idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
idw - Informationsdienst
Wissenschaft
A research team at University Medical Center Mainz has discovered a previously unknown mechanism by which the immune system fights bacterial infections. The scientists found that a specific protein, the so-called chloride channel PACC1, is crucial for immune cells to effectively kill bacteria. If the protein is missing, it leads to increased inflammatory reactions, as well as increased mortality in an animal model in cases of bacterial sepsis. In the long term, the findings could help develop new treatment strategies for bacterial sepsis – especially in light of rising antibiotic resistance. The study was published in the journal Proceedings of the National Academy of Sciences (PNAS).
Sepsis, also known as blood poisoning, is the third leading cause of death in Germany. It occurs when the immune system can no longer contain an infection locally, and as a result, the body’s faulty immune responses cause life-threatening damage to tissues and organs. Despite modern intensive care treatment options, approximately 20 - 50 percent of patients with sepsis die from its consequences.
The immune system combats bacterial pathogens that can trigger sepsis by using phagolysosomes. These are the “digestive chambers” of immune cells: specialized cellular compartments where bacteria are broken down. For the breakdown of bacteria, an acidic environment is necessary. This is regulated by protein complexes on the surface of the cell compartments, known as ion channels. The exact mechanism of action of these ion channels in immune defense has remained largely unclear until now.
A research team led by Prof. Dr. Markus Bosmann, Center for Thrombosis and Hemostasis (CTH) at University Medical Center Mainz, has now demonstrated in the study “Proton-Activated Chloride Channel 1 (PACC1) is essential for innate host defense against bacterial sepsis” that the ion channel PACC1 (Proton-activated Chloride Channel 1) plays a central protective role in life-threatening bacterial infections. The scientists were able to demonstrate that immune cells are no longer able to effectively combat bacteria when PACC1 is absent.
The researchers found that without the ion channel, the digestive chambers were not sufficiently acidic, and bacteria were therefore less effectively degraded. This led to an intensified and misdirected inflammatory response. Furthermore, mortality from bacterial sepsis increased significantly in the animal model. “These effects were not observed in a pure inflammatory response without live bacteria,” emphasizes Professor Bosmann. “This underscores the specific importance of PACC1 for bacterial defense. It is surprising that a single chloride channel plays such a central protective role in the immune system.
The findings provide important insights into how disruptions in bacterial defense can contribute to the development of severe infections such as sepsis. At the same time, they open up potential new approaches for clinical application in the long term, particularly in light of rising antibiotic resistance, which limits treatment options for bacterial sepsis. Thus, a targeted increase in PACC1 activity could serve as a therapeutic principle for the development of novel therapies against bacterial sepsis in the future.
About the University Medical Center of the Johannes Gutenberg University Mainz
The University Medical Center of the Johannes Gutenberg University Mainz is the only medical institution of supra-maximum supply in the German state of Rhineland-Palatinate and an internationally recognized science location. Medical and scientific specialists at more than 60 clinics, institutes and departments work interdisciplinarily to treat around 403,000 patients per year. Highly specialized patient care, research and teaching are inseparably intertwined. Around 3,700 medicine and dentistry students as well as around 590 future medical, commercial and technical professionals are trained in Mainz. With a workforce of approximately 9,000 colleagues the University Medical Center Mainz is one of the largest employers in the region and an important driver of growth and innovation. Find more information online at https://www.unimedizin-mainz.de
Prof. Dr. Markus Bosmann
Centrum für Thrombose und Hämostase (CTH)
University Medical Center Mainz
Markus.Bosmann@unimedizin-mainz.de
Lucien P. Garo, Kevin Brueck, Sarah Walachowski, Archana Jayaraman, Marcel Strueve, Shuang Xu, Hulbert Yang, Matthew Helmkamp, Seung Hoan Choi, Christoph Reinhardt, Markus Bosmann.
Proton-Activated Chloride Channel 1 (PACC1) is essential for innate host defense against bacterial sepsis, PNAS (2026)
DOI: https://www.doi.org/10.1073/pnas.2515768123
https://www.unimedizin-mainz.de/en/newsroom/news/news-releases/newsdetail/articl...
The research findings could aid in the development of novel therapies against bacterial sepsis.
Copyright: UM/Canva
Senior author Prof. Dr. Markus Bosmann, Center for Thrombosis and Hemostasis (CTH) at the University ...
Source: Thomas Böhm
Copyright: UM/Thomas Böhm
Criteria of this press release:
Journalists
Biology, Medicine, Nutrition / healthcare / nursing
transregional, national
Research results, Scientific Publications
English
You can combine search terms with and, or and/or not, e.g. Philo not logy.
You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).
Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.
You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).
If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).
