NIAID Integrated Research Facility

Fort Washington, MD, United States

NIAID Integrated Research Facility

Fort Washington, MD, United States
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Eckelman W.C.,Molecular Tracer LLC | Jones A.G.,Harvard University | Duatti A.,University of Ferrara | Reba R.C.,NIAID Integrated Research Facility
Drug Discovery Today | Year: 2013

Technetium-99m (Tc-99m) has long been a mainstay in clinical nuclear medicine, primarily monitoring biological processes in the heart, kidney, liver, and brain. More recently, Tc-99m chelates have been used as the reporter in targeted nuclear medicine probes that monitor changes in specific protein expression products. The strengths remain the inexpensive source of Tc-99m from the Mo-99/Tc-99m generator, its rich chemistry, high-yield kit formulation, and its widespread availability. Hardware and software advances, such as OSEM reconstructions with scatter and attenuation corrections, have led to quantitation of the injected radioactivity in terms of kBq/cm. © 2013 Elsevier Ltd. All rights reserved.

Woodson S.E.,University of Texas Medical Branch | Holbrook M.R.,University of Texas Medical Branch | Holbrook M.R.,NIAID Integrated Research Facility
Journal of General Virology | Year: 2011

Yellow fever virus (YFV) causes serious disease in endemic areas of South America and Africa, even though a very well tolerated vaccine is available. YFV primarily targets the liver where as many as 80% of hepatocytes may be involved during infection. The objective of this project was to compare and contrast the cytokine response from hepatocytes infected with either wild-type (Asibi) or vaccine (17-D-204) strains of YFV, with the goal of identifying responses that might be correlated with disease severity or vaccine efficacy. We report here that PH5CH8 hepatocytes support a productive infection with both wild-type and vaccine-strain YFV. Infection with either virus resulted in elevated expression of several pro- and anti-inflammatory cytokines [interleukin (IL)-1β, IL-4, IL-6, IL-8, IL-10 and tumour necrosis factor-α) with a corresponding increase in transcription. Hepatocytes infected with vaccine virus had a more profound response than did cells infected with wild-type virus. Pre-stimulation of hepatocytes with IL-6 resulted in reduced viral titres, elevated concentrations of cytokines released from Asibi virus-infected cells and improved cell viability in cells infected with 17-D virus. Data reported here suggest that 17-D virus stimulates an appropriate antiviral inflammatory response in hepatocytes, while Asibi virus can attenuate the host response. These data identify potential mechanisms that are associated with increased virulence in wild-type virus infections and also provide clues towards potential immuneresponse limitations that may be associated with vaccine-related adverse events. © 2011 SGM.

Yoshii K.,Hokkaido University | Sunden Y.,Hokkaido University | Yokozawa K.,Hokkaido University | Igarashi M.,Hokkaido University | And 3 more authors.
Journal of Virology | Year: 2014

Tick-borne encephalitis virus (TBEV) and Omsk hemorrhagic fever virus (OHFV) are highly pathogenic tick-borne flaviviruses; TBEV causes neurological disease in humans, while OHFV causes a disease typically identified with hemorrhagic fever. Although TBEV and OHFV are closely related genetically, the viral determinants responsible for these distinct disease phenotypes have not been identified. In this study, chimeric viruses incorporating components of TBEV and OHFV were generated using infectious clone technology, and their pathological characteristics were analyzed in a mouse model to identify virus-specific determinants of disease. We found that only four amino acids near the C terminus of the NS5 protein were primarily responsible for the development of neurological disease. Mutation of these four amino acids had no effect on viral replication or histopathological features, including inflammatory responses, in mice. These findings suggest a critical role for NS5 in stimulating neuronal dysfunction and degeneration following TBEV infection and provide new insights into the molecular mechanisms underlying the pathogenesis of tick-borne flaviviruses. © 2014, American Society for Microbiology.

Holbrook M.R.,NIAID Integrated Research Facility
Antiviral Research | Year: 2012

In the spring of 1957, an outbreak of severe disease was documented in people living near the Kyasanur forest in Karnataka state, India, which also affected wild nonhuman primates. Collection of samples from dead animals and the use of classical virological techniques led to the isolation of a previously unrecognized virus, named Kyasanur forest disease virus (KFDV), which was found to be related to the Russian spring-summer encephalitis (RSSE) complex of tick-borne viruses. Further evaluation found that KFD, which frequently took the form of a hemorrhagic syndrome, differed from most other RSSE virus infections, which were characterized by neurologic disease. Its association with illness in wild primates was also unique. Hemaphysalis spinigera was identified as the probable tick vector. Despite an estimated annual incidence in India of 400-500 cases, KFD is historically understudied. Most of what is known about the disease comes from studies in the late 1950s and early 1960s by the Virus Research Center in Pune, India and their collaborators at the Rockefeller Foundation. A report in ProMED in early 2012 indicated that the number of cases of KFD this year is possibly the largest since 2005, reminding us that there are significant gaps in our knowledge of the disease, including many aspects of its pathogenesis, the host response to infection and potential therapeutic options. A vaccine is currently in use in India, but efforts could be made to improve its long-term efficacy. © 2012 Elsevier B.V.

Jahrling P.B.,NIAID Integrated Research Facility | Hensley L.E.,NIAID Integrated Research Facility | Barrett K.,National Institute of Allergy and Infectious Diseases | Lane H.C.,National Institute of Allergy and Infectious Diseases | Davey R.T.,National Institute of Allergy and Infectious Diseases
Journal of Infectious Diseases | Year: 2015

The ongoing outbreak of Ebola in West Africa has raised a general awareness that at present there are no Ebola-specific medical countermeasures (MCMs) with proven effectiveness. This paper recapitulates discussions held at the 6th International Filovirus Symposium in March 2014 as well as the subsequent design of a randomized clinical trial design for treating Ebola virus-infected patients evacuated from West Africa to the United States. A number of different drugs or biologics were critically reviewed and 3 different postexposure strategies were identified as being farthest along in development; passive immunotherapy with monoclonal antibodies, postexposure vaccination with constructs involving viral vectors (such as vesicular stomatitis virus), and antisense compounds directly targeting the viral genome such as modified phosphorodiamidate morpholino oligomer-based compounds and small interfering RNA products. At the time of the meetings, there were no investigational new drugs (INDs) in place for the candidate MCMs. Developers and sponsors of these candidate products were strongly encouraged to prepare pre-IND packets and submit pre-IND meeting requests to the Food and Drug Administration. Some of these investigational products have already been used under emergency authorizations to treat patients in Africa as well as patients evacuated to the United States or Western Europe. © 2015 Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

PubMed | University of Texas at Brownsville, Irrua Specialist Teaching Hospital, Kenema Government Hospital, Redeemer's University and 13 more.
Type: Journal Article | Journal: Cell | Year: 2015

The 2013-2015 West African epidemic of Ebola virus disease (EVD) reminds us of how little is known about biosafety level 4 viruses. Like Ebola virus, Lassa virus (LASV) can cause hemorrhagic fever with high case fatality rates. We generated a genomic catalog of almost 200 LASV sequences from clinical and rodent reservoir samples. We show that whereas the 2013-2015 EVD epidemic is fueled by human-to-human transmissions, LASV infections mainly result from reservoir-to-human infections. We elucidated the spread of LASV across West Africa and show that this migration was accompanied by changes in LASV genome abundance, fatality rates, codon adaptation, and translational efficiency. By investigating intrahost evolution, we found that mutations accumulate in epitopes of viral surface proteins, suggesting selection for immune escape. This catalog will serve as a foundation for the development of vaccines and diagnostics. VIDEO ABSTRACT.

LaSala P.R.,West Virginia University | Holbrook M.,University of Texas Medical Branch | Holbrook M.,NIAID Integrated Research Facility
Clinics in Laboratory Medicine | Year: 2010

There has been a remarkable increase in tick-borne flaviviral disease incidence throughout the past 2 decades. Transmission of tick-borne viruses, like other vector-borne agents, is impacted by a very broad set of factors, both natural (eg, climate and ecology) and man-made (eg, human mobility and agricultural patterns). As our encroachment into areas of virus endemicity intensifies, and as changes in global economic and environmental conditions continue to promote the expansion of tick populations, we will undoubtedly continue to observe attendant increases in rates of disease attributable to these vector-borne pathogens. This article focuses on a some of the major tick-borne flaviviral diseases, caused in particular by tick-borne encephalitis virus, louping ill virus, Powassan virus, Kyasanur Forest disease virus, and Omsk hemorrhagic fever virus, as well as their subtypes. © 2010 Elsevier Inc.

Yoshii K.,Hokkaido University | Yoshii K.,University of Texas Medical Branch | Igarashi M.,Hokkaido University | Ito K.,Hokkaido University | And 4 more authors.
Virus Research | Year: 2011

Omsk hemorrhagic fever virus (OHFV) is a member of the tick-borne encephalitis serocomplex of flaviviruses, and causes hemorrhagic disease in humans. In this study, an infectious cDNA of OHFV was constructed to investigate the molecular mechanisms involved in OHFV pathogenesis for the first time. Our cDNA clone was capable of producing infectious virus which is genetically identical to the parental Guriev strain, and the recombinant virus showed similar biological properties to the parental virus including growth kinetics and virulence characteristics. While characterizing the cDNAs, fortuitous mutations at NS2A position 46 and NS5 position 836 were found to affect viral production. By using a viral replicon expressing luciferase, it was shown that both of the mutations produced a defect in RNA replication and that the NS5 mutation induced a temperature-sensitive phenotype, indicating the importance of these residues in RNA replication. This infectious cDNA will be a useful tool to study the replication and pathogenesis of OHFV. © 2010 Elsevier B.V.

Woodson S.E.,University of Texas Medical Branch | Woodson S.E.,U.S. National Institutes of Health | Freiberg A.N.,University of Texas Medical Branch | Holbrook M.R.,University of Texas Medical Branch | Holbrook M.R.,NIAID Integrated Research Facility
Virus Research | Year: 2013

Yellow fever virus (YFV) infection poses a great risk to un-vaccinated individuals living or traveling in the endemic regions of Africa and South America. It is estimated that approximately 30,000 people die each year of this disease. The liver is the main target of YFV, where as many as 80% of the hepatocytes may become involved in the infection. The overwhelming infection of the liver is associated with the observed hemorrhagic disease manifestations such as petechiae, ecchymoses, and hematemesis which are all thought to be linked with the observed coagulation abnormalities that include prolonged clotting times, reduction in clotting factors, fibrin-split products (D-dimers) and elevated prothrombin times. Many factors involved in the coagulation pathway are produced by hepatocytes, such as fibrinogen (FBG) and plasminogen activator inhibitor-1 (PAI-1). Both of these proteins have been indicated in another flavivirus related disease, dengue, as having roles related to the bleeding abnormalities observed and overall outcome of infection. In this study we wanted to determine if FBG and PAI-1 expression levels by human hepatocytes was disrupted or altered by infection with either wild-type Asibi or vaccine strain17-D YFVs. Our findings indicate that YFV infection does affect the transcriptional and translational expression of FBG and PAI-1 in human hepatocytes and that these results are further affected by IL-6 during early stages of infection. These results may lead to further understanding of the molecular mechanism associated with bleeding abnormalities observed during late stage YFV infection. © 2013 Elsevier B.V.

Farese A.M.,University of Maryland, Baltimore | Hankey K.G.,University of Maryland, Baltimore | Cohen M.V.,NIAID Integrated Research Facility | MacVittie T.J.,University of Maryland, Baltimore
Health Physics | Year: 2015

Recovery from severe immunosuppression requires hematopoietic stem cell reconstitution and effective thymopoiesis to restore a functional immune cell repertoire. Herein, a model of immune cell reconstitution consequent to potentially lethal doses of irradiation is described, which may be valuable in evaluating potentialmedical countermeasures. Male rhesus macaqueswere total body irradiated by exposure to 6.00 Gy 250 kVp x-radiation (midline tissue dose, 0.13 Gy min-1), resulting in an approximate LD10/60 (n = 5/59). Animals received medical management, and hematopoietic and immune cell recovery was assessed (n ≤ 14) through 370 d post exposure. A subset of animals (n ≤ 8) was examined through 700 d. Myeloid recovery was assessed by neutrophil and platelet-related parameters. Lymphoid recovery was assessed by the absolute lymphocyte count and FACS-based phenotyping of B-and T-cell subsets. Recent thymic emigrants were identified by T cell receptor excision circle quantification. Severe neutropenia, lymphopenia, and thrombocytopenia resolved within 30 d. Total CD3+ cells mL-1 required 60 d to reach values 60% of normal, followed by subsequent slow recovery to approximately normal by 180 d post irradiation. Recovery of CD3+4+ and CD3 +8+ cell memory and naive subsets were markedly different. Memory populations were ≥ 100%of normal by day 60, whereas naive populations were only 57%normal at 180 d and never fully recovered to baseline post irradiation. Total (CD20+) B cells mL.1 were within normal levels by 77 d post exposure. This animal model elucidates the variable T-and B-cell subset recovery kinetics after a potentially lethal dose of total-body irradiation that are dependent on marrow-derived stem and progenitor cell recovery, peripheral homeostatic expansion, and thymopoiesis. Copyright © 2015 Health Physics Society.

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