Virion-associated influenza hemagglutinin clusters upon sialic acid binding visualized by cryo-electron tomography.

Influenza viruses are enveloped, negative sense single-stranded RNA viruses covered in a dense layer of glycoproteins. Hemagglutinin (HA) accounts for 80-90% of influenza glycoprotein and plays a role in host cell binding and membrane fusion. While previous studies have characterized structures of receptor-free and receptor-bound HA in vitro, the effect of receptor binding on HA organization and structure on virions remains unknown.

Anti-SARS-CoV-2 Activity of Adamantanes In Vitro and in Animal Models of Infection.

Coronavirus disease 2019 (COVID-19) has had devastating effects worldwide, with particularly high morbidity and mortality in outbreaks on residential care facilities. Amantadine, originally licensed as an antiviral agent for therapy and prophylaxis against influenza A virus, has beneficial effects on patients with Parkinson's disease and is used for treatment of Parkinson's disease, multiple sclerosis, acquired brain injury, and various other neurological disorders. Recent observational data suggest an inverse relationship between the use of amantadine and COVID-19.

Divalent siRNAs are bioavailable in the lung and efficiently block SARS-CoV-2 infection.

The continuous evolution of SARS-CoV-2 variants complicates efforts to combat the ongoing pandemic, underscoring the need for a dynamic platform for the rapid development of pan-viral variant therapeutics. Oligonucleotide therapeutics are enhancing the treatment of numerous diseases with unprecedented potency, duration of effect, and safety. Through the systematic screening of hundreds of oligonucleotide sequences, we identified fully chemically stabilized siRNAs and ASOs that target regions of the SARS-CoV-2 genome conserved in all variants of concern, including delta and omicron.

A Newly Engineered A549 Cell Line Expressing ACE2 and TMPRSS2 Is Highly Permissive to SARS-CoV-2, Including the Delta and Omicron Variants.

New variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to emerge, causing surges, breakthrough infections, and devastating losses-underscoring the importance of identifying SARS-CoV-2 antivirals. A simple, accessible human cell culture model permissive to SARS-CoV-2 variants is critical for identifying and assessing antivirals in a high-throughput manner. Although human alveolar A549 cells are a valuable model for studying respiratory virus infections, they lack two essential host factors for SARS-CoV-2 infection: angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2).

Quantitative structural analysis of influenza virus by cryo-electron tomography and convolutional neural networks.

Influenza viruses pose severe public health threats globally. Influenza viruses are extensively pleomorphic, in shape, size, and organization of viral proteins. Analysis of influenza morphology and ultrastructure can help elucidate viral structure-function relationships and aid in therapeutics and vaccine development.