Bone marrow derived cells express human T-cell lymphotropic virus type I (HTLV-I)-related antigens in patients with multiple sclerosis.

Abstract

Mononuclear cells in peripheral blood (PB) and cerebrospinal fluid (CSF) of seven patients and lymph nodes of three patients with clinically definite multiple sclerosis (MS) expressed antigens that reacted with monoclonal antibodies (MoAb) specific for HTLV-I p19 and p24 gag proteins. The labelled cells were visualized with immunoperoxidase staining and indirect immunofluorescence and identified at the ultrastructural level with immunogold technique. The frequency of these cells was low, ranging from 0.1% to less than 0.01% in blood. In CSF it was approximately 10 times lower. Cells reacting with anti-p19 Ab were found in all MS samples, whereas cells reacting with anti-p24 Ab were found in 3 out of 6 blood samples and in 3 out of 7 CSF samples. All lymph nodes (3/3) obtained from MS patients contained cells that reacted with anti-HTLV-I. p19 and p24 Ab. Cells reacting with the same AB were detected in blood of one out of 12 healthy controls. Stained cells were irregular, distinctly larger than lymphocytes, and had abundant cytoplasm, suggesting that they may be monocytes/macrophages. Immunogold particles were located in vacuole-like structures in the cytoplasm. The presence in MS patients of cells that react with HTLV-I Ab indicates that a human retroviral genome is being expressed, and suggests that a virus may be present. Our data support a role for a human retrovirus in multiple sclerosis.