New Populations Of Immune Cells In The Lungs

Populations; Due to their function; the lungs are constantly exposed to various compounds carried in the air, sometimes harmful, sometimes harmless. The lung immune system plays a pivotal role in deciding or not deciding to mount an immune response in order to sustain respiratory function. In some cases, there is a dysfunction of the immune system that responds against harmless compounds, as is the case in the development of asthma.

In this regard, researchers from the University of Liège, under the direction of Professors Fabrice Bureau and Thomas Marichal, previously discovered that specific cells in the lung, called “interstitial macrophages,” could prevent the development of asthma. However, these cells were only rudimentarily characterize.

The development of asthma

In an article publish in Nature Communications, the Immuno physiology Laboratory of the GIGA Institute; headed by Prof. Thomas Marichal, reports that two very distinct sub populations of interstitial macrophages exist; also identifies their local precursors. This new knowledge is a further step towards understanding the regulation of the lung immune system; also developing targeted approaches to prevent respiratory diseases, such as asthma.

A study conduct by the Immunophysiology Laboratory led by Prof. Thomas Marichal (Research Associate, Fund for Scientific Research FNRS, ERC and Welbio Investigator Walloon Excellence in Life Sciences and Biotechnology, GIGA-ULiège) and publish in Nature Communications; reveals new insights regarding a population of cells of the pulmonary immune system: the interstitial macrophages.

These poorly studied cells are involved in preventing the development of asthma; also are therefore a potential target for the development of therapies against immune mediate respiratory diseases such as asthma. In this context, a deeper knowledge of these cells; also is an important prerequisite; which has recently been clarified by the research team.

Distinct sub populations

First, Joey Schyns, the first author of the study, discover that interstitial macrophages in mice are a heterogeneous population compose of two very distinct sub populations. These sub populations exhibit different function, origin and morphology; also are locate in different pulmonary zones. The involvement of each of these sub ,  in the development of chronic respiratory diseases is potentially very different, so it is important, from now on, to consider them as separate entities in future research.

In addition, the researchers also found that a subpopulation of these interstitial macrophages comes directly from specific blood monocytes called “patrolling monocytes” that can exit the bloodstream and reach the lung. This discovery is the first step in an ambitious research project fund by an ERC Starting Grant; deploy by the European Research Council; also obtain by Thomas Marichal last year.

Ultimately, this project should allow a better understanding of the mechanisms underlying the fine regulation of these sub populations of macrophages, and will provide essential elements for the development of target approaches for the prevention of respiratory diseases in which the (dys)functions of these macrophages are involved.