DZL scientist Dr. Bilal Alashkar Alhamwe investigates how contact with the bacterium Acinetobacter lwoffii stimulates the immune system and can thus protect us from chronic inflammatory diseases such as asthma.
We are surrounded by a wide variety of bacteria in our environment every day. They are found not only in soil and water but also on our food and furthermore colonize the human body. Some species can cause disease, while others can even protect us from it. However, the underlying mechanisms at the interface between the immune system and microbes are still largely unknown. DZL scientist Dr. Bilal Alashkar Alhamwe, together with scientists from the Universities of Giessen and Marburg Lung Center (UGMLC) and Philipps-Universität Marburg, has now explored how the bacterium Acinetobacter lwoffii can protect us from chronic inflammatory diseases such as asthma.
It has been known for some time that environmental microbes can protect against the development of asthma. However, how this protection is mediated is not yet clear. In his studies using a mouse model, Alashkar Alhamwe was able to show that contact with the bacterium Acinetobacter lwoffii triggers a pro-inflammatory response. This reaction is controlled by the body's own messenger substances, the interleukins. Elevated levels of interleukin 6 then influence the body's immune cells. It is particularly fascinating to observe the far-reaching physical changes that are triggered by contact with the bacterium. As a result of bacterial stimulation of immune cells, such as T cells, the scientists were able to observe changes in the natural gut flora, known as the gut microbiome. The researchers examined and identified the gut bacteria in more detail and recognized which of them were associated with disease protection. In addition, they observed that a bacterial interaction with Acinetobacter lwoffii led to genetic changes in T cells. According to Alashkar Alhamwe, treatment with the bacterium altered the gastrointestinal microbiome but not the lung microbiome. It still remains unclear whether treatment with the bacterium has a direct effect on the gut microbiome or whether a change in the immunological milieu, altered the composition of bacteria in the gut. In summary, these experiments reveal a new mechanism by which environmental bacteria can prevent asthma. Alashkar Alhamwe is confident that the mechanism linking an inflammatory trigger to changes in gut microbial flora could be useful for developing new strategies for asthma prevention.
The study was published in the journal Allergy in December 2022: