Isolation of Diverse Simian Arteriviruses Causing Hemorrhagic Disease.

Genetically diverse simian arteriviruses (simarteriviruses) naturally infect geographically and phylogenetically diverse monkeys, and cross-species transmission and emergence are of considerable concern. Characterization of most simarteriviruses beyond sequence analysis has not been possible because the viruses fail to propagate in the laboratory. We attempted to isolate 4 simarteriviruses, Kibale red colobus virus 1, Pebjah virus, simian hemorrhagic fever virus, and Southwest baboon virus 1, by inoculating an immortalized grivet cell line (known to replicate simian hemorrhagic fever virus), primary macaque cells, macrophages derived from macaque induced pluripotent stem cells, and mice engrafted with macaque CD34+-enriched hematopoietic stem cells.

Variola Virus and Clade I Mpox Virus Differentially Modulate Cellular Responses Longitudinally in Monocytes During Infection.

Variola virus (VARV), the etiological agent of smallpox, had enormous impacts on global health prior to its eradication. In the absence of global vaccination programs, mpox virus (MPXV) has become a growing public health threat that includes endemic and nonendemic regions across the globe. While human mpox resembles smallpox in clinical presentation, there are considerable knowledge gaps regarding conserved molecular pathogenesis between these 2 orthopoxviruses.

Computed Tomography Imaging for Monitoring of Marburg Virus Disease: a Nonhuman Primate Proof-Of-Concept Study.

Marburg virus (MARV) is a highly virulent zoonotic filovirid that causes Marburg virus disease (MVD) in humans. The pathogenesis of MVD remains poorly understood, partially due to the low number of cases that can be studied, the absence of state-of-the-art medical equipment in areas where cases are reported, and limitations on the number of animals that can be safely used in experimental studies under maximum containment animal biosafety level 4 conditions. Medical imaging modalities, such as whole-body computed tomography (CT), may help to describe disease progression , potentially replacing ethically contentious and logistically challenging serial euthanasia studies.

Expanded Histopathology and Tropism of Ebola Virus in the Rhesus Macaque Model: Potential for Sexual Transmission, Altered Adrenomedullary Hormone Production, and Early Viral Replication in Liver.

The pathogenesis of Ebola virus disease (EVD) is still incomplete, in spite of the availability of a nonhuman primate modelfor more than 4 decades. To further investigate EVD pathogenesis, a natural history study was conducted using 27 Chinese-origin rhesus macaques. Of these, 24 macaques were exposed intramuscularly to Kikwit Ebola virus and euthanized at predetermined time points or when end-stage clinical disease criteria were met, and 3 sham-exposed macaques were euthanized on study day 0.

Development and Characterization of a cDNA-Launch Recombinant Simian Hemorrhagic Fever Virus Expressing Enhanced Green Fluorescent Protein: ORF 2b' Is Not Required for In Vitro Virus Replication.

Simian hemorrhagic fever virus (SHFV) causes acute, lethal disease in macaques. We developed a single-plasmid cDNA-launch infectious clone of SHFV (rSHFV) and modified the clone to rescue an enhanced green fluorescent protein-expressing rSHFV-eGFP that can be used for rapid and quantitative detection of infection. SHFV has a narrow cell tropism in vitro, with only the grivet MA-104 cell line and a few other grivet cell lines being susceptible to virion entry and permissive to infection.

Formulation, Stability, Pharmacokinetic, and Modeling Studies for Tests of Synergistic Combinations of Orally Available Approved Drugs against Ebola Virus In Vivo.

Outbreaks of Ebola ebolavirus (EBOV) have been associated with high morbidity and mortality. Milestones have been reached recently in the management of EBOV disease (EVD) with licensure of an EBOV vaccine and two monoclonal antibody therapies. However, neither vaccines nor therapies are available for other disease-causing filoviruses.

Discovery of Lanama Virus, a Distinct Member of Species (: ), in Wild Vervet Monkeys ().

We report the discovery and sequence-based molecular characterization of a novel virus, lanama virus (LNMV), in blood samples obtained from two wild vervet monkeys (), sampled near Lake Nabugabo, Masaka District, Uganda. Sequencing of the complete viral genomes and subsequent phylogenetic analysis identified LNMV as a distinct member of species , in the undercharacterized picornavirid genus .

The SKI complex is a broad-spectrum, host-directed antiviral drug target for coronaviruses, influenza, and filoviruses.

The SARS-CoV-2 pandemic has made it clear that we have a desperate need for antivirals. We present work that the mammalian SKI complex is a broad-spectrum, host-directed, antiviral drug target. Yeast suppressor screening was utilized to find a functional genetic interaction between proteins from influenza A virus (IAV) and Middle East respiratory syndrome coronavirus (MERS-CoV) with eukaryotic proteins that may be potential host factors involved in replication.

Comparison of Multiplexed Immunofluorescence Imaging to Chromogenic Immunohistochemistry of Skin Biomarkers in Response to Monkeypox Virus Infection.

Over the last 15 years, advances in immunofluorescence-imaging based cycling methods, antibody conjugation methods, and automated image processing have facilitated the development of a high-resolution, multiplexed tissue immunofluorescence (MxIF) method with single cell-level quantitation termed Cell DIVE. Originally developed for fixed oncology samples, here it was evaluated in highly fixed (up to 30 days), archived monkeypox virus-induced inflammatory skin lesions from a retrospective study in 11 rhesus monkeys to determine whether MxIF was comparable to manual H-scoring of chromogenic stains. Six protein markers related to immune and cellular response (CD68, CD3, Hsp70, Hsp90, ERK1/2, ERK1/2 pT202_pY204) were manually quantified (H-scores) by a pathologist from chromogenic IHC double stains on serial sections and compared to MxIF automated single cell quantification of the same markers that were multiplexed on a single tissue section.

Kikwit Ebola Virus Disease Progression in the Rhesus Monkey Animal Model.

Ongoing Ebola virus disease outbreaks in the Democratic Republic of the Congo follow the largest recorded outbreak in Western Africa (2013-2016). To combat outbreaks, testing of medical countermeasures (therapeutics or vaccines) requires a well-defined, reproducible, animal model. Here we present Ebola virus disease kinetics in 24 Chinese-origin rhesus monkeys exposed intramuscularly to a highly characterized, commercially available Kikwit Ebola virus Filovirus Animal Non-Clinical Group (FANG) stock.

Filoviruses Infect Rhesus Macaque Synoviocytes in Vivo and Primary Human Synoviocytes in Vitro.

The most commonly reported symptom of post-Ebola virus disease syndrome in survivors is arthralgia, yet involvement of the joints in acute or convalescent Ebola virus infection is not well characterized in human patients or animal models. Through immunohistochemistry, we found that the lining synovial intima of the stifle (knee) is a target for acute infection by Ebola virus/Kikwit, Ebola virus/Makona-C05, and Marburg virus/Angola in the rhesus macaque model. Furthermore, histologic analysis, immunohistochemistry, RNAscope in situ hybridization, and transmission electron microscopy showed that synoviocytes of the stifle, shoulder, and hip are a target for mouse-adapted Ebola virus/Yambuku-Mayinga infection during acute disease in rhesus macaques.

Post-exposure prophylactic vaccine candidates for the treatment of human Risk Group 4 pathogen infections.

: The development of therapeutics and vaccines to combat Risk Group 4 pathogens, which are associated with high case-fatality rates, is a high priority. Postexposure prophylactic vaccines have the potential to bridge classical therapeutic and vaccine applications, but little progress has been reported to date.: This review provides an overview of postexposure prophylactic vaccine candidates against Risk Group 4 pathogens.

In Vivo Activity of Amodiaquine against Ebola Virus Infection.

During the Ebola virus disease (EVD) epidemic in Western Africa (2013‒2016), antimalarial treatment was administered to EVD patients due to the high coexisting malaria burden in accordance with World Health Organization guidelines. In an Ebola treatment center in Liberia, EVD patients receiving the combination antimalarial artesunate-amodiaquine had a lower risk of death compared to those treated with artemether-lumefantrine. As artemether and artesunate are derivatives of artemisinin, the beneficial anti-Ebola virus (EBOV) effect observed could possibly be attributed to the change from lumefantrine to amodiaquine.

Author Correction: Histology, immunohistochemistry, and in situ hybridization reveal overlooked Ebola virus target tissues in the Ebola virus disease guinea pig model.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Scalable, semi-automated fluorescence reduction neutralization assay for qualitative assessment of Ebola virus-neutralizing antibodies in human clinical samples.

Antibody titers against a viral pathogen are typically measured using an antigen binding assay, such as an enzyme-linked immunosorbent assay (ELISA), which only measures the ability of antibodies to identify a viral antigen of interest. Neutralization assays measure the presence of virus-neutralizing antibodies in a sample. Traditional neutralization assays, such as the plaque reduction neutralization test (PRNT), are often difficult to use on a large scale due to being both labor and resource intensive.

Inhibition of Ebola Virus by a Molecularly Engineered Banana Lectin.

Ebolaviruses cause an often rapidly fatal syndrome known as Ebola virus disease (EVD), with average case fatality rates of ~50%. There is no licensed vaccine or treatment for EVD, underscoring the urgent need to develop new anti-ebolavirus agents, especially in the face of an ongoing outbreak in the Democratic Republic of the Congo and the largest ever outbreak in Western Africa in 2013-2016. Lectins have been investigated as potential antiviral agents as they bind glycans present on viral surface glycoproteins, but clinical use of them has been slowed by concerns regarding their mitogenicity, i.

Peripheral immune response in the African green monkey model following Nipah-Malaysia virus exposure by intermediate-size particle aerosol.

The ability to appropriately mimic human disease is critical for using animal models as a tool for understanding virus pathogenesis. In the case of Nipah virus (NiV), infection of humans appears to occur either through inhalation, contact with or consumption of infected material. In two of these circumstances, respiratory or sinusoidal exposure represents a likely route of infection.

Ebola Virus Isolation Using Huh-7 Cells has Methodological Advantages and Similar Sensitivity to Isolation Using Other Cell Types and Suckling BALB/c Laboratory Mice.

Following the largest Ebola virus disease outbreak from 2013 to 2016, viral RNA has been detected in survivors from semen and breast milk long after disease recovery. However, as there have been few cases of sexual transmission, it is unclear whether every RNA positive fluid sample contains infectious virus. Virus isolation, typically using cell culture or animal models, can serve as a tool to determine the infectivity of patient samples.

Clinical Characterization of Host Response to Simian Hemorrhagic Fever Virus Infection in Permissive and Refractory Hosts: A Model for Determining Mechanisms of VHF Pathogenesis.

Simian hemorrhagic fever virus (SHFV) causes a fulminant and typically lethal viral hemorrhagic fever (VHF) in macaques (Cercopithecinae: spp.) but causes subclinical infections in patas monkeys (Cercopithecinae: ). This difference in disease course offers a unique opportunity to compare host responses to infection by a VHF-causing virus in biologically similar susceptible and refractory animals.

The Human Sodium Iodide Symporter as a Reporter Gene for Studying Middle East Respiratory Syndrome Coronavirus Pathogenesis.

Single photon emission computed tomography (SPECT) is frequently used in oncology and cardiology to evaluate disease progression and/or treatment efficacy. Such technology allows for real-time evaluation of disease progression and when applied to studying infectious diseases may provide insight into pathogenesis. Insertion of a SPECT-compatible reporter gene into a virus may provide insight into mechanisms of pathogenesis and viral tropism.

Ebola virus, but not Marburg virus, replicates efficiently and without required adaptation in snake cells.

Ebola virus (EBOV) disease is a viral hemorrhagic fever with a high case-fatality rate in humans. This disease is caused by four members of the filoviral genus , including EBOV. The natural hosts reservoirs of ebolaviruses remain to be identified.

Persistence of Lassa Virus Associated With Severe Systemic Arteritis in Convalescing Guinea Pigs (Cavia porcellus).

Lassa fever (LF) survivors develop various clinical manifestations including polyserositis, myalgia, epididymitis, and hearing loss weeks to months after recovery from acute infection. We demonstrate a systemic lymphoplasmacytic and histiocytic arteritis and periarteritis in guinea pigs more than 2 months after recovery from acute Lassa virus (LASV) infection. LASV was detected in the arterial tunica media smooth muscle cells by immunohistochemistry, in situ hybridization, and transmission electron microscopy.

Recombinant Lassa Virus Expressing Green Fluorescent Protein as a Tool for High-Throughput Drug Screens and Neutralizing Antibody Assays.

Lassa virus (LASV), a mammarenavirus, infects an estimated 100,000⁻300,000 individuals yearly in western Africa and frequently causes lethal disease. Currently, no LASV-specific antivirals or vaccines are commercially available for prevention or treatment of Lassa fever, the disease caused by LASV. The development of medical countermeasure screening platforms is a crucial step to yield licensable products.

Aerosol exposure to intermediate size Nipah virus particles induces neurological disease in African green monkeys.

Nipah virus (NiV) infection can lead to severe respiratory or neurological disease in humans. Transmission of NiV has been shown to occur through contact with virus contaminated fomites or consumption of contaminated food. Previous results using the African green monkey (AGM) model of NiV infection identified aspects of infection that, while similar to humans, don't fully recapitulate disease.