Baloxavir-oseltamivir combination therapy inhibits the emergence of resistant substitutions in influenza A virus PA gene in a mouse model.

Baloxavir marboxil (BXM) treatment-emergent polymerase acid (PA) I38X amino acid substitution (AAS) in the resistant variants of influenza viruses raise concerns regarding their emergence and spread. This study investigated the impact of 1 or 5 mg/kg BXM and 25 mg/kg oseltamivir phosphate (OS) (single or combination therapy) on the occurrence of resistance-related substitutions during the sequential lung-to-lung passages of AH1N1)pdm09 virus in mice. Deep sequencing analysis revealed that 67% (n = 4/6) of the population treated with BXM single therapy (1 or 5 mg/kg) possessed the treatment-emergent PA-I38X AAS variants (I38T, I38S, and I38V).

Peptide Nucleic Acid (PNA)-Enhanced Specificity of a Dual-Target Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR) Assay for the Detection and Differentiation of SARS-CoV-2 from Related Viruses.

The threat posed by coronaviruses to human health has necessitated the development of a highly specific and sensitive viral detection method that could differentiate between the currently circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other SARS-related coronaviruses (SARSr-CoVs). In this study, we developed a peptide nucleic acid (PNA)-based real-time quantitative polymerase chain reaction (RT-qPCR) assay targeting the N gene to efficiently discriminate SARS-CoV-2 from other SARSr-CoVs in human clinical samples. Without compromising the sensitivity, this method significantly enhanced the specificity of SARS-CoV-2 detection by 100-fold as compared to conventional RT-qPCR.

Accelerated dissociation of IgE-FcεRI complexes by disruptive inhibitors actively desensitizes allergic effector cells.

Background: The remarkably stable interaction of IgE with its high-affinity receptor FcεRI on basophils and mast cells is critical for the induction of allergic hypersensitivity reactions. Because of the exceptionally slow dissociation rate of IgE-FcεRI complexes, such allergic effector cells permanently display allergen-specific IgE on their surface and immediately respond to allergen challenge by releasing inflammatory mediators. We have recently described a novel macromolecular inhibitor that actively promotes the dissociation of IgE from FcεRI through a molecular mechanism termed facilitated dissociation.

Accelerated disassembly of IgE-receptor complexes by a disruptive macromolecular inhibitor.

IgE antibodies bind the high-affinity IgE Fc receptor (FcεRI), found primarily on mast cells and basophils, and trigger inflammatory cascades of the allergic response. Inhibitors of IgE-FcεRI binding have been identified and an anti-IgE therapeutic antibody (omalizumab) is used to treat severe allergic asthma. However, preformed IgE-FcεRI complexes that prime cells before allergen exposure dissociate extremely slowly and cannot be disrupted by strictly competitive inhibitors.

A time-resolved fluorescence resonance energy transfer assay suitable for high-throughput screening for inhibitors of immunoglobulin E-receptor interactions.

The interaction of immunoglobulin E (IgE) antibodies with the high-affinity receptor, FcεRI, plays a central role in initiating most allergic reactions. The IgE-receptor interaction has been targeted for treatment of allergic diseases, and many high-affinity macromolecular inhibitors have been identified. Small molecule inhibitors would offer significant advantages over current anti-IgE treatment, but no candidate compounds have been identified and fully validated.

An engineered disulfide bond reversibly traps the IgE-Fc3-4 in a closed, nonreceptor binding conformation.

IgE antibodies interact with the high affinity IgE Fc receptor, FcεRI, and activate inflammatory pathways associated with the allergic response. The IgE-Fc region, comprising the C-terminal domains of the IgE heavy chain, binds FcεRI and can adopt different conformations ranging from a closed form incompatible with receptor binding to an open, receptor-bound state. A number of intermediate states are also observed in different IgE-Fc crystal forms.

Cloning, expression and characterization of a beta-agarase gene from a marine bacterium, Pseudomonas sp. SK38.

A gene (pagA) encoding beta-agarase from Pseudomonas sp. SK38 was cloned and expressed in Escherichia coli. The structural gene consists of 1011 bp encoding 337 amino acids with a predicted molecular weight of 37326 and has a signal peptide of 18 amino acids.