Human T cell lines established from the cerebrospinal fluid of patients with human T lymphotropic virus type I-associated myelopathy (HAM)

Correlation between P19 presence and MHC class II expression in human fetal astroglial cells cocultured with HTLV-I donor cells

The possibility of a direct infection of human brain by HTLV-I, has been studied using an in vitro model. Human fetal astroglial cells were cocultivated with irradiated HTLV-I donor cell line MT-2, and assayed for the presence of HTLV-I core protein p19 after 1 week. Fifty-six per cent of GFAP positive astrocytes showed the viral core protein p19 and increased expression of Class II MHC antigens. Electron microscopy of astroglial cells exposed to HTLV-I revealed the presence of vacuoli-like structures containing viral core protein p19. Cell intermediate filament cytoskeleton was also disorganized. Even if this study does not provide direct evidence for virus replication inside astroglial cells, all these findings suggest that HTLV-I can indeed enter the cell and exert a cytopathic effect. Therefore the results of the present study are consistent with the hypothesis that astroglial cells could be involved in demyelination processes occurring in the HTLV-I associated neurological disorders, such as human associated myelopathy and tropical spastic paraparesis.

Effect of human T lymphotropic retrovirus-I exposure on cultured human glioma cell lines

Four different human tumor cell lines of glial origin have been exposed to a human T lymphotropic retrovirus (HTLV-I). All these cell lines were positive for the glial marker glial fibrillary acidic protein (GFAP). The presence of virus RNA was demonstrated by in situ hybridization using an HTLV-I, SStI-SStI viral insert as probe. Virus expression has been monitored through an indirect immunofluorescence assay using a monoclonal antibody against virus core protein p19. All the four glioma cell lines tested became positive for p19 after 2 weeks of co-cultivation and showed a clear alteration of GFAP expression.

Characterization of two human lymphoid cell lines producing human T-lymphotropic virus type I (HTLV-I) isolated from patients with HTLV-I-associated myelopathy or encephalopathy

Two cell lines, CNS-5 and CNS-6, were established by cocultivation of sedimented cells in cerebrospinal fluid (CSF) from two anti-human T-lymphotropic virus type I (HTLV-I) antibody-positive male patients with encephalopathy and HTLV-I-associated myelopathy, respectively, with peripheral blood mononuclear cells from a healthy seronegative female. These cell lines, possessing a normal female karyotype, revealed similar characteristics as follows; they expressed HTLV-I-related antigens, they produced C-type retrovirus particles, HTLV-I provirus genomes were integrated into their DNAs, and they had CD4+ activated T-cell markers. In addition, immunocytochemical and immunoelectron microscopic studies showed peculiar immunoreactivity of these cell lines with anti-alpha/beta T-cell antigen receptor (TCR) antibodies; beta Fl, defining beta chain epitope, was only positive in the perinuclear spaces and rough endoplasmic reticulum in some cells, and WT31, recognizing alpha/beta framework, was mostly negative, while CD3 was expressed in the majority of the cells. These facts indicate that HTLV-I-infected cells were present in CSF of these two patients, and suggest that neurological disorders associated with HTLV-I may not be restricted to myelopathy and may include brain abnormalities.

Activated T lymphocytes in cerebrospinal fluid of patients with HTLV-I-associated myelopathy (HAM/TSP)

In order to detect activated T lymphocytes in the cerebrospinal fluid (CSF) of patients with human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), we studied CSF lymphocytes in untreated patients with HAM/TSP and other neurological diseases (OND). Dual-immunofluorescence staining technique was performed using fluorescence microscopy. No significant difference in the CD4+/CD8+ ratio of CSF lymphocytes was observed between HAM/TSP patients and patients with OND. However, both CD4+ and CD8+ CSF lymphocytes of HAM/TSP patients contained higher percentages of HLA-DR-positive cells than those of patients with OND (P less than 0.05), suggesting that the activated CSF T lymphocytes were composed of both CD4+ and CD8+ subsets in patients with HAM/TSP.

Low-titer antibodies reactive with HTLV-I gag p19 in patients with chronic myeloneuropathy

To elucidate the possible association of human T-lymphotropic virus type I (HTLV-I) and chronic neurological diseases, 156 serum samples from patients with various neurological diseases, including multiple sclerosis, chronic progressive myelopathy, chronic inflammatory polyradiculoneuropathy, myasthenia gravis, polymyositis, motor neuron disease, and tension headache, and healthy control subjects were examined for IgG antibodies to HTLV-I by three independent techniques--gelatin particle agglutination test, enzyme-linked immunosorbent assay, and Western blot assay. Specificity of antibodies was assessed by homologous competitive inhibition on Western blot assay. Six patients (3 with chronic progressive myelopathy, 1 with chronic inflammatory polyradiculoneuropathy, 1 with motor neuron disease, and 1 with tension headache) had high-titer HTLV-I antibodies. Twelve patients (5 with multiple sclerosis, 1 with chronic progressive myelopathy, 2 with chronic inflammatory polyradiculoneuropathy, 2 with myasthenia gravis, and 2 with motor neuron disease) had low-titer HTLV-I antibodies that reacted with a single gag protein, p19 or p24, on Western blot assay. In 4 (2 with multiple sclerosis, 1 with chronic progressive myelopathy, and 1 with chronic inflammatory polyradiculoneuropathy) of these 12, the antibodies that were all directed to p19 were determined to be specific by homologous competitive inhibition. In the remaining 8 patients (3 with multiple sclerosis, 1 with chronic inflammatory polyradiculoneuropathy, 2 with myasthenia gravis, and 2 with motor neuron disease), restricted reactions against p19 or p24 were considered to be nonspecific because they were not inhibited by homologous competitive inhibition. The results suggest that in some patients chronic myeloneuropathy diagnosed as chronic progressive multiple sclerosis, chronic progressive myelopathy, and chronic inflammatory polyradiculoneuropathy may be associated with HTLV-I or related retroviruses.

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

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.

Analysis of the provirus genome integrated in T cell lines established from the cerebrospinal fluid of patients with human T lymphotropic virus type I-associated myelopathy (HAM)

T cell lines were established from the cerebrospinal fluid (CSF) lymphocytes of three patients with human T lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM). To elucidate the possible changes of the provirus nucleotide sequences integrated in HAM-derived T cell line cells, DNA from these cells was digested with PstI, which cleaved the provirus genome of HTLV-I at several sites, and three common bands were detected by Southern blot analysis in all cases. These bands were identical in size to those detected in T cell lines established from peripheral blood lymphocytes of adult T cell leukemia (ATL) patients. These results were confirmed with restriction enzymes HindIII and BamHI. These findings suggest that the provirus genome detected in T cell lines derived from CSF of HAM patients is identical to HTLV-I.