The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
S Ciccarese - One of the best experts on this subject based on the ideXlab platform.
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Genomic organization of sheep TRDJ segments and their expression in the delta-chain repertoire in thymus.
Immunogenetics, 2000Co-Authors: S Massari, R Antonacci, C Lanave, S CiccareseAbstract:cDNA sequences obtained from polymerase chain reaction products of reverse-transcribed RNA from sheep thymus showed the presence of a large number of members of the TRDV1 gene family. Some are TRDV1 genes also found in peripheral blood lymphocytes, while four genes had not been described so far. The cDNA sequences also showed extensive Junctional Diversity and a preferential usage of the three TRDJ elements. We characterized the genomic organization of the sheep TRDJ locus and detected a correlation between the nonrandom usage of TRDJ elements during development and their chromosomal order.
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Genomic organization of sheep TRDJ segments and their expression in the δ-chain repertoire in thymus
Immunogenetics, 2000Co-Authors: S Massari, R Antonacci, C Lanave, S CiccareseAbstract:cDNA sequences obtained from polymerase chain reaction products of reverse-transcribed RNA from sheep thymus showed the presence of a large number of members of the TRDV1 gene family. Some are TRDV1 genes also found in peripheral blood lymphocytes, while four genes had not been described so far. The cDNA sequences also showed extensive Junctional Diversity and a preferential usage of the three TRDJ elements. We characterized the genomic organization of the sheep TRDJ locus and detected a correlation between the nonrandom usage of TRDJ elements during development and their chromosomal order.
S Massari - One of the best experts on this subject based on the ideXlab platform.
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Genomic organization of sheep TRDJ segments and their expression in the delta-chain repertoire in thymus.
Immunogenetics, 2000Co-Authors: S Massari, R Antonacci, C Lanave, S CiccareseAbstract:cDNA sequences obtained from polymerase chain reaction products of reverse-transcribed RNA from sheep thymus showed the presence of a large number of members of the TRDV1 gene family. Some are TRDV1 genes also found in peripheral blood lymphocytes, while four genes had not been described so far. The cDNA sequences also showed extensive Junctional Diversity and a preferential usage of the three TRDJ elements. We characterized the genomic organization of the sheep TRDJ locus and detected a correlation between the nonrandom usage of TRDJ elements during development and their chromosomal order.
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Genomic organization of sheep TRDJ segments and their expression in the δ-chain repertoire in thymus
Immunogenetics, 2000Co-Authors: S Massari, R Antonacci, C Lanave, S CiccareseAbstract:cDNA sequences obtained from polymerase chain reaction products of reverse-transcribed RNA from sheep thymus showed the presence of a large number of members of the TRDV1 gene family. Some are TRDV1 genes also found in peripheral blood lymphocytes, while four genes had not been described so far. The cDNA sequences also showed extensive Junctional Diversity and a preferential usage of the three TRDJ elements. We characterized the genomic organization of the sheep TRDJ locus and detected a correlation between the nonrandom usage of TRDJ elements during development and their chromosomal order.
Ellen Hsu - One of the best experts on this subject based on the ideXlab platform.
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Printed in the United States of America IgH Diversity in an Individual with Only One Million
2013Co-Authors: B Lymphocytes, Ada Lee, Solienne Desravines, Ellen HsuAbstract:Immunoglobulin sequences from an individual Xenopus laevis froglet were analyzed for combinatorial and Junctional Diversity. In an animal with about 10 B lymphocytes, at least 26 out of the 56 VH1 genes available in a diploid genome were expressed, as were all JH segments. Junctional Diversity was similar to that observed in Xenopus tadpole sequences, that is, little or no N diversification was found and the recombination site sometimes occurred in a region of V/D or D/J homology. The froglet IgH Diversity is further restricted by the elimination of D-gene participation through direct V to J joining. Of the six complementary-determining regions (CDR) contributing to the structure of the antigen-combining site, CDR3 is the most variable in sequence and structure. Froglet IgH CDR3 are restricted to both aspects. Compared to IgH sequences isolated from a 5-month-old adult, froglet CDR3 were, on the average, two codons shorter; overall, 58 % of the froglet Ig sequences isolated carried CDR3 of-< 7 codons, compared to 30 % of the adult sequences. In addition to being shorter, the tadpole/froglet CDR3 are less variable in sequence, as the absence of N regions also results in the V/D and D/J junctions being derived from germline elements. We therefore suggest that latent anti-adult specificities are not eliminated in situ, in the tadpole, but rather that such germline gene segments, singly or in their combinations thereof, that can potentially react to adult self-epitopes after metamorphosis have been counterselected during the course of evolution
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Junctional Diversity in Xenopus immunoglobulin light chains.
Molecular immunology, 1999Co-Authors: Soléenne Desravines, Ellen HsuAbstract:Xenopus cDNA sequences encoding the homolog of mammalian kappa (kappa) light (L) chains were isolated from isogenic tadpole and adult individuals to investigate whether there existed stage-specific immunoglobulin L chain expression and somatic diversification. In the course of these studies rearrangements to a sixth J(L) gene segment and a pseudogene (J(L)psi) were found, and it is suggested that the order of these gene segments with respect to the L chain constant (C) region exon is: J(L)6-J(L)1-J(L)2-J(L)3-J(L)4-J(L)5-J(L)psi-C(L). The cDNA Junctional Diversity was analyzed; few N and P regions were found and almost all the CDR3 were 9 codons in length. There were restricted patterns of recombination site resolution, and this is attributed to some constraint in JL coding end processing.
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IgH Diversity In an Individual With Only One Million B Lymphocytes
Developmental immunology, 1993Co-Authors: Ada Lee, Soléenne Desravines, Ellen HsuAbstract:Immunoglobulin sequences from an individual Xenopus laevis froglet were analyzed for combinatorial and Junctional Diversity. In an animal with about 106 B lymphocytes, at least 26 out of the 56 VH1 genes available in a diploid genome were expressed, as were all JH segments. Junctional Diversity was similar to that observed in Xenopus tadpole sequences, that is, little or no N diversification was found and the recombination site sometimes occurred in a region of V/D or D/J homology. The froglet IgH Diversity is further restricted by the elimination of D-gene participation through direct V to J joining. Of the six complementary-determining regions (CDR) contributing to the structure of the antigen-combining site, CDR3 is the most variable in sequence and structure. Froglet IgH CDR3 are restricted to both aspects. Compared to IgH sequences isolated from a 5-month-old adult, froglet CDR3 were, on the average, two codons shorter; overall, 58% of the froglet Ig sequences isolated carried CDR3 of ≤ 7 codons, compared to 30% of the adult sequences. In addition to being shorter, the tadpole/froglet CDR3 are less variable in sequence, as the absence of N regions also results in the V/D and D/J junctions being derived from germline elements. We therefore suggest that latent anti-adult specificities are not eliminated in situ, in the tadpole, but rather that such germline gene segments, singly or in their combinations thereof, that can potentially react to adult self-epitopes after metamorphosis have been counterselected during the course of evolution.
Serge Candéias - One of the best experts on this subject based on the ideXlab platform.
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Gene-specific signal joint modifications during V(D)J recombination of TCRAD locus genes in murine and human thymocytes
Immunobiology, 2006Co-Authors: Cédric Touvrey, Evelyne Jouvin-marche, Eve Borel, Patrice Marche, Serge Candéias, C Marche, C CandeiasAbstract:V(D)J recombination assembles functional T-cell receptor (TCR) genes from V, D and J components in developing thymocytes. Extensive processing of V, D and J extremities before they are ligated creates a high degree of Junctional Diversity which results in the generation of a large repertoire of different TCR chains. In contrast, the extremities of the intervening DNA segment, which bear the recombination signal sequences, are generally held to be monomorphic, so that signal joints (SJs) consist of the perfect head-to-head juxtaposition of recombination signal extremities. We analyzed the structure of SJs generated during the recombination of TCRAD locus genes in murine and human thymocytes. Junctional Diversity resulting from N nucleotide additions or from N nucleotide additions and base loss was found for each type of SJ examined. Different patterns of processing/modification were found, suggesting that different enzymatic activities operate during recombination of TCRA and TCRD genes, although they are located within the same genetic locus. Recombination of the deltaRec-1 element generates a diverse repertoire of SJs exhibiting both combinatorial and Junctional Diversity in murine and human thymocytes. Therefore, SJ Diversity appears to be an intrinsic feature of V(D)J recombination in unmanipulated thymocytes.
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Junctional Diversity in signal joints from T cell receptor beta and delta loci via terminal deoxynucleotidyl transferase and exonucleolytic activity.
Journal of Experimental Medicine, 1996Co-Authors: Serge Candéias, K Muegge, S DurumAbstract:The site-specific V(D)J recombination reaction necessary to assemble the genes coding for immunoglobulin (Ig) and T cell receptor (TCR) variable regions is initiated by a precise double strand cut at the border of the recombination signals flanking the genes. Extensive processing of the coding ends before their ligation accounts for most of the Ig and TCR repertoire Diversity. This processing includes both base additions to and loss from the coding ends. On the other hand, it has generally been thought that signal ends are not modified before they are fused, and that signal joints consist of a perfect head-to-head ligation of the recombination signals. In this study, we analyzed signal joints created during the rearrangement of different TCR-beta and TCR-delta genes in thymocytes. We show that a significant fraction (up to 24%) of these signal joints exhibits Junctional Diversity. This Diversity results from N nucleotide additions for TCR-beta signal joints, and from N additions and exonucleolytic digestion for TCR-delta joints. Altogether, our findings suggest that: (a) signal ends can undergo some of the same modifications as coding ends, (b) inversional rearrangement generates more Diversity than deletional events, and (c) fine differences exist in the recombinase/DNA complexes formed at each rearranging locus.
Soléenne Desravines - One of the best experts on this subject based on the ideXlab platform.
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Junctional Diversity in Xenopus immunoglobulin light chains.
Molecular immunology, 1999Co-Authors: Soléenne Desravines, Ellen HsuAbstract:Xenopus cDNA sequences encoding the homolog of mammalian kappa (kappa) light (L) chains were isolated from isogenic tadpole and adult individuals to investigate whether there existed stage-specific immunoglobulin L chain expression and somatic diversification. In the course of these studies rearrangements to a sixth J(L) gene segment and a pseudogene (J(L)psi) were found, and it is suggested that the order of these gene segments with respect to the L chain constant (C) region exon is: J(L)6-J(L)1-J(L)2-J(L)3-J(L)4-J(L)5-J(L)psi-C(L). The cDNA Junctional Diversity was analyzed; few N and P regions were found and almost all the CDR3 were 9 codons in length. There were restricted patterns of recombination site resolution, and this is attributed to some constraint in JL coding end processing.
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IgH Diversity In an Individual With Only One Million B Lymphocytes
Developmental immunology, 1993Co-Authors: Ada Lee, Soléenne Desravines, Ellen HsuAbstract:Immunoglobulin sequences from an individual Xenopus laevis froglet were analyzed for combinatorial and Junctional Diversity. In an animal with about 106 B lymphocytes, at least 26 out of the 56 VH1 genes available in a diploid genome were expressed, as were all JH segments. Junctional Diversity was similar to that observed in Xenopus tadpole sequences, that is, little or no N diversification was found and the recombination site sometimes occurred in a region of V/D or D/J homology. The froglet IgH Diversity is further restricted by the elimination of D-gene participation through direct V to J joining. Of the six complementary-determining regions (CDR) contributing to the structure of the antigen-combining site, CDR3 is the most variable in sequence and structure. Froglet IgH CDR3 are restricted to both aspects. Compared to IgH sequences isolated from a 5-month-old adult, froglet CDR3 were, on the average, two codons shorter; overall, 58% of the froglet Ig sequences isolated carried CDR3 of ≤ 7 codons, compared to 30% of the adult sequences. In addition to being shorter, the tadpole/froglet CDR3 are less variable in sequence, as the absence of N regions also results in the V/D and D/J junctions being derived from germline elements. We therefore suggest that latent anti-adult specificities are not eliminated in situ, in the tadpole, but rather that such germline gene segments, singly or in their combinations thereof, that can potentially react to adult self-epitopes after metamorphosis have been counterselected during the course of evolution.
