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Quantification of B cells and T lymphocyte subsets in bovine leukemia virus infected dairy cows

Melville Paiva Della Libera, Alice Maria; Blagitz, Maiara Garcia; Batista, Camila Freitas; Latorre, Andreia Oliveira; Stricagnolo, Claudia Regina; de Souza, Fernando Nogueira
Fonte: UNIV ESTADUAL LONDRINA; LONDRINA Publicador: UNIV ESTADUAL LONDRINA; LONDRINA
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
56.04%
The aim of the present trial was to determine the frequencies and absolute number of B and T lymphocytes subpopulations in bovine leukemia virus (BLV)-infected dairy cows with distinct lymphocyte profile known as non-leukemic (AL) and persistent lymphocytosis (PL). Thus, 15 animals were selected and divided uniformly in three groups (negative, AL, PL). The BLV infection was detected by agar gel immunodiffusion and enzyme-linked immunosorbent-assay. The lymphocytes subsets were evaluated using monoclonal antibodies by flow cytometry. The results of the present study pointed out to an increase in B lymphocytes, and also an augment in CD5(+) and CD11b(+) cells in animals showing PL. Consequently, it can be observed a decrease in the percentage of T cells subsets in these animals. Conversely, no significant alterations in the absolute number of the T lymphocytes, T CD4(+) cells and T CD8(+) lymphocytes were found in BLV-infected dairy cows with PL. Therefore, the correlation between the absolute numbers of B- and T cell subsets in the peripheral blood applied to each group showed a significant and positive strong correlation between numbers of B cells and T cells or T CD8(+) cells in the PL animals, although the same cannot be predicted for T CD4(+) lymphocytes. No such correlation was encountered for the AL and negative-control animals.; Sao Paulo State Research Foundation (FAPESP); Sao Paulo State Foundation Research (FAPESP) [07/56069-8]

Análise da detecção de C4d, linfócitos B e plasmócitos no processo de rejeição ao aloenxerto renal; Analysis of C4d, B lymphocytes and plasma cells detection in the renal allograft rejection

Martins, Hugo Ludovico
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/04/2010 Português
Relevância na Pesquisa
66.09%
A rejeição ao aloenxerto mediada por mecanismos celulares ou humorais representa uma importante complicação no pós-transplante renal. Estudos anteriores demonstraram que o depósito de C4d peritubular é um marcador de rejeição mediada por anticorpos. A técnica padrão ouro para a pesquisa de C4d é a imunofluorescência em criostato. No entanto, o manuseio do material congelado implica em algumas limitações custo-operacionais, particularmente em nosso meio. Nos casos de rejeição mediada por anticorpos é de relevância patogenética a análise da participação de linfócitos B e plasmócitos, pois são as células responsáveis pela produção de anticorpos. Considerando que até o momento o envolvimento de linfócitos B e plasmócitos no processo de rejeição foi pouco investigado, no presente estudo também será analisada a expressão de CD20 e CD138 em biópsias renais, para caracterização destes componentes celulares. Portanto, o objetivo do presente estudo foi analisar a detecção do fragmento C4d por meio de 4 diferentes técnicas, além de analisar o infiltrado de linfócitos B e plasmócitos em biópsias de enxerto renal, correlacionando estes achados com o C4d peritubular. Foram analisadas 107 biópsias de 82 pacientes submetidos a transplante renal. A pesquisa do C4d foi realizada utilizando-se as técnicas de imunofluorescência [IF] (em cortes de criostato e de parafina) e imuno-histoquímica [IH] (em cortes de criostato e de parafina)...

Tolerância operacional no transplante renal humano: repertório de linfócitos B e de alo e autoanticorpos; Operational tolerance in human kidney transplantation: repertoire of B lymphocytes and alo and autoantibodies

Silva, Hernandez Moura
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 25/04/2011 Português
Relevância na Pesquisa
65.94%
A indução de tolerância imunológica ao aloenxerto, no contexto clínico, permanece um grande desafio para pesquisa científica de tradução. A retirada da imunossupressão em indivíduos transplantados leva à rejeição do enxerto, na grande maioria dos casos. Entretanto, um grupo muito raro de indivíduos transplantados, chamados de tolerantes operacionais (TO), consegue manter a função estável do enxerto após a retirada dos imunossupressores. O estudo desses indivíduos pode contribuir para melhor compreensão dos mecanismos envolvidos na tolerância ao enxerto em humanos, assim como, para a determinação de biomarcadores desse estado de homeostase. Nosso objetivo foi determinar se o estado de tolerância operacional no transplante renal induz um perfil diferencial do componente humoral da resposta imune. Para tal, analisamos o perfil de reatividade de autoanticorpos dirigidos a peptídeos da proteína de choque térmico 60 (HSP60), de alo e autoanticorpos dirigidos às moléculas HLA, o repertório do receptor de células B (BCR) e o perfil funcional de células B supressoras CD19+CD24hiCD38hi (Bregs), comparativamente, nos indivíduos com: TO (n=5), Rejeição Crônica (RC, n=13), função estável do enxerto usando doses habituais de imunossupressores (Est...

Regulação da homeostasia do retículo endoplasmático em linfócitos B na imunodeficiência comum variável.; Regulation of homeostasis of endoplasmic reticulum in B lymphocytes in common variable immunodeficiency.

Rosa, Susana Elaine Alves da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/09/2011 Português
Relevância na Pesquisa
65.98%
A imunodeficiência comum variável (CVID) é caracterizada por hipogamaglobulinemia. Anteriormente identificou-se uma paciente com CVID que apresenta nível aumentado de estresse de retículo endoplasmático (ER), secundário a desregulação da via UPR. No presente trabalho, estendemos esta análise para outros pacientes e avaliamos o perfil de maturação de seus linfócitos B. Métodos: Western-blot, RT-PCR, Q-PCR, Citometria de Fluxo e cultura de células B ex vivo e imortalizadas. Resultados: A análise de 16 pacientes com CVID e 9 indivíduos saudáveis revelou três pacientes com porcentagens aumentadas de linfócitos B imaturos no sangue periférico. A análise da expressão de RNAm para BiP e XBP-1 em linfócitos B destes pacientes, após estímulo com LPS in vitro, identificou que os linfócitos B de um deles apresenta estresse de RE. Conclusão: Identificamos um subgrupo de pacientes com CVID que apresentam linfócitos B imaturos no sangue periférico. Um membro deste subgrupo apresenta estresse aumentado de ER.; Common Variable Immunodeficiency (CVID) is characterized by hypogammaglobulinemia. Previously a CVID patient was identified with increased levels of Endoplasmic Reticulum (ER) stress due to dysregulation of the UPR. In the present study these analyses were performed in other patients and healthy donors. Maturation markers of B lymphocytes were also characterized in these individuals. Methods: Western-blot...

Invasin of Yersinia pseudotuberculosis is not a polyclonal activator of mouse B lymphocytes

De Medeiros, Beatriz Maria Machado; Cangiani, E. E.; Higuti, L.; Satomi, L. C.; Souza, C. D.; Silva, A. R C; Maia, J. M L; Falcão, D. P.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 221-227
Português
Relevância na Pesquisa
65.96%
It is known that the invasin molecule of Yersinia pseudotuberculosis stimulates human peripheral B cells in vitro. In this work we evaluated the in vivo role of invasin as polyclonal activator of B lymphocytes in the mouse experimental model, by comparing strains of Y. pseudotuberculosis expressing invasin and isogenic inv mutants. Swiss mice were infected intravenously with two strains expressing invasin (YpIII pIB1 and an isogenic virulence plasmid-cured strain, YpIII) and with two invasin mutant strains (Yp100 pIB1 and Yp100, plasmid-cured). Spleen cells were sampled on days 7, 14, 21 and 28 after infection. Immunoglobulin (Ig)-secreting spleen cells were detected by protein A plaque assay and specific antibodies were detected in sera by ELISA. The virulent strain YPIII pIB1 (wild type) did not provoke polyclonal activation of B lymphocytes in vivo. In general, fewer Ig-secreting spleen cells of all isotypes were found in the infected animals than in the control animals. Specific IgG antibodies were detected in the sera of animals infected with all strains. The peak response occurred on the 21 st day post-infection, and the Yp100 strain provoked the highest level of these antibodies. We concluded that invasin is not a polyclonal activator of murine B cells.

A study of T CD4, CD8 and B lymphocytes in narcoleptic patients

Coelho,Fernando Morgadinho Santos; Pradella-Hallinan,Márcia; Alves,Gabriela Rodrigues; Bittencourt,Lia Rita Azeredo; Pedrazzoli Neto,Mário; Moreira,Fábio; Tufik,Sérgio
Fonte: Academia Brasileira de Neurologia - ABNEURO Publicador: Academia Brasileira de Neurologia - ABNEURO
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2007 Português
Relevância na Pesquisa
56.04%
Narcolepsy is characterized by excessive daytime sleep and cataplexy. Little is known about the possible difference in pathophysiology between patients with or without cataplexy. OBJECTIVE: To quantify T CD4, T CD8 and B lymphocytes in subgroups of patients with narcolepsy and the presence or absence of the HLA-DQB1*0602 allele between groups. METHOD: Our study was prospective and controlled (transversal) with 22 narcoleptic patients and 23 health control subjects. Patients underwent an all-night polysomnographic recording (PSG) and a multiple sleep latency Test (MSLT). The histocompatibility antigen allele (HLA-DQB1*0602), T CD4, CD8 and B lymphocytes were quantified in control subjects and in narcoleptics. RESULTS: The HLA-DQB1*0602 allele was identified in 10 (62.5%) of our 16 cataplexic subjects and in 2 (33.3%) of the 6 patients without cataplexy (p=0.24). In control subjects, HLA-DQB1*0602 allele was identified in 5 (20%). A significant decrease in T CD4 and B lymphocytes was found in narcoleptic patients with recurrent cataplexy when compared with our patients without cataplexy. CONCLUSION: Autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis were associated with a decrease in sub-group of T CD4 and B lymphocytes. A drop in B lymphocytes count in reumathoid arthritis might...

Blastogenesis and Lymphokine Synthesis by T and B Lymphocytes from Patients with Periodontal Disease

Mackler, B. F.; Altman, L. C.; Wahl, S.; Rosenstreich, D. L.; Oppenheim, J. J.; Mergenhagen, S. E.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1974 Português
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56.05%
Thymus-derived (T) and bone marrow-derived (B) lymphocytes were isolated from human peripheral blood and cultured with various mitogens and antigens. Purified protein derivative of tuberculin stimulated both purified T and B cells from patients with positive skin reactivity to purified protein derivative but did not stimulate nonimmune lymphocytes. Similarly, both T and B lymphocytes from patients with periodontal disease were stimulated to proliferate when incubated with dental plaque, whereas cells from normal individuals without gingivitis were unresponsive. In contrast, one component of plaque, bacterial endotoxins (lipopolysaccharide), minimally stimulated B lymphocytes from both normal or gingivitis patients. T lymphocytes from patients with periodontal disease were also stimulated by plaque antigen to produce chemotactic lymphokine activity (CTX) for human monocytes. B cells purified by the EAC rosetting method nonspecifically produced CTX without concomitant blastogenesis; however, after dissociation of adherent EAC these immune B cells did not spontaneously produce CTX. Lymphokine synthesis by B cells was not dependent on concomitant blastogenesis. Dissociated B cells from periodontitis patients also produced CTX activity after stimulation with dental plaque antigen. Therefore...

Identification of monoclonal antibodies for immunohistochemical staining of feline B lymphocytes in frozen and formalin-fixed paraffin-embedded tissues.

Monteith, C E; Chelack, B J; Davis, W C; Haines, D M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1996 Português
Relevância na Pesquisa
56.04%
Commercially-available monoclonal antibodies to B lymphocytes were evaluated for immunohistochemical staining of feline B lymphocytes in frozen and formalin-fixed, paraffin-embedded tissues using an avidin biotin complex immunoperoxidase immunohistochemical technique. Three monoclonal antibodies: F46A and F72A raised to "carnivore" B lymphocytes and RA3.6B2 raised to murine B lymphocytes, stained B lymphocyte-dependent areas of frozen feline lymphoid tissue. In addition, antibody RA3.6B2 stained B lymphocyte dependent areas in formalin-fixed, paraffin-embedded feline tissues. There was no staining of T lymphocyte-dependent areas in either frozen or formalin-fixed tissues. Dual parameter flow cytometry, using an anti-pan-T lymphocyte antibody, revealed that greater than 99% of the cells stained by RA3.6B2 are a population distinct from T lymphocytes. F46A was shown to stain a sub-population of those cells stained with RA3.6B2. These antibodies may be useful in the identification of feline B lymphocytes using immunohistochemistry and flow cytometry and thereby provide additional tools to study B lymphocyte ontogeny and the significance of lymphocyte phenotype in lymphoid neoplasia in cats.

Identification of hybridomas derived from mouse CD5+ B lymphocytes by fluorescent staining for cytoplasmic CD5 expression.

Sadigh, S; Scott, B B; Mageed, R A; Malcolm, A; Andrew, E M; Maini, R N
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1994 Português
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56.05%
The production of hybridomas derived from CD5+ B lymphocytes is important for studying the immunoglobulin gene repertoire and antibody specificity of this B-lymphocyte subpopulation. However, hybridomas derived from these lymphocytes invariably lose surface membrane expression of CD5 following hybridization. This impedes the unequivocal assignment of the generated hybridomas to the CD5+ B-lymphocyte subpopulation from unsorted, or partially sorted, cells. Recent studies have shown that mRNA transcripts of the CD5 gene and the protein product can be detected in the cytoplasm of some mouse hybridomas, indicating that although surface expression has been lost, they may have been generated from CD5+ B lymphocytes. These studies, however, have been unable to discount completely the possibility that aberrant cytoplasmic expression of the CD5 gene occurred as a direct consequence of the hybridization process. To confirm that cytoplasmic CD5 expression in the hybridomas is in fact directly related to the B-lymphocyte origin we have generated hybridomas from FACS-sorted CD5+ and CD5- murine splenic B lymphocytes, and determined their surface and cytoplasmic CD5 expression by fluorescence-activated cell sorting. Our findings reveal that all hybridomas derived from CD5+ B lymphocytes (nine hybridomas) were negative for surface but positive for cytoplasmic CD5 expression...

T and B lymphocytes. Exclusive role as responders and stimulators in human one-way mixed lymphocyte reaction.

Han, T; Dadey, B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1976 Português
Relevância na Pesquisa
56.08%
Four different combinations of one-way mixed lymphocyte reactions between human peripheral blood T and B lymphocytes (at a ratio of 1:1), purified by the E-rosetting technique, were carried our. A significant mixed lymphocyte reaction was observed only in a combination in which T lymphocytes, as responding cells, and B lymphocytes, as stimulating cells, were utilized. No significant mixed lymphocyte reaction was noted in the other three combinations of cells, using T or B lymphocytes as responders and T lymphocytes as stimulators, and also B lymphocytes as both responders and stimulators. Mixed lymphocyte reactions between T lymphocytes as responders (at constant concentration) and T and B lymphocytes as stimulators (varying proportions) showed that the response decreased proportionately with decreasing numbers of B cells and increasing numbers of T cells used as stimulators. Addition of increasing numbers of stimulating T cells to a constant number of stimulating B cells did not suppress or enhance the T-cell response to B cells. These observations indicate that the human peripheral blood T and B lymphocytes play an exclusive role as responding cells and stimulating cells, respectively.

Lymphocytes with membrane-bound immunoglobulin (B-lymphocytes) in new-born babies

Fröland, S. S.; Natvig, J. B.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1972 Português
Relevância na Pesquisa
56.05%
Lymphocytes with surface-bound immunoglobulins (B-lymphocytes) were detected in cord blood of normal babies by means of immunofluorescent staining of viable cells. The mean value of Ig-positive lymphocytes was 14·3% (range 5–33%). IgM was found on the highest percentage of lymphocytes (mean 9·7%), but IgG was also found in a considerable proportion (mean 7·9%). IgA was usually not demonstrable. IgG2 was the dominating IgG subclass (mean 7·3%). The data indicate that the Ig on any one cell belongs to a single class or IgG subclass. Very few or no lymphocytes were stained with antiserum against the C-terminal half of the IgG Fc fragment. Ig classes and the four IgG subclasses were usually found on a higher percentage of lymphocytes in the child than in the mother investigated at delivery. The presence of B-lymphocytes in cord blood, together with a marked lack of immunoglobulin-producing plasma cells at birth, may be explained by the B-lymphocytes not yet having differentiated to plasma cells in the absence of antigenic stimuli.

Platelet-Activating Factor Antagonists Decrease Follicular Dendritic-Cell Stimulation of Human B Lymphocytes

Halickman, Isaac; Bastien, Yolande; Zhuang, Qianli; Mazer, Monty B; Toledano, Baruch; Mazer, Bruce D
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em 15/06/2005 Português
Relevância na Pesquisa
56.05%
Both B-lymphoblastoid cell lines and tonsillar B lymphocytes express receptors for platelet-activating factor (PAF). In lymph node germinal centres, B lymphocytes interact with follicular dendritic cells (FDCs), which present antigen-containing immune complexes to B lymphocytes. FDCs have phenotypic features that are similar to those of stromal cells and monocytes and may therefore be a source of lipid mediators. In this study, we evaluated the effects of the PAF antagonist WEB 2170 on the activation of tonsillar B lymphocytes by FDCs. FDCs were isolated from tonsils by Bovine Serum Albumin (BSA) gradient centrifugation. After being cultured for 6 to 10 days, they were incubated with freshly isolated B cells in the presence or absence of the specific PAF receptor antagonist WEB 2170. B-lymphocyte proliferation was assessed by [3H]-thymidine incorporation, and immunoglobulin (Ig) G and IgM secretion was assessed by enzyme-linked immunosorbent assay (ELISA). WEB 2170 (10-6 to 10-8 M) inhibited [3H]-thymidine incorporation by up to 35% ± 3%. Moreover, the secretion of IgG and IgM was inhibited by up to 50% by WEB 2170 concentrations ranging from 10-6 to 10-8 M. There was no evidence of toxicity by trypan blue staining, and the addition of WEB 2170 to B cells in the absence of FDCs did not inhibit the spontaneous production of IgG or IgM. The effect of the PAF antagonist is primarily on B lymphocytes...

CD40-stimulated B Lymphocytes Pulsed with Tumor Antigens Are Effective Antigen-presenting Cells That Can Generate Specific T Cells

Lapointe, Réjean; Bellemare-Pelletier, Angélique; Housseau, Frank; Thibodeau, Jacques; Hwu, Patrick
Fonte: HighWire Press (American Association for Cancer Research) Publicador: HighWire Press (American Association for Cancer Research)
Tipo: Artigo de Revista Científica Formato: 280924 bytes; application/pdf
Português
Relevância na Pesquisa
66.03%
Although they are considered as antigen presenting cells (APC), the role of antigen-unspecific B-lymphocytes in antigen presentation and T lymphocyte stimulation remains controversial. In this paper, we tested the capacity of normal human peripheral activated B cells to stimulate T cells using melanoma antigens or melanoma cell lysates. B lymphocytes activated through CD40 ligation and then pulsed with tumor antigens efficiently processed and presented MHC class II restricted peptides to specific CD4+ T cell clones. This suggests that CD40-activated B cells have the functional and molecular competence to present MHC class II epitopes when pulsed with exogenous antigens, thereby making them a relevant source of APC to generate T cells. To test this hypothesis, CD40-activated B cells were pulsed with a lysate prepared from melanoma cells and used to stimulate peripheral autologous T cells. Interestingly, T cells specific to melanoma antigens were generated. Further analysis of these T cell clones revealed that they recognized MHC class II restricted epitopes from tyrosinase, a known melanoma tumor antigen. The efficient antigen presentation by antigen-unspecific activated B cells was correlated with a down-regulation in the expression of HLA-DO...

Contrôle de la réponse immunitaire par l’indoleamine 2,3-dioxygénase : étude de la régulation d’une molécule immuno-suppressive dans les cellules cancéreuses et les lymphocytes B chez l’humain

Godin-Ethier, Jessica
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
Português
Relevância na Pesquisa
56.1%
Le système immunitaire se doit d’être étroitement régulé afin d’éviter que des réponses immunologiques inappropriées ou de trop forte intensité ne surviennent. Ainsi, différents mécanismes permettent de maintenir une tolérance périphérique, mais aussi d’atténuer la réponse lorsque celle-ci n’est plus nécessaire. De tels mécanismes sont cependant aussi exploités par les tumeurs, qui peuvent ainsi échapper à une attaque par le système immunitaire et donc poursuivre leur progression. Ces mécanismes immunosuppresseurs nuisent non seulement à la réponse naturelle contre les cellules tumorales, mais font aussi obstacle aux tentatives de manipulation clinique de l’immunité visant à générer une réponse anti-tumorale par l’immunothérapie. L’un des mécanismes par lesquels les tumeurs s’évadent du système immunitaire est l’expression d’enzymes responsables du métabolisme des acides aminés dont l’une des principales est l’indoleamine 2,3-dioxygénase (IDO). Cette dernière dégrade le tryptophane et diminue ainsi sa disponibilité dans le microenvironnement tumoral, ce qui engendre des effets négatifs sur la prolifération, les fonctions et la survie des lymphocytes T qui y sont présents. Bien que la régulation de l’expression de cette enzyme ait été largement étudiée chez certaines cellules présentatrices d’antigènes...

Étude de la différenciation des lymphocytes T CD8+ effecteurs et mémoires : rôle de la cellule présentatrice d’antigène et de la voie de signalisation Notch

Mathieu, Mélissa
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
Português
Relevância na Pesquisa
56.12%
Lors d’une infection par un pathogène, des lymphocytes T CD8+ naïfs (LTn) spécifiques de l’antigène sont activés, prolifèrent et se différencient en LT effecteurs (LTe). Les LTe produisent différentes cytokines et acquièrent une activité cytotoxique menant à l’élimination du pathogène. Seulement 5 à 10 % des LTe survivront et se différencieront en LT mémoires (LTm), qui sont capables de répondre plus rapidement lors d’une seconde infection par le même pathogène, contribuant au succès de la vaccination. Toutefois, la compréhension de l’ensemble des mécanismes régulant le développement des LTe et des LTm demeure incomplète. Afin de mieux comprendre les signaux requis pour la différenciation des LT CD8+ lors de la réponse immune, nous avons posé deux hypothèses. Nous avons d’abord proposé que différentes cellules présentatrices d’antigène (CPA) fournissent différents signaux au moment de la reconnaissance antigénique influençant ainsi le devenir des LT CD8+. Vu leur potentiel d’utilisation en immunothérapie, nous avons comparé la capacité d’activation des LT CD8+ par les lymphocytes B activés via le CD40 (CD40-B) et les cellules dendritiques (CD). Nous avons montré que l’immunisation avec des CD40-B induit une réponse effectrice mais...

LL-37 promotes rapid sensing of CpG oligodeoxynucleotides by B lymphocytes and plasmacytoid dendritic cells

Hurtado, P.; Peh, C.
Fonte: Amer Assoc Immunologists Publicador: Amer Assoc Immunologists
Tipo: Artigo de Revista Científica
Publicado em //2010 Português
Relevância na Pesquisa
65.88%
LL-37 is a cationic antimicrobial peptide derived from neutrophils and keratinocytes. It plays an important role in protection against bacterial infection in the skin and mucosal surfaces. However, its role within the blood compartment remains unclear given that serum inhibits its bactericidal property. In this study, we show that LL-37 promotes very rapid and highly efficient sensing of CpG motifs in bacterial DNA by human B lymphocytes and plasmacytoid dendritic cells (pDCs) in serum-containing media and in whole blood. LL-37 allowed detection of CpG oligodeoxynucleotide (ODN) within minutes of exposure. Without LL-37, 20-30 times more CpG was required to produce the same effect. The promotion of CpG detection by LL-37 was independent of the backbone of the ODN, as the effect was observed not only in ODNs with modified phosphorothioate backbone, but also in ODNs with natural phosphodiester backbone, as found in genomic DNA. Unmethylated CpG motifs within the phosphodiester ODN and LL-37-mediated delivery are required for pDCs to respond. In keeping with the above, cells responded to CpG-rich bacterial DNA and LL-37, but not to human DNA and LL-37. The ability of LL-37 to enhance delivery of CpG to stimulate immune cells is independent of its amphipathic structure and its bactericidal property. LL-37 aids the delivery of CpG to B cells and pDCs...

Enumeration of T and B lymphocytes in whole peripheral blood: absence of a null cell population.

Pepys, E O; Tennent, G A; Pepys, M B
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1981 Português
Relevância na Pesquisa
56.04%
Alkaline phosphatase-labelled F(ab')2 polyvalent anti-human immunoglobulin stained a mean of 12% (s.d. 4.2) of lymphocytes in the whole peripheral blood of 15 normal individuals. However, when the sensitivity of detection of the bound anti-immunoglobulin reagent was enhanced by adding complexes of alkaline phosphatase with F(ab')2 anti-alkaline phosphatase, a mean of 22.1% (s.d. 7.8) of lymphocytes were positive. The mean number of T lymphocytes demonstrated in the same blood samples using a monoclonal anti-T lymphocyte antibody (OKT3) was 78% (s.d. 4.1) and was not increased by immunoenzyme enhancement. In five individuals the blood was washed at 37 degrees C to remove passively adsorbed IgG and was then studied using the enhanced method together with monoclonal anti-kappa and anti-lambda antibodies. The mean +/- s.d. number of kappa-positive lymphocytes was 15.5 +/- 4.6% and lambda-positive was 7.9 +/- 1.1%. The sum of these was the same as the number of cells stained either with anti-kappa and anti-lambda together or with the conventional polyvalent anti-immunoglobulin, confirming that the enhancement procedure was detecting integral membrane immunoglobulin and not passively adsorbed IgG. Application to the same blood sample of both the anti-T cell antibody and the enhancement procedure with polyvalent anti-immunoglobulin stained 99-100% of lymphocytes. The present observations confirm that there are two populations among the B-lymphocytes...

The peripheral blood compartment in patients with Graves' disease: activated T lymphocytes and increased transitional and pre-naive mature B lymphocytes

Van der Weerd, K; Van Hagen, P M; Schrijver, B; Kwekkeboom, D J; De Herder, W W; Ten Broek, M R J; Postema, P T E; Van Dongen, J J M; Staal, F J T; Dik, W A
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
56.08%
Graves' disease (GD) is an autoimmune disease that involves aberrant B and T lymphocyte responses. Detailed knowledge about lymphocyte subpopulation composition will therefore enhance our understanding of the pathogenesis of GD and might support the development of new immunomodulatory treatment approaches. The aim of this study was to gain detailed insight into the composition of the peripheral blood lymphocyte compartment in GD before and during anti-thyroid drug therapy. Major B and T lymphocyte subpopulations were investigated by flow cytometry in peripheral blood from newly diagnosed GD patients (n = 5), GD patients treated with anti-thyroid drugs (n = 4), patients with recurrent GD (n = 7) and healthy controls (HC; n = 10). In GD patients, numbers of activated T lymphocytes [human leucocyte antigen D-related (HLA-DR)+ and CD25+] were increased. The B lymphocyte compartment in GD was characterized by significantly higher numbers of transitional (CD38highCD27−, P < 0·03) and pre-naive mature (CD38lowCD27−IgD+CD5+, P < 0·04) B lymphocytes, while memory populations were slightly decreased. The increased numbers of CD5+, transitional and pre-naive mature B lymphocytes correlated positively with fT4 plasma levels. GD is associated with increased numbers of activated T lymphocytes and transitional and pre-naive mature CD5+ B lymphocytes within the peripheral blood. The increase in CD5+ B lymphocytes was due mainly to an increase in transitional and pre-naive mature B lymphocytes. Increased fT4 plasma levels might be associated with this increase in transitional and pre-naive mature CD5+ B lymphocytes.

Severe combined immunodeficiency with B lymphocytes: in vitro correction of defective immunoglobulin production by addition of normal T lymphocytes.

Seeger, R C; Robins, R A; Stevens, R H; Klein, R B; Waldman, D J; Zeltzer, P M; Kessler, S W
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1976 Português
Relevância na Pesquisa
56.05%
A 6 1/2-month-old male with severe combined immunodeficiency (SCID) had a low percentage and number of T cells (11%; 241/mm3) and a high percentage and number of B cells (52%; 1187/mm3) and null cells (37%; 868/mm3). In vitro studies were performed to determine if this child's primary defect involved differentiation of both T and B lymphocytes or if failure of B lymphocytes to differentiate into immunoglobulin producing cells was secondary to T lymphocyte abnormalities. Immunoglobulin production by lymphocytes in response to polyclonal mitogens (pokeweed mitogen and foetal calf serum) was measured by pulse-labelling cells with 3H-leucine and then precipitating cytoplasmic and secreted immunoglobulins with polyvalent anti-human immunoglobulin and S. aureus (Cowan strain I) protein A. The patient's lymphocytes did not synthesize immunoglobulins in vitro in response to mitogens. They did not suppress synthesis of immunoglobulins by normal lymphocytes. However, addition of normal purified T cells, which themselves did not synthesize immunoglobulins, enabled the patient's B lymphocytes to become immunoglobulin synthesizing and secreting cells. Gamma, mu, and light chains were secreted. This suggests that the primary abnormality was in the T-cell axis at the level of lymphoid stem cells or prothymocytes and that failure of B lymphocytes to become immunoglobulin-producing cells was secondary to this defect.

B lymphocytes not required for progression from insulitis to diabetes in non-obese diabetic mice

Charlton, Brett; Da Zhang, Ming; Slattery, Robyn
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Português
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56.07%
Previous studies have implicated B lymphocytes in the pathogenesis of diabetes in the non-obese diabetic (NOD) mouse. While it is clear that B lymphocytes are necessary, it has not been clear at which stage of disease they play a role; early, late or both. To clarify when B lymphocytes are needed, T lymphocytes were transferred from 5-week-old NOD female mice to age-matched NOD/severe combined immunodeficiency (SCID) recipient mice. NOD/SCID mice, which lack functionally mature T and B lymphocytes, do not normally develop insulitis or insulin-dependent diabetes melitus (IDDM). The NOD/SCID mice that received purified T lymphocytes from 5-week-old NOD mice subsequently developed insulitis and diabetes even though they did not have detectable B lymphocytes. This suggests that while B lymphocytes may be essential for an initial priming event they are not requisite for disease progression in the NOD mouse.