Monocytes/macrophages are immune system-like cells important for normal brain function. In the healthy brain, resident microglia are the major macrophage cell population; however, in brain tumors, peripheral monocytes/macrophages can infiltrate the brain and participate in brain tumor growth. Distinguishing these two populations is often challenging, owing to a paucity of universally accepted and reliable markers.
To identify discriminatory marker sets for microglia and peripheral monocytes/macrophages, Verena Haage, a graduate student in the laboratory of Dr. Helmut Kettenmann, employed a large meta-analytic approach. This project was performed in collaboration with Dr. David H. Gutmann, Director of the Washington University NF Center. Using this approach, they discovered a robust set of microglia and peripheral monocyte/macrophage expression markers to discriminate these monocyte populations in both health and disease.