“The myeloid side of the brain”

Part of the Progress in Neuroscience Seminar (PINS) series Marco Prinz, M.D. Medical Director, Professor of Neuropathology Institute of Neuropathology University of Freiburg Abstract The diseased brain hosts a heterogeneous population of myeloid cells, including parenchymal microglia, perivascular cells, meningeal macrophages and blood-borne monocytes. To date, the different types of brain myeloid cells have been discriminated solely on the basis of their localization, morphology and surface epitope expression. However, recent data suggest that resident microglia may be functionally distinct from bone marrow- or blood-derived phagocytes, which invade the CNS under pathological conditions. During the last few years, research on brain myeloid cells has been markedly changed by the advent of new tools in imaging, genetics and immunology. These methodologies have yielded unexpected results, which challenge the traditional view of brain macrophages. On the basis of these new studies brain myeloid subtypes can be differentiated with regard to their origin, function and fate in the brain (1,2). Publications Masuda T, Sankowski, Staszewski O, Böttcher C, Amann L, Scheiwe C, Nessler S, Kunz P, van Loo G, Coenen VA, Reinacher PC, Michel A, Sure U, Gold R, Priller J, Stadelmann C, Prinz M: Spatial and temporal heterogeneity of mouse and human microglia at single-cell resolution. Nature 566, 388-392 (2019).Jordão MJC, Sankowski R, Brendecke SM, Sagar, Locatelli G, Tai Y-H, Tay TL, Schramm E, Armbruster S, Hagemeyer N, Groß O, Mai D, Çiçek Ö, Falk T, Kerschensteinher M, Grün D, Prinz M: Single-cell profiling identifies myeloid cell subsets with distnct fates during neuroinflammation. Science 363 (6425), eaat7554 (2019).Geirsdottir L, David E, Keren-Shaul H, Bohlen S, Neuber J, Weiner A, Balic A, Dutertre C, Pfeigel C, Tautz D, Peri F, Vizioli J, Matiasek K, Scheiwe C, Meckel S, Ulitsky I, Ginhoux F, Erny D, Amit I, Prinz M: Cross-species single-cell analysis reveals divergence of the primate microglia program. Cell, 179(7):1609-1622.e16 (2019).