908 resultados para Asthma, NFATc2´, NFAT1, TH2, TH1, TH17, CD8 longlived memory cells
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Pathogenesis of chronically developing alveolar echinococcosis (AE) is characterized by a continuous, granulomatous, periparasitic infiltration of immune cells surrounding the metacestode of Echinococcus multilocularis (E.multilocularis) in the affected liver. A detailed cytokine and chemokine profile analysis of the periparasitic infiltrate in the liver has, however, not yet been carried out in a comprehensive way all along the whole course of infection in E. multilocularis intermediate hosts. We thus assessed the hepatic gene expression profiles of 18 selected cytokine and chemokine genes using qRT-PCR in the periparasitic immune reaction and the subsequent adjacent, not directly affected, liver tissue of mice from day 2 to day 360 post intra-hepatic injection of metacestode. DNA microarray analysis was also used to get a more complete picture of the transcriptional changes occurring in the liver surrounding the parasitic lesions. Profiles of mRNA expression levels in the hepatic parasitic lesions showed that a mixed Th1/Th2 immune response, characterized by the concomitant presence of IL-12, IFN- and IL-4, was established very early in the development of E. multilocularis. Subsequently, the profile extended to a combined tolerogenic profile associating IL-5, IL-10 and TGF-. IL-17 was permanently expressed in the liver, mostly in the periparasitic infiltrate; this was confirmed by the increased mRNA expression of both IL-17A and IL-17F from a very early stage, with a subsequent decrease of IL-17A after this first initial rise. All measured chemokines were significantly expressed at a given stage of infection; their expression paralleled that of the corresponding Th1, Th2 or Th17 cytokines. In addition to giving a comprehensive insight in the time course of cytokines and chemokines in E. multilocularis lesion, this study contributes to identify new targets for possible immune therapy to minimize E. multilocularis-related pathology and to complement the only parasitostatic effect of benzimidazoles in AE.
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Allergen-induced asthma is the leading form of asthma and a chronic condition worldwide. Common allergens are known to contribute to the pathogenesis of this disease. Murine models of allergic asthma have mostly used an intraperitoneal route of sensitization (not airway) to study this disease. Allergic asthma pathophysiology involves the activation of TH2-specific cells, which triggers production of IgE antibodies, the up-regulation of TH2-specific cytokines (i.e. IL-4, IL-5, IL-9 and IL-13), increased airway eosinophilia, and mucin hypersecretion. Although there are several therapeutics currently treating asthmatic patients, some of these treatments can result in drug tolerance and may be linked to increased mortality. CpG oligodeoxynucleotides (ODNs) is a synthetic ligand that targets Toll-like Receptor (TLR) 9. It has been evaluated as a therapeutic agent for the treatment of cancer, infectious diseases, and for treating allergy and asthma. PUL-042 is also a synthetic TLR ligand and is composed of two agonists against TLR2/6 heterodimer and TLR9. Previous studies have evaluated PUL-042 for its ability to confer resistance against bacterial and viral lung infection. These findings, combined with studies performed using CpG ODNs, led to speculation that PUL-042 dampens the immune response in allergen-induced asthma. My thesis research investigated airway route sensitization and airway delivery of PUL-042 to evaluate its effects in reducing an allergen-induced asthma phenotype in a murine model. The results of this study contribute to the foundation for future investigations to evaluate the efficacy of PUL-042 as a novel therapy in allergic-asthma disease.
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Interleukin (IL)-12 has strong antitumor activity in transplantable tumor systems in the mouse. The present study was designed to determine whether tumor induction by 3-methylcholanthrene (3-MC), a carcinogenic hydrocarbon, can be inhibited by IL-12. BALB/cBy mice were injected subcutaneously with 25 micrograms or 100 micrograms of 3-MC and treated with 100 ng, 10 ng, or 1 ng of IL-12 for 5 days a week for 18 weeks, with a schedule of 3 weeks on and 1 week off. In mice injected with 25 micrograms of 3-MC, treatment with 100 ng of IL-12 delayed tumor appearance and reduced tumor incidence. Tumor appearance was also delayed in mice injected with 100 micrograms of 3-MC and treated with 100 ng of IL-12, but the final tumor incidence was the same as in non-IL-12-treated mice. In contrast to the characteristically round, hard, well-circumscribed, and protruding tumor induced by 3-MC, a percentage of tumors induced in IL-12-treated mice had atypical characteristics: flat, soft, and invasive. Atypical tumors had a longer latent period and were more frequently seen in mice injected with 100 micrograms of 3-MC and treated with 100 ng of IL-12. Interferon gamma, IL-10, and tumor necrosis factor could be induced throughout the treatment period by IL-12, indicating that repeated injections of IL-12 do not induce a state of tachyphylaxis. High production of interferon gamma by CD8 T cells and a TH2-->TH1 or TH0 shift in the cytokine secretion profile of CD4 T cells were also seen in the IL-12-treated mice. IL-12 provides a powerful new way to explore the defensive role of the immune system in tumorigenesis.
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INTRODUO: A infeco por HIV-1 um grave problema de sade pblica causando elevada taxa de morbidade e mortalidade. Entretanto, alguns indivduos so considerados resistentes infeco por HIV-1, mesmo aps repetidas exposies ao vrus. Vrios fatores imunolgicos e genticos podem estar associados a resistncia infeco, como ativao de componentes da imunidade inata e tambm devido ao baixo perfil de ativao das clulas T. possvel que nos indivduos expostos e no infectados por HIV-1 (ENI) ocorra uma importante atuao das clulas T secretoras de IL-17 e IL-22, e tambm as clulas T reguladoras, pois so necessrias para a manuteno e homeostase das mucosas associadas ao intestino (GALT). OBJETIVO: Avaliar o fentipo e a funo de clulas TCD4+ e TCD8+ em casais sorodiscordante ao HIV-1, compostos por indivduos ENI e os parceiros infectados por HIV-1. MTODOS: Os casais sorodiscordantes ao HIV-1, consistiam de 23 indivduos expostos no-infectados (ENI), 14 mulheres e 9 homens, com mediana de 41 anos e 21 parceiros infectados por HIV-1 (HIV), 20 homens e 1 mulher com mediana de 41 anos. Os controles saudveis foram 24 indivduos (14 mulheres e 10 homens) com mediana de 37 anos. Os casais sorodiscordantes foram compostos por 16 heterossexuais e 7 homossexuais, com tempo de relacionamento de 13 anos. As frequncias de clulas Th17, Th22 e Tc22, as clulas T polifuncionais foram analisadas em clulas mononucleares (CMNs) do sangue perifrico, estimulados com peptdeos da regio Gag do HIV-1 e da enterotoxina B do Staphylococcus aureus (SEB), a frequncia de clulas T reguladoras, o perfil fenotpico de exausto/diferenciao e a expresso da integrina alfa4?7 e CCR9 em clulas T, foram realizados por citometria de fluxo. RESULTADOS: No grupo HIV, as clulas T CD4+ e CD8+ do sangue perifrico mostrou maior frequncia de CD95 e PD-1 e baixa expresso de CD127 comparado ao grupo ENI e controle. A frequncia de clulas Th17 em CMNs aumentou nos grupos ENI e HIV-1 na condio sem estmulo, contudo, aps estmulo com os peptdeos da regio p24 da Gag do HIV-1 induziu resposta somente no grupo HIV-1. O grupo ENI mostrou resposta antgeno-especifica somente para IL-22. Alm disto, avaliando as clulas Tc22 e Th22, foi verificado aumento da resposta aos peptdeos da Gag e tambm ao SEB, nos grupos HIV e ENI. A presena de clulas T polifuncionais antgeno-especificas, secretoras de 5-4 citocinas, foi detectada apenas em clulas T CD38+ no grupo HIV, enquanto os indivduos ENI mostraram resposta polifuncional por clulas T CD38- somente ao estmulo policlonal por SEB. Uma diminuio do nmero absoluto de clulas T reguladoras (CD4+CD25+CD127low/-Foxp3+) foi detectada no grupo HIV comparado ao ENI e controle, com maior expresso de molculas HLA-DR e CD95. Alm disto, foi detectado diminuio na frequncia de clulas TCD8+ ?4?7+ no grupo ENI e de clulas TCD4+ alfa4beta7+ nos grupos ENI e HIV. Houve uma correlao positiva entre as clulas Tc22 e Th22 com as clulas TCD8+ e TCD4+ que expressam alfa4beta7, no grupo ENI e HIV-1. CONCLUSO: Os indivduos ENI so capazes de desenvolver resposta antgeno-especficas relacionadas com a IL-22, que possui importante funo na imunidade de mucosas. Alm disto, mostram presena de clulas T polifuncionais com baixo perfil de ativao a estmulo policlonal. Os dados evidenciam que os indivduos ENI, mostram induo de clulas Tc22, aumento de expresso de molculas de migrao para o intestino e equilbrio entre as clulas efetoras e Treg, que em conjunto, devem exercer importante papel para a resistncia infeco por HIV-1
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Periodontal disease is a chronic inflammatory condition primarily caused by bacteria in dental biofilm, which interact with the host, thus determining the nature of the resulting disease. Despite the wide knowledge about the pathogenesis of these diseases, the exact composition of the T cell profile during the active phase of the disease (Th1, Th2 or Th17) remains unknown. This study aimed to evaluate by immunohistochemical expression, the presence of the markers (IL-17, IL-23 and RORt), involved in Th17 response in clinically healthy gingiva cases (n = 32), biofilm-induced gingivitis (n = 30), chronic periodontitis (n = 32) and aggressive periodontitis (n = 25), in order to analyze if the expression and/or distribution of these molecules in lymphocytes and macrophages, present in the inflammatory infiltrate of periodontal tissue, influences the tissue destruction observed in these diseases. The morphological analysis of cases was performed which assessed the intensity of the inflammatory infiltrate in mild, moderate and intense. For each case, in the area with the most representative immunostaining, 5 fields were chosen and analyzed, both for the intensity of the inflammatory infiltrate as for the quantity of immunostained cells, based on predetermined scores: score 0 (absence of inflammatory infiltrate/immunostaining), score 1 (the infiltrate/immunostaining covered less than 25% of the field area), score 2 (the infiltrate/immunostaining occupied between 25 and 50%) and score 3 (infiltrate/immunostaining present in over 50% of the field area). From this, a median was generated representing each case. The intensity of the inflammatory infiltrate correlated with the disease progression, in other words, it was crescent from clinically healthy gingiva to aggressive periodontitis (P <0.001). It was detected the presence of IL-17, IL-23 and RORt in most of the evaluated cases and the number of immunostained cells correlated with the intensity of the inflammatory infiltrate (P <0.001) and with the clinical parameters analyzed (P <0.001), showing a positive correlation, mainly moderate. Aggressive periodontitis showed a higher percentage of immunostaining for all markers in relation to other clinical conditions assessed, suggesting a possible association of these markers with the progression of this disease, in which the higher the loss of periodontal support, the greater the amount of inflammatory infiltrate and larger the number of immunostained cells.
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Memory T cells develop early during the preclinical stages of autoimmune diseases and have traditionally been considered resistant to tolerance induction. As such, they may represent a potent barrier to the successful immunotherapy of established autoimmune diseases. It was recently shown that memory CD8+ T cell responses are terminated when Ag is genetically targeted to steady-state dendritic cells. However, under these conditions, inactivation of memory CD8+ T cells is slow, allowing transiently expanded memory CD8+ T cells to exert tissue-destructive effector function. In this study, we compared different Ag-targeting strategies and show, using an MHC class II promoter to drive Ag expression in a diverse range of APCs, that CD8+ memory T cells can be rapidly inactivated by MHC class II+ hematopoietic APCs through a mechanism that involves a rapid and sustained downregulation of TCR, in which the effector response of CD8+ memory cells is rapidly truncated and Ag-expressing target tissue destruction is prevented. Our data provide the first demonstration that genetically targeting Ag to a broad range of MHC class II+ APC types is a highly efficient way to terminate memory CD8+ T cell responses to prevent tissue-destructive effector function and potentially established autoimmune diseases. Copyright 2010 by The American Association of Immunologists, Inc.
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Ihon T-solulymfoomat (cutaneous T-cell lymphoma, CTCL) ovat ryhm imukudossypi, joiden esiintyvyys on nousussa erityisesti lnsimaissa. Taudin syntymekanismit ovat suurelta osin tuntemattomat, diagnostiikka on vaikeaa ja siksi usein viivstynytt eik parantavaa hoitoa ole. CTCL ilmenee iho-oirein, vaikka sypsolut eivt ole iholla normaalisti esiintyvi soluja, vaan elimistn puolustusjrjestelmn soluja, jotka ovat tuntemattomasta syyst vaeltaneet iholle. Sypsolut ovat kypsi T-auttajasoluja (Th-soluja) ja ilmentvt tyypin 2 immuunivasteelle ominaisia sytokiineja. Kromosomaalinen epstabiilius on tautiryhmn keskeinen piirre. CTCL-potilailla on lisntynyt riski sairastua mys muihin sypiin, erityisesti keuhkosypn ja non-Hodgkin lymfoomiin. Vitskirjatutkimuksen tavoitteena oli havaita CTCL:n syntymekanismeja selvittvi kromosomi- ja geenimuutoksia. Erityisesti tavoitteena oli identifioida molekyylej, jotka soveltuisivat diagnostisiksi merkkiaineiksi tai tsmhoidon kohteeksi. Tyss on tutkittu kahta tautiryhmn yleisint muotoa, mycosis fungoidesta (MF) ja Sezaryn syndroomaa (SS) sek harvinaisempaa vaikeasti diagnosoitavaa subkutaanista pannikuliitin kaltaista T-solulymfoomaa (SPTL). Lisksi on tutkittu CTCL:n liittyv keuhkosyp ja verrattu sit tavalliseen (primaariin) keuhkosypn. Tutkimusmenetelmin on kytetty esimerkiksi molekyylisytogeneettisi metodeja ja mikrosiruja. Vitskirjatyss havaittiin ensimminen CTCL:lle ominainen toistuva geenitason muutos: puutos- tai katkoskohta NAV3-geeniss. Tmn geenipoikkeavuuden havaittiin esiintyvn useissa taudin alaryhmiss (MF, SS, SPTL). NAV3-geenipuutoksen osoittaminen FISH-tekniikalla on sovellettavissa kliiniseen diagnostiikkaan. Tutkimukset geenipuutoksen aiheuttamista toiminnallisista seurauksista ovat kynniss. Tyss saatiin mys uutta tietoa taudin syntymekanismeista havaitsemalla useiden Th1-tyypin immuunivasteelle ominaisten geenien alentunut ilmeneminen CTCL-potilailla. Tmn lisksi potilasnytteiss havaittiin eriden solun pinta-antigeenien lisntynyt ilmeneminen, mik luo pohjan uusien vasta-ainepohjaisten tsmhoitojen kehittmiselle. Vitskirjatutkimuksessa todettiin mys CTCL:n liittyvn keuhkosyvn eroavan kromosomi- ja geenimuutosten suhteen verrokkikeuhkosyvst, mik jatkossa antaa aiheen tutkia sypkantasolujen merkityst CTCL:n ja sen liitnniskasvainten kehittymisen taustalla.
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The relay hypothesis [R. Nayak, S. Mitra-Kaushik, M.S. Shaila, Perpetuation of immunological memory: a relay hypothesis, Immunology 102 (2001) 387-395] was earlier proposed to explain perpetuation of immunological memory without requiring long lived memory cells or persisting antigen. This hypothesis envisaged cycles of interaction and proliferation of complementary idiotypic B cells (Burnet cells) and anti-idiotypic B cells (Jerne cells) as the primary reason for perpetuation of immunological memory. The presence of pepti-domimics of antigen in anti-idiotypic antibody and their presentation to antigen specific T cells was postulated to be primary reason for perpetuation of T cell memory. Using a viral hemagglutinin as a model, in this work, we demonstrate the presence of peptidomimics in the variable region of ail anti-idiotypic antibody capable of functionally mimicking the antigen derived peptides. A CD8(+) CTL clone was generated against the hemagglutinin protein which specifically responds to either peptidomimic synthesizing cells or peptidomimic pulsed antigen presenting cells. Thus, it appears reasonable that a population of activated antigen specific T cells is maintained in the body by presentation of peptidomimic through Jerne cells and other antigen presenting cells long after immunization. (C) 2007 Elsevier Inc. All rights reserved.
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HIV,,Th1,Th1,,CD4~(+)CD8~(+) TAPC,Fas/FasLHIVCD4~(+) T,BNK,,HIV/,,HIV,,AIDS
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During many chronic infections virus-specific CD8 T cells succumb to exhaustion as they lose their ability to respond to antigenic activation. Combinations of IL-12, IL-18, and IL-21 have been shown to induce the antigen-independent production of interferon (IFN)- by effector and memory CD8 T cells. In this study we investigated whether exhausted CD8 T cells are sensitive to activation by these cytokines. We show that effector and memory, but not exhausted, CD8 T cells produce IFN- and upregulate CD25 following exposure to certain combinations of IL-12, IL-18, and IL-21. The unresponsiveness of exhausted CD8 T cells is associated with downregulation of the IL-18-receptor- (IL-18R). Although IL-18R expression is connected with the ability of memory CD8 T cells to self-renew and efflux rhodamine 123, the IL-18R(lo) exhausted cells remained capable of secreting this dye. To further evaluate the consequences of IL-18R downregulation, we tracked the fate of IL-18R-deficient CD8 T cells in chronically infected mixed bone marrow chimeras and discovered that IL-18R affects the initial but not later phases of the response. The antigen-independent responsiveness of exhausted CD8 T cells was also investigated following co-infection with Listeria monocytogenes, which induces the expression of IL-12 and IL-18. Although IL-18R(hi) memory cells upregulated CD25 and produced IFN-, the IL-18R(lo) exhausted cells failed to respond. Collectively, these findings indicate that as exhausted T cells adjust to the chronically infected environment, they lose their susceptibility to antigen-independent activation by cytokines, which compromises their ability to detect bacterial co-infections.
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Whooping cough remains a problem despite vaccination, and worldwide resurgence of pertussis is evident. Since cellular immunity plays a role in long-term protection against pertussis, we studied pertussis-specific T-cell responses. Around the time of the preschool acellular pertussis (aP) booster dose at 4 years of age, T-cell memory responses were compared in children who were primed during infancy with either a whole-cell pertussis (wP) or an aP vaccine. Peripheral blood mononuclear cells (PBMCs) were isolated and stimulated with pertussis vaccine antigens for 5 days. T cells were characterized by flow-based analysis of carboxyfluorescein succinimidyl ester (CFSE) dilution and CD4, CD3, CD45RA, CCR7, gamma interferon (IFN-), and tumor necrosis factor alpha (TNF-) expression. Before the aP preschool booster vaccination, both the proliferated pertussis toxin (PT)-specific CD4<sup>+</sup> and CD8<sup>+</sup> T-cell fractions (CFSE<sup>dim</sup>) were higher in aP-than in wP-primed children. Post-booster vaccination, more pertussis-specific CD4<sup>+</sup> effector memory cells (CD45RA<sup>-</sup> CCR7<sup>-</sup>) were induced in aP-primed children than in those primed with wP. The booster vaccination did not appear to significantly affect the T-cell memory subsets and functionality in aP-primed or wP-primed children. Although the percentages of Th1 cytokine-producing cells were alike in aP- and wP-primed children pre-booster vaccination, aP-primed children produced more Th1 cytokines due to higher numbers of proliferated pertussis-specific effector memory cells. At present, infant vaccinations with four aP vaccines in the first year of life result in pertussis-specific CD4<sup>+</sup> and CD8<sup>+</sup> effector memory T-cell responses that persist in children until 4 years of age and are higher than those in wP-primed children. The booster at 4 years of age is therefore questionable; this may be postponed to 6 years of age.
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Two different types of pertussis vaccines are currently available to protect children against whooping cough, the first-generation whole-cell (Pw) vaccines and the more recent acellular (Pa) vaccines. Both types provide good protection, yet induce different types of immune responses in 6-month-old infants, with a strong Th1 response induced by Pw vaccines compared to a mixed Th1/Th2 response and a delay in non-specific IFN-gamma secretions after the administration of Pa vaccines. We show here that at 13 months of age, most Pw- or Pa-vaccinated children display Bordetella pertussis-specific T-cell responses, in addition to significant antibody levels, although a higher Th2/Th1 cytokine ratio remained in Pa recipients compared to Pw recipients. In contrast, the proportion of children with tetanus toxin-specific T-cell responses was lower in Pa than in Pw vaccine recipients, although most children had protective anti-tetanus toxin IgG levels. In addition, the global Th2 bias observed in 6-month-old infants vaccinated with a Pa vaccine was normalized at 13 months.
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Infant CD4+ T-cell responses to bacterial infections or vaccines have been extensively studied, whereas studies on CD8 + T-cell responses focused mainly on viral and intracellular parasite infections. Here we investigated CD8 + T-cell responses upon Bordetella pertussis infection in infants, children, and adults and pertussis vaccination in infants. Filamentous hemagglutinin-specific IFN- secretion by circulating lymphocytes was blocked by anti-MHC-I or -MHC-II antibodies, suggesting that CD4 + and CD8 + T lymphocytes are involved in IFN- production. Flow cytometry analyses confirmed that both cell types synthesized antigen-specific IFN-, although CD4 + lymphocytes were the major source of this cytokine. IFN- synthesis by CD8 + cells was CD4 + T cell dependent, as evidenced by selective depletion experiments. Furthermore, IFN- synthesis by CD4 + cells was sometimes inhibited by CD8 + lymphocytes, suggesting the presence of CD8 + regulatory T cells. The role of this dual IFN- secretion by CD4 + and CD8 + T lymphocytes in pertussis remains to be investigated. 2012 Violette Dirix et al.
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The cellular prion protein (PrPC) is widely expressed in neural and non-neural tissues, but its function is unknown. Elucidation of the part played by PrPC in adaptive immunity has been a particular conundrum: increased expression of cell surface PrPC has been documented during T-cell activation, yet the functional significance of this activation remains unclear, with conflicting data on the effects of Prnp gene knockout on various parameters of T-cell immunity. We show here that Prnp mRNA is highly inducible within 824 h of T-cell activation, with surface protein levels rising from 24 h. When measured in parallel with CD69 and CD25, PrPC is a late activation antigen. Consistent with its up-regulation being a late activation event, PrP deletion did not alter T-cell-antigen presenting cell conjugate formation. Most important, activated PrP0/0 T cells demonstrated much reduced induction of several T helper (Th) 1, Th2, and Th17 cytokines, whereas others, such as TNF- and IL-9, were unaffected. These changes were investigated in the context of an autoimmune model and a bacterial challenge model. In experimental autoimmune encephalomyelitis, PrP-knockout mice showed enhanced disease in the face of reduced IL-17 responses. In a streptococcal sepsis model, this constrained cytokine program was associated with poorer local control of infection, although with reduced bacteremia. The findings indicate that PrPC is a potentially important molecule influencing T-cell activation and effector function.
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TLR are evolutionarily conserved molecules that play a key role in the initiation of innate antimicrobial immune responses. Through their influence on dendritic cell maturation, these receptors are also thought to indirectly shape the adaptive immune response. However, no data are currently available regarding both TLR expression and function in human CD8+ T cell subsets. We report that a subpopulation of CD8+ T cells, i.e., effector, but neither naive nor central memory cells, constitutively expresses TLR3. Moreover, the ligation of the receptor by a specific agonist in TLR3-expressing CD8+ T cells increased IFN-gamma secretion induced by TCR-dependent and -independent stimulation, without affecting proliferation or specific cytolytic activity. These results thereby suggest that TLR3 ligands can not only indirectly influence the adaptive immune response through modulation of dendritic cell activation, but also directly increase IFN-gamma production by Ag-specific CD8+ T cells. Altogether, the present work might open new perspectives for the use of TLR ligands as adjuvants for immunotherapy.
