New publication COVID Nature communication

publication antiviral response against SARS-CoV2  in Nature communication​

Severe forms of Covid-19 often result from an inefficient and/or late production of type I and III interferons. This cytokines are centre in the host protection against viral infection. The source of this immune response defect could be the cells of the immune system, the plasmacytoid dendritic cells.

http://​https://doi.org/10.1038/s41467-023-36140-9

"The interferon response constitutes a first barrier of defence of the body against viral infections. This host response is initiated by receptor-mediated recognition of viral elements and leads to the production of molecules, including interferon, that alert surrounding cells. This response inhibits viral spread and the recruitment of immune cells to the site of infection.

In this publication, we have demonstrated that one cell type, i.e. plasmacytoid dendritic cells, are the predominant source of interferon in the detection of SARS-CoV-2 infected cells. Mechanistically, this detection requires cell contacts by adhesion of plasmacytoid dendritic cells with infected cells. In turn, plasmacytoid dendritic cells limit viral spread through an antiviral response directly targeted to SARS-CoV-2 infected cells. Our real-time imaging analyses on living cells show that this specialised function allows plasmacytoid dendritic cells to effectively stop viral replication. By exploring the response of plasmacytoid dendritic cells in patients with SARS-CoV-2, we demonstrate that their response is inversely proportional to the severity of the disease. The plasmacytoid dendritic cell response is particularly impaired in patients severely affected by COVID-19. In summary, we propose that activation of plasmacytoid dendritic cells is essential to control SARS-CoV-2 infection. Failure to deploy this response may be key to understanding severe COVID-19 cases."

press release by INSERM :

https://www.calameo.com/read/00515445013b2c5a0b15f