Differential production of and migratory response to beta chemokines by human microglia and astrocytes

Little is known about the participation of beta chemokines in inflammatory processes within the central nervous system. The release of three of these peptides (macrophage inflammatory protein [MIP]-1alpha, MIP-1beta, and monocyte chemoattractant protein-1) from human fetal microglial cell and astrocyte cultures was assessed following stimulation by lipopolysaccharide, interleukin-1beta, and tumor necrosis factor-alpha. Although striking differences were found between these two types of glial cells in their responsiveness to lipopolysaccharide and cytokines, both microglia and astrocytes produced all three beta chemokines. Only microglial cells, however, demonstrated an increased migratory response to the beta chemokines. The results of this in vitro study suggest that beta chemokines may play an important role in the trafficking of mononuclear phagocytes within the brain.