FOR 1336: From Monocytes to Brain Macrophages – Conditions Influencing the Fate of Myeloid Cells in the Brain (2010 – 2017)

The major aim of the Research Unit is the coordinated investigation of the functional, spatial, temporal and developmental diversity of myeloid cells in the central nervous system (CNS). The brain hosts a heterogenous population of myeloid cells, including microglia, perivascular cells, meningeal macrophages and disease-associated blood-borne monocytes. In contrast to other glial cells, brain macrophages are more related to the peripheral immune system than to the neuroectoderm. Thus far, the different types of brain macrophages have been discriminated solely on the basis of their localisation, morphology and surface epitope expression. However, recent data suggest that resident microglia may be functionally distinct from bone marrow-derived macrophages, which invade the CNS under pathological conditions.
During the last few years, research on brain macrophages has been dramatically changed by the advent of novel tools in imaging, genetics and immunology. These new methodologies have yielded unexpected results, which challenge the traditional view of brain macrophages. Based on these recent studies, performed in part by members of this Research Unit, we propose a new classification of brain macrophage subtypes with regard to their origin, function and fate within the CNS.