Rapid identification of PKU-associated mutations by multiplex DGGE analysis of the PAH gene.
Explore the source record for details and available documents.
Electrophoresis↗
Biomedical subjects
J Raus
Publications and source records attributed to J Raus.
T cell vaccination: clinical application in autoimmune diseases.
T cell responses to myelin basic protein (MBP) are implicated to play an important role in the pathogenesis of multiple sclerosis (MS). These MBP autoreactive T cells are found to undergo in vivo activation and clonal expansion in patients with MS. They accumulate in the brain compartment and may reside in the brain lesions of patients with MS. As MBP-reactive T cells potentially hold a central position in initiation and perpetuation of the brain inflammation, specific immune therapies designed to deplete them may improve the clinical course of the disease. We review here the recent application of T cell vaccination in patients with MS to deplete circulating MBP-reactive T cells. The results of our phase I clinical trial indicate that T cell vaccination with inactivated MBP autoreactive T cells induces specific regulatory T cell network of the host immune system to deplete circulating MBP-reactive T cells in a clonotype-specific fashion. The immunity induced by T cell vaccination is clonotype specific and long-lasting. Our longitudinal clinical evaluation further suggests a moderately lower rate of clinical exacerbation, disability score, and brain lesions (measured by magnetic resonance imaging) in vaccinated patients than in matched controls. Our study should encourage further investigation on the treatment efficacy of T cell vaccination and further improvement for its clinical administration in other human autoimmune diseases. This review discusses the immune regulation and therapeutic administration of T cell vaccination in human autoimmune diseases, exemplified by our recent T cell vaccination trial in MS.
Autoimmune Diseases↗
T cell vaccination in multiple sclerosis.
T cell responses to myelin basic protein (MBP) are implicated to play an important role in the pathogenesis of multiple sclerosis (MS). These MBP autoreactive T cells are found to undergo in vivo activation and clonal expansion in patients with MS. They accumulate in the brain compartment and may reside in the brain lesions of patients with MS. As MBP-reactive T cells potentially hold a central position in initiation and perpetuation of the brain inflammation, specific immune therapies designed to deplete them may improve the clinical course of the disease. In this paper, the therapeutic potential of T cell vaccination in the treatment of MS is discussed in context of its immunological and clinical effect. The results of our phase one clinical trial indicate that T cell vaccination with inactivated MBP autoreactive T cells induces specific regulatory T cell network of the host immune system to deplete circulating MBP-reactive T cells in a clonotype-specific fashion. The immunity induced by T cell vaccination is clonotype-specific and long-lasting. Our longitudinal clinical evaluation further suggests a moderate reduction of rate of clinical exacerbation, disability score and the brain lesions (measured by magnetic resonance imaging) in vaccinated patients, as compared to matched controls. Our study should encourage further investigation on the treatment efficacy of T cell vaccination and further improvement for its clinical application.
Autoantibodies↗
Mono- and bispecific single-chain antibody fragments for cancer therapy.
Especially when dealing with solid cancers, single-chain antibody fragments (scFvs) have a lot of advantages. Due to their small size (27 kDa), these proteins clear more rapidly from the blood, and penetrate faster and deeper into tissues, than whole antibodies. Furthermore, the lack of constant regions ensures that they are not retained in tissues such as the liver and kidney. This reduces possible toxic side-effects. Single-chain construction is normally done by polymerase chain reaction (PCR). To decrease the overall cost of oligonucleotide primer synthesis, time-consuming primer design, multiple PCR reactions and individual PCR optimization, we designed a universal single-step overlap extension PCR protocol using hybridoma cDNA as a template. To overcome the lack of effector function, bispecific scFvs, consisting of an scFv produced against a tumour-associated antigen fused to a T cell marker-specific scFv, are being created, starting from already assembled scFv, by means of two additional PCR reactions. In this paper we describe both PCR methods that were successfully used to create scFvs against the human transferrin receptor, the human interleukin-2 receptor, the human CD3 molecule, a breast tumour-associated antigen and an anti-transferrin-anti-CD3 bispecific scFv.
Antibodies, Bispecific↗
Immunotherapy for cancer: construction, expression and functional characterization of chimeric antibodies.
Monoclonal antibodies (Mabs) are a potential key component for the treatment of cancer, because of their specificity and multiple effector functions. Hybridoma technology and progress in genetic engineering made it possible to customize antibody molecules, rendering them more suitable for selective application. A widely used technique is the construction of mouse-human hybrid molecules by recombinant DNA techniques. These so-called chimeric antibodies contain the murine variable (V) regions fused to the human constant (C) regions. In this report, a general approach is described for the production of chimeric antibodies. The gene segments encoding the murine variable heavy and light chain are isolated by the polymerase chain reaction and cloned into expression vectors containing the human gamma 1 heavy chain gene and the human K light chain gene, respectively. Subsequently, these constructs are transfected into a non-Ig-producing murine hybridoma, eg SP2/0 cells. The in vitro study of the functional characteristics and biological properties of the thus obtained chimeric antibodies are discussed.
Antibodies, Monoclonal↗
In vivo clonotypic regulation of human myelin basic protein-reactive T cells by T cell vaccination.
Autoreactive T cells specific for myelin basic protein (MBP) are implicated in the pathogenesis of multiple sclerosis. The mechanism by which MBP-reactive T cells are regulated in vivo remains unknown, but is thought to involve the clonotypic regulatory network that can be induced by immunization with attenuated T cells and TCR peptides. We reported previously that immunization of multiple sclerosis patients with irradiated MBP-reactive T cells (T cell vaccination) induced T cell responses to the immunizing clones, resulting in a clonal depletion of circulating MBP-reactive T cells. In this study, we demonstrated that in the majority of the recipients, MBP-reactive T cells remained undetectable in circulation over a period of 1 to 3 yr after vaccination, while they reappeared in some individuals (three of nine), coinciding with clinical exacerbation. The reappearing MBP-reactive T cells were found to originate from clonal origins different from those of T cells persisting before immunization, suggesting a shift of the T cell repertoire to other determinants of MBP. The immunization induces predominantly CD8+ regulatory T cells capable of lysing the immunizing clones in a clonotype-specific manner. The T cell responses induced by immunization were restricted to the immunizing clones and did not affect MBP-reactive clones not used for immunization. Our data further suggest that different hypervariable regions of the TCR may be involved in the observed clonotypic interaction. This study provides useful information for designing future clinical trials using T cell vaccination and other TCR-based therapeutic strategies.
Amino Acid Sequence↗
Depletion of myelin-basic-protein autoreactive T cells by T-cell vaccination: pilot trial in multiple sclerosis.
In a pilot trial, eight patients with multiple sclerosis were matched to control patients and received T-cell vaccination with irradiated T cells reactive to myelin basic protein (MBP) to deplete circulating MBP-reactive T cells. In the 2 years before and after vaccination, exacerbations decreased in five vaccinated patients (numbers 1, 2, 6-8) with relapsing-remitting disease from sixteen to three, respectively, and from twelve to ten in their matched controls. Magnetic resonance imaging showed a mean 8.0% increase in brain lesion size in the vaccinated patients compared with a 39.5% increase in the controls. Lesions and/or relapses worsened in three cases after vaccination in association with reappearance of circulating MBP-reactive T cells.
Adult↗
Clonal depletion of human myelin basic protein-reactive T-cells by T-cell vaccination.
Explore the source record for details and available documents.
Cytotoxicity, Immunologic↗
Increased frequency of gamma delta T cells in cerebrospinal fluid and peripheral blood of patients with multiple sclerosis. Reactivity, cytotoxicity, and T cell receptor V gene rearrangements.
Infiltrating gamma delta T cells are potentially involved in the central nervous system demyelination in multiple sclerosis (MS). To further study this hypothesis, we analyzed the frequency and functional properties of gamma delta T cells in peripheral blood (PB) and paired cerebrospinal fluid (CSF) of patients with MS and control subjects, including patients with other neurologic diseases (OND) and healthy individuals. The frequency analysis was performed under limiting dilution condition using rIL-2 and PHA. After PHA stimulation, a significantly increased frequency of gamma delta T cells was observed in PB (14.7 x 10(-4)) and in CSF (15.8 x 10(-4)) of MS patients as compared with 4.3 x 10(-4) in PB and 3.9 x 10(-4) detected in CSF of patients with OND. The frequency was represented equally in OND patients and normal individuals. Similarly, the IL-2-responsive gamma delta T cells occurred at a higher frequency in PB of control subjects (1.1 x 10(-4)) in OND patients and 1.5 x 10(-4) in normal individuals). Forty-three percent (13 of 30) of the gamma delta T cell clones isolated from PB and CSF of MS patients responded to heat shock protein (HSP70) but not HSP65, whereas only 2 of 30 control gamma delta T cell clones reacted to the HSP. The majority of the gamma delta T cell clones were able to induce non-MHC-restricted cytolysis of Daudi cells. All clones displayed a substantial reactivity to bacterial superantigens staphylococcal enterotoxin B and toxic shock syndrome toxin-1, irrespective of their gamma delta V gene usage. Furthermore, the gamma delta T cell clones expressed predominantly TCRDV2 and GV2 genes (26 of 35 clones), whereas the clones derived from CSF of MS patients expressed either DV1 or DV2 genes. The obtained gamma delta clones, in general, represented rather heterogeneous clonal origins, even though a predominant clonal origin was found in a set of 10 gamma delta clones derived from one patient with MS. The present study provides new evidence supporting a possible role of gamma delta T cells in the secondary inflammatory processes in MS.
Base Sequence↗
Clonal expansion of myelin basic protein-reactive T cells in patients with multiple sclerosis: restricted T cell receptor V gene rearrangements and CDR3 sequence.
Myelin basic protein (MBP)-reactive T cells are thought to play an important role in the pathogenesis of multiple sclerosis (MS). In some patients with MS, these autoreactive T cells display a limited heterogeneity in their epitope recognition and T cell receptor (TCR) variable (V) gene usage. These individual-dependent properties of MBP-reactive T cells have led to the speculation that they may represent clonal expansion in vivo in some MS patients. In the present study, 51 MBP-reactive T cell clones derived from patients with MS and healthy individuals were examined for their epitope recognition and the TCR V alpha and V beta gene rearrangements. The V gene junctional region sequences of identified alpha and beta genes were further analyzed to probe their clonal origins, as the sequences are unique for individual clones. Our data showed that 26 clones derived from nine patients with MS shared a predominant reactivity to the immunodominant regions of MBP, 84-102, 110-129 and 143-168, and used various TCR V alpha and V beta rearrangements. The V gene usage of the clones was restricted to certain V alpha V beta combination(s) in a given MS patient, but varied among different patients. The sequence analysis revealed that the clones generated from a given patient shared a limited or a single junctional region sequence pattern(s), indicating their oligoclonal or monoclonal origin(s). In contrast, 25 MBP-reactive T cell clones derived from normal individuals exhibited unfocused epitope recognition and V gene usage. Thus, the limited heterogeneity of MBP-reactive T cells in their structural and functional characteristics reflects their clonal expansion in vivo in some patients with MS.
Amino Acid Sequence↗
Superantigen reactivity of gamma delta T cell clones isolated from patients with multiple sclerosis and controls.
gamma delta T cells have been implicated as playing a role in the demyelinating processes of multiple sclerosis (MS). However, the nature of the ligands which lead to activation and accumulation of gamma delta T cells in the brain lesions remains unknown. This study was undertaken to examine whether gamma delta T cells derived from cerebrospinal fluid and blood of MS patients could be stimulated by bacterial superantigens: staphylococcal enterotoxins A and B and toxic shock syndrome toxin-1. A panel of 16 gamma delta T cell clones isolated from MS patients and controls was found to react with the superantigens used at a nanogram range and displayed specific cytotoxic activity toward target cells pulsed with the corresponding superantigens. The responses of the gamma delta T cell clones did not require MHC-matched accessory cells and were not blocked by antibodies to the MHC molecules, suggesting a non-MHC restricted interaction. The superantigen reactivity was associated with both V delta 2+/V gamma 2+ and V delta 1+/V gamma 1+ subsets, reportedly found in the MS lesions. Our data suggest an alternative pathway which may account for gamma delta T cell activation in MS.
B-Lymphocytes↗
Importance of HLA-DRB1 and DQA1 genes and of the amino acid polymorphisms in the functional domain of DR beta 1 chain in multiple sclerosis.
The association of some HLA class II alleles with multiple sclerosis (MS) has been amply documented. In the present study the role of HLA class II haplotypes and genotypes and of polymorphic amino acids at the DR beta 1 locus, located in the antigen binding groove and the CD4 binding domain of the DR beta 1 chain, were studied in 78 unrelated Caucasian chronic progressive MS (CP MS) patients and 204 controls. The results confirmed the positive association of the DRB1*1501 allele and through linkage also of the DRB1*1501-DQA1*0102 haplotype with MS. In addition, the results showed that the DRB1*1501/DRB1*0400 or DR beta 1Ala71+ His13+ genotype conferred the highest relative risk for MS (RR = 9.14). Alleles encoding for DR beta 1Phe47+, DR beta 1Asp70+ and DR beta 1Thr140+, DQ alpha 1Phe25+, DQ alpha 1Leu69+ residues were protective and the highest protection (RR = 0.24) was provided by the DR beta 1(Phe47+)-DQ alpha 1Phe25+ and DR beta 1(Ser13+)-DQ alpha 1Phe25+ haplotypes. Our results suggest that both DQ and DR alpha beta heterodimers might contribute to the increased or decreased risk to develop MS by the shape of their antigen-binding groove.
Adult↗
Activation and clonal expansion of human myelin basic protein-reactive T cells by bacterial superantigens.
Autoreactive T cells specific for myelin basic protein (MBP) are part of the normal T cell repertoire and are present both in patients with multiple sclerosis (MS) and healthy individuals. There is evidence suggesting in vivo activation and persistent clonal expansion of MBP-reactive T cells in MS. This study was undertaken to investigate the potential role of bacterial superantigens (SA) in the activation of MBP-reactive T cells. Twenty-seven MBP-reactive T cell clones generated from 10 MS patients and one normal individual were examined for reactivity to SA, in association with their T cell receptor V beta gene usage. The majority of the clones responded to at least one of the SA tested, staphylococcal enterotoxins (SEA and SEB) and toxic shock syndrome toxin-1 (TSST-1). The clones reactive to SEA and SEB expressed various V beta genes while T cell reactivity to TSST-1 correlated with the V beta 2 expression. Furthermore, circulating MBP-reactive T cells could be expanded from lymphocyte cultures primarily exposed to respective SA in more than 50% of MS patients and normal individuals tested. However, activation and expansion of circulating MBP-reactive T cells by SA was not directly associated with the disease. This study lends support to the potential role of SA in the activation of MBP-reactive T cells and suggests that an altered regulatory mechanism may account for further expansion and persistence of MBP-reactive T cells in MS.
Adult↗
Peptide transporter genes (TAP) polymorphisms and genetic susceptibility to rheumatoid arthritis.
The association of rheumatoid arthritis (RA) with HLA-DRB1 alleles indicates that at least one RA susceptibility gene is linked to the HLA class II region. Transporter associated with protein processing (TAP) genes, which lie upstream of the HLA-structural genes, may also contribute to disease susceptibility. We investigated polymorphisms of the peptide transporter genes, TAP 1 and TAP 2, by PCR-ASO hybridization techniques in 82 RA patients and 66 control individuals. Although there was a suggestion of linkage between some TAP polymorphisms and RA, these seem to be dependent on HLA-DRB1*04, since these positive associations disappeared when HLA-DRB1*04 positive RA patients and controls were compared. Furthermore, no particular TAP allele or haplotype was associated with any clinical or immunological subgroup of RA. We conclude that the TAP genes do not have a major influence on susceptibility to RA in the European Caucasian population.
Adult↗
Quantification of cytokine mRNA expression by RT-PCR and electrochemiluminescence.
Variable gene expression constitutes a major mechanism for controlling cell development and cell function. To investigate these changed mRNA levels, a sensitive and quantitative assay is required. We describe a quick and easy method to quantify specific mRNAs by a combination of PCR and an electrochemiluminescent (ECL) detection of the amplified products. Total cellular RNA is reverse-transcribed and amplified with a biotinylated forward primer and a Tris (2,2'-bipyridine) ruthenium (II) (TBR)-labeled reverse primer. The amplification product is captured on streptavidin-coated paramagnetic beads and quantified by ECL detection using the QPCR system 5000. The results can be converted to quantitative values with an external standard curve. This method permits accurate and reliable quantitation of cytokine mRNA expression.
Clone Cells↗
Quantitative analysis of lymphokine mRNA expression by an automated, non-radioactive method.
Variable gene expression, thus giving rise to variable mRNA levels, constitutes a major mechanism for controlling cell development and cell function. In order to investigate these changed mRNA levels, a sensitive and quantitative assay is required. A quick and easy method is described to quantify specific mRNA's by a combination of the polymerase chain reaction (PCR) and an electro-chemiluminescenct (ECL) detection of the amplified products. Total cellular RNA is reverse transcribed and amplified with a biotinylated forward primer and a TBR (Tris (2,2'-bipyridine) ruthenium (II)) labelled reverse primer. The amplification product is captured on streptavidin-coated paramagnetic beads and quantified by ECL detection using the QPCR system 5000. The results can be converted to quantitative values with an external standard curve. In the present study, cytokine mRNA expression in T lymphocytes was quantified. Cytokine mRNA was measured at the attomolar range in a dynamic range up to three orders of magnitude. The ECL detection is quantitative, rapid and accurate.
Base Sequence↗
Metabolites of 4-chlorotestosterone acetate in cattle urine as diagnostic markers for its illegal use.
Seven metabolites of 4-chlorotestosterone acetate were identified in urine of cattle that received a single injection of the drug. The steroids were isolated by means of a series of clean-up steps carried out before and after enzymatic hydrolysis. The obtained extract was fractionated by high-performance liquid chromatography and each fraction was examined both by high-performance thin-layer chromatography and by capillary gas chromatography-mass spectrometry of the m-ethoxime-trimethylsilyl derivatives. The metabolites were tentatively identified by studying the mass spectra of selected peaks not found in blank samples. The structures of two metabolites, viz. 4-chloroandrost-4-ene-3,17-dione and 4-chloroandrost-4-ene-3 alpha,17 beta-diol were confirmed by chemical synthesis. The synthesized metabolites and 4-chloro-17 alpha-testosterone, a third metabolite which was identified tentatively, were located on the thin-layer chromatograms obtained. This study led to the conclusion that the illegal use of 4-chlorotestosterone acetate can be detected by identifying one or more of its metabolites in urine.
Animals↗
Increased frequency of interleukin 2-responsive T cells specific for myelin basic protein and proteolipid protein in peripheral blood and cerebrospinal fluid of patients with multiple sclerosis.
Equal numbers of CD4+ T cells recognizing myelin basic protein (MBP) and proteolipid protein (PLP) are found in the circulation of normal individuals and multiple sclerosis (MS) patients. We hypothesized that if myelin-reactive T cells are critical for the pathogenesis of MS, they would exist in a different state of activation as compared with myelin-reactive T cells cloned from the blood of normal individuals. This was investigated in a total of 62 subjects with definitive MS. While there were no differences in the frequencies of MBP- and PLP-reactive T cells after primary antigen stimulation, the frequency of MBP or PLP but not tetanus toxoid-reactive T cells generated after primary recombinant interleukin (rIL-2) stimulation was significantly higher in MS patients as compared with control individuals. Primary rIL-2-stimulated MBP-reactive T cell lines were CD4+ and recognized MBP epitopes 84-102 and 143-168 similar to MBP-reactive T cell lines generated with primary MBP stimulation. In the cerebrospinal fluid (CSF) of MS patients, MBP-reactive T cells generated with primary rIL-2 stimulation accounted for 7% of the IL-2-responsive cells, greater than 10-fold higher than paired blood samples, and these T cells also selectively recognized MBP peptides 84-102 and 143-168. In striking contrast, MBP-reactive T cells were not detected in CSF obtained from patients with other neurologic diseases. These results provide definitive in vitro evidence of an absolute difference in the activation state of myelin-reactive T cells in the central nervous system of patients with MS and provide evidence of a pathogenic role of autoreactive T cells in the disease.
Adult↗