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Fornari TA, Donate PB, Macedo C, Marques MMC, Magalhães DA, Passos GAS. Age-related deregulation of Aire and peripheral tissue antigen genes in the thymic stroma of non-obese diabetic (NOD) mice is associated with autoimmune type 1 diabetes mellitus (DM-1). Mol Cell Biochem 2010; 342:21-8. [PMID: 20414703 DOI: 10.1007/s11010-010-0464-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 04/12/2010] [Indexed: 12/16/2022]
Abstract
Gene expression of peripheral tissue antigens (PTAs) in stromal medullary thymic epithelial cells (mTECs) is a key process to the negative selection of autoreactive thymocytes. This phenomenon was termed "promiscuous gene expression" (PGE), which is partially controlled by the Aire gene. Nevertheless, reasons for the correlation of Aire and PTAs with the emergence of autoimmune diseases are largely unknown, though it may be a result of a chronological effect. Although the effect of Aire mutations in pathogenic autoimmunity is well know, it could not be a unique cause for autoimmunity. Independently of mutations, temporal deregulation of Aire expression may imbalance Aire-dependent PTAs and/or wide PGE. This deregulation may be an early warning sign for autoimmune diseases as it guarantees autoantigen representation in the thymus. To assess this hypothesis, we studied the expression levels of Aire, Aire-dependent (Ins2) and Aire-independent (Gad67 and Col2a1) PTAs using real-time-PCR of the thymic stromal cells of NOD mice during the development of autoimmune type 1 diabetes mellitus (DM-1). Wide PGE was studied by microarrays in which the PTA genes were identified through parallel CD80(+) mTEC 3.10 cell line expression profiling. The results show that Aire gene was down-regulated in young pre-autoimmune (pre-diabetic) NOD mice. PGE and specific PTA genes were down-regulated in adult autoimmune diabetic animals. These findings represent evidence indicating that chronological deregulation of genes important to negative selection may be associated with the development of an autoimmune disease (DM-1) in mice.
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Affiliation(s)
- Thaís A Fornari
- Molecular Immunogenetics Group, Department of Genetics, Faculty of Medicine of Ribeirão Preto, University of São Paulo (USP), 3900 Via Bandeirantes, Ribeirão Preto, SP, Brazil
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Dulude G, Cheynier R, Gauchat D, Abdallah A, Kettaf N, Sékaly RP, Gratton S. The magnitude of thymic output is genetically determined through controlled intrathymic precursor T cell proliferation. THE JOURNAL OF IMMUNOLOGY 2008; 181:7818-24. [PMID: 19017971 DOI: 10.4049/jimmunol.181.11.7818] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The thymus plays a crucial role in providing the immune system with naive T cells showing a diverse TCR repertoire. Whereas the diversity of thymic production is mainly ensured by TCR rearrangement at both the TRA and TRB loci, the number of cells reaching the double-positive differentiation stage defines the extent of thymic output. A quantitative analysis of TCR excision circles (TREC; signal-joint TRECs and DJbetaTRECs) produced at different stages of thymopoiesis was performed in nine laboratory mouse strains. The results clearly demonstrate that the magnitude of thymic output is directly proportional to the extent of proliferation in the double-negative 4 thymocyte subset. Strikingly, intrathymic precursor T cell proliferation was found to be strain dependent, thus suggesting a genetic regulation of thymic output. The inherited character of thymic output was further confirmed by the transmission of the phenotype in a recessive fashion in F(1) progeny of the different parental strains. Our results provide the first demonstration of the genetic regulation of thymic output.
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Affiliation(s)
- Gaël Dulude
- Laboratoire d'Immunologie, Centre de Recherches du Centre Hospitalier de l'Université Montréal, Saint-Luc, Montréal, Québec, Canada
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Macedo C, Magalhães DA, Tonani M, Marques MC, Junta CM, Passos GAS. Genes that code for T cell signaling proteins establish transcriptional regulatory networks during thymus ontogeny. Mol Cell Biochem 2008; 318:63-71. [DOI: 10.1007/s11010-008-9857-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2007] [Accepted: 06/13/2008] [Indexed: 01/20/2023]
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Sousa Cardoso R, Magalhães DAR, Baião AMT, Junta CM, Macedo C, Marques MMC, Sakamoto-Hojo ET, Donadi EA, Passos GAS. Onset of promiscuous gene expression in murine fetal thymus organ culture. Immunology 2006; 119:369-75. [PMID: 16903901 PMCID: PMC1819582 DOI: 10.1111/j.1365-2567.2006.02441.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
T-cell differentiation and induction of tolerance to self-antigens occurs mainly in the thymus. Thymic stromal cells, specifically medullary thymic epithelial cells, express a diverse set of genes encoding parenchymal organ-specific proteins. This phenomenon has been termed promiscuous gene expression (PGE) and has been implicated in preventing organ-specific autoimmunity by inducing T-cell tolerance to self antigens. Early thymopoiesis and the critical factors involved in T-cell differentiation can be reproduced in vitro by murine fetal thymus organ culture (FTOC), which mimics the natural thymic microenvironment. To evaluate the occurrence of PGE in FTOC, gene expression profiling during in vitro thymic development in BALB/c mice was performed using a set of nylon cDNA microarrays containing 9216 sequences. The statistical analysis of the microarray data (sam program) revealed the temporal repression and induction of 57 parenchymal and seven lymphoid organ-specific genes. Most of the genes analysed are repressed during early thymic development (15-17 days post-coitum). The expression of the autoimmune regulator (AIRE) gene at 16 days post-coitum marks the onset of PGE. This precedes the induction of parenchymal organ genes during the late developmental phase at 20 days post-coitum. The mechanism of T-cell tolerance induction begins during fetal development and continues into adulthood. Our findings are significant because they show a fine demarcation of PGE onset, which plays a central role in induction of T-cell tolerance.
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Affiliation(s)
- Renato Sousa Cardoso
- Molecular Immunogenetics Group, Department of Genetics, Faculty of Medicine, University of Sao Paulo, Sao Paulo, Brazil
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Marques MMC, Junta CM, Cardoso RS, Mello SS, Sakamoto-Hojo ET, Donadi EA, Passos GAS. Changes in the gene expression profiling of the thymus in response to fibrosarcoma growth. Mol Cell Biochem 2005; 276:81-8. [PMID: 16132688 DOI: 10.1007/s11010-005-3240-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2004] [Accepted: 03/03/2005] [Indexed: 10/25/2022]
Abstract
The aim of this study was to determine whether subcutaneous injection of tumor cells into Balb-c mice, which induces a fibrosarcoma at the site of injection, produced a differential expression profile in the thymus that could be correlated with tumor growth. A dynamic transcriptional profile of the thymus in response to tumor development was observed using nylon cDNA microarrays. The Cluster-Tree View and the SAM programs were used to reveal induced and repressed genes during tumor growth. This experimental model-system showed that this approach is adequate to detect the presence of tumor cells in vivo.
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Affiliation(s)
- Márcia M C Marques
- Molecular Immunogenetics Group, Department of Genetics, Faculty of Medicine, University of São Paulo (USP), 14040-900, Ribeirão Preto, SP, Brazil
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Seltmann M, Horsch M, Drobyshev A, Chen Y, de Angelis MH, Beckers J. Assessment of a systematic expression profiling approach in ENU-induced mouse mutant lines. Mamm Genome 2005; 16:1-10. [PMID: 15674728 DOI: 10.1007/s00335-004-3012-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Accepted: 09/09/2004] [Indexed: 10/25/2022]
Abstract
Comparative genomewide expression profiling is a powerful tool in the effort to annotate the mouse genome with biological function. The systematic analysis of RNA expression data of mouse lines from the Munich ENU mutagenesis screen might support the understanding of the molecular biology of such mutants and provide new insights into mammalian gene function. In a direct comparison of DNA microarray experiments of individual versus pooled RNA samples of organs from ENU-induced mouse mutants, we provide evidence that individual RNA samples may outperform pools in some aspects. Genes with high biological variability in their expression levels (noisy genes) are identified as false positives in pooled samples. Evidence suggests that highly stringent housing conditions and standardized procedures for the isolation of organs significantly reduce biological variability in gene expression profiling experiments. Data on wild-type individuals demonstrate the positive effect of controlling variables such as social status, food intake before organ sampling, and stress with regard to reproducibility of gene expression patterns. Analyses of several organs from various ENU-induced mutant lines in general show low numbers of differentially expressed genes. We demonstrate the feasibility to detect transcriptionally affected organs employing RNA expression profiling as a tool for molecular phenotyping.
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Affiliation(s)
- Matthias Seltmann
- GSF-National Research Center for Environment and Health, Institute of Experimental Genetics, Ingolstaedter Landstr. 1, Neuherberg, D-85764, Germany
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Cardoso RS, Junta CM, Macedo C, Magalhães DAR, Silveira ELV, Paula MO, Marques MMC, Mello SS, Zárate-Bladés CR, Nguyen C, Houlgatte R, Donadi EA, Sakamoto-Hojo ET, Passos GAS. Hybridization signatures of gamma-irradiated murine fetal thymus organ culture (FTOC) reveal modulation of genes associated with T-cell receptor V(D)J recombination and DNA repair. Mol Immunol 2005; 43:464-72. [PMID: 16337489 DOI: 10.1016/j.molimm.2005.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2004] [Accepted: 03/04/2005] [Indexed: 10/25/2022]
Abstract
In this study, we observed the occurrence of TRBV8.1-DB2.1 V(D)J recombination in murine fetal thymus organ culture (FTOC), in which the thymic microenvironment is mimicked. Since ionizing radiation affects T-cell development, we irradiated FTOCs with gamma rays to evaluate the modulation of genes implicated in TRBV8.1-BD2.1 rearrangements. The nylon cDNA microarray method was employed to monitor the expression of 9216 genes, which were organized in coexpression clusters. Clustering analysis showed similar expression profiling of genes implicated in the V(D)J recombination and DNA double strand break (DSB) repair processes such as XRCC4, RAG-2, Artemis and DNA-PK-cs, thus suggesting overlap between the two processes. The RUNX3 gene, whose coded protein binds to the enhancers of TR genes, was also modulated and the DNA cross-linking LR1 gene, which plays a role in the opening of hairpin DNA structures and whose expression pattern is similar to Artemis, may play a role in the control of V(D)J recombination. Furthermore, our data demonstrate that the FTOC model system and cDNA microarray method are useful tools to evidentiate genes that may play a role in both processes V(D)J recombination and DNA repair.
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Affiliation(s)
- Renato S Cardoso
- Molecular Immunogenetics Group, Department of Genetics, Faculty of Medicine, University of São Paulo (USP), 14040-900 Ribeirão Preto, SP, Brazil
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Magalhães DAR, Macedo C, Junta CM, Mello SS, Marques MMC, Cardoso RS, Sakamoto-Hojo ET, Donadi EA, Passos GAS. Hybridization signatures during thymus ontogeny reveals modulation of genes coding for T-cell signaling proteins. Mol Immunol 2004; 42:1043-8. [PMID: 15829294 DOI: 10.1016/j.molimm.2004.09.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Accepted: 09/29/2004] [Indexed: 11/22/2022]
Abstract
Non-manipulated inbred mouse strains constitutes an interesting model-system for in vivo studies on thymus ontogeny due to the possibility to observe the molecular events of the thymocyte maturation. In previous studies, using RT-PCR method, we have found that several immune system genes such as interleukins and MHC are differentially expressed during ontogeny of the thymus whose genes act as modulators of T-cell differentiation. To determine which other genes are modulated on a large-scale basis, we measured the levels of mRNA expression in mouse fetal thymus (14-17 days of gestation) by hybridization with cDNA microarrays containing 1,576 cDNA sequences derived from the IMAGE MTB library. T-cell maturation was monitored by detection of the T-cell receptor beta TRBV8.1-BD2.1 rearranged DNA segment. Each developmental phase of thymus, displayed a characteristic expression profile, as evaluated by the Cluster and Tree-View softwares. Genes differentially and significantly expressed were selected on the basis of significance analysis of the microarray data (SAM program). With the reclustering of only significantly expressed genes, it was possible to characterize the phases of thymus ontogeny, based on the differential profile of expression. Our method provided the detection of genes implicated in the cell signaling, such as the hematopoietic cell signal transducer gene, genes implicated in T-cell calcium influx (tyrosine phosphatase) and calcium signaling proteins (vesicle transport binding protein 3, proline rich Gla, casein kinase alpha 1 and Down syndrome homolog protein 1) and a gene important for the protein transport, including T-cell receptors chains, towards the cell membrane (Golgi SNAP receptor complex member 2). The results demonstrate that the cDNA microarray used to explore the gene expression was useful for understanding the modulation of several cell-signaling genes, including the calcium cascade pathway, which is important for individual stages of T-cell maturation and control of anergy during thymus ontogeny.
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Affiliation(s)
- Danielle A R Magalhães
- Molecular Immunogenetics Group, Department of Genetics, Faculty of Medicine, University of São Paulo (USP), 14040-900 Ribeirão Preto, SP, Brazil
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Espanhol AR, Cardoso RS, Junta CM, Victorero G, Loriod B, Nguyen C, Passos GAS. Large scale gene expression analysis of CBA/J mouse strain fetal thymus using cDNA-array hybridizations. Mol Cell Biochem 2004; 260:65-8. [PMID: 15228087 DOI: 10.1023/b:mcbi.0000026055.24084.98] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The CBA/J inbred mouse strain constitutes an interesting in vivo model-system for studies on molecular genetics of thymus ontogeny. Using RT-PCR method we have found previously that several immune system related genes as interleukins and MHC are differentially expressed. During this period the onset of T-cell receptor beta rearrangements also occur. To know which other genes are modulated during the ontogeny of the thymus, the mRNA expression levels of fetal thymus (15 and 16 days gestation) of CBA/J mouse strain were measured by hybridization with a set of four macroarrays containing a panel of 6,144 IMAGE cDNA clones from MTB thymus library. We found 145 differentially expressed sequences; 44 were up- and 101 down-regulated in the thymus at 15-16 days gestation. Among these sequences, only 20 are identified as genes whose functions are known and 125 are still unknown. Our data demonstrated that, despite intense research on maturation of the immune system focusing on the activity of several well-characterized genes, the large scale expression profile during thymus ontogeny is still an open matter. The use of cDNA-array technology is an affordable method to identify new genes that may play a role in this phenomenon.
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Affiliation(s)
- Aline R Espanhol
- Grupo de Imunogenética Molecular, Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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