cGAS binds to the misplaced DNA, triggering the formation of cyclic GMP-AMP (cGAMP). DNA is usually found in the nucleus of a cell, so its presence in the cytoplasm indicates either cellular damage or microbial infection. This pathway kicks off with the detection of misplaced DNA by an enzyme called cGAMP synthase (cGAS). ![]() Although helpful in containing viral spread across the body, prolonged and misregulated production of interferons can impair lung cell regeneration and worsen disease outcome.Ĭurious to determine how exactly cell fusion triggers IFN-β activation, the team of scientists turned to one of the central signaling pathways of the innate immune system, the cGAS–STING pathway (Figure 3). IFN-β is particularly closely linked to the innate immune response and, crucially, the activation of inflammation. Interferons are a class of signaling proteins produced and released by host cells in response to viral infection, warning other nearby cells of danger. 2022įollowing cell fusion and the formation of syncytia, Liu et al. witnessed upregulation of interferon-beta (IFN-β). FROM: “SARS-COV-2 SPIKE PROTEIN–INDUCED CELL FUSION ACTIVATES THE CGAS-STING PATHWAY AND THE INTERFERON RESPONSE” LIU ET AL. Schematic representation of the S1/S2 and S2’ cleavage sites along the SARS-CoV-2 spike protein. Importantly, the syncytia formed in response to SARS-CoV-2 infection do not seem to heal or regenerate with time, as they do in response to the flu.įIGURE 2. ![]() Even though syncytia are crucial to the formation of our muscle tissue, when induced in response to viral infection they are pathological. Syncytia are large, cell-like structures that form when two or more cells join together essentially, an amorphous mass of cytoplasm and nuclei (Figure 1). The presence of syncytia, along with alveolar destruction and massive blood clotting, are all characteristic of severe Covid-19. discovered that SARS-CoV-2 spike protein can prompt cells in the lungs to fuse together, causing damage to their DNA and triggering an immune response that culminates in excessive inflammation.Īlthough the impacts of SARS-CoV-2 infection have been recorded across the board -from the liver to the heart to the brain, and beyond- nowhere is the damage quite as intense as in the lungs. Published in Science Signaling, Liu et al. New work by a group of researchers at Peking Union Medical College adds another piece to the mosaic of causes. The mechanisms by which SARS-CoV-2 triggers such an intense inflammatory response are still being uncovered. This is evidenced by the hyper-inflammation commonly associated with severe Covid-19. Inflammation, though an important part of defense against microbes, can sometimes get out of hand, leading to multiorgan injury and even death. When it comes to SARS-CoV-2 infection, our very own immune system can end up contributing to the damage. ![]() Other articles in the series include: lectins, Covid-19 and brain injury, long Covid, STING, monocytes, and ORF8. This is part of a series of stories on inflammation triggered by SARS-CoV-2 infection. SARS-CoV-2 Infection Causes Cell Fusion In The Lungs, Triggering Inflammation
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |