IL-16 expression in lymphocytes and microglia in HIV-1 encephalitis

Neuropathol Appl Neurobiol. 2004 Jun;30(3):233-42. doi: 10.1046/j.0305-1846.2003.00527.x.


IL-16 is a natural ligand for the CD4 molecule and is known for its chemotactic and anti-HIV-1 activities. We determined IL-16 expression in human brain tissue with HIV-1 encephalitis by specific immunocytochemistry and showed that infiltrating lymphocytes and activated microglia express IL-16. IL-16 immunoreactivity was particularly pronounced in microglial nodules. In vitro, human foetal microglia and not astrocytes produce IL-16, and HIV-1 infection up-regulates microglial IL-16 release in a Nef-dependent manner. These results support the notion that, in the brain, IL-16 is a macrophage-lineage specific modulator of the inflammatory response and HIV-1 expression. Recruitment of IL-16+ T cells and microglia/macrophages may represent an innate response to HIV-1 infection in the central nervous system that counterbalances viral stimulatory factors.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AIDS Dementia Complex / genetics
  • AIDS Dementia Complex / metabolism*
  • Astrocytes / metabolism
  • Brain / pathology
  • Cells, Cultured
  • HIV-1*
  • Humans
  • Immunohistochemistry
  • Interleukin-16 / biosynthesis*
  • Interleukin-16 / genetics
  • Lipopolysaccharides / pharmacology
  • Lymphocytes / metabolism*
  • Microglia / metabolism*
  • Paraffin Embedding
  • Stimulation, Chemical
  • T-Lymphocytes / metabolism
  • Tissue Fixation


  • Interleukin-16
  • Lipopolysaccharides