24 results on '"Duthoit C"'
Search Results
2. Gene Editing/Gene Therapies: GENE EDITING ON PRIMARY AND STEM CELLS USING BIOLOGICAL RNA DELIVERY APPROACH: KEY SAFETY CONSIDERATIONS FOR GENE THERAPY
- Author
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Duthoit, C., primary, Martin, N., additional, Lindler, L., additional, Iché, A., additional, Gayon, R., additional, Pavlovic, G., additional, Sorg, T., additional, and Bouillé, P., additional
- Published
- 2023
- Full Text
- View/download PDF
3. Induction of tolerance and immunity by redirected B cell-specific cytolytic T lymphocytes
- Author
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Nguyen, P, Duthoit, C T, and Geiger, T L
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- 2007
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4. Dermatomyosite induite par la pravastatine
- Author
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Zuech, P., primary, Pauwels, C., additional, Duthoit, C., additional, Méry, L., additional, Somogyi, A., additional, Louboutin, A., additional, and Veyssier-Belot, C., additional
- Published
- 2005
- Full Text
- View/download PDF
5. Multicenter study on TGPO autoantibody prevalence in various thyroid and non-thyroid diseases; relationships with thyroglobulin and thyroperoxidase autoantibody parameters.
- Author
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Estienne, V., Duthoit, C., Di Costanzo, V., Lejeune, P-J, Rotondi, M., Kornfeld, S., Finke, R., Lazarus, J. H., Feldt-Rasmussen, U., Franke, W. G., Smyth, P., D'Herbomez, M., Conte-Devolx, B., Persani, L., Carella, C., Jourdain, J. R., Izembart, M., Toubert, M-E, Pinchera, A., and Weetman, A.
- Published
- 1999
- Full Text
- View/download PDF
6. Molecular model, calcium sensitivity, and disease specificity of a conformational thyroperoxidase B-cell epitope.
- Author
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Estienne, V, Blanchet, C, Niccoli-Sire, P, Duthoit, C, Durand-Gorde, J M, Geourjon, C, Baty, D, Carayon, P, and Ruf, J
- Abstract
While studying the humoral mechanisms involved in thyroid autoimmunity, we located a B-cell autoepitope in the extracellular C-terminal region of human thyroperoxidase. Structural modeling showed that this region encompasses both a Sushi-like and an epidermal growth factor-like domain, the flexible arrangement of which was putatively stabilized by calcium. The recombinant peptide was found to contain the previously identified conformational thyroperoxidase autoepitope. The occurrence of a calcium-induced conformational change was confirmed using a recombinant peptide monoclonal antibody, the decrease of which in binding to calcium-saturated thyroperoxidase was reversed by a chelating agent. The disease specificity of recombinant peptide, which was more frequently recognized by Hashimoto's than by Graves' patients, adds to its potential value as a diagnostic and preventive tool in the context of B-cell autoimmunity.
- Published
- 1999
7. A conformational B-cell epitope on the C-terminal end of the extracellular part of human thyroid peroxidase.
- Author
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Estienne, V, Duthoit, C, Vinet, L, Durand-Gorde, J M, Carayon, P, and Ruf, J
- Abstract
To investigate the B-cell autoimmune epitopes on human thyroid peroxidase (TPO), we generated proteolytic peptides by enzymatic hydrolysis of TPO in nondenaturing and nonreducing conditions. The hydrolysate was chromatographed on a reverse phase column. We eluted a material immunoreactive with both a TPO monoclonal antibody recognizing a linear epitope (mAb47, amino acid 713-721) and TPO autoantibodies (aAb) from patients. The aAb immunoreactivity, but not that of mAb47, was lost after reduction. Western blots after electrophoresis without reduction showed that the aAb and mAb47 were immunoreactive with a 66-kDa band and that aAb identified a doublet at 20 kDa. For electrophoresis under reducing conditions, the 66-kDa band resolved into two peptides of 40 and 26 kDa, whereas the doublet at 20 kDa remained unchanged. None of these reduced peptides was immunoreactive with aAb, whereas the 40-kDa peptide was immunoreactive with mAb47. The 40-kDa peptide extends from amino acid 549 to 933 of TPO, and its last 192 amino acids overlap the autoimmune 20-kDa peptide. After iodine labeling, the 20-kDa peptide lost its immunoreactivity. We conclude that the C-terminal end of the extracellular part of TPO, which includes all the tyrosine residues of the 20-kDa peptide, contains at least one conformational B-cell epitope involved in autoimmune thyroid diseases.
- Published
- 1998
8. Optical flow image analysis of facial expressions of human emotion - Forensic applications
- Author
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Duthoit, C. J., Sztynda, T., Sara Lal, Jap, B. T., and Agbinya, J. I.
- Subjects
ComputerApplications_MISCELLANEOUS ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION - Abstract
© 2008 ICST. The objective of this study was to induce emotions in individuals to determine if specific facial movements could be detected and analysed by the optical flow technique. This analysis is in the form of motion vector plots. The procedure ascertains if specific emotions can be defined as a set of facial movements which are common to most people when they experience a particular emotion. 'Emotion vector maps' would then be established for specific emotions. These vector sets could then be applied to automated facial image analysis for security/forensic purposes. Individuals were videotaped while watching emotion-inducing short films. After the viewing of each short film, volunteers completed a brief self-reporting questionnaire to establish the emotions they experienced. The image sequences were then analysed according to emotion, by using optical flow analysis. Results were statistically analysed. Trends and analyses are presented in relation to security and video surveillance. Issues and the development of pattern recognition systems applied to human facial images for security purposes are briefly discussed.
9. NEW OR UNCOMMON PLANT DISEASES AND PESTS IN ENGLAND AND WALES
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STOREY, I. F., primary, WILCOX, H. J., additional, DUTHOIT, C. M. G., additional, and NEWTON, H. C. F., additional
- Published
- 1953
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10. Cereal Root Eelworm on Grasses in the West Midlands.
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Duthoit, C. M. G. and Newton, H. C. F.
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HETERODERA ,ORCHARD grass ,GRASSES ,WORMS ,AGRICULTURE - Abstract
This article presents information on Heterodera found on the roots of cocksfoot, Dactylis glomerata. In 1951 plants with cysts on the roots were found in a four-year-old stand of seed cocksfoot at Middleton, England, and on experimental plots in a field at High Hatton, Salop, where oats had been seriously affected by Cereal Root eelworm, cysts were found on perennial ryegrass, Italian ryegrass, cocksfoot, meadow fescue and timothy. Although no biological tests were made, the cysts were carefully examined and are believed to have been Heterodera major.
- Published
- 1953
11. 505 - Tissue Engineering: EFFICIENT AND SAFE DELIVERY OF MULTIPLE BIOLOGICAL mRNAS USING BACTERIOPHAGE-CHIMERIC LENTIVIRUS-LIKE PARTICLES.
- Author
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Gayon, R., Benuzzi, E., Turban, A., Samain, F., Iché, A., Martin, N., Duthoit, C., Garmy-Susini, B., and Bouillé, P.
- Subjects
- *
TISSUE engineering , *TISSUES - Published
- 2023
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12. Development of HPV16 mouse and dog models for more accurate prediction of human vaccine efficacy.
- Author
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Totain E, Lindner L, Martin N, Misseri Y, Iché A, Birling MC, Sorg T, Herault Y, Bousquet-Melou A, Bouillé P, Duthoit C, Pavlovic G, and Boullier S
- Abstract
Background: Animal models are essential to understand the physiopathology of human diseases but also to evaluate new therapies. However, for several diseases there is no appropriate animal model, which complicates the development of effective therapies. HPV infections, responsible for carcinoma cancers, are among these. So far, the lack of relevant animal models has hampered the development of therapeutic vaccines. In this study, we used a candidate therapeutic vaccine named C216, similar to the ProCervix candidate therapeutic vaccine, to validate new mouse and dog HPV preclinical models. ProCervix has shown promising results with classical subcutaneous murine TC-1 cell tumor isografts but has failed in a phase II study., Results: We first generated E7/HPV16 syngeneic transgenic mice in which the expression of the E7 antigen could be switched on through the use of Cre-lox recombination. Non-integrative LentiFlash
® viral particles were used to locally deliver Cre mRNA, resulting in E7/HPV16 expression and GFP reporter fluorescence. The expression of E7/HPV16 was monitored by in vivo fluorescence using Cellvizio imaging and by local mRNA expression quantification. In the experimental conditions used, we observed no differences in E7 expression between C216 vaccinated and control groups. To mimic the MHC diversity of humans, E7/HPV16 transgenes were locally delivered by injection of lentiviral particles in the muscle of dogs. Vaccination with C216, tested with two different adjuvants, induced a strong immune response in dogs. However, we detected no relationship between the level of cellular response against E7/HPV16 and the elimination of E7-expressing cells, either by fluorescence or by RT-ddPCR analysis., Conclusions: In this study, we have developed two animal models, with a genetic design that is easily transposable to different antigens, to validate the efficacy of candidate vaccines. Our results indicate that, despite being immunogenic, the C216 candidate vaccine did not induce a sufficiently strong immune response to eliminate infected cells. Our results are in line with the failure of the ProCervix vaccine that was observed at the end of the phase II clinical trial, reinforcing the relevance of appropriate animal models., (© 2023. The Author(s).)- Published
- 2023
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13. CRISPR/Cas9-mediated gene knockout and interallelic gene conversion in human induced pluripotent stem cells using non-integrative bacteriophage-chimeric retrovirus-like particles.
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Mianné J, Nasri A, Van CN, Bourguignon C, Fieldès M, Ahmed E, Duthoit C, Martin N, Parrinello H, Louis A, Iché A, Gayon R, Samain F, Lamouroux L, Bouillé P, Bourdin A, Assou S, and De Vos J
- Subjects
- Alleles, CRISPR-Cas Systems, Gene Conversion, Gene Editing methods, Gene Knockout Techniques, Humans, RNA metabolism, Retroviridae genetics, Bacteriophages genetics, Induced Pluripotent Stem Cells metabolism
- Abstract
Background: The application of CRISPR/Cas9 technology in human induced pluripotent stem cells (hiPSC) holds tremendous potential for basic research and cell-based gene therapy. However, the fulfillment of these promises relies on the capacity to efficiently deliver exogenous nucleic acids and harness the repair mechanisms induced by the nuclease activity in order to knock-out or repair targeted genes. Moreover, transient delivery should be preferred to avoid persistent nuclease activity and to decrease the risk of off-target events. We recently developed bacteriophage-chimeric retrovirus-like particles that exploit the properties of bacteriophage coat proteins to package exogenous RNA, and the benefits of lentiviral transduction to achieve highly efficient, non-integrative RNA delivery in human cells. Here, we investigated the potential of bacteriophage-chimeric retrovirus-like particles for the non-integrative delivery of RNA molecules in hiPSC for CRISPR/Cas9 applications., Results: We found that these particles efficiently convey RNA molecules for transient expression in hiPSC, with minimal toxicity and without affecting the cell pluripotency and subsequent differentiation. We then used this system to transiently deliver in a single step the CRISPR-Cas9 components (Cas9 mRNA and sgRNA) to generate gene knockout with high indel rate (up to 85%) at multiple loci. Strikingly, when using an allele-specific sgRNA at a locus harboring compound heterozygous mutations, the targeted allele was not altered by NHEJ/MMEJ, but was repaired at high frequency using the homologous wild type allele, i.e., by interallelic gene conversion., Conclusions: Our results highlight the potential of bacteriophage-chimeric retrovirus-like particles to efficiently and safely deliver RNA molecules in hiPSC, and describe for the first time genome engineering by gene conversion in hiPSC. Harnessing this DNA repair mechanism could facilitate the therapeutic correction of human genetic disorders in hiPSC., (© 2021. The Author(s).)
- Published
- 2022
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14. FAK alternative splice mRNA variants expression pattern in colorectal cancer.
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Devaud C, Tilkin-Mariamé AF, Vignolle-Vidoni A, Souleres P, Denadai-Souza A, Rolland C, Duthoit C, Blanpied C, Chabot S, Bouillé P, Lluel P, Vergnolle N, Racaud-Sultan C, and Ferrand A
- Subjects
- Animals, Biomarkers, Tumor genetics, Colorectal Neoplasms genetics, Female, Gene Expression Regulation, Neoplastic, HCT116 Cells, HT29 Cells, Humans, Liver Neoplasms genetics, Liver Neoplasms pathology, Lung Neoplasms genetics, Lung Neoplasms pathology, Mice, Neoplasm Invasiveness, Neoplasm Transplantation, RNA Isoforms genetics, Up-Regulation, Alternative Splicing, Colorectal Neoplasms pathology, Focal Adhesion Kinase 1 genetics, Liver Neoplasms secondary, Lung Neoplasms secondary
- Abstract
The Focal adhesion kinase (FAK) is a ubiquitous cytoplasmic tyrosine-kinase promoting tumor progression and metastasis processes by acting in cancer cells and their tumor microenvironment partners. FAK overexpression in primary colon tumors and their metastasis is associated to poor colorectal cancer (CRC) patients' outcome. Eight FAK mRNA alternative splice variants have been described and contribute to additional level of FAK activity regulation, some of them corresponding to overactivated FAK isoforms. To date, FAK mRNA alternative splice variants expression and implication in CRC processes remain unknown. Here, using different human CRC cells lines displaying differential invasive capacities in an in vivo murine model recapitulating the different steps of CRC development from primary tumors to liver and lung metastasis, we identified three out of the eight mRNA variants (namely FAK
0 , FAK28 and FAK6 ) differentially expressed along the CRC process and the tumor sites. Our results highlight an association between FAK0 and FAK6 expressions and the metastatic potential of the most aggressive cell lines HT29 and HCT116, suggesting that FAK0 and FAK6 could represent aggressiveness markers in CRC. Our findings also suggest a more specific role for FAK28 in the interactions between the tumors cells and their microenvironment. In conclusion, targeting FAK0 , the common form of FAK, might not be a good strategy based on the numerous roles of this kinase in physiological processes. In contrast, FAK6 or FAK28 splice variants, or their corresponding protein isoforms, may putatively represent future therapeutic target candidates in the development of CRC primary tumors and metastasis., (© 2019 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)- Published
- 2019
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15. Highly efficient in vitro and in vivo delivery of functional RNAs using new versatile MS2-chimeric retrovirus-like particles.
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Prel A, Caval V, Gayon R, Ravassard P, Duthoit C, Payen E, Maouche-Chretien L, Creneguy A, Nguyen TH, Martin N, Piver E, Sevrain R, Lamouroux L, Leboulch P, Deschaseaux F, Bouillé P, Sensébé L, and Pagès JC
- Abstract
RNA delivery is an attractive strategy to achieve transient gene expression in research projects and in cell- or gene-based therapies. Despite significant efforts investigating vector-directed RNA transfer, there is still a requirement for better efficiency of delivery to primary cells and in vivo. Retroviral platforms drive RNA delivery, yet retrovirus RNA-packaging constraints limit gene transfer to two genome-molecules per viral particle. To improve retroviral transfer, we designed a dimerization-independent MS2-driven RNA packaging system using MS2-Coat-retrovirus chimeras. The engineered chimeric particles promoted effective packaging of several types of RNAs and enabled efficient transfer of biologically active RNAs in various cell types, including human CD34(+) and iPS cells. Systemic injection of high-titer particles led to gene expression in mouse liver and transferring Cre-recombinase mRNA in muscle permitted widespread editing at the ROSA26 locus. We could further show that the VLPs were able to activate an osteoblast differentiation pathway by delivering RUNX2- or DLX5-mRNA into primary human bone-marrow mesenchymal-stem cells. Thus, the novel chimeric MS2-lentiviral particles are a versatile tool for a wide range of applications including cellular-programming or genome-editing.
- Published
- 2015
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16. A role for VAV1 in experimental autoimmune encephalomyelitis and multiple sclerosis.
- Author
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Jagodic M, Colacios C, Nohra R, Dejean AS, Beyeen AD, Khademi M, Casemayou A, Lamouroux L, Duthoit C, Papapietro O, Sjöholm L, Bernard I, Lagrange D, Dahlman I, Lundmark F, Oturai AB, Soendergaard HB, Kemppinen A, Saarela J, Tienari PJ, Harbo HF, Spurkland A, Ramagopalan SV, Sadovnick DA, Ebers GC, Seddighzadeh M, Klareskog L, Alfredsson L, Padyukov L, Hillert J, Clanet M, Edan G, Fontaine B, Fournié GJ, Kockum I, Saoudi A, and Olsson T
- Subjects
- Animals, CD4-Positive T-Lymphocytes immunology, Encephalomyelitis, Autoimmune, Experimental immunology, Interferon-gamma genetics, Multiple Sclerosis immunology, Polymorphism, Single Nucleotide, Proto-Oncogene Proteins c-vav genetics, Quantitative Trait Loci, Rats, Tumor Necrosis Factor-alpha genetics, Encephalomyelitis, Autoimmune, Experimental physiopathology, Multiple Sclerosis physiopathology, Proto-Oncogene Proteins c-vav physiology
- Abstract
Multiple sclerosis, the most common cause of progressive neurological disability in young adults, is a chronic inflammatory disease. There is solid evidence for a genetic influence in multiple sclerosis, and deciphering the causative genes could reveal key pathways influencing the disease. A genome region on rat chromosome 9 regulates experimental autoimmune encephalomyelitis, a model for multiple sclerosis. Using interval-specific congenic rat lines and association of single-nucleotide polymorphisms with inflammatory phenotypes, we localized the gene of influence to Vav1, which codes for a signal-transducing protein in leukocytes. Analysis of seven human cohorts (12,735 individuals) demonstrated an association of rs2546133-rs2617822 haplotypes in the first VAV1 intron with multiple sclerosis (CA: odds ratio, 1.18; CG: odds ratio, 0.86; TG: odds ratio, 0.90). The risk CA haplotype also predisposed for higher VAV1 messenger RNA expression. VAV1 expression was increased in individuals with multiple sclerosis and correlated with tumor necrosis factor and interferon-gamma expression in peripheral blood and cerebrospinal fluid cells. We conclude that VAV1 plays a central role in controlling central nervous system immune-mediated disease and proinflammatory cytokine production critical for disease pathogenesis.
- Published
- 2009
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17. [Pravastatin-induced dermatomyositis].
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Zuech P, Pauwels C, Duthoit C, Méry L, Somogyi A, Louboutin A, and Veyssier-Belot C
- Subjects
- Aged, Female, Humans, Hypercholesterolemia drug therapy, Time Factors, Anticholesteremic Agents adverse effects, Anticholesteremic Agents therapeutic use, Dermatomyositis chemically induced, Pravastatin adverse effects, Pravastatin therapeutic use
- Abstract
Introduction: The toxic myopathy caused by statins (HMG-CoA reductase inhibitors) is well established. Recent reports add to these effects systemic immune diseases including systemic lupus erythematosus, vasculitis, polymyositis or dermatomyositis., Exegesis: We report a case of dermatomyositis in a 69-year-old patient treated with pravastatin [Elisor]. She presented with typical features of dermatomyositis 2 years after she started a treatment with pravastatin. The treatment was discontinued and she slowly improved, with a transient dermocorticosteroid treatment. Eight other patients with dermatomyositis and chronic treatment with HMG-CoA reductase inhibitors are reported in the literature. All of them presented with classical features of dermatomyositis. The discontinuation of the treatment was followed by spontaneous clinical and biological improvement in 3/9 patients. The other patients received high doses of corticosteroids and improved, except one patient who died of respiratory failure (pulmonary fibrosis) despite the adjunction of oral cyclophosphamide [Endoxan]. In these patients, dermatomyositis can be considered as a severe adverse reaction to HMG-CoA reductase inhibitors although a distinct casual link cannot be definitely established., Conclusion: The increasing prescription of statins has led to the parallel increment of reported side-effects, where autoimmune diseases are now described. Among them, our case of dermatomyositis in a patient receiving pravastatin adds to the eight reported cases in the literature and highlights the potential role of statins as triggers of immune systemic diseases.
- Published
- 2005
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- View/download PDF
18. T cell activation correlates with an increased proportion of antigen among the materials acquired from target cells.
- Author
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Hudrisier D, Riond J, Garidou L, Duthoit C, and Joly E
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- Animals, Biotin metabolism, Cell Line, Tumor, Cells, Cultured, Cytokines metabolism, Histocompatibility Antigens immunology, Interferon-gamma biosynthesis, Mice, Mice, Inbred C57BL, Peptide Fragments immunology, Plasma Cells metabolism, Receptors, Antigen, T-Cell antagonists & inhibitors, Receptors, Antigen, T-Cell biosynthesis, Receptors, Antigen, T-Cell metabolism, T-Lymphocytes, Cytotoxic metabolism, Antigens biosynthesis, Lymphocyte Activation immunology, Plasma Cells immunology, T-Lymphocytes, Cytotoxic immunology
- Abstract
We have investigated the density of peptides required to elicit different biological responses in cytotoxic T lymphocytes (CTL), including trogocytosis (i.e., the phenomenon whereby the lymphocytes actively capture fragments of plasma membrane from those cells with which they establish an immune synapse). We have used two separate mouse models of CTL recognising defined peptides presented by MHC class I molecules. In both systems, triggering of cytotoxicity and capture of membrane components reached saturation with low densities of ligand. On the other hand, down-modulation of cell-surface levels of TCR, induction of IFN-gamma production and detection of peptide captured required much higher ligand densities. Interestingly, fratricide (i.e., killing between CTL sharing the same specificity), a mechanism proposed to account for CTL exhaustion, was detected only at antigen concentrations still well above that second threshold leading to full blown activation. Taken together, our results show that the different thresholds that govern the elicitation of different CTL functions correlate with different proportions of antigen among the target cell components being captured via trogocytosis.
- Published
- 2005
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19. Androgen-dependent expression of FcgammaRIIB2 by thyrocytes from patients with autoimmune Graves' disease: a possible molecular clue for sex dependence of autoimmune disease.
- Author
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Estienne V, Duthoit C, Reichert M, Praetor A, Carayon P, Hunziker W, and Ruf J
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- Antigens, CD genetics, Antigens, CD physiology, Cells, Cultured, Estradiol pharmacology, Gene Expression Regulation, Graves Disease etiology, Humans, Immunoglobulin G metabolism, RNA, Messenger biosynthesis, Receptors, IgG genetics, Receptors, IgG physiology, Sex Factors, Thyroid Gland drug effects, Antigens, CD metabolism, Dihydrotestosterone pharmacology, Graves Disease metabolism, Receptors, IgG metabolism, Thyroid Gland metabolism
- Abstract
Thyrocyte expression of HLA class I and class II antigens and related accessory molecules would convert these epithelial cells into functional antigen-presenting cells. Here we show that whereas normal thyrocytes express FcRn, Graves' disease thyrocytes also express FcgammaRIIB2. We further find that expression of FcgammaRIIB2, but not FcRn, is repressed by dihydrotestosterone. By mediating the uptake and transport of autoantibodies, we suggest that these IgG Fc receptors contribute in various ways to the onset and/or progression of autoimmune thyroid diseases. The androgen-mediated decrease of FcgammaRIIB2 expression in Graves' disease thyrocytes also provides a rationale for the predominant susceptibility of women to develop an autoimmune thyroid disease. Our findings open up a new prospect to autoimmunity, linking the role of the target organ to the sex dependence in autoimmune disease.
- Published
- 2002
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20. Analysis of a conformational B cell epitope of human thyroid peroxidase: identification of a tyrosine residue at a strategic location for immunodominance.
- Author
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Estienne V, Duthoit C, Blanchin S, Montserret R, Durand-Gorde JM, Chartier M, Baty D, Carayon P, and Ruf J
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- Animals, CHO Cells, Circular Dichroism, Cricetinae, DNA Primers, Epitope Mapping, Humans, Immunodominant Epitopes metabolism, Iodide Peroxidase analysis, Iodide Peroxidase genetics, Models, Immunological, Models, Molecular, Molecular Conformation, Mutagenesis, Site-Directed, Recombinant Proteins analysis, Recombinant Proteins metabolism, Transfection, Tyrosine metabolism, Epitopes, B-Lymphocyte chemistry, Iodide Peroxidase immunology, Tyrosine analysis
- Abstract
Thyroid peroxidase (TPO) is involved in autoimmune thyroid diseases and high titers of TPO autoantibodies directed to various conformational B cell epitopes are frequently present in patients' sera. Deciphering these epitopes is a difficult task, but can give insight into the structural basis of autoimmune recognition. TPO is a membrane-bound enzyme with the extracellular part organized in three protein domains, but of unknown three-dimensional structure. We previously localized a TPO B cell epitope within amino acid residues 742-848, a region encompassing the two C-terminal, extracellular domains of the protein. We found that at least one of the three tyrosine residues of the peptide 742-848 might be involved in autoantibody binding. In this study, we show by site-directed mutagenesis that the autoepitope contains tyrosine 772 located near the hinge area between the two protein domains, suggesting they are both involved in the epitope structure. The B cell epitopes of TPO are clustered in two overlapping immunodominant regions. To map the newly localized epitope with respect of these regions, competition experiments were performed using a reference panel of TPO mAb and a further mAb previously found to be specific for the TPO peptide 742-848 at variance with all the other ones. Here, we show that the tyrosine 772-bearing epitope in the peptide 742-848 maps in a region that partly overlaps the reported two immunodominant regions. These results are suggestive of a complex TPO folding that involves all the three TPO protein domains to form a highly conformational immunodominant region.
- Published
- 2002
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21. Hydrogen peroxide-induced production of a 40 kDa immunoreactive thyroglobulin fragment in human thyroid cells: the onset of thyroid autoimmunity?
- Author
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Duthoit C, Estienne V, Giraud A, Durand-Gorde JM, Rasmussen AK, Feldt-Rasmussen U, Carayon P, and Ruf J
- Subjects
- Adenoma surgery, Adult, Cell Death drug effects, Cells, Cultured, Humans, Immunoglobulins, Thyroid-Stimulating immunology, Middle Aged, Oxidation-Reduction, Peptide Fragments immunology, Protein Binding, Thyroid Gland drug effects, Thyroid Neoplasms surgery, Hydrogen Peroxide pharmacology, Peptide Fragments metabolism, Thyroglobulin metabolism, Thyroid Gland metabolism, Thyroiditis, Autoimmune immunology
- Abstract
We recently reported that, during in vitro thyroid-hormone synthesis, H(2)O(2) stress cleaved thyroglobulin (Tg) into C-terminal peptides. These peptides were found to contain the immunodominant region of Tg recognized by Tg autoantibodies from patients with an autoimmune thyroid disease. To test the hypothesis that Tg fragmentation is an early upstream initiating event involved in Tg autoimmune response and the consequence of oxidative injuries, we studied the effect of H(2)O(2) stress on human thyroid cells. In culture conditions allowing Tg synthesis and iodine organification by the cells, we found that bolus addition of increasing millimolar doses of H(2)O(2) induced a dose-response appearance of floating cells in the culture medium. These cells apparently resulted from a necrotic process, and they bore iodinated Tg fragments. These fragments were found to be similar to those previously obtained in vitro from purified Tg. In both cases, Tg peptides were recognized by a well-defined monoclonal antibody directed to the immunodominant region of Tg. The smallest immunoreactive Tg peptide had a molecular mass of 40 kDa and entered human thyrocytes more efficiently than the entire Tg. These data suggest that thyrocytes exposed to locally increased H(2)O(2) doses accumulate fragmented Tg for further delivery into surrounding living thyrocytes in the course of an autoimmune response.
- Published
- 2001
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22. Production of immunoreactive thyroglobulin C-terminal fragments during thyroid hormone synthesis.
- Author
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Duthoit C, Estienne V, Delom F, Durand-Gorde JM, Mallet B, Carayon P, and Ruf J
- Subjects
- Amino Acid Sequence genetics, Epitope Mapping, Humans, Immunologic Techniques, Molecular Sequence Data, Molecular Weight, Peptide Fragments chemistry, Peptide Fragments immunology, Peptide Fragments metabolism, Reactive Oxygen Species metabolism, Thyroglobulin immunology, Thyroglobulin metabolism, Tissue Distribution, Peptide Fragments biosynthesis, Thyroglobulin biosynthesis, Thyroid Hormones biosynthesis
- Abstract
Here, we studied the fragmentation of the prothyroid hormone, thyroglobulin (Tg), which occurs during thyroid hormone synthesis, a process which involves iodide, thyroperoxidase, and the H2O2-generating system, consisting of glucose and glucose oxidase. Various peptides were found to be immunoreactive to autoantibodies to Tg from patients and monoclonal antibodies directed against the immunodominant region of Tg. The smallest peptide (40 kDa) bore thyroid hormones and was identified at the C-terminal end of the Tg molecule, which shows homologies with acetylcholinesterase. Similar peptides were obtained by performing metal-mediated oxidation of Tg via a Fenton reaction. It was concluded that the oxidative stress induced during hormone synthesis generates free radicals, which, in turn, cleave Tg into immunoreactive peptides.
- Published
- 2000
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23. Thyroglobulin monoclonal antibody cross-reacting with thyroperoxidase induces in syngeneic mice anti-idiotypic monoclonal antibodies with dual autoantigen binding properties. The intertope hypothesis.
- Author
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Duthoit C, Estienne V, Durand-Gorde JM, Carayon P, and Ruf J
- Subjects
- Animals, Antibody Affinity, Antibody Specificity, Cross Reactions, Humans, Ligands, Male, Mice, Mice, Inbred BALB C, Antibodies, Monoclonal immunology, Autoantibodies immunology, Autoantigens immunology, Immunoglobulin Idiotypes immunology, Iodide Peroxidase immunology, Thyroglobulin immunology
- Abstract
Autoimmune thyroid diseases are characterized by antibodies (Ab) directed to thyroglobulin (Tg) and thyroperoxidase (TPO). Some of them, TGPO Ab, are Tg Ab with an interspecies idiotype (Id) reacting with TPO. Taking advantage of a carefully studied TGPO monoclonal antibody (mAb), we examined the basis of the hypothesis that TPO Ab would ultimately derive from TGPO Ab through idiotypic induction. We repeatedly immunized naive, syngeneic mice with the TGPO mAb and we derived three novel mAb directed to both Tg and TPO. The most reactive of them, mAb 4F8, was further purified, radiolabeled and its binding properties studied by radioimmunoassay. mAb 4F8 bound to Tg, TPO, the immunogen Ab1 and even to itself, being thus considered as a self-binding Ab2. Competitive binding inhibition experiments demonstrated that Tg, TPO, Ab1 and Ab2 cross-reacted for Ab2 binding to Tg, TPO and Ab1. Fine specificity mapping using panels of specific mAb revealed that Ab1 and Ab2 were similar because they were directed against the same immunodominant regions on Tg and TPO. We propose that unique Id of TGPO Ab resemble dominant epitopes of Tg as well as paratopes of Ab directed against dominant TPO epitopes. This category of Id that we called intertopes may induce TPO-monospecific Ab from TGPO Ab by idiotypically driven somatic mutations.
- Published
- 1999
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24. Genomic organization of the human thyroid hormone receptor alpha (c-erbA-1) gene.
- Author
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Laudet V, Begue A, Henry-Duthoit C, Joubel A, Martin P, Stehelin D, and Saule S
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Chickens, Cloning, Molecular, DNA, Exons, Humans, Introns, Molecular Sequence Data, Multigene Family, Proto-Oncogene Proteins metabolism, RNA Splicing, Restriction Mapping, Sequence Homology, Nucleic Acid, Zinc Fingers, Chromosomes, Human, Pair 17, Proto-Oncogene Proteins genetics, Receptors, Thyroid Hormone genetics
- Abstract
The thyroid hormone receptor alpha (THRA or c-erbA-1) gene belongs to a family of genes which encode nuclear receptors for various hydrophobic ligands such as steroids, vitamin D, retinoic acid and thyroid hormones. These receptors are composed of several domains important for hormone-binding, DNA-binding, dimerization and activation of transcription. We show here that the human THRA gene is organized in 10 exons distributed along 27 kbp of genomic DNA on chromosome 17. The position of the introns in human THRA is highly conserved when compared to the chicken gene despite their differing lengths. The N-terminal A/B domain as well as the 5' untranslated region is encoded by two exons. Interestingly, each of the putative zinc fingers of the receptor DNA-binding domain is encoded by one exon and the hormone-binding domain is assembled from three exons. The two last exons of the gene are alternatively spliced to generate two different messenger RNAs. In addition, we confirm that another gene, belonging to the nuclear receptor superfamily, ear-1, overlaps with the 3' region of THRA in an opposite transcriptional orientation.
- Published
- 1991
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