Scavenger Cells Protect the Body's Tissue in a Specific Way

Researchers publish results on organ-specific properties of macrophages in the Nature Communications journal.

Macrophages are cells in the immune system that belong to the phagocyte family, or so-called scavenger cells. They reside in almost all tissues of the body, for example in the small intestine, liver, brain, and skin. Here, macrophages contribute to eliminating invading pathogens and also support tissue homeostasis and the healing of wounds. As they are adapted to the requirements of the respective tissue, macrophages acquire special functions. This means that, for example, macrophages residing in the gut are significantly different to those in the liver.

Working under the direction of Professor Oliver Pabst, researchers from RWTH’s Institute of Molecular Medicine have investigated how the functional differences between the various macrophages are formed. In his doctoral thesis, Girmay Desalegn investigated how precursors of macrophages, so-called monocytes, develop in the small intestine and other tissues and how this process is influenced by inflammatory reactions. He was able to show that local signals in the gut instruct monocytes to switch certain genes on or off, so that they gradually acquire specific properties for the small intestine. These signals are absent in other tissues or are replaced by other signals and the macrophages subsequently activate other gene expression profiles and functions.

If there is an inflammatory reaction, two changes occur: first, more monocytes or macrophages are recruited into the small intestine and second, there is a dramatic change in their gene expression. As a result, macrophages can perform different functions and react dynamically to the tissue type and condition.

The researchers published their results in the renowned journal Nature Communications under the title "Inflammation Triggers Immediate Rather Than Progressive Changes in Monocyte Differentiation in the Small Intestine".

Source: Press and Communications