There are tiny cilia in the airways that ensure that dust, pollen and pathogens cannot penetrate the lungs. Researchers have just discovered how this protective mechanism works in the defense against bacteria in the trachea and bronchi and what role peptides play in this.
Millions of cilia, also known as cilia, lie like a carpet on the mucous membrane of the airways. The continuous undulating movement of these tiny hairs removes mucus and unwanted substances adhering to it from the airways. This is very important, because without this protective mechanism foreign substances such as pollen, bacteria and viruses from the air we breathe would cause inflammation of the lungs much more frequently . In a new project by an international research team, initiated by Professor Bernd Bufe from the Chair of Molecular Immunology and Immune Sensing at Kaiserslautern University of Applied Sciences together with Professor Wolfgang Kummer from the Anatomical Institute at the University of Giessen , an exciting new mechanism has been deciphered that helps our body’s own defenses to keep pathogens away from the respiratory organs .
Professor Bernd Bufe, who researches the diverse effects of bacterial metabolites on the immune defense at the Zweibrücken campus, has now discovered together with his colleagues , that the cilia beat faster on contact with certain bacterial peptides and thus transport the germs from the lungs towards the trachea and throat as if on a conveyor belt. From there, the contaminated mucus enters the stomach by swallowing and is then digested. The bacteria are rendered harmless in the process. The focus here is on peptides, which are mainly found in pathogens . If they are present, they trigger the cilia movement by means of a sophisticated biochemical reaction.
At the moment, the researchers have only completely decoded this mechanism in the mouse model . “In humans, we will find other peptides that cause this reaction because we are attacked by different bacteria than mice,” says Professor Bufe. However, once this protective mechanism is understood in humans, there are numerous opportunities for new drugs. “We could, for example be in a position in the future to help people to help people who have cystic fibrosis,” he notes, “with these patients particle transport from the lungs only works to a limited extent.” Also for the Prevention In other risk groups for lung infections, such as smokers or COPD patients, such an active ingredient could one day be used to protect them from pneumonia. “We have discovered the messenger substances, which trigger this change in the cilia beat,” explains Bufe. “This is very important, as it gives us starting points to control the cilia beat in a targeted manner We do not yet know whether viral petptides can also trigger these mechanisms. But in view of the current corona infections, this is already an exciting question,” explains the researcher. Further studies should therefore show whether this endogenous mechanism also plays a role in the defense against viruses and whether there are differences in the effectiveness of these defense mechanisms in different people.
The new study, in which Kaiserslautern University of Applied Sciences played a key role, has just been published in the extremely renowned journal Immunity (4/2020 DOI XXX) under the title “Chemosensory cell-derived acetylcholine drives tracheal mucociliary clearance in response to virulence-associated formyl peptides” .
Text: Susanne Lilischkis
