Astrocytes Exert and Control Immune Responses in the Brain

Astrocytes are the most abundant cell type of the Central Nervous System (CNS) and exert several important functions. Firstly, astrocytes strongly contribute to mechanical holding of the nervous tissue and to blood brain barrier generation and maintenance. Besides this structural role, astrocytes regulate neuron-glia communication by secreting neurotrophic factors and modulating neurotransmitter release and metabolism, control cerebral blood flow, keep CNS protected from pathogens while allowing passage of nutrients and maintaining tissue homeostasis. This review will focus on the ability of astrocytes in initiating and tuning cerebral immune responses, and will emphasize the importance of these astrocytic properties in both neuroinflammation and neuroprotection settings.