IMMUNE ACTIVATION: Edited by Irini Sereti and Marcus AltfeldImmune activation in the central nervous system throughout the course of HIV infectionSpudich, Serena S.Author Information Department of Neurology, Yale University, New Haven, Connecticut, USA Correspondence to Serena S. Spudich, MD, MA, Department of Neurology, Yale University, 300 George Street, Rm 8300c, New Haven, CT 06520, USA. Tel: +1 203 737 1969;. e-mail: firstname.lastname@example.org Current Opinion in HIV and AIDS: March 2016 - Volume 11 - Issue 2 - p 226-233 doi: 10.1097/COH.0000000000000243 Buy Metrics Abstract Purpose of review Robust and dynamic innate and adaptive responses characterize the acute central nervous system (CNS) response to HIV and other viral infections. In a state of chronic infection or viral latency, persistent immune activation associates with abnormality in the CNS. Understanding this process is critical, as immune-mediated abnormality in nonrenewable CNS cells may result in long-term neurologic sequelae for HIV-infected individuals. Recent findings In humans, immune activation is reduced by suppressive combination antiretroviral therapy, but persists at abnormally elevated levels on treatment. CNS immune activation is initiated in acute infection and progressively increases until combination antiretroviral therapy is started. Newly identified characteristics of the CNS immune surveillance network include features of homeostasis and function of brain microglial cells, lymphatic drainage from CNS to cervical lymph nodes, and cells in cerebrospinal fluid associated with neurocognitive impairment. Summary More research is required to determine whether early intervention to reduce infection limits the immunopathology established by sustained immune responses that ultimately fail to resolve infection, and to unravel mechanisms of persistent immune activation during treated HIV so that strategies can be developed to therapeutically protect the brain. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.