Natural killer cell activation after infection with lactate dehydrogenase-elevating virus.

Early after infection, lactate dehydrogenase-elevating virus (LDV) alters the immune system by polyclonally activating B lymphocytes, which leads to IgG2a-restricted hypergammaglobulinaemia, and by suppressing the secretion of Th2 cytokines. Considering that these alterations may involve cells of the innate immune system and cytokines such as interferon-gamma (IFN-gamma), we analysed the effect of LDV on natural killer (NK) cells. Within a few days of infection, a strong and transient NK cell activation, characterized by enhanced IFN-gamma message expression and cytolysis, was observed.

Analysis of the Fv1 alleles involved in the susceptibility of mice to lactate dehydrogenase-elevating virus-induced polioencephalomyelitis.

Development of polioencephalomyelitis in mice infected with lactate dehydrogenase-elevating virus (LDV) requires expression of N-tropic ecotropic MuLV retroviruses. 129/Sv mice are resistant to N-tropic MuLV expression and therefore do not develop LDV-induced polioencephalomyelitis. The Fv1 gene determines the susceptibility to retrovirus replication.

Is there a causal link between hepatitis B vaccination and multiple sclerosis?

After the publication of case reports of hepatitis B vaccinees with onset or relapse of multiple sclerosis (MS), followed by a media-driven scare campaign in France, the perception that hepatitis B vaccine causes MS has developed. This has led to a fall in the acceptance of hepatitis B vaccination particularly in French-speaking communities which was accelerated by court decisions in favour of vaccination "victims" and the suspension of routine vaccination of pre-adolescents in French schools as a "precautionary measure". This situation has arisen in spite of the absence of scientific data to support a causal link between vaccination and multiple sclerosis.

[Viral infection of the central nervous system: from experimental model to human application].

The Daniel's strain of Theiler's virus, a murine picorna virus, induces a neurological disease characterized by an acute encephalomyelitis, followed by a persistent infection of the white matter. This late demyelinating disease is studied as a model for multiple sclerosis because of its chronicity and similarity to the histology of the lesions. This mouse model of viral infection allows a review of the various major aspects of the immune response to an infection of the central nervous system.

The Th1/Th2 balance does not account for the difference of susceptibility of mouse strains to Theiler's virus persistent infection.

Theiler's virus causes a persistent infection with demyelination that is studied as a model for multiple sclerosis. Inbred strains of mice differ in their susceptibility to viral persistence due to both H-2 and non-H-2 genes. A locus with a major effect on persistence has been mapped on chromosome 10, close to the Ifng locus, using a cross between susceptible SJL/J and resistant B10.

Expression of costimulatory molecules and cytokines in CSF and peripheral blood mononuclear cells from multiple sclerosis patients.

We amplified the mRNA for cytokines in peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) cells from 18 multiple sclerosis (MS) patients and 21 other neurological patients, using the reverse transcription polymerase chain reaction (RT-PCR). Radioactive hybridization of the amplified DNA allowed quantitation of mRNA levels. Expression of tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma and interleukin (IL)-10 mRNA was elevated in CSF cells from MS patients.

B7-1 (CD80), B7-2 (CD86), interleukin-12 and transforming growth factor-beta mRNA expression in CSF and peripheral blood mononuclear cells from multiple sclerosis patients.

Costimulatory molecules B7-1 (CD80) and B7-2 (CD86) are differently involved in T cell stimulation. In chronic experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS), B7-1 was preferentially involved in pathophysiology of relapses. We used reverse transcription polymerase chain reaction (RT-PCR) to amplify the mRNA coding for these molecules in cerebrospinal fluid (CSF) cells and peripheral blood mononuclear cells (PBMC) from 18 MS patients and 21 other neurological patients.

Data on cytokine mRNA expression in CSF and peripheral blood mononuclear cells from MS patients as detected by PCR.

Reverse transcription polymerase chain reaction (RT-PCR) was used to amplify the mRNA coding for different cytokines in peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) cells from 18 multiple sclerosis (MS) patients as compared with 21 other neurological patients. mRNA levels were quantitated by radioactive hybridization of the PCR products. Expression of tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and interleukin (IL)-10 mRNA was elevated in CSF cells of MS patients.

Viruses and multiple sclerosis.

Animal models illustrate how viruses and host genetic factors may interact to cause immune-mediated demyelination. Similar mechanisms may take place in at least some forms of multiple sclerosis, a disease that is histopathologically heterogeneous. No 'multiple sclerosis virus' has been found yet, although recent data on human herpesvirus-6 antigens in multiple sclerosis brain warrant further investigation.

Lymphocytic choriomeningitis virus-induced alterations of T helper-mediated responses in mice developing autoimmune hemolytic anemia during the course of infection.

The effect of LCMV on CD4+ T lymphocytes was analyzed in C3HeB/FeJ mice after infection with the Docile strain of this virus. Our results indicated that LCMV triggers: i) an inhibition of Th2 lymphocyte differentiation induced by concomitant immunization with a nonviral protein antigen; ii) a depression of T helper-dependent antibody responses elicited by such an immunization; and iii) a CD4+ cell-mediated proliferation of spleen cells leading to increased interleukin-4 and interferon-gamma message expression and IgG2a-restricted total immunoglobulin secretion. Taken together, these results indicate that LCMV profoundly affects CD4+ cell-mediated immune responses in infected animals.

Diagnosis and clinical management of neurological disorders caused by cytomegalovirus in AIDS patients. European Union Concerted Action on Virus Meningitis and Encephalitis.

Cytomegalovirus (CMV) infections are common and severe complications of HIV infection. The virus involves the nervous system, causing encephalitis, polyradiculomyelitis and peripheral neuropathies. Due to their limited sensitivity, traditional virological approaches, such as virus isolation or antigen detection in the CSF are useful only in limited instances, e.

Encephalitis in immunocompetent patients due to herpes simplex virus type 1 or 2: determination by polymerase chain reaction and detection of intrathecal virus-specific oligoclonal antibodies.

Serum and cerebrospinal fluid (CSF) of 13 patients have been examined to confirm and precise the diagnosis of herpes simplex virus encephalitis (HSVE). By amplifying the DNA with a nested polymerase chain reaction (PCR), we could demonstrate the herpetic origin of these cases of encephalitis. DNA of HSV type 1 or type 2 was directly identified and differentiated, by the use of both type-specific primes in the same reaction.

The infection of mouse by Theiler's virus: from genetics to immunology.

Theiler's virus is a picornavirus of mouse which causes an acute encephalomyelitis followed by a persistent infection of the white matter of the spinal cord with chronic inflammation and demyelination. This late disease is studied as a model for multiple sclerosis. Inbred strains of mice differ in their susceptibility to persistent infection and demyelination.

Involvement of CD4+ cells in the protection of C58 mouse against polioencephalomyelitis induced by lactate dehydrogenase-elevating virus.

Immunosuppression, occurring naturally with aging, or experimentally after cyclophosphamide treatment or irradiation, is required for the development in C58 mice infected with lactate dehydrogenase-elevating virus (LDV) of a severe polioencephalomyelitis that is caused by viral destruction of anterior horn neurons. Here it is shown that depletion of T helper lymphocytes by administration of an anti-CD4 antibody was followed by a progressive paralysis typical of polioencephalomyelitis in C58/J mice inoculated with a neurovirulent strain of LDV. Although it was clear that other cell subsets are also required to assure complete protection of genetically-susceptible mice, our results show that T helper lymphocytes play a major role in the prevention of LDV-induced polioencephalomyelitis.

The detection of intrathecal synthesis of anti-herpes simplex IgG antibodies: comparison between an antigen-mediated immunoblotting technique and antibody index calculations. European Union Concerted Action on Virus Meningitis and Encephalitis.

The detection of intrathecal antibody synthesis was compared by the calculation of antibody indices (AI) derived from ELISA techniques with the detection of virus-specific oligoclonal IgGs by an antigen-mediated capillary blot technique. Twenty-seven paired serum and cerebrospinal fluid (CSF) samples were examined from 15 immunocompetent patients with herpes simplex virus encephalitis (HSE) diagnosed by PCR on early CSF samples. These techniques were also applied to paired samples from 20 multiple sclerosis (MS) patients, 10 patients with other inflammatory neurological diseases and 10 patients with non inflammatory neurological disorders.

Cytokine mRNA expression in CSF and peripheral blood mononuclear cells in multiple sclerosis: detection by RT-PCR without in vitro stimulation.

We amplified the mRNA for cytokines in peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) cells from 18 multiple sclerosis (MS) patients and 21 other neurological patients, using reverse transcription polymerase chain reaction (RT-PCR). A radioactive hybridization of the amplified DNA allowed quantitation of mRNA levels. Expression of tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma and interleukin (IL)-10 mRNA was elevated in CSF cells of MS patients.

IL-4-independent regulation of in vivo IL-9 expression.

We focused on the role of IL-4 in the regulation of the Th2 cytokine IL-9. In vivo, IL-9 mRNA was detected in lymph nodes after immunization with soluble Ags. IL-9 expression preceded that of IL-4, and was not affected in IL-4 knockout mice.

Specific diagnostic methods for herpesvirus infections of the central nervous system: a consensus review by the European Union Concerted Action on Virus Meningitis and Encephalitis.

Background: Herpesvirus infections of the central nervous system are often severe but are fortunately rare. The incidence of these infections has however, increased in recent years as a consequence of an increase in the number of immune-compromised individuals. New diagnostic procedures have improved our ability to diagnose these infections and herpesviruses may yet be implicated as the cause of further neurological diseases with no known aetiology.

The role of laboratory investigation in the diagnosis and management of patients with suspected herpes simplex encephalitis: a consensus report. The EU Concerted Action on Virus Meningitis and Encephalitis.

As effective therapies for the treatment of herpes simplex encephalitis (HSE) have become available, the virology laboratory has acquired a role of primary importance in the early diagnosis and clinical management of this condition. Several studies have shown that the polymerase chain reaction (PCR) of CSF for the detection of herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2) DNA provides a reliable method for determining an aetiological diagnosis of HSE. The use of PCR in combination with the detection of a specific intrathecal antibody response to HSV currently represents the most reliable strategy for the diagnosis and monitoring of the treatment of adult patients with HSE.

The anti-Hu syndrome: a clinical and immunological study of 7 cases.

The authors describe the clinical and biological data of seven patients with anti-Hu antibodies. Six of them displayed a small cell lung carcinoma (SCLC), but no cancer was detected in the 7th patient in spite of an extensive workup. The clinical heterogeneity of the anti-Hu syndrome is emphasized.

The diagnosis of tuberculous meningitis.

The incidence of tuberculosis (TB) is expected to increase substantially during the next 10 years as well as its extrapulmonary manifestations, often in association with the HIV panepidemic. TB meningitis displays some clinical and radiological characteristics but the "gold standard" for diagnosis remains the identification of Mycobacterium tuberculosis in the CSF by direct staining of culture. Direct staining, however, is rarely successful and culturing of M.