Screening for the illegal use of clostebol acetate in cattle by identification of its urinary metabolites.
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Biomedical subjects
Publications and source records attributed to J Raus.
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Autoreactive T cells specific for myelin proteins, such as myelin basic protein (MBP), are thought to play an important role in the pathogenesis of multiple sclerosis (MS). In MS, these MBP-reactive T cells are activated and clonally expanded in vivo and found to accumulate in the brain compartment, suggesting their pathologic role in the disease. There is experimental evidence supporting the beliefs that MBP-reactive T cells are regulated in vivo by the clonotypic regulatory network. This concept has led to the paradigm of T cell vaccination where attenuated MBP-reactive T cells are used as vaccines to effectively prevent and treat experimental autoimmune encephalomyelitis, an animal model for MS. In this paper, the recent evidence regarding the pathologic relevance of MBP-reactive T cell in MS is reviewed. In particular, we discuss our recent clinical trial in which patients with MS were vaccinated with inactivated autologous MBP-reactive T cell clones to investigate the nature of clonotypic responses in vivo, and whether the responses are effective in depleting circulating MBP-reactive T cells in patients with MS. Our study presented in this paper demonstrated the successful depletion of MBP-reactive T cells by T cell vaccination and touched upon important issues related to the clinical application of T cell vaccination in humans. This review provides new insights into the current development in designing effective therapeutic strategies, such as T cell vaccination, to treat patients with MS and other autoimmune diseases.
There are compelling data to indicate that the susceptibility to multiple sclerosis (MS) is inherited, at least in part. Particular HLA genotypes may be associated with MS and recently also polymorphisms in the T-cell receptor (TCR) genes have been reported to correlate with the disease; however, these data have been difficult to confirm. We investigated the TCRA and TCRB chain genes of HLA-typed Belgian CP MS patients employing four DNA restriction fragment length polymorphisms (RFLPs) detected with TCR constant (TCRAC1, TCRBC2) and variable (TCRBV8, TCRBV11) gene segments. Similar frequencies in patients and controls were observed for all RFLPs studied. Although the HLA DR2 genotype was significantly associated with MS, no interactive effects were seen with MS, DR2, TCRAC1, TCRBC2 and TCRBV alleles. We conclude that, while a clear association with HLA DR2 is observed, little convincing evidence exists for an association of CP MS with RFLPs of the TCRA or TCRB chain genes.
In the present study a tetranucleotide (TGGA)n repeat polymorphism 5' to the myelin basic protein (MBP) gene was evaluated in a group of HLA-class II-typed, chronic progressive multiple sclerosis (MS) patients. This polymorphism has been reported by others to be associated with MS. Contrary to these reports we observed similar allele frequencies in patients and controls. Our results indicate that there is no association between MS and a polymorphism 5' to the MBP gene.
Multiple sclerosis (MS) is known to be associated with HLA-DR2, but it is possible that additional major histocompatibility complex (MHC) genes confer disease susceptibility. The most recent candidate genes for MHC-encoded susceptibility are the TAP genes, which are located between the HLA-DQ and DP loci, and encode for proteins believed to transport antigenic peptides from the cytoplasm into the endoplasmic reticulum. We studied TAP 1 and TAP 2 gene polymorphisms in 65 chronic progressive MS patients and 66 healthy subjects. No significant differences in the frequencies of TAP polymorphisms were observed between both groups. These data suggest that TAP is not a susceptibility gene for MS and that the disease-predisposing haplotype does not extend as far as TAP.
When residues of nortestosterone (NT) were found in the urine of cattle, racehorses or bodybuilders, exogenic administration was thought to be proven. In previous literature, no records were found of the endogenic presence of this molecule. In the horse-racing world, Houghton and Courthot found that NT is normally present in the urine of the stallion. Belgian and Dutch researchers found that NT is also present in the urine and edible parts of the intact boar. Vandenbroeck et al. (1991) suggested the endogenous presence of NT (in the beta form) in the pregnant cow. Meyer (1992) reported the presence of NT (in the alpha form) in relatively high amounts in the urine of the cow peri-partum and the neo-natal calf. These observations may have important consequences for veterinary meat inspection in the EU. Therefore, in Belgium a large scale experiment was set up in co-operation with the EU Community Reference Laboratory (RIVM). In this paper the present state of the results in this area is presented. A large number of urine samples (> 50) of pregnant non-treated cows were collected and analysed by gas chromatography-mass spectrometry (GC-MS) in 4 different laboratories. Further samples (> 100) were taken, but only analysed in one laboratory. The results proved clearly that NT may indeed be detectable in the alpha form in the urine of pregnant cows, from at least 2 months, but most probably from 4-5 months before partus.
We evaluated the TNF-beta gene polymorphism in two HLA-associated autoimmune diseases, multiple sclerosis (MS) and rheumatoid arthritis (RA). The TNF-beta allele and genotype frequencies were not significantly different in the patient populations, compared to controls. An increased frequency of the TNF-beta*2 allele was observed in HLA-DR2+ vs. HLA-DR2- MS patients. No such association was seen in HLA-DR4+ RA patients.
In order to identify new susceptibility markers for Rheumatoid Arthritis (RA), we analysed the dinucleotide repeat polymorphism at the T cell receptor delta locus (TCRD) in 65 RA patients and 99 healthy Belgian controls. A significant under-representation of the A4-A5 TCRD genotype was observed in the RA population.
OBJECTIVES: To investigate whether T-cell receptor (TCR) beta chain germline alleles, either alone or in combination with a particular HLA-genotype, are associated with rheumatoid arthritis (RA). METHODS: Three restriction fragment length polymorphisms (RFLPs), detected with TCR constant (TCRBC2) and variable (TCRBV8, TCRBV11) gene segments were analysed in a representative group of Belgian, HLA class II-typed patients with RA, and in a group of Belgian control subjects. RESULTS: The study confirmed the known association of RA with the HLA-DRB1*0401/0404 genotype (RR = 2.14, 95% CI = 1.16-4.00) in the Belgian RA population. This association was even more pronounced in the patients with more severe RA (RR = 3.26, 95% CI = 1.55-6.89). These data suggest that the HLA-DRB1*04 genotype can be used as a marker for disease severity. Similar frequencies in patients and controls were observed for all TCRB RFLPs studied, and this was in spite of subgrouping the RA population according to criteria for disease stratification. CONCLUSION: While a clear association with HLA DRB1*0401/0404 is observed, no interactive effects were seen with RA, DR4, TCRBC2 and TCRBV alleles, implying that the combined presence of these polymorphic markers does not cause an increased susceptibility to RA, and does not predispose for more aggressive RA, nor for familial aggregation of the disease. These results argue against the hypothesis that TCRB polymorphisms play a crucial role in the susceptibility for RA.
Six MS-patients were inoculated three times with autologous attenuated MBP-specific T cell clones at two month intervals. No toxic effects were observed. After the third inoculation the precursor frequency of the MBP-specific T cells dropped to undetectable levels in all patients. Injection of attenuated MBP-specific T cells gave rise to a pronounced response of anti-clonotypic T cells and a limited anti-ergotypic response. The anti-clonotypic T cells proliferated in the presence of the vaccine clones and were inhibitory and cytotoxic for the same vaccine clones. This clinical trial shows for the first time that antigen specific T cell vaccination in humans is feasible. The results obtained are highly promising for future treatments of Multiple Sclerosis and other autoimmune diseases.
Activated autoreactive T cells are potentially pathogenic and regulated by clonotypic networks. Experimental autoimmune diseases can be treated by inoculation with autoreactive T cells (T cell vaccination). In the present study, patients with multiple sclerosis were inoculated with irradiated myelin basic protein (MBP)-reactive T cells. T cell responses to the inoculates were induced to deplete circulating MBP-reactive T cells in the recipients. Regulatory T cell lines isolated from the recipients inhibited T cells used for vaccination. The cytotoxicity of the CD8+ T cell lines was restricted by major histocompatibility antigens. Thus, clonotypic interactions regulating autoreactive T cells in humans can be induced by T cell vaccination.
A murine/human chimeric antibody, with specificity for the human interleukin-2 receptor, was developed by genetic engineering. For this purpose, the light and heavy chain variable region exons encoding the murine monoclonal antibody 2C8 were isolated and inserted into expression vectors containing the human kappa and gamma-1 constant regions. After transfection by electroporation of the chimeric genes into murine Sp 2/0 hybridoma cells, transfectomas secreting the complete chimeric antibody were selected. The chimeric antibody has similar binding properties as the original murine antibody. The in vitro cytotoxic effects of the murine and the chimeric antibodies were compared.
Recently, we have established that major depression is characterized by hyperhaptoglobinemia, which may be regarded as an index of an "acute" phase response in that illness. The present study investigates the psychopathological correlates of increased plasma concentrations of haptoglobin (Hp) in major depression. To this end, the authors studied the Hp levels in relation to depressive items of the Structured Clinical Interview for DSM-III (SCID) and the Hamilton Rating Scale for Depression (HRSD) in 90 depressed subjects. There was a significant positive relationship between the SCID symptoms anorexia/weight loss, sleep, and psychomotor disorders and Hp plasma concentrations. Hp plasma levels were significantly and positively correlated with overall severity of illness (HRSD). The HRSD symptom correlates of higher Hp levels were loss of interest, middle insomnia, and psychomotor retardation. Up to 31.4% of the variance in Hp plasma values could be explained by psychomotor disorders, anorexia, weight loss, middle insomnia, and less diurnal variation of mood. It is suggested that hyperhaptoglobinemia, as an index of an "acute" phase response in major depression, is related to the somatic dimension of depressive illness.
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Some groups have recently reported higher titers of autoantibodies in depressed subjects than in normal controls. The present study investigates whether depressed patients exhibit increased antiphospholipid antibody titers compared with normal controls. The authors measured the binding index (BI) of antiphosphatidylserine (APSA), antipartial thromboplastin (APTA) and anticardiolipin (ACA) in 22 minor, 23 simple major and 20 melancholic depressives, 10 healthy controls and 104 normal controls with negative autoantibody sera. Depressed subjects exhibited significantly higher APSA and APTA antibody titers compared with normal controls. A large number of depressed subjects (+/- 54%) showed APTA and APSA positivity, defined as BI > or = 2 standard deviations above the mean BI of normal controls. There was a significant discrimination (> or = 2.8 standard deviations) between melancholic subjects and healthy controls with respect to BI of ACA, APSA and APTA. However, by using a more conservative value for phospholipid positivity (i.e., BI > or = 5 standard deviations above the mean BI of a reference sample of normal sera), the subject's autoantibody titers were, on the whole, within the normal range. Our results point towards a higher expression of antiphospholipid antibodies during depression but a much lower incidence of positive patients than in classical autoimmune disorders, such as systemic lupus erythematosus.
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