Base de dados : MEDLINE
Pesquisa : G05.365.036 [Categoria DeCS]
Referências encontradas : 1357 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 136 ir para página                         

  1 / 1357 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29320559
[Au] Autor:Rettig TA; Ward C; Bye BA; Pecaut MJ; Chapes SK
[Ad] Endereço:Division of Biology, Kansas State University, Manhattan, Kansas, United States of America.
[Ti] Título:Characterization of the naive murine antibody repertoire using unamplified high-throughput sequencing.
[So] Source:PLoS One;13(1):e0190982, 2018.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Antibody specificity and diversity are generated through the enzymatic splicing of genomic gene segments within each B cell. Antibodies are heterodimers of heavy- and light-chains encoded on separate loci. We studied the antibody repertoire from pooled, splenic tissue of unimmunized, adult female C57BL/6J mice, using high-throughput sequencing (HTS) without amplification of antibody transcripts. We recovered over 90,000 heavy-chain and over 135,000 light-chain immunoglobulin sequences. Individual V-, D-, and J-gene segment usage was uniform among the three mouse pools, particularly in highly abundant gene segments, with low frequency V-gene segments not being detected in all pools. Despite the similar usage of individual gene segments, the repertoire of individual B-cell CDR3 amino acid sequences in each mouse pool was highly varied, affirming the combinatorial diversity in the B-cell pool that has been previously demonstrated. There also was some skewing in the V-gene segments that were detected depending on chromosomal location. This study presents a unique, non-primer biased glimpse of the conventionally housed, unimmunized antibody repertoire of the C57BL6/J mouse.
[Mh] Termos MeSH primário: Especificidade de Anticorpos
Linfócitos B/imunologia
Cadeias Pesadas de Imunoglobulinas/genética
Cadeias Leves de Imunoglobulina/genética
Região Variável de Imunoglobulina/genética
[Mh] Termos MeSH secundário: Animais
Diversidade de Anticorpos
Linfócitos B/metabolismo
Feminino
Sequenciamento de Nucleotídeos em Larga Escala/métodos
Camundongos
Camundongos Endogâmicos C57BL
Análise de Sequência de DNA/métodos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Immunoglobulin Heavy Chains); 0 (Immunoglobulin Light Chains); 0 (Immunoglobulin Variable Region)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180212
[Lr] Data última revisão:
180212
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180111
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0190982


  2 / 1357 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28924003
[Au] Autor:Greiff V; Weber CR; Palme J; Bodenhofer U; Miho E; Menzel U; Reddy ST
[Ad] Endereço:Department of Biosystems Science and Engineering, Swiss Federal Institute of Technology Zurich, CH-4058 Basel, Switzerland.
[Ti] Título:Learning the High-Dimensional Immunogenomic Features That Predict Public and Private Antibody Repertoires.
[So] Source:J Immunol;199(8):2985-2997, 2017 Oct 15.
[Is] ISSN:1550-6606
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Recent studies have revealed that immune repertoires contain a substantial fraction of public clones, which may be defined as Ab or TCR clonal sequences shared across individuals. It has remained unclear whether public clones possess predictable sequence features that differentiate them from private clones, which are believed to be generated largely stochastically. This knowledge gap represents a lack of insight into the shaping of immune repertoire diversity. Leveraging a machine learning approach capable of capturing the high-dimensional compositional information of each clonal sequence (defined by CDR3), we detected predictive public clone and private clone-specific immunogenomic differences concentrated in CDR3's N1-D-N2 region, which allowed the prediction of public and private status with 80% accuracy in humans and mice. Our results unexpectedly demonstrate that public, as well as private, clones possess predictable high-dimensional immunogenomic features. Our support vector machine model could be trained effectively on large published datasets (3 million clonal sequences) and was sufficiently robust for public clone prediction across individuals and studies prepared with different library preparation and high-throughput sequencing protocols. In summary, we have uncovered the existence of high-dimensional immunogenomic rules that shape immune repertoire diversity in a predictable fashion. Our approach may pave the way for the construction of a comprehensive atlas of public mouse and human immune repertoires with potential applications in rational vaccine design and immunotherapeutics.
[Mh] Termos MeSH primário: Linfócitos B/fisiologia
Regiões Determinantes de Complementaridade/genética
Imunoterapia/métodos
Receptores de Antígenos de Linfócitos B/genética
Receptores de Antígenos de Linfócitos T/genética
Linfócitos T/fisiologia
Vacinas/imunologia
[Mh] Termos MeSH secundário: Animais
Diversidade de Anticorpos
Seleção Clonal Mediada por Antígeno
Células Clonais
Conjuntos de Dados como Assunto
Sequenciamento de Nucleotídeos em Larga Escala
Seres Humanos
Camundongos
Camundongos Endogâmicos BALB C
Camundongos Endogâmicos C57BL
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Complementarity Determining Regions); 0 (Receptors, Antigen, B-Cell); 0 (Receptors, Antigen, T-Cell); 0 (Vaccines)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171101
[Lr] Data última revisão:
171101
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:170920
[St] Status:MEDLINE
[do] DOI:10.4049/jimmunol.1700594


  3 / 1357 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28757211
[Au] Autor:Qiao Q; Wang L; Meng FL; Hwang JK; Alt FW; Wu H
[Ad] Endereço:Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
[Ti] Título:AID Recognizes Structured DNA for Class Switch Recombination.
[So] Source:Mol Cell;67(3):361-373.e4, 2017 Aug 03.
[Is] ISSN:1097-4164
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Activation-induced cytidine deaminase (AID) initiates both class switch recombination (CSR) and somatic hypermutation (SHM) in antibody diversification. Mechanisms of AID targeting and catalysis remain elusive despite its critical immunological roles and off-target effects in tumorigenesis. Here, we produced active human AID and revealed its preferred recognition and deamination of structured substrates. G-quadruplex (G4)-containing substrates mimicking the mammalian immunoglobulin switch regions are particularly good AID substrates in vitro. By solving crystal structures of maltose binding protein (MBP)-fused AID alone and in complex with deoxycytidine monophosphate, we surprisingly identify a bifurcated substrate-binding surface that explains structured substrate recognition by capturing two adjacent single-stranded overhangs simultaneously. Moreover, G4 substrates induce cooperative AID oligomerization. Structure-based mutations that disrupt bifurcated substrate recognition or oligomerization both compromise CSR in splenic B cells. Collectively, our data implicate intrinsic preference of AID for structured substrates and uncover the importance of G4 recognition and oligomerization of AID in CSR.
[Mh] Termos MeSH primário: Citidina Desaminase/metabolismo
DNA/metabolismo
Switching de Imunoglobulina
Região de Troca de Imunoglobulinas
Recombinação Genética
[Mh] Termos MeSH secundário: Desaminases APOBEC/genética
Desaminases APOBEC/metabolismo
Animais
Diversidade de Anticorpos
Linfócitos B/enzimologia
Linfócitos B/imunologia
Citidina Desaminase/química
Citidina Desaminase/genética
DNA/química
DNA/genética
Seres Humanos
Camundongos
Modelos Moleculares
Mutação
Conformação de Ácido Nucleico
Ligação Proteica
Conformação Proteica
Baço/enzimologia
Baço/imunologia
Relação Estrutura-Atividade
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
9007-49-2 (DNA); EC 3.5.4.- (AICDA (activation-induced cytidine deaminase)); EC 3.5.4.5 (APOBEC Deaminases); EC 3.5.4.5 (Cytidine Deaminase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:171007
[Lr] Data última revisão:
171007
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170801
[St] Status:MEDLINE


  4 / 1357 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28505201
[Au] Autor:Fantini M; Pandolfini L; Lisi S; Chirichella M; Arisi I; Terrigno M; Goracci M; Cremisi F; Cattaneo A
[Ad] Endereço:Bio@SNS Laboratory, Scuola Normale Superiore, Pisa, Italy.
[Ti] Título:Assessment of antibody library diversity through next generation sequencing and technical error compensation.
[So] Source:PLoS One;12(5):e0177574, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Antibody libraries are important resources to derive antibodies to be used for a wide range of applications, from structural and functional studies to intracellular protein interference studies to developing new diagnostics and therapeutics. Whatever the goal, the key parameter for an antibody library is its complexity (also known as diversity), i.e. the number of distinct elements in the collection, which directly reflects the probability of finding in the library an antibody against a given antigen, of sufficiently high affinity. Quantitative evaluation of antibody library complexity and quality has been for a long time inadequately addressed, due to the high similarity and length of the sequences of the library. Complexity was usually inferred by the transformation efficiency and tested either by fingerprinting and/or sequencing of a few hundred random library elements. Inferring complexity from such a small sampling is, however, very rudimental and gives limited information about the real diversity, because complexity does not scale linearly with sample size. Next-generation sequencing (NGS) has opened new ways to tackle the antibody library complexity quality assessment. However, much remains to be done to fully exploit the potential of NGS for the quantitative analysis of antibody repertoires and to overcome current limitations. To obtain a more reliable antibody library complexity estimate here we show a new, PCR-free, NGS approach to sequence antibody libraries on Illumina platform, coupled to a new bioinformatic analysis and software (Diversity Estimator of Antibody Library, DEAL) that allows to reliably estimate the complexity, taking in consideration the sequencing error.
[Mh] Termos MeSH primário: Anticorpos/genética
Diversidade de Anticorpos/genética
Biblioteca Gênica
Sequenciamento de Nucleotídeos em Larga Escala
[Mh] Termos MeSH secundário: Anticorpos/imunologia
Diversidade de Anticorpos/imunologia
Análise por Conglomerados
Biologia Computacional/métodos
Simulação por Computador
Seres Humanos
Anticorpos de Cadeia Única/genética
Anticorpos de Cadeia Única/imunologia
Recombinação V(D)J
Fluxo de Trabalho
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antibodies); 0 (Single-Chain Antibodies)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170920
[Lr] Data última revisão:
170920
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170516
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0177574


  5 / 1357 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28215280
[Au] Autor:Methot SP; Di Noia JM
[Ad] Endereço:Institut de Recherches Cliniques de Montréal (IRCM), Montreal, QC, Canada; Mcgill University, Montreal, QC, Canada. Electronic address: stephenpatrick.methot@ircm.qc.ca.
[Ti] Título:Molecular Mechanisms of Somatic Hypermutation and Class Switch Recombination.
[So] Source:Adv Immunol;133:37-87, 2017.
[Is] ISSN:1557-8445
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In order to promote an efficient humoral immune response, germinal center B cells modify both the antigen recognition and effector domains by programmed genetic alterations of their antibody genes. To do so, B cells use the enzyme activation-induced deaminase (AID), which transforms deoxycytidine into deoxyuridine at the immunoglobulin genes, triggering mutagenic DNA repair. Data accumulated during the past decade have significantly advanced our understanding of how AID activity is regulated and preferentially targeted to the immunoglobulin genes. There is also a better understanding of the ways by which AID-catalyzed uracil is recognized and the ensuing downstream processing underpinning the mechanisms of somatic hypermutation and class switch recombination. Here, we critically review these advances in the context of their relevance for the humoral immune response. A detailed understanding of these molecular mechanisms is paramount to uncover the basis of B cell intrinsic immunodeficiency, as well as to suggest tools and strategies that might allow boosting antibody gene diversification in the context of immunizations or infections that require the elicitation of rare or highly mutated antibody variants.
[Mh] Termos MeSH primário: Linfócitos B/imunologia
Imunidade Humoral
Switching de Imunoglobulina
Síndromes de Imunodeficiência/imunologia
Hipermutação Somática de Imunoglobulina
[Mh] Termos MeSH secundário: Animais
Diversidade de Anticorpos/genética
Citidina Desaminase
Seres Humanos
Recombinação Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
EC 3.5.4.- (AICDA (activation-induced cytidine deaminase)); EC 3.5.4.5 (Cytidine Deaminase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170803
[Lr] Data última revisão:
170803
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170221
[St] Status:MEDLINE


  6 / 1357 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28179494
[Au] Autor:Gupta NT; Adams KD; Briggs AW; Timberlake SC; Vigneault F; Kleinstein SH
[Ad] Endereço:Interdepartmental Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520.
[Ti] Título:Hierarchical Clustering Can Identify B Cell Clones with High Confidence in Ig Repertoire Sequencing Data.
[So] Source:J Immunol;198(6):2489-2499, 2017 Mar 15.
[Is] ISSN:1550-6606
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Adaptive immunity is driven by the expansion, somatic hypermutation, and selection of B cell clones. Each clone is the progeny of a single B cell responding to Ag, with diversified Ig receptors. These receptors can now be profiled on a large scale by next-generation sequencing. Such data provide a window into the microevolutionary dynamics that drive successful immune responses and the dysregulation that occurs with aging or disease. Clonal relationships are not directly measured, but they must be computationally inferred from these sequencing data. Although several hierarchical clustering-based methods have been proposed, they vary in distance and linkage methods and have not yet been rigorously compared. In this study, we use a combination of human experimental and simulated data to characterize the performance of hierarchical clustering-based methods for partitioning sequences into clones. We find that single linkage clustering has high performance, with specificity, sensitivity, and positive predictive value all >99%, whereas other linkages result in a significant loss of sensitivity. Surprisingly, distance metrics that incorporate the biases of somatic hypermutation do not outperform simple Hamming distance. Although errors were more likely in sequences with short junctions, using the entire dataset to choose a single distance threshold for clustering is near optimal. Our results suggest that hierarchical clustering using single linkage with Hamming distance identifies clones with high confidence and provides a fully automated method for clonal grouping. The performance estimates we develop provide important context to interpret clonal analysis of repertoire sequencing data and allow for rigorous testing of other clonal grouping algorithms.
[Mh] Termos MeSH primário: Diversidade de Anticorpos
Processamento Automatizado de Dados/métodos
Linfócitos B/fisiologia
[Mh] Termos MeSH secundário: Imunidade Adaptativa/genética
Evolução Biológica
Células Clonais
Análise por Conglomerados
Biologia Computacional
Simulação por Computador
Conjuntos de Dados como Assunto
Ligação Genética
Sequenciamento de Nucleotídeos em Larga Escala
Seres Humanos
Imunoglobulinas/genética
Hipermutação Somática de Imunoglobulina
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Immunoglobulins)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170915
[Lr] Data última revisão:
170915
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:170210
[St] Status:MEDLINE
[do] DOI:10.4049/jimmunol.1601850


  7 / 1357 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28135270
[Au] Autor:Wang S
[Ad] Endereço:Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California, United States of America.
[Ti] Título:Optimal Sequential Immunization Can Focus Antibody Responses against Diversity Loss and Distraction.
[So] Source:PLoS Comput Biol;13(1):e1005336, 2017 Jan.
[Is] ISSN:1553-7358
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Affinity maturation is a Darwinian process in which B lymphocytes evolve potent antibodies to encountered antigens and generate immune memory. Highly mutable complex pathogens present an immense antigenic diversity that continues to challenge natural immunity and vaccine design. Induction of broadly neutralizing antibodies (bnAbs) against this diversity by vaccination likely requires multiple exposures to distinct but related antigen variants, and yet how affinity maturation advances under such complex stimulation remains poorly understood. To fill the gap, we present an in silico model of affinity maturation to examine two realistic new aspects pertinent to vaccine development: loss in B cell diversity across successive immunization periods against different variants, and the presence of distracting epitopes that entropically disfavor the evolution of bnAbs. We find these new factors, which introduce additional selection pressures and constraints, significantly influence antibody breadth development, in a way that depends crucially on the temporal pattern of immunization (or selection forces). Curiously, a less diverse B cell seed may even favor the expansion and dominance of cross-reactive clones, but only when conflicting selection forces are presented in series rather than in a mixture. Moreover, the level of frustration due to evolutionary conflict dictates the degree of distraction. We further describe how antigenic histories select evolutionary paths of B cell lineages and determine the predominant mode of antibody responses. Sequential immunization with mutationally distant variants is shown to robustly induce bnAbs that focus on conserved elements of the target epitope, by thwarting strain-specific and distracted lineages. An optimal range of antigen dose underlies a fine balance between efficient adaptation and persistent reaction. These findings provide mechanistic guides to aid in design of vaccine strategies against fast mutating pathogens.
[Mh] Termos MeSH primário: Vacinas contra a AIDS/imunologia
Diversidade de Anticorpos/genética
Diversidade de Anticorpos/imunologia
Linfócitos B/imunologia
Modelos Genéticos
Modelos Imunológicos
[Mh] Termos MeSH secundário: Vacinas contra a AIDS/genética
Anticorpos Neutralizantes/genética
Anticorpos Neutralizantes/imunologia
Afinidade de Anticorpos/genética
Afinidade de Anticorpos/imunologia
Reações Antígeno-Anticorpo/genética
Reações Antígeno-Anticorpo/imunologia
Linfócitos B/citologia
Evolução Biológica
Sobrevivência Celular/genética
Sobrevivência Celular/imunologia
Células Cultivadas
Simulação por Computador
Variação Genética
Seres Humanos
Imunização/métodos
Esquemas de Imunização
Fenômenos Imunogenéticos/genética
Modelos Estatísticos
Processos Estocásticos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (AIDS Vaccines); 0 (Antibodies, Neutralizing)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170616
[Lr] Data última revisão:
170616
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170131
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pcbi.1005336


  8 / 1357 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27828971
[Au] Autor:Walther S; Tietze M; Czerny CP; König S; Diesterbeck US
[Ad] Endereço:Department of Animal Sciences, Institute of Veterinary Medicine, Division of Microbiology and Animal Hygiene, Faculty of Agricultural Sciences, Georg-August University Goettingen, Goettingen, Germany.
[Ti] Título:Development of a Bioinformatics Framework for the Detection of Gene Conversion and the Analysis of Combinatorial Diversity in Immunoglobulin Heavy Chains in Four Cattle Breeds.
[So] Source:PLoS One;11(11):e0164567, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:We have developed a new bioinformatics framework for the analysis of rearranged bovine heavy chain immunoglobulin (Ig) variable regions by combining and refining widely used alignment algorithms. This bioinformatics framework allowed us to investigate alignments of heavy chain framework regions (FRHs) and the separate alignments of FRHs and heavy chain complementarity determining regions (CDRHs) to determine their germline origin in the four cattle breeds Aubrac, German Black Pied, German Simmental, and Holstein Friesian. Now it is also possible to specifically analyze Ig heavy chains possessing exceptionally long CDR3Hs. In order to gain more insight into breed specific differences in Ig combinatorial diversity, somatic hypermutations and putative gene conversions of IgG, we compared the dominantly transcribed variable (IGHV), diversity (IGHD), and joining (IGHJ) segments and their recombination in the four cattle breeds. The analysis revealed the use of 15 different IGHV segments, 21 IGHD segments, and two IGHJ segments with significant different transcription levels within the breeds. Furthermore, there are preferred rearrangements within the three groups of CDR3H lengths. In the sequences of group 2 (CDR3H lengths (L) of 11-47 amino acid residues (aa)) a higher number of recombination was observed than in sequences of group 1 (L≤10 aa) and 3 (L≥48 aa). The combinatorial diversity of germline IGHV, IGHD, and IGHJ-segments revealed 162 rearrangements that were significantly different. The few preferably rearranged gene segments within group 3 CDR3H regions may indicate specialized antibodies because this length is unique in cattle. The most important finding of this study, which was enabled by using the bioinformatics framework, is the discovery of strong evidence for gene conversion as a rare event using pseudogenes fulfilling all definitions for this particular diversification mechanism.
[Mh] Termos MeSH primário: Diversidade de Anticorpos/genética
Bovinos/genética
Biologia Computacional/métodos
Conversão Gênica
Cadeias Pesadas de Imunoglobulinas/genética
[Mh] Termos MeSH secundário: Algoritmos
Animais
Diversidade de Anticorpos/imunologia
Cruzamento
Bovinos/classificação
Bovinos/imunologia
Regiões Determinantes de Complementaridade/genética
Regiões Determinantes de Complementaridade/imunologia
Expressão Gênica/genética
Expressão Gênica/imunologia
Rearranjo Gênico do Linfócito B/genética
Rearranjo Gênico do Linfócito B/imunologia
Cadeias Pesadas de Imunoglobulinas/imunologia
Região Variável de Imunoglobulina/genética
Região Variável de Imunoglobulina/imunologia
Análise de Sequência de DNA
Hipermutação Somática de Imunoglobulina/genética
Hipermutação Somática de Imunoglobulina/imunologia
Especificidade da Espécie
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Complementarity Determining Regions); 0 (Immunoglobulin Heavy Chains); 0 (Immunoglobulin Variable Region)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170703
[Lr] Data última revisão:
170703
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161110
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0164567


  9 / 1357 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27497872
[Au] Autor:Butler JE; Santiago-Mateo K; Wertz N; Sun X; Sinkora M; Francis DL
[Ad] Endereço:Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA. Electronic address: john-butler@uiowa.edu.
[Ti] Título:Antibody repertoire development in fetal and neonatal piglets. XXIV. Hypothesis: The ileal Peyer patches (IPP) are the major source of primary, undiversified IgA antibodies in newborn piglets.
[So] Source:Dev Comp Immunol;65:340-351, 2016 12.
[Is] ISSN:1879-0089
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The ileal Peyers patches (IPP) of newborn germfree (GF) piglets were isolated into blind loops and the piglets colonized with a defined probiotic microflora. After 5 weeks, IgA levels in the intestinal lavage (IL) of loop piglets remained at GF levels and IgM comprised ∼70% while in controls, IgA levels were elevated 5-fold and comprised ∼70% of total Igs. Loop piglets also had reduced serum IgA levels suggesting the source of serum IgA had been interrupted. The isotype profile for loop contents was intermediate between that in the IL of GF and probiotic controls. Surprisingly, colonization alone did not result in repertoire diversification in the IPP. Rather, colonization promoted pronounced proliferation of fully switched IgA(+)IgM(-) B cells in the IPP that supply early, non-diversified "natural" SIgA antibodies to the gut lumen and a primary IgA response in serum.
[Mh] Termos MeSH primário: Linfócitos B/fisiologia
Íleo/imunologia
Imunoglobulina A Secretora/genética
Nódulos Linfáticos Agregados/imunologia
Suínos/imunologia
[Mh] Termos MeSH secundário: Animais
Animais Recém-Nascidos
Diversidade de Anticorpos
Diferenciação Celular
Proliferação Celular
Células Cultivadas
Microbioma Gastrointestinal/imunologia
Vida Livre de Germes
Switching de Imunoglobulina
Imunoglobulina M/genética
Memória Imunológica
Ativação Linfocitária
Probióticos/administração & dosagem
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Immunoglobulin A, Secretory); 0 (Immunoglobulin M)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171120
[Lr] Data última revisão:
171120
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160808
[St] Status:MEDLINE


  10 / 1357 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27469325
[Au] Autor:Prigent J; Lorin V; Kök A; Hieu T; Bourgeau S; Mouquet H
[Ad] Endereço:Laboratory of Humoral Response to Pathogens, Department of Immunology, Institut Pasteur, Paris, France.
[Ti] Título:Scarcity of autoreactive human blood IgA memory B cells.
[So] Source:Eur J Immunol;46(10):2340-2351, 2016 Oct.
[Is] ISSN:1521-4141
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Class-switched memory B cells are key components of the "reactive" humoral immunity, which ensures a fast and massive secretion of high-affinity antigen-specific antibodies upon antigenic challenge. In humans, IgA class-switched (IgA ) memory B cells and IgA antibodies are abundant in the blood. Although circulating IgA memory B cells and their corresponding secreted immunoglobulins likely possess major protective and/or regulatory immune roles, little is known about their specificity and function. Here, we show that IgA and IgG memory B-cell antibodies cloned from the same healthy humans share common immunoglobulin gene features. IgA and IgG memory antibodies have comparable lack of reactivity to vaccines, common mucosa-tropic viruses and commensal bacteria. However, the IgA memory B-cell compartment contains fewer polyreactive clones and importantly, only rare self-reactive clones compared to IgG memory B cells. Self-reactivity of IgAs is acquired following B-cell affinity maturation but not antibody class switching. Together, our data suggest the existence of different regulatory mechanisms for removing autoreactive clones from the IgG and IgA memory B-cell repertoires, and/or different maturation pathways potentially reflecting the distinct nature and localization of the cognate antigens recognized by individual B-cell populations.
[Mh] Termos MeSH primário: Diversidade de Anticorpos
Autoanticorpos/metabolismo
Linfócitos B/fisiologia
Imunoglobulina A/metabolismo
Memória Imunológica
[Mh] Termos MeSH secundário: Afinidade de Anticorpos
Formação de Anticorpos
Autoantígenos/metabolismo
Autoimunidade
Seleção Clonal Mediada por Antígeno
Células Clonais
Seres Humanos
Switching de Imunoglobulina
Imunoglobulina G/metabolismo
Análise de Célula Única
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Autoantibodies); 0 (Autoantigens); 0 (Immunoglobulin A); 0 (Immunoglobulin G)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170628
[Lr] Data última revisão:
170628
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160730
[St] Status:MEDLINE
[do] DOI:10.1002/eji.201646446



página 1 de 136 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde