The discovery of the mechanism by which lung cells defend themselves against influenza opens the way to better treatments against viral infections and in particular Covid-19.
- The mechanism of the lungs’ immune response to influenza has been discovered.
- Immune cells sacrifice themselves to prevent the virus from spreading.
- Knowledge of this mechanism should help to better fight other viral infections such as Covid-19.
The flu is a common respiratory illness but it still causes between 300,000 and 600,000 deaths each year worldwide. It is caused by the influenza virus, which infects the upper and lower respiratory tract, particularly the lungs. The flu virus is known to mutate regularly, making annual vaccination essential to protect against the different strains circulating each year. Despite advances in the development of vaccines and antiviral treatments, influenza remains a major public health problem.
The immune response of lung cells
To understand how lung cells defend themselves against the flu virus, a team of researchers from Trinity College Dublin in Ireland conducted an in-depth study. Their work, published in the journal iScience, revealed a key defense mechanism used by lung cells to counter infection. When a flu virus enters lung cells, the viral RNA and flu viruses stimulate two different molecular pathways that trigger a cascade of chemical reactions.
The essential role of gasdermins in the immune response
The researchers discovered that this cascade of reactions leads to the activation of two specific proteins, called “gasdermin D” and “gasdermin E.” These proteins play an essential role in the antiviral response of lung cells. By forming pores in lung epithelial cells, gasdermins allow the release of special agents called cytokines. Cytokines play a crucial role in strengthening the immune system by stimulating an inflammatory response and recruiting other immune cells to fight infection.
Prevent the spread of the virus
Besides cytokine release, gasdermins play another important role in the antiviral response. When they form membrane pores, this causes the cells infected with the influenza virus to die. This programmed cell death, called pyroptosis, prevents the spread of the virus into healthy lung tissue. In other words, lung cells sacrifice themselves to prevent the virus from spreading and infecting other cells.
Implications for the treatment of different viral infections
The results of this study have implications far beyond the flu. By understanding the mechanism by which lung cells defend themselves against the flu virus, researchers hope to be able to develop better treatments for other viral infections, including Covid-19. Indeed, many respiratory infections, such as influenza and Covid-19, share similar characteristics and affect the respiratory tract. Understanding how lung cells fight influenza could therefore help develop new treatment strategies for these diseases.