Axonal damage induced by invading T cells in organotypic central nervous system tissue in vitro: involvement of microglial cells

Brain Pathol. 2000 Jul;10(3):365-77. doi: 10.1111/j.1750-3639.2000.tb00268.x.

Abstract

Neuroinflammation in the course of multiple sclerosis and experimental autoimmune encephalomyelitis results in demyelination and, recently demonstrated, axonal loss. Invading neuroantigen specific T cells are the crucial cellular elements in these processes. Here we demonstrate that invasion of activated T cells induces a massive microglial attack on myelinated axons in entorhinal-hippocampal slice cultures. Flow cytometry analysis of activation markers revealed that the activation state of invading MBP-specific T cells was significantly lower in comparison to PMA-activated T cells. Moreover, MBP-specific T cells showed a significantly lower secretion of IFN-gamma. Conversely, MBP-specific T cells displayed a significantly higher potential to trigger activation of microglial cells, i.e. upregulation of MHC class II and ICAM-1 expression, and, most importantly, microglial phagocytosis of pre-traced axons. Our data suggest that this was mediated via specific cellular interactions of T cells and microglial cells since IFN-gamma alone was not sufficient to induce axonal damage while such damage was apparent in response to TNF-alpha which is released by activated microglial cells. TNF-alpha secretion by both T cell populations was negligible. Thus, MBP-specific T cells which invade nervous tissue in the course of neuroinflammation are more effective in axon-damaging recruiting microglial cells than activated T cells of other specificities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / pathology*
  • Cell Survival
  • Cytokines / metabolism
  • Entorhinal Cortex / pathology*
  • Hippocampus / pathology*
  • Histocompatibility Antigens Class II / metabolism
  • Intercellular Adhesion Molecule-1 / metabolism
  • Interferon-gamma / pharmacology
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred Strains
  • Microglia / cytology
  • Microglia / drug effects
  • Microglia / physiology*
  • Neurons / physiology
  • Organ Culture Techniques
  • Phagocytosis / drug effects
  • Phagocytosis / physiology
  • T-Lymphocytes / metabolism
  • T-Lymphocytes / physiology*
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Cytokines
  • Histocompatibility Antigens Class II
  • Tumor Necrosis Factor-alpha
  • Intercellular Adhesion Molecule-1
  • Interferon-gamma