Treatment efficacy of cidofovir and brincidofovir against clade II Monkeypox virus isolates.

While historically confined to endemic areas, Monkeypox virus (MPXV) infection has increasingly garnered international attention due to sporadic outbreaks in non-endemic countries in the last two decades and its potential for human-to-human transmission. In 2022, a multi-country outbreak of mpox disease was declared by the World Health Organization (WHO) and nearly 100 000 mpox cases have been reported since the beginning of this pandemic. The clade II variant of the virus appears to be responsible for the vast majority of these infections.

Delayed treatment of cynomolgus macaques with a FVM04/CA45 monoclonal antibody cocktail provides complete protection against lethal Sudan virus infection.

Unlabelled: Sudan ebolavirus (SUDV) is a member of the genus (Family ) and has caused sporadic outbreaks of Ebola disease (EBOD), or more specifically Sudan virus disease (SVD), with high mortality rates in Africa. Current vaccines and therapies that have been developed for filoviruses are almost all specific for Ebola virus (EBOV; of the species ), and there is a current lack of therapeutics specific for SUDV. The recent SUDV outbreak in Uganda, which was distributed across multiple districts, including Kampala, a densely populated urban center, highlights the critical need for the development of novel SUDV-specific or pan-Ebola virus therapeutics.

Mucosal Vaccination with a Newcastle Disease Virus-Vectored Vaccine Reduces Viral Loads in SARS-CoV-2-Infected Cynomolgus Macaques.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged following an outbreak of unexplained viral illness in China in late 2019. Since then, it has spread globally causing a pandemic that has resulted in millions of deaths and has had enormous economic and social consequences. The emergence of SARS-CoV-2 saw the rapid and widespread development of a number of vaccine candidates worldwide, and this never-before-seen pace of vaccine development led to several candidates progressing immediately through clinical trials.

Protective Efficacy of Lyophilized Vesicular Stomatitis Virus-Based Vaccines in Animal Model.

We evaluated the in vitro effects of lyophilization for 2 vesicular stomatitis virus-based vaccines by using 3 stabilizing formulations and demonstrated protective immunity of lyophilized/reconstituted vaccine in guinea pigs. Lyophilization increased stability of the vaccines, but specific vesicular stomatitis virus-based vaccines will each require extensive analysis to optimize stabilizing formulations.

The rVSV-EBOV vaccine provides limited cross-protection against Sudan virus in guinea pigs.

Recombinant vesicular stomatitis viruses (rVSVs) engineered to express heterologous viral glycoproteins have proven to be remarkably effective vaccines. Indeed, rVSV-EBOV, which expresses the Ebola virus (EBOV) glycoprotein, recently received clinical approval in the United States and Europe for its ability to prevent EBOV disease. Analogous rVSV vaccines expressing glycoproteins of different human-pathogenic filoviruses have also demonstrated efficacy in pre-clinical evaluations, yet these vaccines have not progressed far beyond research laboratories.

The Nucleocapsid Proteins of SARS-CoV-2 and Its Close Relative Bat Coronavirus RaTG13 Are Capable of Inhibiting PKR- and RNase L-Mediated Antiviral Pathways.

Coronaviruses (CoVs), including severe acute respiratory syndrome CoV (SARS-CoV), Middle East respiratory syndrome CoV (MERS-CoV), and SARS-CoV-2, produce double-stranded RNA (dsRNA) that activates antiviral pathways such as PKR and OAS/RNase L. To successfully replicate in hosts, viruses must evade such antiviral pathways. Currently, the mechanism of how SARS-CoV-2 antagonizes dsRNA-activated antiviral pathways is unknown.

Cell-Free Dot Blot: an Ultra-Low-Cost and Practical Immunoassay Platform for Detection of Anti-SARS-CoV-2 Antibodies in Human and Animal Sera.

Since its emergence in late 2019, the coronavirus disease 2019 (COVID-19) pandemic has caused severe disruption to key aspects of human life globally and highlighted the need for timely, adaptive, and accessible pandemic response strategies. Here, we introduce the cell-free dot blot (CFDB) method, a practical and ultra-low-cost immune diagnostic platform capable of rapid response and mass immunity screening for the current and future pandemics. Similar in mechanism to the widely used enzyme-linked immunosorbent assays (ELISAs), our method is novel and advantageous in that (i) it uses linear DNA to produce the target viral antigen fused to a SpyTag peptide in a cell-free expression system without the need for traditional cloning and antigen purification, (ii) it uses SpyCatcher2-Apex2, an Escherichia coli-produced peroxidase conjugate as a universal secondary detection reagent, obviating the need for commercial or sophisticated enzyme conjugates, and (iii) sera are spotted directly on a nitrocellulose membrane, enabling a simple "dipping" mechanism for downstream incubation and washing steps, as opposed to individual processing of wells in a multiwell plate.

Generation and Characterization of a SARS-CoV-2-Susceptible Mouse Model Using Adeno-Associated Virus (AAV6.2FF)-Mediated Respiratory Delivery of the Human ACE2 Gene.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the aetiological agent of coronavirus disease 2019 (COVID-19) that has caused a pandemic with millions of human infections. There continues to be a pressing need to develop potential therapies and vaccines to inhibit SARS-CoV-2 infection to mitigate the ongoing pandemic. Epidemiological data from the current pandemic indicates that there may be sex-dependent differences in disease outcomes.

More tools for our toolkit: The application of HEL-299 cells and dsRNA-nanoparticles to study human coronaviruses in vitro.

Human coronaviruses (HCoVs) are important human pathogens, as exemplified by the current SARS-CoV-2 pandemic. While the ability of type I interferons (IFNs) to limit coronavirus replication has been established, the ability of double-stranded (ds)RNA, a potent IFN inducer, to inhibit coronavirus replication when conjugated to a nanoparticle is largely unexplored. Additionally, the number of IFN competent cell lines that can be used to study coronaviruses in vitro are limited.

Pandemic 1918 Influenza Virus Does Not Cause Lethal Infection in Rhesus or Cynomolgus Macaques.

The 1918 H1N1 influenza pandemic was among the most severe in history, taking the lives of approximately 50 million people worldwide, and novel prophylactic vaccines are urgently needed to prevent another pandemic. Given that macaques are physiologically relevant preclinical models of human immunology that have advanced the clinical treatment of infectious diseases, a lethal pandemic influenza challenge model would provide a stringent platform for testing new influenza vaccine concepts. To this end, we infected rhesus macaques and Mauritian cynomolgus macaques with highly pathogenic 1918 H1N1 influenza virus and assessed pathogenesis and disease severity.

Single Immunization with Recombinant ACAM2000 Vaccinia Viruses Expressing the Spike and the Nucleocapsid Proteins Protects Hamsters against SARS-CoV-2-Caused Clinical Disease.

Increasing cases of SARS-CoV-2 breakthrough infections from immunization with current spike protein-based COVID-19 vaccines highlight the need to develop alternative vaccines using different platforms and/or antigens. In this study, we expressed SARS-CoV-2 spike and nucleocapsid proteins based on a novel vaccinia virus (VACV) ACAM2000 platform (rACAM2000). In this platform, the vaccinia virus host range and immunoregulatory gene E3L was deleted to make the virus attenuated and to enhance innate immune responses, and another host range gene, K3L, was replaced with a poxvirus ortholog gene, taterapox virus 037 (TATV037), to make virus replication competent in both hamster and human cells.

Host parameters and mode of infection influence outcome in SARS-CoV-2-infected hamsters.

The golden hamster model of SARS-CoV-2 infection recapitulates key characteristics of COVID-19. In this work we examined the influence of the route of exposure, sex, and age on SARS-CoV-2 pathogenesis in hamsters. We report that delivery of SARS-CoV-2 by a low- versus high-volume intranasal or intragastric route results in comparable viral titers in the lung and viral shedding.

Intranasal vaccination with a Newcastle disease virus-vectored vaccine protects hamsters from SARS-CoV-2 infection and disease.

The pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19). Worldwide efforts are being made to develop vaccines to mitigate this pandemic. We engineered two recombinant Newcastle disease virus (NDV) vectors expressing either the full-length SARS-CoV-2 spike protein (NDV-FLS) or a version with a 19 amino acid deletion at the carboxy terminus (NDV-Δ19S).

SARS-CoV-2 infection and transmission in the North American deer mouse.

Widespread circulation of SARS-CoV-2 in humans raises the theoretical risk of reverse zoonosis events with wildlife, reintroductions of SARS-CoV-2 into permissive nondomesticated animals. Here we report that North American deer mice (Peromyscus maniculatus) are susceptible to SARS-CoV-2 infection following intranasal exposure to a human isolate, resulting in viral replication in the upper and lower respiratory tract with little or no signs of disease. Further, shed infectious virus is detectable in nasal washes, oropharyngeal and rectal swabs, and viral RNA is detectable in feces and occasionally urine.

A novel mouse AAV6 hACE2 transduction model of wild-type SARS-CoV-2 infection studied using synDNA immunogens.

More than 100 million people have been infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Common laboratory mice are not susceptible to wild-type SARS-CoV-2 infection, challenging the development and testing of effective interventions. Here, we describe the development and testing of a mouse model for SARS-CoV-2 infection based on transduction of the respiratory tract of laboratory mice with an adeno-associated virus vector () expressing human ACE-2 ().

Evaluation of mobile real-time polymerase chain reaction tests for the detection of severe acute respiratory syndrome coronavirus 2.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), calls for prompt and accurate diagnosis and rapid turnaround time for test results to limit transmission. Here, we evaluated two independent molecular assays, the Biomeme SARS-CoV-2 test, and the Precision Biomonitoring TripleLock SARS-CoV-2 test on a field-deployable point-of-care real-time PCR instrument, Franklin three9, in combination with Biomeme M1 Sample Prep Cartridge Kit for RNA 2.0 (M1) manual extraction system for rapid, specific, and sensitive detection of SARS-COV-2 in cell culture, human, and animal clinical samples.

H7N9 Influenza Virus Containing a Polybasic HA Cleavage Site Requires Minimal Host Adaptation to Obtain a Highly Pathogenic Disease Phenotype in Mice.

Low pathogenic avian influenza (LPAI) H7N9 viruses have recently evolved to gain a polybasic cleavage site in the hemagglutinin (HA) protein, resulting in variants with increased lethality in poultry that meet the criteria for highly pathogenic avian influenza (HPAI) viruses. Both LPAI and HPAI variants can cause severe disease in humans (case fatality rate of ~40%). Here, we investigated the virulence of HPAI H7N9 viruses containing a polybasic HA cleavage site (H7N9-PBC) in mice.

Generation and Characterization of a Mouse-Adapted Makona Variant of Ebola Virus.

Ebola virus (EBOV) is a zoonotic pathogen that poses a significant threat to public health, causing sporadic yet devastating outbreaks that have the potential to spread worldwide, as demonstrated during the 2013-2016 West African outbreak. Mouse models of infection are important tools for the development of therapeutics and vaccines. Exposure of immunocompetent mice to clinical isolates of EBOV is nonlethal; consequently, EBOV requires prior adaptation in mice to cause lethal disease.

Impact of intensive care unit supportive care on the physiology of Ebola virus disease in a universally lethal non-human primate model.

Background: There are currently limited data for the use of specific antiviral therapies for the treatment of Ebola virus disease (EVD). While there is anecdotal evidence that supportive care may be effective, there is a paucity of direct experimental data to demonstrate a role for supportive care in EVD. We studied the impact of ICU-level supportive care interventions including fluid resuscitation, vasoactive medications, blood transfusion, hydrocortisone, and ventilator support on the pathophysiology of EVD in rhesus macaques infected with a universally lethal dose of Ebola virus strain Makona C07.

Dynamic Histone Acetylation of H3K4me3 Nucleosome Regulates MCL1 Pre-mRNA Splicing.

Pre-mRNA splicing is a cotranscriptional process affected by the chromatin architecture along the body of coding genes. Recruited to the pre-mRNA by splicing factors, histone deacetylases (HDACs) and K-acetyltransferases (KATs) catalyze dynamic histone acetylation along the gene. In colon carcinoma HCT 116 cells, HDAC inhibition specifically increased KAT2B occupancy as well as H3 and H4 acetylation of the H3K4 trimethylated (H3K4me3) nucleosome positioned over alternative exon 2 of the MCL1 gene, an event paralleled with the exclusion of exon 2.