Expression data from polarized adult human microglia

Myeloid cells are prominent cellular constituents of the CNS. Under physiologic conditions, these include microglia within the parenchyma and systemic compartment derived macrophages localized to the perivascular spaces. Defining the relative distribution and functions of microglia versus blood-derived macrophages in the CNS parenchyma under pathologic conditions remains a challenge due to limitations in being able to distinguish these cell types. Approaches to distinguishing microglia and macrophages in experimental models include use of chimeric and parabiotic animals and molecular genetic techniques to selectively differentially label or delete a specific cell type. The current report will compare gene expression of human microglia and macrophages under distinct states of activation or “polarization” and relate these to their roles in tissue injury and protection /repair in the central nervous system (CNS). We used Affymetrix Human Gene HT 2.0 microarrays to compare whole transcriptomes of microglia and macrophages under defined polarization conditions. Microglia isolated from the adult human brain of 3 donors were exposed to different polarization conditions: M0 (no cytokine treatment), Mtgf (TGFβ), M1 (GMSCF+IFNy+LPS), M2a (MCSF+IL4+IL13) and M2c (MCSF+IL10+IL4+IL13) over a period of 7 days