Inflammation is the body's natural defense against harmful stimuli, marked by heat, pain, redness, swelling, and impaired tissue function. When properly regulated, inflammation helps eliminate harmful agents and promotes tissue repair. However, when inflammation becomes excessive, it can lead to tissue damage and disease. Various immune cells play crucial roles in this process, collaborating to manage inflammation. The specific immune cells involved can differ based on the type of harmful stimulus, impacting the overall outcome of the inflammatory response.
A research team at the Max Planck Institute for Immunobiology and Epigenetics utilized advanced microscopy techniques to observe the real-time interactions of activated mast cells and other immune cells during allergic reactions in living mouse tissues. Under the leadership of Tim Lämmermann, Director at the Institute of Medical Biochemistry at the University of Münster, the researchers discovered that neutrophils were found inside mast cells. "We were astonished to see living neutrophils within living mast cells. This unexpected finding likely would not have been identified using traditional experimental methods outside of a living organism, underscoring the profound capabilities of intravital microscopy," remarks Tim Lämmermann.
With the assistance of an international research team, scientists confirmed the formation of Neutrophil Extracellular Traps (MITs) in human samples and examined the subsequent fate of the trapped cells. Their findings revealed that trapped neutrophils eventually undergo cell death, with their remnants being retained inside mast cells. “This is where the story takes an unexpected turn. Mast cells not only recycle the material from neutrophils to enhance their own function and metabolism, but they also release these components in a delayed fashion, which can trigger further immune responses and sustain inflammation,” explains Michael Mihlan.
“This new insight into the interplay between mast cells and neutrophils adds a significant dimension to our understanding of allergic reactions and inflammation. It reveals that mast cells can leverage neutrophils to amplify their functions—an important factor that could influence chronic allergic conditions characterized by recurrent inflammation,” notes Tim Lämmermann.
The research team is now investigating this interaction in the context of mast cell-mediated inflammatory diseases in humans, aiming to explore whether these findings could pave the way for novel treatments for allergies and inflammatory disorders.
Source:https://www.iefreiburg.mpg.de/5858667/news_publication_22309887_transferred