A group of scientists from the National Center for Microbiology (CNM) has led an investigation in which new data have been provided on persulfidation, an essential mechanism in immune defense against infection caused by the fungus "Aspergillus fumigatus".
The study, coordinated by this center of the Carlos III Health Institute (ISCIII) and published in the specialized journal "iScience", provides information about a biological stage in which the activity of different proteins can condition the immune system’s response. Thanks to these results, progress is being made in understanding how the epithelial cells of the lung alveoli react to infection by this opportunistic pathogen, responsible for severe conditions in people with compromised defenses.
Persulfidation is a post-translational modification based on a chemical change in proteins that allows organisms to adjust their activity and react quickly to various biological stimuli. Previous work had already shown that the correct functioning of this process is decisive for mounting an effective immune response against infections such as those caused by "Aspergillus fumigatus".
Proteins involved in persulfidation
The research led by the member of the CNM-ISCIII Research Reference Laboratory in Mycology, Jorge Amich, has managed to catalog the set of proteins that undergo persulfidation during infection, and has found that a significant portion of them is linked to transcription, RNA metabolism, and its translation. These findings reinforce the idea that this mechanism has an important role in protein synthesis and its subsequent function.
Among the affected proteins, the team has identified calprotectin as one of the persulfidated ones. This molecule, composed of two small peptides, plays a prominent role in the immune response against pathogenic microorganisms. In addition, they have observed that persulfidation protects it against oxidative damage, allowing it to maintain its defensive capacity against pathogens.
As the authors emphasize, "this detail is crucial, since when an infection occurs, one of the responses of the immune system is based on subjecting microorganisms to very high oxidative stress." "The fact that persulfidation protects the activity of calprotectin is fundamental for all of our antimicrobial immune arsenal to work well," they have concluded.