The Experts below are selected from a list of 1851 Experts worldwide ranked by ideXlab platform

Christina L. Hutson - One of the best experts on this subject based on the ideXlab platform.

  • pharmacokinetics and efficacy of a potential smallpox therapeutic brincidofovir in a lethal Monkeypox Virus animal model
    MSphere, 2021
    Co-Authors: Christina L. Hutson, Christine M Hughes, Jeffrey B. Doty, Ashley V Kondas, Mathew R Mauldin, Irma M Grossi, Clint N Morgan, Sharon Dietz Ostergaard, Yoshinori Nakazawa
    Abstract:

    ABSTRACT Smallpox, caused by Variola Virus (VARV), was eradicated in 1980; however, VARV bioterrorist threats still exist, necessitating readily available therapeutics. Current preparedness activities recognize the importance of oral antivirals and recommend therapeutics with different mechanisms of action. Monkeypox Virus (MPXV) is closely related to VARV, causing a highly similar clinical human disease, and can be used as a surrogate for smallpox antiviral testing. The prairie dog MPXV model has been characterized and used to study the efficacy of antipoxVirus therapeutics, including recently approved TPOXX (tecovirimat). Brincidofovir (BCV; CMX001) has shown antiviral activity against double-stranded DNA Viruses, including poxViruses. To determine the exposure of BCV following oral administration to prairie dogs, a pharmacokinetics (PK) study was performed. Analysis of BCV plasma concentrations indicated variability, conceivably due to the outbred nature of the animals. To determine BCV efficacy in the MPXV prairie dog model, groups of animals were intranasally challenged with 9 × 105 plaque-forming units (PFU; 90% lethal dose [LD90]) of MPXV on inoculation day 0 (ID0). Animals were divided into groups based on the first day of BCV treatment relative to inoculation day (ID–1, ID0, or ID1). A trend in efficacy was noted dependent upon treatment initiation (57% on ID–1, 43% on ID0, and 29% on ID1) but was lower than demonstrated in other animal models. Analysis of the PK data indicated that BCV plasma exposure (maximum concentration [Cmax]) and the time of the last quantifiable concentration (AUClast) were lower than in other animal models administered the same doses, indicating that suboptimal BCV exposure may explain the lower protective effect on survival. IMPORTANCE Preparedness activities against highly transmissible Viruses with high mortality rates have been highlighted during the ongoing coronaVirus disease 2019 (COVID-19) pandemic. Smallpox, caused by variola Virus (VARV) infection, is highly transmissible, with an estimated 30% mortality. Through an intensive vaccination campaign, smallpox was declared eradicated in 1980, and routine smallpox vaccination of individuals ceased. Today9s current population has little/no immunity against VARV. If smallpox were to reemerge, the worldwide results would be devastating. Recent FDA approval of one smallpox antiviral (tecovirimat) was a successful step in biothreat preparedness; however, orthopoxViruses can become resistant to treatment, suggesting the need for multiple therapeutics. Our paper details the efficacy of the investigational smallpox drug brincidofovir in a Monkeypox Virus (MPXV) animal model. Since brincidofovir has not been tested in vivo against smallpox, studies with the related Virus MPXV are critical in understanding whether it would be protective in the event of a smallpox outbreak.

  • analgesia during Monkeypox Virus experimental challenge studies in prairie dogs cynomys ludovicianus
    Journal of The American Association for Laboratory Animal Science, 2019
    Co-Authors: Christina L. Hutson, Darin S Carroll, Christine M Hughes, Paul Hudson, Johanna S Salzer, Nadia Gallardoromero, Jessica D Ayers, Jeff B Doty, Yoshi Nakazawa, Nishi Patel
    Abstract:

    Because human patients with Monkeypox Virus (MPXV) infection report painful symptoms, it is reasonable to assume that animals infected with MPXV experience some degree of pain. Understanding whether and how analgesics affect MPXV disease progression is crucial when planning in vivo challenge experiments. In the current study, we challenged prairie dogs with a low dose (4 ×10³ pfu) of MPXV and treated with meloxicam (NSAID) or buprenorphine (opioid); control animals did not receive analgesia or received analgesia without MPXV challenge. Subsets of animals from each group were serially euthanized during the course of the study. Disease progression and viral kinetics were similar between groups, but MXPVinfected, meloxicam-treated animals showed increasing trends of morbidity and mortality compared with other groups. Differences between no-analgesia MPXV-infected control animals and MPXV-infected animals treated with buprenorphine were minimal. The findings in the current study allow more informed decisions concerning the use of analgesics during experimental MPXV challenge studies, thereby improving animal welfare. In light of these findings, we have modified our pain scale for this animal model to include the use of buprenorphine for pain relief when warranted after MPXV challenge.

  • RESEARCH ARTICLE Further Assessment of Monkeypox Virus Infection in Gambian Pouched Rats (Cricetomys gambianus) Using In Vivo Bioluminescent Imaging
    2016
    Co-Authors: Elizabeth A Falendysz, Darin S Carroll, Christina L. Hutson, Johanna S Salzer, Nadia Gallardo-romero, Juan G Lopera, Faye Lorenzsonn, Jeffrey Doty, E. Osorio, Tonie E Rocke
    Abstract:

    Monkeypox is a zoonosis clinically similar to smallpox in humans. Recent evidence has shown a potential risk of increased incidence in central Africa. Despite attempts to isolate the Virus from wild rodents and other small mammals, no reservoir host has been identified. In 2003,Monkeypox Virus (MPXV) was accidentally introduced into the U.S. via the pet trade and was associated with the Gambian pouched rat (Cricetomys gambianus). There-fore, we investigated the potential reservoir competence of the Gambian pouched rat for MPXV by utilizing a combination of in vivo and in vitro methods. We inoculated three ani-mals by the intradermal route and three animals by the intranasal route, with one mock-infected control for each route. Bioluminescent imaging (BLI) was used to track replicating Virus in infected animals and virological assays (e.g. real time PCR, cell culture) were used to determine viral load in blood, urine, ocular, nasal, oral, and rectal swabs. Intradermal inoculation resulted in clinical signs of Monkeypox infection in two of three animals. One severely ill animal was euthanized and the other affected animal recovered. In contrast, intranasal inoculation resulted in subclinical infection in all three animals. All animals

  • Research Article Comparison of Monkeypox Virus Clade Kinetics and Pathology within the Prairie Dog Animal Model Using a Serial Sacrifice Study Design
    2016
    Co-Authors: Christina L. Hutson, Darin S Carroll, Kevin L Karem, Nadia Gallardo-romero, Inger K. Damon
    Abstract:

    Copyright © 2015 Christina L. Hutson et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Monkeypox Virus (MPXV) infection of the prairie dog is valuable to studying systemic orthopoxVirus disease. To further characterize differences inMPXV clade pathogenesis, groups of prairie dogs were intranasally infected (8×103 p.f.u.) with Congo Basin (CB) o

  • Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus
    PLoS neglected tropical diseases, 2015
    Co-Authors: Christina L. Hutson, Russell L. Regnery, Yoshinori J. Nakazawa, Joshua S. Self, Victoria A. Olson, Zachary Braden, Sonja Weiss, Jean Malekani, Eddie Jackson, Mallory Tate
    Abstract:

    Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox Virus (MPXV) and Monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a Monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species’ competence as a host for the Virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable Virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable Virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

Bernard Moss - One of the best experts on this subject based on the ideXlab platform.

  • Identification of wild-derived inbred mouse strains highly susceptible to Monkeypox Virus infection for use as small animal models
    2016
    Co-Authors: Jeffrey L Americo, Bernard Moss, Patricia L Earl
    Abstract:

    Infection with Monkeypox Virus (MPXV) causes disease manifestations in humans that are similar, although usually less severe, than those of smallpox. Since routine vaccination for smallpox ceased more than 30 years ago, there is concern that MPXV could be used for bioterrorism. Thus, there is a need to develop animal models to study MPXV infection. Accordingly, we screened 38 inbred mouse strains for susceptibility to MPXV. Three highly susceptible wild-derived inbred strains were identified, of which CAST/EiJ was further developed as a model. Using an intranasal route of infection with an isolate of the Congo Basin clade of MPXV, CAST/EiJ mice exhibited weight loss, morbidity, and death in a dose-dependent manner with a calculated 50 % lethal dose (LD50) of 680 PFU, whereas there were no deaths of BALB/c mice at a 10,000-fold higher dose. CAST/EiJ mice exhibited greater MPXV sensitivity when infected via the intraperitoneal route, with an LD50 of 14 PFU. Both routes resulted in MPXV replication in the lung, spleen, and liver. Intranasal infection with an isolate of the less-pathogenic West African clade yielded an LD50 of 7,600 PFU. The immune competence of CAST/EiJ mice was established by immunization with vaccinia Virus, which induced antigen-specific T- and B-lymphocyte responses and fully protected mice from lethal doses of MPXV. The new mouse model has the following advantages for studying pathogenesis of MPXV, as well as for evaluation of potential vaccines and therapeu-tics: relative sensitivity to MPXV through multiple routes, genetic homogeneity, available immunologica

  • genetic studies of the susceptibility of classical and wild derived inbred mouse strains to Monkeypox Virus
    Virology, 2015
    Co-Authors: Patricia L Earl, Jeffrey L Americo, Bernard Moss
    Abstract:

    Previously, we screened 38 inbred mouse strains for susceptibility to Monkeypox Virus (MPXV) and focused on wild-derived CAST mice because of their extreme vulnerability. Here, we provide further analysis of inbred mouse strains. NZW/Lac and C58 mice exhibited more weight loss than other classical inbred strains but all survived intranasal challenges with 10(4) to 10(6)PFU of MPXV. Mice from three wild derived strains, in addition to CAST, exhibited severe weight loss and died or were euthanized. LD50 values for CASA, MOLF and PERA were 100, 6800 and >10(5)PFU, respectively. CASA was inbred independently from the same founders as CAST, whereas MOLF and PERA are genetically and geographically distinct. The MPXV susceptibility of the F1 progeny of CAST and either C57BL/6 or BALB/c indicated that resistance is dominant. Back-crossing the F1 progeny of C57BL/6 and CAST to CAST suggested more than one independent resistant locus.

  • comparative live bioluminescence imaging of Monkeypox Virus dissemination in a wild derived inbred mouse mus musculus castaneus and outbred african dormouse graphiurus kelleni
    Virology, 2015
    Co-Authors: Patricia L Earl, Jeffrey L Americo, Catherine A Cotter, Bernard Moss
    Abstract:

    Monkeypox Virus belongs to the orthopoxVirus genus, infects rodents and monkeys in Africa, produces a smallpox-like zoonotic disease in humans, and has the potential for global spread and exploitation for bioterrorism. Several small animal models for studying Monkeypox Virus pathogenesis have been investigated. The African dormouse is a candidate natural host but is outbred and no immunological reagents exist. Although not a natural host, the CAST/EiJ mouse is inbred and animals and reagents are commercially available. We compared the dissemination of Monkeypox Virus by bioluminescence imaging in CAST/EiJ mice and dormice. In CAST/EiJ mice, intense replication occurred at the intranasal site of inoculation and Virus spread rapidly to lungs and abdominal organs, which had a lower Virus burden. Compared to CAST/EiJ mice, dormice exhibited a greater variation of Virus spread, a slower time course, less replication in the head and chest, and more replication in abdominal organs prior to death.

  • lethal Monkeypox Virus infection of cast eij mice is associated with a deficient gamma interferon response
    Journal of Virology, 2012
    Co-Authors: Patricia L Earl, Jeffrey L Americo, Bernard Moss
    Abstract:

    Monkeypox Virus (MPXV) is endemic in Africa, where it causes disease in humans resembling smallpox. A recent importation of MPXV-infected animals into the United States raises the possibility of global spread. Rodents comprise the major reservoir of MPXV, and a variety of such animals, even those native to North America, are susceptible. In contrast, common inbred strains of mice, including BALB/c and C57BL/6, are greatly resistant to MPXV. However, several inbred strains of mice derived from wild mice, including CAST/EiJ, exhibit morbidity and mortality at relatively low inoculums of MPXV. Elucidating the basis for the susceptibility of CAST/EiJ mice could contribute to an understanding of MPXV pathogenicity and host defense mechanisms and enhance the value of this mouse strain as a model system for evaluation of therapeutics and vaccines. Here we compared Virus dissemination and induced cytokine production in CAST/EiJ mice to those in the resistant BALB/c strain. Following intranasal infection, robust Virus replication occurred in the lungs of both strains, although a relatively higher inoculum was required for BALB/c. However, while spread to other internal organs was rapid and efficient in CAST/EiJ mice, the Virus was largely restricted to the lungs in BALB/c mice. Gamma interferon (IFN-γ) and CCL5 were induced in lungs of BALB/c mice concomitant with Virus replication but not in CAST/EiJ mice. The importance of IFN-γ in protection against MPXV disease was demonstrated by the intranasal administration of the mouse cytokine to CAST/EiJ mice and the resulting protection against MPXV. Furthermore, C57BL/6 mice with inactivation of the IFN-γ gene or the IFN-γ receptor gene exhibited enhanced sensitivity to MPXV.

  • identification of wild derived inbred mouse strains highly susceptible to Monkeypox Virus infection for use as small animal models
    Journal of Virology, 2010
    Co-Authors: Jeffrey L Americo, Bernard Moss, Patricia L Earl
    Abstract:

    Infection with Monkeypox Virus (MPXV) causes disease manifestations in humans that are similar, although usually less severe, than those of smallpox. Since routine vaccination for smallpox ceased more than 30 years ago, there is concern that MPXV could be used for bioterrorism. Thus, there is a need to develop animal models to study MPXV infection. Accordingly, we screened 38 inbred mouse strains for susceptibility to MPXV. Three highly susceptible wild-derived inbred strains were identified, of which CAST/EiJ was further developed as a model. Using an intranasal route of infection with an isolate of the Congo Basin clade of MPXV, CAST/EiJ mice exhibited weight loss, morbidity, and death in a dose-dependent manner with a calculated 50% lethal dose (LD 50 ) of 680 PFU, whereas there were no deaths of BALB/c mice at a 10,000-fold higher dose. CAST/EiJ mice exhibited greater MPXV sensitivity when infected via the intraperitoneal route, with an LD 50 of 14 PFU. Both routes resulted in MPXV replication in the lung, spleen, and liver. Intranasal infection with an isolate of the less-pathogenic West African clade yielded an LD 50 of 7,600 PFU. The immune competence of CAST/EiJ mice was established by immunization with vaccinia Virus, which induced antigen-specific T- and B-lymphocyte responses and fully protected mice from lethal doses of MPXV. The new mouse model has the following advantages for studying pathogenesis of MPXV, as well as for evaluation of potential vaccines and therapeutics: relative sensitivity to MPXV through multiple routes, genetic homogeneity, available immunological reagents, and commercial production.

Patricia L Earl - One of the best experts on this subject based on the ideXlab platform.

  • Identification of wild-derived inbred mouse strains highly susceptible to Monkeypox Virus infection for use as small animal models
    2016
    Co-Authors: Jeffrey L Americo, Bernard Moss, Patricia L Earl
    Abstract:

    Infection with Monkeypox Virus (MPXV) causes disease manifestations in humans that are similar, although usually less severe, than those of smallpox. Since routine vaccination for smallpox ceased more than 30 years ago, there is concern that MPXV could be used for bioterrorism. Thus, there is a need to develop animal models to study MPXV infection. Accordingly, we screened 38 inbred mouse strains for susceptibility to MPXV. Three highly susceptible wild-derived inbred strains were identified, of which CAST/EiJ was further developed as a model. Using an intranasal route of infection with an isolate of the Congo Basin clade of MPXV, CAST/EiJ mice exhibited weight loss, morbidity, and death in a dose-dependent manner with a calculated 50 % lethal dose (LD50) of 680 PFU, whereas there were no deaths of BALB/c mice at a 10,000-fold higher dose. CAST/EiJ mice exhibited greater MPXV sensitivity when infected via the intraperitoneal route, with an LD50 of 14 PFU. Both routes resulted in MPXV replication in the lung, spleen, and liver. Intranasal infection with an isolate of the less-pathogenic West African clade yielded an LD50 of 7,600 PFU. The immune competence of CAST/EiJ mice was established by immunization with vaccinia Virus, which induced antigen-specific T- and B-lymphocyte responses and fully protected mice from lethal doses of MPXV. The new mouse model has the following advantages for studying pathogenesis of MPXV, as well as for evaluation of potential vaccines and therapeu-tics: relative sensitivity to MPXV through multiple routes, genetic homogeneity, available immunologica

  • genetic studies of the susceptibility of classical and wild derived inbred mouse strains to Monkeypox Virus
    Virology, 2015
    Co-Authors: Patricia L Earl, Jeffrey L Americo, Bernard Moss
    Abstract:

    Previously, we screened 38 inbred mouse strains for susceptibility to Monkeypox Virus (MPXV) and focused on wild-derived CAST mice because of their extreme vulnerability. Here, we provide further analysis of inbred mouse strains. NZW/Lac and C58 mice exhibited more weight loss than other classical inbred strains but all survived intranasal challenges with 10(4) to 10(6)PFU of MPXV. Mice from three wild derived strains, in addition to CAST, exhibited severe weight loss and died or were euthanized. LD50 values for CASA, MOLF and PERA were 100, 6800 and >10(5)PFU, respectively. CASA was inbred independently from the same founders as CAST, whereas MOLF and PERA are genetically and geographically distinct. The MPXV susceptibility of the F1 progeny of CAST and either C57BL/6 or BALB/c indicated that resistance is dominant. Back-crossing the F1 progeny of C57BL/6 and CAST to CAST suggested more than one independent resistant locus.

  • comparative live bioluminescence imaging of Monkeypox Virus dissemination in a wild derived inbred mouse mus musculus castaneus and outbred african dormouse graphiurus kelleni
    Virology, 2015
    Co-Authors: Patricia L Earl, Jeffrey L Americo, Catherine A Cotter, Bernard Moss
    Abstract:

    Monkeypox Virus belongs to the orthopoxVirus genus, infects rodents and monkeys in Africa, produces a smallpox-like zoonotic disease in humans, and has the potential for global spread and exploitation for bioterrorism. Several small animal models for studying Monkeypox Virus pathogenesis have been investigated. The African dormouse is a candidate natural host but is outbred and no immunological reagents exist. Although not a natural host, the CAST/EiJ mouse is inbred and animals and reagents are commercially available. We compared the dissemination of Monkeypox Virus by bioluminescence imaging in CAST/EiJ mice and dormice. In CAST/EiJ mice, intense replication occurred at the intranasal site of inoculation and Virus spread rapidly to lungs and abdominal organs, which had a lower Virus burden. Compared to CAST/EiJ mice, dormice exhibited a greater variation of Virus spread, a slower time course, less replication in the head and chest, and more replication in abdominal organs prior to death.

  • lethal Monkeypox Virus infection of cast eij mice is associated with a deficient gamma interferon response
    Journal of Virology, 2012
    Co-Authors: Patricia L Earl, Jeffrey L Americo, Bernard Moss
    Abstract:

    Monkeypox Virus (MPXV) is endemic in Africa, where it causes disease in humans resembling smallpox. A recent importation of MPXV-infected animals into the United States raises the possibility of global spread. Rodents comprise the major reservoir of MPXV, and a variety of such animals, even those native to North America, are susceptible. In contrast, common inbred strains of mice, including BALB/c and C57BL/6, are greatly resistant to MPXV. However, several inbred strains of mice derived from wild mice, including CAST/EiJ, exhibit morbidity and mortality at relatively low inoculums of MPXV. Elucidating the basis for the susceptibility of CAST/EiJ mice could contribute to an understanding of MPXV pathogenicity and host defense mechanisms and enhance the value of this mouse strain as a model system for evaluation of therapeutics and vaccines. Here we compared Virus dissemination and induced cytokine production in CAST/EiJ mice to those in the resistant BALB/c strain. Following intranasal infection, robust Virus replication occurred in the lungs of both strains, although a relatively higher inoculum was required for BALB/c. However, while spread to other internal organs was rapid and efficient in CAST/EiJ mice, the Virus was largely restricted to the lungs in BALB/c mice. Gamma interferon (IFN-γ) and CCL5 were induced in lungs of BALB/c mice concomitant with Virus replication but not in CAST/EiJ mice. The importance of IFN-γ in protection against MPXV disease was demonstrated by the intranasal administration of the mouse cytokine to CAST/EiJ mice and the resulting protection against MPXV. Furthermore, C57BL/6 mice with inactivation of the IFN-γ gene or the IFN-γ receptor gene exhibited enhanced sensitivity to MPXV.

  • identification of wild derived inbred mouse strains highly susceptible to Monkeypox Virus infection for use as small animal models
    Journal of Virology, 2010
    Co-Authors: Jeffrey L Americo, Bernard Moss, Patricia L Earl
    Abstract:

    Infection with Monkeypox Virus (MPXV) causes disease manifestations in humans that are similar, although usually less severe, than those of smallpox. Since routine vaccination for smallpox ceased more than 30 years ago, there is concern that MPXV could be used for bioterrorism. Thus, there is a need to develop animal models to study MPXV infection. Accordingly, we screened 38 inbred mouse strains for susceptibility to MPXV. Three highly susceptible wild-derived inbred strains were identified, of which CAST/EiJ was further developed as a model. Using an intranasal route of infection with an isolate of the Congo Basin clade of MPXV, CAST/EiJ mice exhibited weight loss, morbidity, and death in a dose-dependent manner with a calculated 50% lethal dose (LD 50 ) of 680 PFU, whereas there were no deaths of BALB/c mice at a 10,000-fold higher dose. CAST/EiJ mice exhibited greater MPXV sensitivity when infected via the intraperitoneal route, with an LD 50 of 14 PFU. Both routes resulted in MPXV replication in the lung, spleen, and liver. Intranasal infection with an isolate of the less-pathogenic West African clade yielded an LD 50 of 7,600 PFU. The immune competence of CAST/EiJ mice was established by immunization with vaccinia Virus, which induced antigen-specific T- and B-lymphocyte responses and fully protected mice from lethal doses of MPXV. The new mouse model has the following advantages for studying pathogenesis of MPXV, as well as for evaluation of potential vaccines and therapeutics: relative sensitivity to MPXV through multiple routes, genetic homogeneity, available immunological reagents, and commercial production.

Victoria A. Olson - One of the best experts on this subject based on the ideXlab platform.

  • characterization of Monkeypox Virus dissemination in the black tailed prairie dog cynomys ludovicianus through in vivo bioluminescent imaging
    PLOS ONE, 2019
    Co-Authors: Zachary P Weiner, Johanna S Salzer, Ashley V Kondas, Clint N Morgan, Elizabeth Lemasters, James A Ellison, Jeffery B Doty, Brock E Martin, Panayampalli Subbian Satheshkumar, Victoria A. Olson
    Abstract:

    Monkeypox Virus (MPXV) is a member of the genus OrthopoxVirus, endemic in Central and West Africa. This viral zoonosis was introduced into the United States in 2003 via African rodents imported for the pet trade and caused 37 human cases, all linked to exposure to MPXV-infected black-tailed prairie dogs (Cynomys ludovicianus). Prairie dogs have since become a useful model of MPXV disease, utilized for testing of potential medical countermeasures. In this study, we used recombinant MPXV containing the firefly luciferase gene (luc) and in vivo imaging technology to characterize MPXV pathogenesis in the black-tailed prairie dog in real time. West African (WA) MPXV could be visualized using in vivo imaging in the nose, lymph nodes, intestines, heart, lung, kidneys, and liver as early as day 6 post infection (p.i.). By day 9 p.i., lesions became visible on the skin and in some cases in the spleen. After day 9 p.i., luminescent signal representing MPXV replication either increased, indicating a progression to what would be a fatal infection, or decreased as infection was resolved. Use of recombinant luc+ MPXV allowed for a greater understanding of how MPXV disseminates throughout the body in prairie dogs during the course of infection. This technology will be used to reduce the number of animals required in future pathogenesis studies as well as aid in determining the effectiveness of potential medical countermeasures.

  • Monkeypox Virus host factor screen using haploid cells identifies essential role of garp complex in extracellular Virus formation
    Journal of Virology, 2017
    Co-Authors: Susan Realegeno, Darin S Carroll, Inger K. Damon, Victoria A. Olson, Andreas S Puschnik, Amrita Kumar, Cynthia S Goldsmith, Jillybeth Burgado, Suryaprakash Sambhara, Tetsuya Hirata
    Abstract:

    Monkeypox Virus (MPXV) is a human pathogen that is a member of the OrthopoxVirus genus, which includes Vaccinia Virus and Variola Virus (the causative agent of smallpox). Human Monkeypox is considered an emerging zoonotic infectious disease. To identify host factors required for MPXV infection, we performed a genome-wide insertional mutagenesis screen in human haploid cells. The screen revealed several candidate genes, including those involved in Golgi trafficking, glycosaminoglycan biosynthesis, and glycosylphosphatidylinositol (GPI)-anchor biosynthesis. We validated the role of a set of vacuolar protein sorting (VPS) genes during infection, VPS51 to VPS54 (VPS51–54), which comprise the Golgi-associated retrograde protein (GARP) complex. The GARP complex is a tethering complex involved in retrograde transport of endosomes to the trans-Golgi apparatus. Our data demonstrate that VPS52 and VPS54 were dispensable for mature virion (MV) production but were required for extracellular Virus (EV) formation. For comparison, a known antiviral compound, ST-246, was used in our experiments, demonstrating that EV titers in VPS52 and VPS54 knockout (KO) cells were comparable to levels exhibited by ST-246-treated wild-type cells. Confocal microscopy was used to examine actin tail formation, one of the viral egress mechanisms for cell-to-cell dissemination, and revealed an absence of actin tails in VPS52KO- or VPS54KO-infected cells. Further evaluation of these cells by electron microscopy demonstrated a decrease in levels of wrapped Viruses (WVs) compared to those seen with the wild-type control. Collectively, our data demonstrate the role of GARP complex genes in double-membrane wrapping of MVs necessary for EV formation, implicating the host endosomal trafficking pathway in orthopoxVirus infection. IMPORTANCE Human Monkeypox is an emerging zoonotic infectious disease caused by Monkeypox Virus (MPXV). Of the two MPXV clades, the Congo Basin strain is associated with severe disease, increased mortality, and increased human-to-human transmission relative to the West African strain. Monkeypox is endemic in regions of western and central Africa but was introduced into the United States in 2003 from the importation of infected animals. The threat of MPXV and other orthopoxViruses is increasing due to the absence of routine smallpox vaccination leading to a higher proportion of naive populations. In this study, we have identified and validated candidate genes that are required for MPXV infection, specifically, those associated with the Golgi-associated retrograde protein (GARP) complex. Identifying host targets required for infection that prevents extracellular Virus formation such as the GARP complex or the retrograde pathway can provide a potential target for antiviral therapy.

  • Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus
    PLoS neglected tropical diseases, 2015
    Co-Authors: Christina L. Hutson, Russell L. Regnery, Yoshinori J. Nakazawa, Joshua S. Self, Victoria A. Olson, Zachary Braden, Sonja Weiss, Jean Malekani, Eddie Jackson, Mallory Tate
    Abstract:

    Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox Virus (MPXV) and Monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a Monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species’ competence as a host for the Virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable Virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable Virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  • comparison of Monkeypox Virus clade kinetics and pathology within the prairie dog animal model using a serial sacrifice study design
    BioMed Research International, 2015
    Co-Authors: Darin S Carroll, Christine M Hughes, Christina L. Hutson, Victoria A. Olson, Tamas Nagy, Nadia Gallardoromero, Clifton P Drew, Sherif R Zaki, Jeanine Sanders
    Abstract:

    Monkeypox Virus (MPXV) infection of the prairie dog is valuable to studying systemic orthopoxVirus disease. To further characterize differences in MPXV clade pathogenesis, groups of prairie dogs were intranasally infected ( p.f.u.) with Congo Basin (CB) or West African (WA) MPXV, and 28 tissues were harvested on days 2, 4, 6, 9, 12, 17, and 24 postinfection. Samples were evaluated for the presence of Virus and gross and microscopic lesions. Virus was recovered from nasal mucosa, oropharyngeal lymph nodes, and spleen earlier in CB challenged animals (day 4) than WA challenged animals (day 6). For both groups, primary viremia (indicated by viral DNA) was seen on days 6–9 through day 17. CB MPXV spread more rapidly, accumulated to greater levels, and caused greater morbidity in animals compared to WA MPXV. Histopathology and immunohistochemistry (IHC) findings, however, were similar. Two animals that succumbed to disease demonstrated abundant viral antigen in all organs tested, except for brain. Dual-IHC staining of select liver and spleen sections showed that apoptotic cells (identified by TUNEL) tended to colocalize with poxVirus antigen. Interestingly splenocytes were labelled positive for apoptosis more often than hepatocytes in both MPXV groups. These findings allow for further characterization of differences between MPXV clade pathogenesis, including identifying sites that are important during early viral replication and cellular response to viral infection.

  • transmissibility of the Monkeypox Virus clades via respiratory transmission investigation using the prairie dog Monkeypox Virus challenge system
    PLOS ONE, 2013
    Co-Authors: Darin S Carroll, Christine M Hughes, Christina L. Hutson, Nadia F Gallardoromero, Cody Clemmons, Johanna S Salzer, Tamas Nagy, Victoria A. Olson
    Abstract:

    Monkeypox Virus (MPXV) is endemic within Africa where it sporadically is reported to cause outbreaks of human disease. In 2003, an outbreak of human MPXV occurred in the US after the importation of infected African rodents. Since the eradication of smallpox (caused by an orthopoxVirus (OPXV) related to MPXV) and cessation of routine smallpox vaccination (with the live OPXV vaccinia), there is an increasing population of people susceptible to OPXV diseases. Previous studies have shown that the prairie dog MPXV model is a functional animal model for the study of systemic human OPXV illness. Studies with this model have demonstrated that infected animals are able to transmit the Virus to naive animals through multiple routes of exposure causing subsequent infection, but were not able to prove that infected animals could transmit the Virus exclusively via the respiratory route. Herein we used the model system to evaluate the hypothesis that the Congo Basin clade of MPXV is more easily transmitted, via respiratory route, than the West African clade. Using a small number of test animals, we show that transmission of Viruses from each of the MPXV clade was minimal via respiratory transmission. However, transmissibility of the Congo Basin clade was slightly greater than West African MXPV clade (16.7% and 0% respectively). Based on these findings, respiratory transmission appears to be less efficient than those of previous studies assessing contact as a mechanism of transmission within the prairie dog MPXV animal model.

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  • analgesia during Monkeypox Virus experimental challenge studies in prairie dogs cynomys ludovicianus
    Journal of The American Association for Laboratory Animal Science, 2019
    Co-Authors: Christina L. Hutson, Darin S Carroll, Christine M Hughes, Paul Hudson, Johanna S Salzer, Nadia Gallardoromero, Jessica D Ayers, Jeff B Doty, Yoshi Nakazawa, Nishi Patel
    Abstract:

    Because human patients with Monkeypox Virus (MPXV) infection report painful symptoms, it is reasonable to assume that animals infected with MPXV experience some degree of pain. Understanding whether and how analgesics affect MPXV disease progression is crucial when planning in vivo challenge experiments. In the current study, we challenged prairie dogs with a low dose (4 ×10³ pfu) of MPXV and treated with meloxicam (NSAID) or buprenorphine (opioid); control animals did not receive analgesia or received analgesia without MPXV challenge. Subsets of animals from each group were serially euthanized during the course of the study. Disease progression and viral kinetics were similar between groups, but MXPVinfected, meloxicam-treated animals showed increasing trends of morbidity and mortality compared with other groups. Differences between no-analgesia MPXV-infected control animals and MPXV-infected animals treated with buprenorphine were minimal. The findings in the current study allow more informed decisions concerning the use of analgesics during experimental MPXV challenge studies, thereby improving animal welfare. In light of these findings, we have modified our pain scale for this animal model to include the use of buprenorphine for pain relief when warranted after MPXV challenge.

  • Monkeypox Virus host factor screen using haploid cells identifies essential role of garp complex in extracellular Virus formation
    Journal of Virology, 2017
    Co-Authors: Susan Realegeno, Darin S Carroll, Inger K. Damon, Victoria A. Olson, Andreas S Puschnik, Amrita Kumar, Cynthia S Goldsmith, Jillybeth Burgado, Suryaprakash Sambhara, Tetsuya Hirata
    Abstract:

    Monkeypox Virus (MPXV) is a human pathogen that is a member of the OrthopoxVirus genus, which includes Vaccinia Virus and Variola Virus (the causative agent of smallpox). Human Monkeypox is considered an emerging zoonotic infectious disease. To identify host factors required for MPXV infection, we performed a genome-wide insertional mutagenesis screen in human haploid cells. The screen revealed several candidate genes, including those involved in Golgi trafficking, glycosaminoglycan biosynthesis, and glycosylphosphatidylinositol (GPI)-anchor biosynthesis. We validated the role of a set of vacuolar protein sorting (VPS) genes during infection, VPS51 to VPS54 (VPS51–54), which comprise the Golgi-associated retrograde protein (GARP) complex. The GARP complex is a tethering complex involved in retrograde transport of endosomes to the trans-Golgi apparatus. Our data demonstrate that VPS52 and VPS54 were dispensable for mature virion (MV) production but were required for extracellular Virus (EV) formation. For comparison, a known antiviral compound, ST-246, was used in our experiments, demonstrating that EV titers in VPS52 and VPS54 knockout (KO) cells were comparable to levels exhibited by ST-246-treated wild-type cells. Confocal microscopy was used to examine actin tail formation, one of the viral egress mechanisms for cell-to-cell dissemination, and revealed an absence of actin tails in VPS52KO- or VPS54KO-infected cells. Further evaluation of these cells by electron microscopy demonstrated a decrease in levels of wrapped Viruses (WVs) compared to those seen with the wild-type control. Collectively, our data demonstrate the role of GARP complex genes in double-membrane wrapping of MVs necessary for EV formation, implicating the host endosomal trafficking pathway in orthopoxVirus infection. IMPORTANCE Human Monkeypox is an emerging zoonotic infectious disease caused by Monkeypox Virus (MPXV). Of the two MPXV clades, the Congo Basin strain is associated with severe disease, increased mortality, and increased human-to-human transmission relative to the West African strain. Monkeypox is endemic in regions of western and central Africa but was introduced into the United States in 2003 from the importation of infected animals. The threat of MPXV and other orthopoxViruses is increasing due to the absence of routine smallpox vaccination leading to a higher proportion of naive populations. In this study, we have identified and validated candidate genes that are required for MPXV infection, specifically, those associated with the Golgi-associated retrograde protein (GARP) complex. Identifying host targets required for infection that prevents extracellular Virus formation such as the GARP complex or the retrograde pathway can provide a potential target for antiviral therapy.

  • RESEARCH ARTICLE Further Assessment of Monkeypox Virus Infection in Gambian Pouched Rats (Cricetomys gambianus) Using In Vivo Bioluminescent Imaging
    2016
    Co-Authors: Elizabeth A Falendysz, Darin S Carroll, Christina L. Hutson, Johanna S Salzer, Nadia Gallardo-romero, Juan G Lopera, Faye Lorenzsonn, Jeffrey Doty, E. Osorio, Tonie E Rocke
    Abstract:

    Monkeypox is a zoonosis clinically similar to smallpox in humans. Recent evidence has shown a potential risk of increased incidence in central Africa. Despite attempts to isolate the Virus from wild rodents and other small mammals, no reservoir host has been identified. In 2003,Monkeypox Virus (MPXV) was accidentally introduced into the U.S. via the pet trade and was associated with the Gambian pouched rat (Cricetomys gambianus). There-fore, we investigated the potential reservoir competence of the Gambian pouched rat for MPXV by utilizing a combination of in vivo and in vitro methods. We inoculated three ani-mals by the intradermal route and three animals by the intranasal route, with one mock-infected control for each route. Bioluminescent imaging (BLI) was used to track replicating Virus in infected animals and virological assays (e.g. real time PCR, cell culture) were used to determine viral load in blood, urine, ocular, nasal, oral, and rectal swabs. Intradermal inoculation resulted in clinical signs of Monkeypox infection in two of three animals. One severely ill animal was euthanized and the other affected animal recovered. In contrast, intranasal inoculation resulted in subclinical infection in all three animals. All animals

  • Research Article Comparison of Monkeypox Virus Clade Kinetics and Pathology within the Prairie Dog Animal Model Using a Serial Sacrifice Study Design
    2016
    Co-Authors: Christina L. Hutson, Darin S Carroll, Kevin L Karem, Nadia Gallardo-romero, Inger K. Damon
    Abstract:

    Copyright © 2015 Christina L. Hutson et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Monkeypox Virus (MPXV) infection of the prairie dog is valuable to studying systemic orthopoxVirus disease. To further characterize differences inMPXV clade pathogenesis, groups of prairie dogs were intranasally infected (8×103 p.f.u.) with Congo Basin (CB) o

  • further assessment of Monkeypox Virus infection in gambian pouched rats cricetomys gambianus using in vivo bioluminescent imaging
    PLOS Neglected Tropical Diseases, 2015
    Co-Authors: Elizabeth A Falendysz, Darin S Carroll, Christina L. Hutson, Jeffrey B. Doty, Jorge E. Osorio, Juan Lopera, Nadia F Gallardoromero, Johanna S Salzer, Faye Lorenzsonn, Tonie E Rocke
    Abstract:

    Monkeypox is a zoonosis clinically similar to smallpox in humans. Recent evidence has shown a potential risk of increased incidence in central Africa. Despite attempts to isolate the Virus from wild rodents and other small mammals, no reservoir host has been identified. In 2003, Monkeypox Virus (MPXV) was accidentally introduced into the U.S. via the pet trade and was associated with the Gambian pouched rat (Cricetomys gambianus). Therefore, we investigated the potential reservoir competence of the Gambian pouched rat for MPXV by utilizing a combination of in vivo and in vitro methods. We inoculated three animals by the intradermal route and three animals by the intranasal route, with one mock-infected control for each route. Bioluminescent imaging (BLI) was used to track replicating Virus in infected animals and virological assays (e.g. real time PCR, cell culture) were used to determine viral load in blood, urine, ocular, nasal, oral, and rectal swabs. Intradermal inoculation resulted in clinical signs of Monkeypox infection in two of three animals. One severely ill animal was euthanized and the other affected animal recovered. In contrast, intranasal inoculation resulted in subclinical infection in all three animals. All animals, regardless of apparent or inapparent infection, shed Virus in oral and nasal secretions. Additionally, BLI identified viral replication in the skin without grossly visible lesions. These results suggest that Gambian pouched rats may play an important role in transmission of the Virus to humans, as they are hunted for consumption and it is possible for MPXV-infected pouched rats to shed infectious Virus without displaying overt clinical signs.