Expression of interleukin-16 by tumor-associated macrophages/activated microglia in high-grade astrocytic brain tumors

Arch Immunol Ther Exp (Warsz). Jan-Feb 2007;55(1):41-7. doi: 10.1007/s00005-007-0003-0.

Abstract

Introduction: Macrophages/microglial cells are considered as immune cells in the central nervous system. Interleukin (IL)-16 is a proinflammatory cytokine produced by activated monocytic cells.

Materials and methods: Expression of IL-16 was analyzed by immunohistochemistry in human astrocytic brain tumors and the rat C6 glioblastoma tumor model. IL-16 was detected in both human astrocytic brain tumors and rat C6 glioma.

Results: Compared with human control brains, a significant increase in the percentages of parenchymal IL-16+ macrophages/microglia was observed already in grade II astrocytomas, indicating that IL-16+ immunostaining could be a descriptor of a macrophage/microglia subset in astrocytic brain tumors. A further increase was observed at the transition from grade II to III astrocytomas. This increase in IL-16 immunoreactivity correlated with WHO grades of human astrocytic brain tumors.

Conclusions: Therefore, IL-16 might be a so far unknown factor in the regulation of the local inflammatory milieu of human and experimental astrocytomas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • Astrocytoma / immunology*
  • Astrocytoma / metabolism
  • Brain Neoplasms / immunology*
  • Brain Neoplasms / metabolism
  • Cell Line, Tumor
  • Female
  • Glioblastoma / immunology*
  • Glioblastoma / metabolism
  • Glioblastoma / pathology
  • Humans
  • Inflammation Mediators / metabolism
  • Interleukin-16 / biosynthesis*
  • Macrophages / immunology*
  • Macrophages / pathology
  • Male
  • Microglia / immunology*
  • Microglia / metabolism
  • Middle Aged
  • Rats
  • Rats, Sprague-Dawley

Substances

  • Inflammation Mediators
  • Interleukin-16