Fig. 1
From: Potential pharmacological approaches for the treatment of HIV-1 associated neurocognitive disorders
(Figure adapted from Saylor et al. [6])
Neuropathogenesis of HAND. HIV-1 can enter the brain as a cell free virion or encased within infected monocytes or macrophages. Once in the CNS HIV-1 targets microglia, and to a lesser extent, astrocytes. Upon activation, these cells release numerous inflammatory markers (IL-1β, TNFα, CCL2 etc.) and can shed HIV-1 viral proteins (e.g. gp120, Tat). Chronic secretion of such factors which can exacerbate viral replication and pathogenic immune signalling ultimately leading to neuronal injury. HIV-1 infection in the brain may cause disruption of glutamate homeostasis leading to excitotoxicity