/2018] [Accepted: 02/08/2018] [Indexed: 11/16/2022] Open
Abstract
Mammarenavirusesare single-stranded RNA viruses with a bisegmented ambisense genome. Ingestion has been shown as a natural route of transmission for both Lassa virus (LASV) and Lymphocytic choriomeningitis virus (LCMV). Due to the mechanism of transmission, epithelial tissues are among the first host cells to come in contact with the viruses, and as such they potentially play a role in spread of virus to naïve hosts. The role of the intestinal epithelia during arenavirus infection remains to be uncharacterized. We have utilized a well-established cell culture model, Caco-2, to investigate the role of intestinal epithelia during intragastric infection. We found that LCMV-Armstrong, LCMV-WE, and Mopeia (MOPV) release infectious progeny via similar patterns. However, the reassortant virus, ML-29, containing the L segment of MOPV and S segment of LASV, exhibits a unique pattern of viral release relative to LCMV and MOPV. Furthermore, we have determined attachment efficacy to Caco-2 cells is potentially responsible for observed replication kinetics of these viruses in a polarized Caco-2 cell model. Collectively, our data shows that viral dissemination and interaction with intestinal epithelia may be host, tissue, and viral specific.
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Korns Johnson D, Homann D. Accelerated and improved quantification of lymphocytic choriomeningitis virus (LCMV) titers by flow cytometry. PLoS One 2012; 7:e37337. [PMID: 22615984 PMCID: PMC3355137 DOI: 10.1371/journal.pone.0037337] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 04/20/2012] [Indexed: 01/06/2023] Open
Abstract
Lymphocytic choriomeningitis virus (LCMV), a natural murine pathogen, is a member of the Arenavirus family, may cause atypical meningitis in humans, and has been utilized extensively as a model pathogen for the study of virus-induced disease and immune responses. Historically, viral titers have been quantified by a standard plaque assay, but for non-cytopathic viruses including LCMV this requires lengthy incubation, so results cannot be obtained rapidly. Additionally, due to specific technical constraints of the plaque assay including the visual detection format, it has an element of subjectivity along with limited sensitivity. In this study, we describe the development of a FACS-based assay that utilizes detection of LCMV nucleoprotein (NP) expression in infected cells to determine viral titers, and that exhibits several advantages over the standard plaque assay. We show that the LCMV-NP FACS assay is an objective and reproducible detection method that requires smaller sample volumes, exhibits a ∼20-fold increase in sensitivity to and produces results three times faster than the plaque assay. Importantly, when applied to models of acute and chronic LCMV infection, the LCMV-NP FACS assay revealed the presence of infectious virus in samples that were determined to be negative by plaque assay. Therefore, this technique represents an accelerated, enhanced and objective alternative method for detection of infectious LCMV that is amenable to adaptation for other viral infections as well as high throughput diagnostic platforms.
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Affiliation(s)
- Darlynn Korns Johnson
- Integrated Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, Colorado, United States of America
- Department of Anesthesiology, University of Colorado Denver, Aurora, Colorado, United States of America
- * E-mail: (DKJ); (DH)
| | - Dirk Homann
- Integrated Department of Immunology, University of Colorado Denver and National Jewish Health, Denver, Colorado, United States of America
- Department of Anesthesiology, University of Colorado Denver, Aurora, Colorado, United States of America
- * E-mail: (DKJ); (DH)
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Abstract
Viral infections of laboratory mice have considerable impact on research results, and prevention of such infections is therefore of crucial importance. This chapter covers infections of mice with the following viruses: herpesviruses, mousepox virus, murine adenoviruses, polyomaviruses, parvoviruses, lactate dehydrogenase-elevating virus, lymphocytic choriomeningitis virus, mammalian orthoreovirus serotype 3, murine hepatitis virus, murine norovirus, murine pneumonia virus, murine rotavirus, Sendai virus, and Theiler’s murine encephalomyelitis virus. For each virus, there is a description of the agent, epizootiology, clinical symptoms, pathology, methods of diagnosis and control, and its impact on research.
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Zapata JC, Pauza CD, Djavani MM, Rodas JD, Moshkoff D, Bryant J, Ateh E, Garcia C, Lukashevich IS, Salvato MS. Lymphocytic choriomeningitis virus (LCMV) infection of macaques: a model for Lassa fever. Antiviral Res 2011; 92:125-38. [PMID: 21820469 DOI: 10.1016/j.antiviral.2011.07.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 07/07/2011] [Accepted: 07/18/2011] [Indexed: 12/14/2022]
Abstract
Arenaviruses such as Lassa fever virus (LASV) and lymphocytic choriomeningitis virus (LCMV) are benign in their natural reservoir hosts, and can occasionally cause severe viral hemorrhagic fever (VHF) in non-human primates and in human beings. LCMV is considerably more benign for human beings than Lassa virus, however certain strains, like the LCMV-WE strain, can cause severe disease when the virus is delivered as a high-dose inoculum. Here we describe a rhesus macaque model for Lassa fever that employs a virulent strain of LCMV. Since LASV must be studied within Biosafety Level-4 (BSL-4) facilities, the LCMV-infected macaque model has the advantage that it can be used at BSL-3. LCMV-induced disease is rarely as severe as other VHF, but it is similar in cases where vascular leakage leads to lethal systemic failure. The LCMV-infected macaque has been valuable for describing the course of disease with differing viral strains, doses and routes of infection. By monitoring system-wide changes in physiology and gene expression in a controlled experimental setting, it is possible to identify events that are pathognomonic for developing VHF and potential treatment targets.
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Affiliation(s)
- Juan C Zapata
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, United States
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Fichet-Calvet E, Lecompte E, Koivogui L, Daffis S, ter Meulen J. Reproductive characteristics of Mastomys natalensis and Lassa virus prevalence in Guinea, West Africa. Vector Borne Zoonotic Dis 2008; 8:41-8. [PMID: 18237265 DOI: 10.1089/vbz.2007.0118] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We recently reported increased prevalence of Lassa virus (LASV) infection in Mastomys natalensis during the rainy season in Guinea, West Africa. Here, the association of LASV prevalence with fecundity, fertility, and the age structure of the rodent population was analyzed using data from the previous study. The animals reproduced throughout the year, but highest fecundity was observed during the rainy season. Accordingly, the rodent population was aged at the beginning and young at the end of the rainy season. Lassa virus infection was observed in all age groups, including the very young, which is compatible with vertical transmission. However, since the prevalence of infection showed a trend with increasing age in the younger age groups, horizontal transmission by yet unknown mechanisms may also play a role in LASV transmission. Multivariate analysis did not show an association of LASV prevalence with any demographic variable studied. Rodent behavior influencing virus transmissibility and contaminated environment may therefore be responsible for spatial and seasonal variations in LASV prevalence in M. natalensis.
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Affiliation(s)
- Elisabeth Fichet-Calvet
- Department of Systematics and Evolution, Museum National d'Histoire Naturelle, Paris, France.
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Basolateral entry and release of New and Old World arenaviruses from human airway epithelia. J Virol 2008; 82:6034-8. [PMID: 18417570 DOI: 10.1128/jvi.00100-08] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transmission of arenaviruses from rodent hosts to humans is generally thought to occur through inhalation or ingestion of dust or droplets containing viral particles. Here we demonstrate that two identified arenavirus receptors, alpha-dystroglycan (alpha-DG) and transferrin receptor 1 (TfR1), are expressed in polarized human airway epithelia. Lymphocytic choriomeningitis virus strains with high or low alpha-DG affinity and Junin virus, which binds TfR1, efficiently infected polarized epithelia only when applied to the basolateral surface or when injury compromised tight junction integrity. Viral egress from infected epithelia exhibited basolateral polarity. This study demonstrates that respiratory entry of arenaviruses occurs via basolateral receptors.
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Salguero FJ, Sánchez-Martín MA, Díaz-San Segundo F, de Avila A, Sevilla N. Foot-and-mouth disease virus (FMDV) causes an acute disease that can be lethal for adult laboratory mice. Virology 2005; 332:384-96. [PMID: 15661169 DOI: 10.1016/j.virol.2004.11.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2004] [Revised: 10/29/2004] [Accepted: 11/06/2004] [Indexed: 11/27/2022]
Abstract
Foot-and-mouth disease virus (FMDV) is a picornavirus that causes an acute vesicular disease of cloven-hoofed animals. This virus continues to be threat to livestock worldwide with outbreaks causing severe economic losses. However, very little is known about FMDV pathogenesis, partially due to the inconveniences of working with cattle and swine, the main natural hosts of the virus. Here we demonstrate that C57BL/6 and BALB/C adult mice are highly susceptible to FMDV infection when the virus is administered subcutaneously or intraperitoneally. The first clinical signs are ruffled fur, apathy, humped posture, and wasting, which are followed by neurological signs such as hind-limb paralysis. Within 2-3 days of disease onset, the animals die. Virus is found in all major organs, indicating a systemic infection. Mice developed microvesicles near the basal layer of the epithelium, event that precedes the vesiculation characteristics of FMD. In addition, a lymphoid depletion in spleen and thymus and severe lymphopenia is observed in the infected mice. When these mice were immunized with conventional inactivated FMDV vaccine, they were protected (100% of vaccinated animals) against challenge with a lethal dose of FMDV. The data indicate that this mouse model may facilitate the study of FMDV pathogenesis, and the development of new effective vaccines for FMD.
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Affiliation(s)
- Francisco J Salguero
- Centro de Investigación en Sanidad Animal, INIA, 28130 Valdeolmos, Madrid, Spain
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Abstract
Lassa virus is a RNA virus belonging to the family of Arenaviridae. It was discovered as the causative agent of a hemorrhagic fever--Lassa fever--about 30 years ago. Lassa fever is endemic in West Africa and is estimated to affect some 100,000 people annually. Great progress in the understanding of the life cycle of arenaviruses, including Lassa virus, has been made in recent years. New insights have been gained in the pathogenesis and molecular epidemiology of Lassa fever, and state-of the-art technologies for diagnosing this life-threatening disease have been developed. The intention of this review is to summarize in particular the recent literature on Lassa virus and Lassa fever. Several aspects ranging from basic research up to clinical practice and laboratory diagnosis are discussed and linked together.
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Affiliation(s)
- Stephan Günther
- Department of Virology, Bernhard-Nocht-Institute of Tropical Medicine, Hamburg, Germany.
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Rodas JD, Lukashevich IS, Zapata JC, Cairo C, Tikhonov I, Djavani M, Pauza CD, Salvato MS. Mucosal arenavirus infection of primates can protect them from lethal hemorrhagic fever. J Med Virol 2004; 72:424-35. [PMID: 14748066 PMCID: PMC2562566 DOI: 10.1002/jmv.20000] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Arenaviruses are transmitted from rodents to human beings by blood or mucosal exposure. The most devastating arenavirus in terms of human disease is Lassa fever virus, causing up to 300,000 annual infections in West Africa. We used a model for Lassa fever in which Rhesus macaques were infected with a related virus, lymphocytic choriomeningitis virus (LCMV). Our goals were to determine the outcome of infection after mucosal inoculation and later lethal challenge, to characterize protective immune responses, and to test cross-protection between a virulent (LCMV-WE) and an avirulent (LCMV-ARM) strain of virus. Although intravenous infections in the monkey model were uniformly lethal, intragastric infections recapitulated the spectrum of clinical outcomes seen in human exposure to Lassa fever virus: death, recovery from disease, and most often, subclinical infection. Plaque neutralization, ELISA, lymphocyte proliferation, and chromium-release assays were used to monitor humoral and cellular immune responses. Cross protection between the two strains was observed. The three out of seven monkeys that experienced protection were also the three with the strongest cell-mediated immunity.
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Affiliation(s)
- Juan D. Rodas
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland
| | - Igor S. Lukashevich
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland
| | - Juan C. Zapata
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland
| | - Cristiana Cairo
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland
| | - Ilia Tikhonov
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland
| | - Mahmoud Djavani
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland
| | - C. David Pauza
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland
| | - Maria S. Salvato
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland
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Lukashevich IS, Tikhonov I, Rodas JD, Zapata JC, Yang Y, Djavani M, Salvato MS. Arenavirus-mediated liver pathology: acute lymphocytic choriomeningitis virus infection of rhesus macaques is characterized by high-level interleukin-6 expression and hepatocyte proliferation. J Virol 2003; 77:1727-37. [PMID: 12525606 PMCID: PMC140927 DOI: 10.1128/jvi.77.3.1727-1737.2003] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2002] [Accepted: 10/22/2002] [Indexed: 11/20/2022] Open
Abstract
Lymphocytic choriomeningitis virus (LCMV) and Lassa virus can cause hemorrhagic fever and liver disease in primates. The WE strain of LCMV (LCMV-WE) causes a fatal Lassa fever-like disease in rhesus macaques and provides a model for arenavirus pathogenesis in humans. LCMV-WE delivered intravenously or intragastrically to rhesus macaques targets hepatocytes and induces high levels of liver enzymes, interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), and soluble tumor necrosis factor receptors (sTNFRI and -II) in plasma during acute infection. Proinflammatory cytokines TNF-alpha and IL-1beta were not detected in plasma of infected animals, but increased plasma gamma interferon was noted in fatally infected animals. Immunohistochemistry of acute liver biopsies revealed that 25 to 40% of nuclei were positive for proliferation antigen Ki-67. The increases in IL-6, sIL-6R, sTNFR, and proliferation antigen that we observe are similar to the profile of incipient liver regeneration after surgical or toxic injury (N. Fausto, Am. J. Physiol. 277:G917-G921, 1999). Although IL-6 was not directly induced by virus infection in vitro, peripheral blood mononuclear cells from acutely infected monkeys produced higher levels of IL-6 upon lipopolysaccharide stimulation than did healthy controls. Our data confirm that acute infection is associated with weak inflammatory responses in tissues and initiates a program of liver regeneration in primates.
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Affiliation(s)
- Igor S Lukashevich
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland 21201, USA.
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Lukashevich IS, Djavani M, Rodas JD, Zapata JC, Usborne A, Emerson C, Mitchen J, Jahrling PB, Salvato MS. Hemorrhagic fever occurs after intravenous, but not after intragastric, inoculation of rhesus macaques with lymphocytic choriomeningitis virus. J Med Virol 2002; 67:171-86. [PMID: 11992578 PMCID: PMC2398702 DOI: 10.1002/jmv.2206] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Arenaviruses can cause hemorrhagic fever and death in primates and guinea pigs, but these viruses are not highly pathogenic for most rodent carriers. In the United States, arenaviruses precipitated outbreaks of hepatitis in captive monkeys, and they present an emerging health threat in the tropical areas of Africa and South America. We describe infection of rhesus macaques with the prototype arenavirus, lymphocytic choriomeningitis virus (LCMV), using the WE strain that has been known to cause both encephalopathy and multifocal hemorrhage. Five macaques were inoculated: two by the intravenous (i.v.) and three by the intragastric (i.g.) route. Whereas the two i.v.-inoculated monkeys developed signs and lesions consistent with fatal hemorrhagic fever, the i.g.-inoculated monkeys had an attenuated infection with no disease. Pathological signs of the primate i.v. infection differ significantly from guinea pig arenavirus infections and make this a superior model for human viral hemorrhagic disease.
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Affiliation(s)
- Igor S. Lukashevich
- Institute of Human Virology, University of Maryland, Biotech Center, Baltimore, Maryland
| | - Mahmoud Djavani
- Institute of Human Virology, University of Maryland, Biotech Center, Baltimore, Maryland
| | - Juan D. Rodas
- Institute of Human Virology, University of Maryland, Biotech Center, Baltimore, Maryland
| | - Juan C. Zapata
- Institute of Human Virology, University of Maryland, Biotech Center, Baltimore, Maryland
| | - Amy Usborne
- Wisconsin Regional Primate Research Center, Madison, Wisconsin
| | - Carol Emerson
- Wisconsin Regional Primate Research Center, Madison, Wisconsin
| | - Jacque Mitchen
- Wisconsin Regional Primate Research Center, Madison, Wisconsin
| | | | - Maria S. Salvato
- Institute of Human Virology, University of Maryland, Biotech Center, Baltimore, Maryland
- Wisconsin Regional Primate Research Center, Madison, Wisconsin
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Djavani M, Yin C, Lukashevich IS, Rodas J, Rai SK, Salvato MS. Mucosal immunization with Salmonella typhimurium expressing Lassa virus nucleocapsid protein cross-protects mice from lethal challenge with lymphocytic choriomeningitis virus. JOURNAL OF HUMAN VIROLOGY 2001; 4:103-8. [PMID: 11437313 PMCID: PMC2391007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
OBJECTIVES Lassa fever virus (LAS) is transmitted to man by rodent carriers and is fatal in a third of untreated cases. Our goal is to provide immune protection from Lassa fever by mucosal vaccination. STUDY DESIGN/METHODS Mice were vaccinated intragastrically with control vectors or with vectors (vaccinia or Salmonella) expressing LAS nucleocapsid protein (NP). Mice were challenged intracranially with a lethal dose of the related arenavirus, lymphocytic choriomeningitis virus (LCMV), as a measure of the vaccine's ability to elicit cross-protection. RESULTS Salmonella and vaccinia vectors expressing LAS NP each protected a third of the mice from lethal challenge with LCMV. All mice vaccinated with a vector expressing LCMV NP were protected as expected. CONCLUSIONS The LAS recombinant Salmonella vector is comparable to the LAS recombinant vaccinia vector in its ability to cross-protect mice from lethal challenge. Nucleocapsid protein is an inadequate immunogen on its own, but provides sufficient cross-protection to make it a useful component of a broadly reactive arenavirus vaccine.
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Affiliation(s)
- Mahmoud Djavani
- Institute of Human Virology, University of Maryland Biotechnology Center, Baltimore, Maryland, USA
| | - Cheng Yin
- Department of Pathology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Igor S. Lukashevich
- Institute of Human Virology, University of Maryland Biotechnology Center, Baltimore, Maryland, USA
| | - Juan Rodas
- Institute of Human Virology, University of Maryland Biotechnology Center, Baltimore, Maryland, USA
| | - Sharath K. Rai
- Fred Hutchinson Cancer Research Center, Seattle, Washington, USA
| | - Maria S. Salvato
- Institute of Human Virology, University of Maryland Biotechnology Center, Baltimore, Maryland, USA
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Djavani M, Yin C, Xia L, Lukashevich IS, Pauza CD, Salvato MS. Murine immune responses to mucosally delivered Salmonella expressing Lassa fever virus nucleoprotein. Vaccine 2000; 18:1543-54. [PMID: 10618553 DOI: 10.1016/s0264-410x(99)00439-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Arenaviruses are emerging pathogens known to infect via the mucosa, however no formal attempts to make mucosal vaccines have been undertaken. Here we describe a recombinant aroA attenuated Salmonella typhimurium that expresses the nucleoprotein (NP) gene of Lassa fever virus (LAS). The complete NP gene was cloned downstream of the bacterial groEL promotor and integrated into the aroA locus of S. typhimurium. Lassa NP protein was detected in whole cell extracts from the recombinant Salmonella by immunoblot analysis with serum from Lassa-infected people. Mice were inoculated by intragastric intubation with 5 x 10(9) S. typhimurium and boosted with the same recombinant Salmonella 21 days after the primary inoculation. Both local mucosal IgA and serum immunoglobulins against Lassa NP were observed. Splenic cytotoxic T-lymphocyte responses to LAS NP were detected after the boost and they cross-reacted with target cells infected with the related arenavirus, lymphocytic choriomeningitis virus. Recombinant Salmonella elicits humoral and cell mediated immune responses against Lassa fever virus in mice and should be considered as a potential vaccine strategy in man.
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Affiliation(s)
- M Djavani
- Department of Pathology and Laboratory Medicine, University of Wisconsin Medical School, Madison, WI 53706, USA
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Yin C, Djavani M, Schenkel AR, Schmidt DS, Pauza CD, Salvato MS. Dissemination of lymphocytic choriomeningitis virus from the gastric mucosa requires G protein-coupled signaling. J Virol 1998; 72:8613-9. [PMID: 9765400 PMCID: PMC110272 DOI: 10.1128/jvi.72.11.8613-8619.1998] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/1998] [Accepted: 07/28/1998] [Indexed: 11/20/2022] Open
Abstract
The gastric mucosa is an important portal of entry for lymphocytic choriomeningitis virus (LCMV) infections. Within hours after intragastric (i.g.) inoculation, virus appears in the gastric epithelia, then in the mesenteric lymph nodes and spleen, and then in the liver and brain. By 72 h i.g.-inoculated virus is widely disseminated and equivalent to intravenous (i.v.) infection (S. K. Rai, B. K. Micales, M. S. Wu, D. S. Cheung, T. D. Pugh, G. E. Lyons, and M. S. Salvato. Am. J. Pathol. 151:633-639, 1997). Pretreatment of mice with a G protein inhibitor, pertussis toxin (PTx), delays LCMV dissemination after i.g., but not after i.v., inoculation. Delayed infection was confirmed by plaque assays, by reverse transcription-PCR, and by in situ hybridization. The differential PTx effect on i.v. and i.g. infections indicates that dissemination from the gastric mucosa requires signals transduced through heterotrimeric G protein complexes. PTx has no direct effect on LCMV replication, but it modulates integrin expression in part by blocking chemokine signals. LCMV infection of macrophages up-regulates CD11a, and PTx treatment counteracts this. PTx may prevent early LCMV dissemination by inhibiting the G protein-coupled chemotactic response of macrophages infected during the initial exposure, thus blocking systemic virus spread.
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Affiliation(s)
- C Yin
- Department of Pathology and Laboratory Medicine, University of Wisconsin Medical School, Madison, Wisconsin 53706, USA
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Baker DG. Natural pathogens of laboratory mice, rats, and rabbits and their effects on research. Clin Microbiol Rev 1998; 11:231-66. [PMID: 9564563 PMCID: PMC106832 DOI: 10.1128/cmr.11.2.231] [Citation(s) in RCA: 247] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Laboratory mice, rats, and rabbits may harbor a variety of viral, bacterial, parasitic, and fungal agents. Frequently, these organisms cause no overt signs of disease. However, many of the natural pathogens of these laboratory animals may alter host physiology, rendering the host unsuitable for many experimental uses. While the number and prevalence of these pathogens have declined considerably, many still turn up in laboratory animals and represent unwanted variables in research. Investigators using mice, rats, and rabbits in biomedical experimentation should be aware of the profound effects that many of these agents can have on research.
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Affiliation(s)
- D G Baker
- Division of Laboratory Animal Medicine, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70810, USA.
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17
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Rai SK, Micales BK, Wu MS, Cheung DS, Pugh TD, Lyons GE, Salvato MS. Timed appearance of lymphocytic choriomeningitis virus after gastric inoculation of mice. THE AMERICAN JOURNAL OF PATHOLOGY 1997; 151:633-9. [PMID: 9250174 PMCID: PMC1857995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Arenaviruses present an emerging health threat in agrarian areas of Africa and South America; however, the natural routes of arenaviral infections are not clearly understood. Our previous studies with lymphocytic choriomeningitis virus (LCMV), the prototype arenavirus, implicate oral and intragastric routes as natural routes of infection. Our studies raised many questions about the primary site of infection and the route of dissemination after gastric infection. In this report, we use in situ hybridization to detect LCMV in various organs at different time points (0 to 96 hours). After gastric inoculation, the gastric mucosa is the initial site of viral infection, followed by infection of the spleen and liver, then ileum and last, lung, kidney, brain, and esophagus. Furthermore, our observations suggest that virus is disseminated lymphatically rather than by a hematogenous route. Infectious center assays using mononuclear cells from stomach, blood, and spleen of mice infected by the gastric route confirmed active infection with LCMV and the presence of mononuclear cells producing infectious virus in these tissues. This is the first identification of gastric epithelia as a primary site of virus infection.
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Affiliation(s)
- S K Rai
- Department of Pathology and Laboratory Medicine, University of Wisconsin Medical School, Madison 53706, USA
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