Apoptosis of T lymphocytes in the spinal cord lesions in HTLV-I-associated myelopathy: a possible mechanism to control viral infection in the central nervous system

J Neuropathol Exp Neurol. 1994 Nov;53(6):617-24. doi: 10.1097/00005072-199411000-00009.

Abstract

Immunocytochemical staining of spinal cords from five autopsied patients with HAM/TSP was performed using the monoclonal antibody TIA-1, a marker of cytotoxic T lymphocytes (CTL). Many TIA-1+, CD8+ cells are distributed in active inflammatory lesions. The number of TIA-1+ cells is related to the amount of HTLV-I proviral DNA in situ. The protein TIA-1 has been associated with the induction of apoptosis in target cells. In active inflammatory lesions, we found cells undergoing apoptosis, most of them identified as helper-inducer CD45RO T lymphocytes, which were consistent with in vivo cellular tropism of HTLV-I in patients with HAM/TSP. These findings suggest that CTL-induced apoptosis of T lymphocytes may be one of the possible mechanisms which eliminate HTLV-I-infected cells from the central nervous system. In addition, many T lymphocytes in the inflammatory lesions expressed bcl-2 oncoprotein, suggesting that infiltrated T lymphocytes may be resistant to apoptosis. Expression of bcl-2 oncoprotein may explain the longstanding inflammatory process in the central nervous system of HAM/TSP.

MeSH terms

  • Antibodies, Monoclonal
  • Apoptosis*
  • DNA, Viral / analysis
  • Humans
  • Immunotherapy*
  • Paraparesis, Tropical Spastic / pathology*
  • Paraparesis, Tropical Spastic / therapy*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-bcl-2
  • Spinal Cord Diseases / pathology
  • Spinal Cord Diseases / therapy*
  • T-Lymphocytes, Cytotoxic / immunology*

Substances

  • Antibodies, Monoclonal
  • DNA, Viral
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2