Virus World

Respiratory virus infections in humans cause a broad-spectrum of diseases that result in substantial morbidity and mortality annually worldwide. To reduce the global burden of respiratory viral diseases, preventative and therapeutic interventions that are accessible and effective are urgently needed, especially in countries that are disproportionately affected. Repurposing generic medicine has the potential to bring new treatments for infectious diseases to patients efficiently and equitably. In this study, we found that intranasal delivery of neomycin, a generic aminoglycoside antibiotic, induces the expression of interferon-stimulated genes (ISGs) in the nasal mucosa that is independent of the commensal microbiota.

Prophylactic or therapeutic administration of neomycin provided significant protection against upper respiratory infection and lethal disease in a mouse model of COVID-19. Furthermore, neomycin treatment protected Mx1 congenic mice from upper and lower respiratory infections with a highly virulent strain of influenza A virus. In Syrian hamsters, neomycin treatment potently mitigated contact transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In healthy humans, intranasal application of neomycin-containing Neosporin ointment was well tolerated and effective at inducing ISG expression in the nose in a subset of participants. These findings suggest that neomycin has the potential to be harnessed as a host-directed antiviral strategy for the prevention and treatment of respiratory viral infections.

Published in PNAS (April 22, 2024):

https://doi.org/10.1073/pnas.2319566121

The new coronavirus may be using part of our immune system against us.The novel coronavirus is known to use a keyhole called the ACE2 receptor to "unlock" a cell and get inside, where it replicates and wreaks havoc. Now, researchers have found that the gene that encodes the ACE2 receptor may be stimulated by interferons, one of the body's main defenses against viruses. When a foreign pathogen invades, interferons act like "first responders"; the immune system releases these proteins to alert other cells that there's a pathogen in the body. But when interferons rush to alert the body to the coronavirus, they're actually stimulating the gene that ramps up expression of ACE2 receptors, which may lead to more ACE2 production and allow SARS-CoV-2 to infect even more cells.....

This finding is important, given that interferons are being tested as a possible treatment for the new coronavirus. However, it's still unclear whether an interferon treatment would help or harm patients. "It might be that in some patients, because of the timing or the dose, interferon can contain the virus, while in others, interferon promotes more infection," Ordovas-Montanes said in a statement. "We want to better understand where the balance lies and how we can maintain a productive antiviral response without producing more target cells for the virus to infect."...

Original report to be published in Cell:

https://doi.org/10.1016/j.cell.2020.04.035

https://www.cell.com/pb-assets/products/coronavirus/CELL_CELL-D-20-00767.pdf