Classically and alternatively activated bone marrow derived macrophages differ in cytoskeletal functions and migration towards specific CNS cell types

Background: Macrophages play an important role in neuroinflammatory diseases such as multiple sclerosis (MS) and spinal cord injury (SCI), being involved in both damage and repair. The divergent effects of macrophages might be explained by their different activation status: classically activated (CA/M1), pro-inflammatory, macrophages and alternatively activated (AA/M2), growth promoting, macrophages. Little is known about the effect of macrophages with these phenotypes in the central nervous system (CNS) and how they influence pathogenesis. The aim of this study was therefore to determine the characteristics of these phenotypically different macrophages in the context of the CNS in an in vitro setting. Results: Here we show that bone marrow derived CA and AA macrophages have a distinct migratory capacity towards medium conditioned by various cell types of the CNS. AA macrophages were preferentially attracted by the low weight (