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1.
Rev Chilena Infectol ; 33(4): 395-402, 2016 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-27905623

RESUMO

BACKGROUND: Bloodstream infections (BSIs) due to Enterococcus faecium (E. faecium), particularly those due to vancomycin-resistant enterococcus (VRE), are still a therapeutic challenge. AIM: To evaluate mortality from BSI due to E. faecium and VRE in central Taiwan. MATERIALS AND METHODS: We retrospectively analyzed cases of significant E. faecium BSI in the Changhua Christian Hospital System between January 1, 2010 and December 31, 2013. RESULTS: Of the 76 cases, 28 patients (36.8%) were admitted to intensive care units (ICUs) at the onset of BSI, 10 (13.2%) cases were associated with polymicrobial bacteremia, and 29 (38.2%) cases were associated with entry via the biliary tract. VRE was observed in 18 (23.7%) cases. The 30-day mortality rate was 13.1% (10/76). Multivariate logistic regression analysis showed that bacteremia of non-biliary tract origin (OR = 8.43, 95% confidence interval (95% CI) = 1.32-54.00, p = 0.002) and ICU admission (OR = 4.2, 95% CI = 1.7-10.0, p = 0.002) were significant risk factors for 30-day mortality, whereas appropriate antimicrobial therapy was a protective factor for 30-day mortality (OR = 0.33, 95% CI = 0.14-0.79, p = 0.013). CONCLUSIONS: Our results underscore the need to assist patients admitted to ICUs with E. faecium BSIs with a non-biliary tract origin. We emphasize the use of appropriate antimicrobial therapy for E. faecium BSI with the aim to rescue more patients with these infections.


Assuntos
Bacteriemia/microbiologia , Bacteriemia/mortalidade , Enterococos Resistentes à Vancomicina/isolamento & purificação , Bacteriemia/tratamento farmacológico , Feminino , Humanos , Incidência , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Taiwan/epidemiologia , Resistência a Vancomicina
2.
Rev. chil. infectol ; Rev. chil. infectol;33(4): 395-402, ago. 2016. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-830110

RESUMO

Background: Bloodstream infections (BSIs) due to Enterococcus faecium (E. faecium), particularly those due to vancomycin-resistant enterococcus (VRE), are still a therapeutic challenge. Aim: To evaluate mortality from BSI due to E. faecium and VRE in central Taiwan. Materials and Methods: We retrospectively analyzed cases of significant E. faecium BSI in the Changhua Christian Hospital System between January 1, 2010 and December 31, 2013. Results: Of the 76 cases, 28 patients (36.8%) were admitted to intensive care units (ICUs) at the onset of BSI, 10 (13.2%) cases were associated with polymicrobial bacteremia, and 29 (38.2%) cases were associated with entry via the biliary tract. VRE was observed in 18 (23.7%) cases. The 30-day mortality rate was 13.1% (10/76). Multivariate logistic regression analysis showed that bacteremia of non-biliary tract origin (OR = 8.43, 95% confidence interval (95% CI) = 1.32-54.00, p = 0.002) and ICU admission (OR = 4.2, 95% CI = 1.7-10.0, p = 0.002) were significant risk factors for 30-day mortality, whereas appropriate antimicrobial therapy was a protective factor for 30-day mortality (OR = 0.33, 95% CI = 0.14-0.79, p = 0.013). Conclusions: Our results underscore the need to assist patients admitted to ICUs with E. faecium BSIs with a non-biliary tract origin. We emphasize the use of appropriate antimicrobial therapy for E. faecium BSI with the aim to rescue more patients with these infections.


Antecedentes: Las infecciones del torrente sanguíneo por Enterococcus faecium, particularmente aquellas causadas por enterococos resistentes a vancomicina (ERV), representan aún un desafío para los tratamientos. Este estudio está orientado a la evaluación de la mortalidad debido a la infección del torrente sanguíneo (ITS) por E. faecium y por enterococos resistentes a vancomicina (ERV) en Taiwán central. Materiales y Métodos: Analizamos de forma retrospectiva casos de ITS causadas por E. faecium genuinas en el Sistema del Hospital Changhua Christian, entre los días 1 de enero de 2010 y 31 de diciembre de 2013. Resultados: De los 76 casos analizados, 28 pacientes fueron ingresados a las Unidades de Cuidados Intensivos (UCI) al comienzo de una ITS (36,8%), 10 casos fueron asociados a bacteriemia polimicrobiana (13,2%), y 29 casos tuvieron como puerta de entrada la vía biliar. En 18 casos se pudieron observar ERV (23,7%). La mortalidad a 30 días fue de 13,1% (10/76). El análisis multivariado mediante regresión logística mostró que la bacteriemia de origen no biliar (OR = 8,43, 95% intervalo de confianza (95% CI) = 1,32-54,00; p = 0,002), y el ingreso a la UCI (OR = 4,2; 95% CI = 1,7-10,0; p = 0,002), fueron factores de riesgo significativos para el rango de mortalidad de 30 días, así como un tratamiento de antimicrobiano apropiado constituye un factor protector en contra la mortalidad (OR = 0,33; 95% CI = 0,14-0,79; p = 0,013). Conclusiones: Nuestros resultados destacan la necesidad de asistir a los pacientes ingresados a la UCI con ITS por E. faecium con origen no biliar. Hacemos énfasis a la aplicación de una antibioterapia adecuada para sacar adelante a un mayor número de pacientes con este tipo de infecciones.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Bacteriemia/microbiologia , Bacteriemia/mortalidade , Enterococos Resistentes à Vancomicina/isolamento & purificação , Taiwan/epidemiologia , Testes de Sensibilidade Microbiana , Incidência , Estudos Retrospectivos , Fatores de Risco , Bacteriemia/tratamento farmacológico , Resistência a Vancomicina
3.
J Immunol ; 195(8): 3705-15, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26363052

RESUMO

PU.1 is an ETS family transcription factor that is important for the development of multiple hematopoietic cell lineages. Previous work demonstrated a critical role for PU.1 in promoting Th9 development and in limiting Th2 cytokine production. Whether PU.1 has functions in other Th lineages is not clear. In this study, we examined the effects of ectopic expression of PU.1 in CD4(+) T cells and observed decreased expression of genes involved with the function of T follicular helper (Tfh) cells, including Il21 and Tnfsf5 (encoding CD40L). T cells from conditional mutant mice that lack expression of PU.1 in T cells (Sfpi1(lck-/-)) demonstrated increased production of CD40L and IL-21 in vitro. Following adjuvant-dependent or adjuvant-independent immunization, we observed that Sfpi1(lck-/-) mice had increased numbers of Tfh cells, increased germinal center B cells (GCB cells), and increased Ab production in vivo. This correlated with increased expression of IL-21 and CD40L in Tfh cells from Sfpi1(lck-/-) mice compared with control mice. Finally, although blockade of IL-21 did not affect GCB cells in Sfpi1(lck-/-) mice, anti-CD40L treatment of immunized Sfpi1(lck-/-) mice decreased GCB cell numbers and Ag-specific Ig concentrations. Together, these data indicate an inhibitory role for PU.1 in the function of Tfh cells, germinal centers, and Tfh-dependent humoral immunity.


Assuntos
Linfócitos B/imunologia , Ligante de CD40/imunologia , Regulação da Expressão Gênica/imunologia , Centro Germinativo/imunologia , Proteínas Proto-Oncogênicas/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Transativadores/imunologia , Animais , Linfócitos B/citologia , Linfócitos B/metabolismo , Ligante de CD40/genética , Ligante de CD40/metabolismo , Centro Germinativo/citologia , Centro Germinativo/metabolismo , Imunidade Humoral/fisiologia , Interleucinas/biossíntese , Interleucinas/genética , Interleucinas/imunologia , Camundongos , Camundongos Knockout , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas/genética , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/metabolismo , Transativadores/biossíntese , Transativadores/genética
4.
PLoS One ; 10(2): e0115330, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25646897

RESUMO

Lunasin is a naturally occurring peptide isolated from soybeans and has been explored in cancer treatment. Lunasin inhibits NF-κB activation and thus pro-inflammatory cytokine and mediator production in macrophages. In this study we demonstrate that lunasin can effectively suppress allergic airway inflammation in two murine models of asthma. In an OVA+Alum sensitization model, intranasal lunasin treatment at the time of OVA challenges significantly reduced total cells counts in bronchoalveolar lavage (BAL) fluid and eosinophilia, peribronchiolar inflammatory infiltration, goblet cell metaplasia and airway IL-4 production. In an OVA+LPS intranasal sensitization model, lunasin treatment either at the time of sensitization or challenge has similar effects in suppress allergic airway inflammation including significantly reduced total cell and eosinophil counts in BAL fluid, inflammatory gene Fizz1 expression in the lung, and IL-4 production by OVA re-stimulated cells from mediastinal lymph nodes. We further show that intranasal instillation of OVA+lunasin significantly increases OVA-specific regulatory T cell (Treg) accumulation in the lung comparing to OVA only treatment. Taken together, our results suggest lunasin as an anti-inflammatory agent can be potentially used in asthma therapy or as an adjuvant to enhance the induction of antigen-specific Tregs and thus boost the efficacy of allergy immunotherapy.


Assuntos
Antígenos/imunologia , Asma/imunologia , Hipersensibilidade/complicações , Pulmão/imunologia , Proteínas de Soja/farmacologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Compostos de Alúmen , Animais , Asma/complicações , Asma/tratamento farmacológico , Líquido da Lavagem Broncoalveolar/imunologia , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Feminino , Células Caliciformes/efeitos dos fármacos , Células Caliciformes/imunologia , Lipopolissacarídeos/farmacologia , Pulmão/efeitos dos fármacos , Camundongos , Ovalbumina/imunologia , Proteínas de Soja/uso terapêutico
5.
Oncol Rep ; 32(5): 1897-904, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25176343

RESUMO

Type VI collagen (COL6), an extracellular matrix protein, is important in maintaining the integrity of lung tissue. An increase in COL6 mRNA and protein deposition was found in the lungs of patients with pulmonary fibrosis, a chronic inflammatory condition with a strong association with lung cancer. In the present study, we demonstrated overexpression of COL6 in the lungs of non-small cell lung cancers. We hypothesized that excessive COL6 in the lung interstitium may exert stimulatory effects on the adjacent cells. In vitro stimulation of monocytes with COL6 resulted in the production of IL-23, which may promote tumor development in an environment of IL-23-mediated lung inflammation, where tissue modeling occurs concurrently with excessive COL6 production. In addition, COL6 was capable of stimulating signaling pathways that activate focal adhesion kinase and extracellular signal­regulated kinase 1/2 in lung epithelial cells, which may also facilitate the development of lung neoplasms. Taken together, our data suggest the potential role of COL6 in promoting lung neoplasia in diseased lungs where COL6 is overexpressed.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Colágeno Tipo VI/genética , Colágeno Tipo VI/metabolismo , Neoplasias Pulmonares/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular , Células Epiteliais/metabolismo , Matriz Extracelular/metabolismo , Humanos , Subunidade p19 da Interleucina-23/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Monócitos/imunologia , Transdução de Sinais
6.
Vaccine ; 32(42): 5411-9, 2014 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-25131731

RESUMO

The addition of an appropriate adjuvant that activates the innate immunity is essential to subsequent development of the adaptive immunity specific to the vaccine antigens. Thus, any innovation capable of improving the immune responses may lead to a more efficacious vaccine. We recently identified a novel immune modulator using a naturally occurring seed peptide called lunasin. Lunasin was originally isolated from soybeans, and it is a small peptide containing 43 amino acids. Our studies revealed stimulatory effects of lunasin on innate immune cells by regulating expression of a number of genes that are important for immune responses. The objective was to define the effectiveness of lunasin as an adjuvant that enhances immune responses. The immune modulating functions of lunasin were characterized in dendritic cells (DCs) from human peripheral blood mononuclear cells (PBMCs). Lunasin-treated conventional DCs (cDCs) not only expressed elevated levels of co-stimulatory molecules (CD86, CD40) but also exhibited up-regulation of cytokines (IL1B, IL6) and chemokines (CCL3, CCL4). Lunasin-treated cDCs induced higher proliferation of allogeneic CD4+ T cells when comparing with medium control treatment in the mixed leukocyte reaction (MLR). Immunization of mice with ovalbumin (OVA) and lunasin inhibited the growth of OVA-expressing A20 B-lymphomas, which was correlated with OVA-specific CD8+ T cells. In addition, lunasin was an effective adjuvant for immunization with OVA, which together improved animal survival against lethal challenge with influenza virus expressing the MHC class I OVA peptide SIINFEKL (PR8-OTI). These results suggest that lunasin may function as a vaccine adjuvant by promoting DC maturation, which in turn enhances the development of protective immune responses to the vaccine antigens.


Assuntos
Adjuvantes Imunológicos/farmacologia , Células Dendríticas/imunologia , Proteínas de Soja/farmacologia , Animais , Antígenos CD/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Quimiocinas/imunologia , Citocinas/imunologia , Células Dendríticas/citologia , Feminino , Humanos , Ativação Linfocitária , Teste de Cultura Mista de Linfócitos , Linfoma de Células B/tratamento farmacológico , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/prevenção & controle , Ovalbumina
7.
Cancer Immunol Immunother ; 63(3): 283-95, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24363024

RESUMO

Immunostimulatory cytokines can enhance anti-tumor immunity and are part of the therapeutic armamentarium for cancer treatment. We have previously reported that post-transplant lymphoma patients have an acquired deficiency of signal transducer and activator of transcription 4, which results in defective IFNγ production during clinical immunotherapy. With the goal of further improving cytokine-based immunotherapy, we examined the effects of a soybean peptide called lunasin that synergistically works with cytokines on natural killer (NK) cells. Peripheral blood mononuclear cells of healthy donors and post-transplant lymphoma patients were stimulated with or without lunasin in the presence of IL-12 or IL-2. NK activation was evaluated, and its tumoricidal activity was assessed using in vitro and in vivo tumor models. Chromatin immunoprecipitation assay was performed to evaluate the histone modification of gene loci that are regulated by lunasin and cytokine. Adding lunasin to IL-12- or IL-2-stimulated NK cells demonstrated synergistic effects in the induction of IFNG and GZMB involved in cytotoxicity. The combination of lunasin and cytokines (IL-12 plus IL-2) was capable of restoring IFNγ production by NK cells from post-transplant lymphoma patients. In addition, NK cells stimulated with lunasin plus cytokines displayed higher tumoricidal activity than those stimulated with cytokines alone using in vitro and in vivo tumor models. The underlying mechanism responsible for the effects of lunasin on NK cells is likely due to epigenetic modulation on target gene loci. Lunasin represents a different class of immune modulating agent that may augment the therapeutic responses mediated by cytokine-based immunotherapy.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Imunoterapia/métodos , Células Matadoras Naturais/efeitos dos fármacos , Linfoma/terapia , Fragmentos de Peptídeos/administração & dosagem , Proteínas de Soja/administração & dosagem , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Citotoxicidade Imunológica/efeitos dos fármacos , Citotoxicidade Imunológica/genética , Metilação de DNA/efeitos dos fármacos , Sinergismo Farmacológico , Granzimas/genética , Granzimas/metabolismo , Humanos , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-12/administração & dosagem , Interleucina-12/imunologia , Interleucina-2/administração & dosagem , Interleucina-2/imunologia , Células Matadoras Naturais/imunologia , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/genética , Linfoma/genética , Linfoma/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos SCID , Dados de Sequência Molecular , Fator de Transcrição STAT4/genética , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Cancer Immunol Immunother ; 62(6): 1073-82, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23604103

RESUMO

The antitumor activity of monoclonal antibodies is mediated by effector cells, such as natural killer (NK) cells, that express Fc receptors for immunoglobulin. Efficacy of monoclonal antibodies, including the CD20 antibody rituximab, could be improved by agents that augment the function of NK cells. Interleukin (IL)-18 is an immunostimulatory cytokine that has antitumor activity in preclinical models. The effects of IL-18 on NK cell function mediated through Fcγ receptors were examined. Human NK cells stimulated with immobilized IgG in vitro secreted IFN-γ as expected; such IFN-γ production was partially inhibited by blocking CD16 with monoclonal antibodies. IL-18 augmented IFN-γ production by NK cells stimulated with immobilized IgG or CD16 antibodies. NK cell IFN-γ production in response to immobilized IgG and/or IL-18 was inhibited by chemical inhibitors of Syk and several other kinases involved in CD16 signaling pathways. IL-18 augmented antibody-dependent cellular cytotoxicity (ADCC) of human NK cells against rituximab-coated Raji cells in vitro. IL-18 and rituximab acted synergistically to promote regression of human lymphoma xenografts in SCID mice. Inasmuch as IL-18 costimulates IFN-γ production and ADCC of NK cells activated through Fc receptors in vitro and augments antitumor activity of rituximab in vivo, it is an attractive cytokine to combine with monoclonal antibodies for treatment of human cancer.


Assuntos
Interleucina-18/farmacologia , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Murinos/administração & dosagem , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Imunoglobulina G/imunologia , Imunoglobulinas/metabolismo , Interferon gama/biossíntese , Interleucina-18/administração & dosagem , Células Matadoras Naturais/metabolismo , Linfoma/tratamento farmacológico , Linfoma/imunologia , Camundongos , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Neoplasias/metabolismo , Receptores Fc/metabolismo , Receptores de IgG/imunologia , Receptores de IgG/metabolismo , Rituximab , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Blood ; 118(23): 6097-106, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21998209

RESUMO

Signal Transducer and Activator of Transcription 4 (STAT4) is a transcription factor that is activated by IL-12 signaling and promotes Th1-cell differentiation and IFN-γ production. Defective IFN-γ production because of STAT4 mRNA and protein deficiency occurs after autologous stem cell transplantation for lymphoma. In the present study, we investigated the mechanisms of STAT4 deficiency in lymphoma patients. The tumor-bearing state is not responsible, because STAT4 levels were not significantly different in PBMCs obtained from healthy control subjects compared with those from lymphoma patients before treatment. STAT4 protein levels were significantly decreased in PBMCs and T cells obtained from lymphoma patients after standard-dose chemotherapy. Furthermore, treatment of control PBMC cultures or a natural killer cell line with chemotherapy drugs in vitro also resulted in reduced STAT4 protein and diminished, IL-12-induced IFN-γ production. Translation of STAT4 protein was not impaired in chemotherapy-treated cells, whereas the STAT4 protein half-life was significantly reduced. Chemotherapy drugs promoted the ubiquitination and proteasomal degradation of STAT4. Treatment with the proteasome inhibitor bortezomib reversed chemotherapy-induced STAT4 deficiency and defective IFN-γ production. We conclude that acquired STAT4 deficiency in lymphoma patients is a consequence of treatment with chemotherapy, results that have important implications for the design of optimal immunotherapy for lymphoma.


Assuntos
Etoposídeo/efeitos adversos , Linfoma/tratamento farmacológico , Linfoma/genética , Fator de Transcrição STAT4/genética , Fator de Transcrição STAT4/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos Alquilantes/efeitos adversos , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Fitogênicos/efeitos adversos , Antineoplásicos Fitogênicos/farmacologia , Ácidos Borônicos/farmacologia , Bortezomib , Carmustina/efeitos adversos , Carmustina/farmacologia , Células Cultivadas , Interações Medicamentosas , Etoposídeo/farmacologia , Citometria de Fluxo , Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-12/genética , Interleucina-12/metabolismo , Interleucina-2/genética , Interleucina-2/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/fisiologia , Linfoma/patologia , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/patologia , Camundongos , Camundongos Endogâmicos C57BL , Biossíntese de Proteínas/efeitos dos fármacos , Pirazinas/farmacologia , Estabilidade de RNA/efeitos dos fármacos , Fator de Transcrição STAT4/deficiência , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Ubiquitina/metabolismo
10.
PLoS One ; 6(7): e22189, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21779390

RESUMO

BACKGROUND: T cell development results in the generation of both mature αß and γδ T cells. While αß T cells predominate in secondary lymphoid organs, γδ T cells are more abundant in mucosal tissues. PU.1, an Ets family transcription factor, also identified as the spleen focus forming virus proviral integration site-1 (Sfpi1) is essential for early stages of T cell development, but is down regulated during the DN T-cell stage. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we show that in mice specifically lacking PU.1 in T cells using an lck-Cre transgene with a conditional Sfpi1 allele (Sfpi1(lck-/-)) there are increased numbers of γδ T cells in spleen, thymus and in the intestine when compared to wild-type mice. The increase in γδ T cell numbers in PU.1-deficient mice is consistent in γδ T cell subsets identified by TCR variable regions. PU.1-deficient γδ T cells demonstrate greater proliferation in vivo and in vitro. CONCLUSIONS/SIGNIFICANCE: The increase of γδ T cell numbers in Lck-Cre deleter strains, where deletion occurs after PU.1 expression is diminished, as well as the observation that PU.1-deficient γδ T cells have greater proliferative responses than wild type cells, suggests that PU.1 effects are not developmental but rather at the level of homeostasis. Thus, our data shows that PU.1 has a negative influence on γδ T cell expansion.


Assuntos
Proteínas Proto-Oncogênicas/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/metabolismo , Transativadores/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Proliferação de Células , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Interferon gama/metabolismo , Interleucina-17/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas/genética , Transativadores/genética
11.
Nat Immunol ; 11(6): 527-34, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20431622

RESUMO

CD4(+) helper T cells acquire effector phenotypes that promote specialized inflammatory responses. We show that the ETS-family transcription factor PU.1 was required for the development of an interleukin 9 (IL-9)-secreting subset of helper T cells. Decreasing PU.1 expression either by conditional deletion in mouse T cells or the use of small interfering RNA in human T cells impaired IL-9 production, whereas ectopic PU.1 expression promoted IL-9 production. Mice with PU.1-deficient T cells developed normal T helper type 2 (T(H)2) responses in vivo but showed attenuated allergic pulmonary inflammation that corresponded to lower expression of Il9 and chemokines in peripheral T cells and in lungs than that of wild-type mice. Together our data suggest a critical role for PU.1 in generating the IL-9-producing (T(H)9) phenotype and in the development of allergic inflammation.


Assuntos
Diferenciação Celular , Hipersensibilidade , Interleucina-9/metabolismo , Proteínas Proto-Oncogênicas/imunologia , Linfócitos T/imunologia , Transativadores/imunologia , Animais , Feminino , Humanos , Inflamação , Interleucina-9/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
J Immunol ; 183(8): 4887-94, 2009 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19801513

RESUMO

The Ets transcription factor PU.1 is a master regulator for the development of multiple lineages during hematopoiesis. The expression pattern of PU.1 is dynamically regulated during early T lineage development in the thymus. We previously revealed that PU.1 delineates heterogeneity of effector Th2 populations. In this study, we further define the function of PU.1 on the Th2 phenotype using mice that specifically lack PU.1 in T cells using an lck-Cre transgene with a conditional Sfpi1 allele (Sfpi1(lck-/-)). Although deletion of PU.1 by the lck-Cre transgene does not affect T cell development, Sfpi1(lck-/-) T cells have a lower activation threshold than wild-type T cells. When TCR engagement is limiting, Sfpi1(lck-/-) T cells cultured in Th2 polarizing conditions secrete higher levels of Th2 cytokines and have greater cytokine homogeneity than wild-type cells. We show that PU.1 modulates the levels of TCR expression in CD4(+) T cells by regulating the DNA-binding activity of GATA-3 and limiting GATA-3 regulation of TCR gene expression. GATA-3-dependent regulation of TCR expression is also observed in Th1 and Th2 cells. In CD4(+) T cells, PU.1 expression segregates into subpopulations of cells that have lower levels of surface TCR, suggesting that PU.1 contributes to the heterogeneity of TCR expression. Thus, we have identified a mechanism whereby increased GATA-3 function in the absence of the antagonizing activity of PU.1 leads to increased TCR expression, a reduced activation threshold, and increased homogeneity in Th2 populations.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Fator de Transcrição GATA3/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Células Th2/imunologia , Transativadores/metabolismo , Animais , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/imunologia , Citocinas/biossíntese , Citocinas/imunologia , Feminino , Fator de Transcrição GATA3/genética , Fator de Transcrição GATA3/imunologia , Técnicas de Silenciamento de Genes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/imunologia , RNA Interferente Pequeno/imunologia , RNA Interferente Pequeno/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Células Th2/metabolismo , Transativadores/genética , Transativadores/imunologia
13.
J Immunol ; 183(3): 1598-606, 2009 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-19592658

RESUMO

Th2 cells can be subdivided into subpopulations depending on the level of a cytokine and the subsets of cytokines they produce. We have recently identified the ETS family transcription factor PU.1 as regulating heterogeneity in Th2 populations. To define additional factors that might contribute to Th2 heterogeneity, we examined the PU.1 interacting protein IFN-regulatory factor (IRF)4. When Th2 cells are separated based on levels of IL-10 secretion, IRF4 expression segregates into the subset of Th2 cells expressing high levels of IL-10. Infection of total Th2 cells, and IL-10 nonsecreting cells, with retrovirus-expressing IRF4, resulted in increased IL-4 and IL-10 expression, no change in IL-5 or IL-13 production and decreased Il9 transcription. Transfection of an IRF4-specific small interfering RNA into Th2 cells decreases IL-10 production. IRF4 directly binds the Il10 gene as evidenced by chromatin immunoprecipitation assay, and regulates Il10 control elements in a reporter assay. IRF4 interacts with PU.1, and in PU.1-deficient T cells there was an increase in IRF4 binding to the Il10 gene, and in the ability of IRF4 to induce IL-10 production compared with wild-type cells and Il10 promoter activity in a reporter assay. Further heterogeneity of IRF4 expression was observed in Th2 cells analyzed for expression of multiple Th2 cytokines. Thus, IRF4 promotes the expression of a subset of Th2 cytokines and contributes to Th2 heterogeneity.


Assuntos
Citocinas/biossíntese , Regulação da Expressão Gênica/imunologia , Fatores Reguladores de Interferon/fisiologia , Células Th2/imunologia , Animais , Interleucina-10/genética , Camundongos , Ligação Proteica , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/metabolismo
14.
Immunology ; 127(4): 587-95, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19604309

RESUMO

T-cell responses to a cytokine milieu instruct the development of multiple effector phenotypes. While transforming growth factor-beta(1) (TGF-beta(1)) inhibits the development of T helper type 1 (Th1) and Th2 cells, we demonstrate that like interleukin-6 (IL-6) and IL-4, IL-12 can inhibit the development of TGF-beta(1)-induced Foxp3-expressing adaptive T regulatory (aTreg) cells. Signal transducer and activator of transcription 4 (STAT4) is critical for the response to IL-12, although there is a parallel pathway involving T box expressed in T cells (T-bet), and cells from mice double-deficient in STAT4 and T-bet are refractory to the inhibition of aTreg-cell development by IL-12. While the ability of these cytokines to promote Th differentiation may contribute to this effect, we observe that culture with IL-12, or other instructive cytokines, results in an increase in repressive chromatin modifications at the Foxp3 locus that limit STAT5 binding to Foxp3, without observed effects on IL-2 signalling pathways. In a model of allergic lung inflammation there are increased percentages of Treg cells in the lungs of Stat4(-/-) mice, compared with wild-type mice, and increases in Treg cells correlate with decreased allergic inflammation. Overall, these results suggest an important role for STAT4 in regulating Treg-cell development.


Assuntos
Fator de Transcrição STAT4/imunologia , Linfócitos T Reguladores/imunologia , Animais , Diferenciação Celular/imunologia , Células Cultivadas , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/metabolismo , Interleucina-12/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Hipersensibilidade Respiratória/imunologia , Fator de Crescimento Transformador beta1/imunologia
15.
Blood ; 113(23): 5887-90, 2009 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-19359411

RESUMO

IL-12 activates STAT4, which is a critical regulator of inflammation and T helper type I (Th1) lineage development in murine systems. The requirement for STAT4 in the generation of human Th1 cells has not been examined thoroughly. Compared with control Th1 cultures, expression of the Th1 genes IFNgamma, IL-12Rbeta2, and TNFalpha is greatly reduced in Th1 cultures of CD4 T cells isolated from lymphoma patients after autologous stem cell transplantation who have acquired STAT4 deficiency. Moreover, IL-4 and IL-5 production is increased in patient Th1 cultures though there are no defects in the development of Th2 cells. Reconstitution of STAT4 in patient T cells allowed recovery of IFNgamma and IL-12Rbeta2 expression, whereas ectopic expression of IL-12Rbeta2 did not rescue STAT4 expression, and increased IFNgamma production only to levels intermediate between control and patient samples. These results demonstrate that, as in murine systems, STAT4 is required for optimal human Th1 lineage development.


Assuntos
Diferenciação Celular/imunologia , Fator de Transcrição STAT4/deficiência , Fator de Transcrição STAT4/metabolismo , Células Th1/citologia , Células Th1/metabolismo , Células Cultivadas , Humanos , Linfoma/genética , Linfoma/imunologia , Linfoma/metabolismo , Receptores de Interleucina-12/metabolismo , Fator de Transcrição STAT4/genética , Células Th1/imunologia
16.
Immunity ; 29(5): 679-90, 2008 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-18993086

RESUMO

Transcriptional regulatory networks direct the development of specialized cell types. The transcription factors signal tranducer and activator of transcription 4 (Stat4) and T-bet are required for the interleukin-12 (IL-12)-stimulated development of T helper 1 (Th1) cells, although the hierarchy of activity by these factors has not been clearly defined. In this report, we show that these factors did not function in a linear pathway and that each factor played a unique role in programming chromatin architecture for Th1 gene expression, with subsets of genes depending on Stat4, T-bet, or both for expression in Th1 cells. T-bet was not able to transactivate expression of Stat4-dependent genes in the absence of endogenous Stat4 expression. Thus, T-bet requires Stat4 to achieve complete IL-12-dependent Th1 cell-fate determination. These data provide a basis for understanding how transiently activated and lineage-specific transcription factors cooperate in promoting cellular differentiation.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Regulação da Expressão Gênica , Fator de Transcrição STAT4/metabolismo , Proteínas com Domínio T/metabolismo , Células Th1/imunologia , Animais , Linfócitos T CD4-Positivos/metabolismo , Cromatina/genética , Cromatina/isolamento & purificação , Técnicas de Inativação de Genes , Interferon gama/imunologia , Interferon gama/metabolismo , Interleucina-12/imunologia , Interleucina-12/metabolismo , Interleucina-4/imunologia , Interleucina-4/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Células Th1/metabolismo , Transcrição Gênica , Transdução Genética
17.
J Immunol ; 181(7): 5062-70, 2008 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-18802110

RESUMO

STAT4, a critical regulator of inflammation in vivo, can be expressed as two alternative splice forms, a full-length STAT4alpha, and a STAT4beta isoform lacking a C-terminal transactivation domain. Each isoform is sufficient to program Th1 development through both common and distinct subsets of target genes. However, the ability of these isoforms to mediate inflammation in vivo has not been examined. Using a model of colitis that develops following transfer of CD4(+) CD45RB(high) T cells expressing either the STAT4alpha or STAT4beta isoform into SCID mice, we determined that although both isoforms mediate inflammation and weight loss, STAT4beta promotes greater colonic inflammation and tissue destruction. This correlates with STAT4 isoform-dependent expression of TNF-alpha and GM-CSF in vitro and in vivo, but not Th1 expression of IFN-gamma or Th17 expression of IL-17, which were similar in STAT4alpha- and STAT4beta-expressing T cells. Thus, higher expression of a subset of inflammatory cytokines from STAT4beta-expressing T cells correlates with the ability of STAT4beta-expressing T cells to mediate more severe inflammatory disease.


Assuntos
Citocinas/biossíntese , Mediadores da Inflamação/fisiologia , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Fator de Transcrição STAT4/fisiologia , Índice de Gravidade de Doença , Células Th1/imunologia , Animais , Células Cultivadas , Feminino , Mediadores da Inflamação/metabolismo , Doenças Inflamatórias Intestinais/genética , Transfusão de Linfócitos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos SCID , Camundongos Transgênicos , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/deficiência , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiologia , Estrutura Terciária de Proteína/genética , Receptores de Antígenos de Linfócitos T/fisiologia , Fator de Transcrição STAT4/biossíntese , Fator de Transcrição STAT4/deficiência , Fator de Transcrição STAT4/genética , Deleção de Sequência , Células Th1/metabolismo , Células Th1/transplante , Ativação Transcricional/genética , Ativação Transcricional/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima/genética , Regulação para Cima/imunologia , Redução de Peso/genética , Redução de Peso/imunologia
18.
J Immunol ; 181(5): 3346-52, 2008 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-18714006

RESUMO

The IL-18Ralpha-chain is expressed on Th1 but not Th2 cells. We have recently shown that Stat4 is an important component of programming the Il18r1 locus (encoding IL-18Ralpha) for maximal expression in Th1 cells. Il18r1 is reciprocally repressed during Th2 development. In this report, we demonstrate the establishment of DH patterns that are distinct among undifferentiated CD4 T, Th1, and Th2 cells. Stat6 is required for the repression of Il18r1 expression and in Stat6-deficient Th2 cultures, mRNA levels, histone acetylation, and H3K4 methylation levels are intermediate between levels observed in Th1 and Th2 cells. Despite the repressive effects of IL-4 during Th2 differentiation, we observed only modest binding of Stat6 to the Il18r1 locus. In contrast, we observed robust GATA-3 binding to a central region of the locus where DNase hypersensitivity sites overlapped with conserved non-coding sequences in Il18r1 introns. Ectopic expression of GATA-3 in differentiated Th1 cells repressed Il18r1 mRNA and surface expression of IL-18Ralpha. These data provide further mechanistic insight into transcription factor-dependent establishment of Th subset-specific patterns of gene expression.


Assuntos
Diferenciação Celular , Montagem e Desmontagem da Cromatina , Fator de Transcrição GATA3/fisiologia , Subunidade alfa de Receptor de Interleucina-18/genética , Fator de Transcrição STAT6/fisiologia , Células Th1/citologia , Células Th2/citologia , Animais , Regulação da Expressão Gênica , Camundongos , Camundongos Knockout , Ligação Proteica
19.
J Interferon Cytokine Res ; 28(6): 367-80, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18593332

RESUMO

Blocking the function of Stat (signal transducer and activator of transcription) proteins, which are critical for antiviral responses, has evolved as a common mechanism for pathogen immune evasion. The poxvirus-encoded phosphatase H1 is critical for viral replication, and may play an additional role in the evasion of host defense by dephosphorylating Stat1 and blocking interferon (IFN)-stimulated innate immune responses. Vaccinia virus (VACV) H1 can inhibit the phosphorylation of the transcription factor Stat1 after IFN-gamma stimulation of epithelial cells, greatly attenuating IFN-induced biological functions. In this study, we demonstrate that VACV infection is capable of inhibiting the phosphorylation of Stat1 and Stat2 after stimulation of fibroblasts or bone marrow-derived macrophages with either type I or type II IFNs, but did not inhibit the activation of Stat3 or Stat5 in either cell type. By using recombinant proteins for in vitro assays, we observe that variola virus H1 is more active than VACV H1, although it has similar selectivity for Stat targets. Differential effects of VACV infection were observed on the induction of IFN-stimulated genes, with complete inhibition of some genes by VACV infection, while others were less affected. Despite the IFN-gamma-induced expression of some genes in VACV-infected cells, IFN-gamma was unable to rescue the VACV-mediated inhibition of MHC class II antigen presentation. Moreover, VACV infection can affect the IFN-induced expression of Stat1-dependent and Stat1-independent genes, suggesting that the virus may target additional IFN-activated pathways. Thus, VACV targets multiple signaling pathways in the evasion of antiviral immune responses.


Assuntos
Fibroblastos/imunologia , Fibroblastos/virologia , Regulação da Expressão Gênica/imunologia , Interferon Tipo I/imunologia , Interferon gama/imunologia , Macrófagos/imunologia , Macrófagos/virologia , Fator de Transcrição STAT1/imunologia , Vaccinia virus/imunologia , Animais , Apresentação de Antígeno , Técnicas de Cultura de Células , Citocinas/metabolismo , Fibroblastos/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interferon Tipo I/farmacologia , Interferon gama/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células NIH 3T3 , Fator de Transcrição STAT1/genética , Transdução de Sinais , Linfócitos T/imunologia , Vírus da Varíola/imunologia
20.
J Immunol ; 179(12): 8322-31, 2007 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18056377

RESUMO

The Ras-related GTPases Rap1a and 1b have been implicated in multiple biological events including cell adhesion, free radical production, and cancer. To gain a better understanding of Rap1 function in mammalian physiology, we deleted the Rap1a gene. Although loss of Rap1a expression did not initially affect mouse size or viability, upon backcross into C57BL/6J mice some Rap1a-/- embryos died in utero. T cell, B cell, or myeloid cell development was not disrupted in Rap1a-/- mice. However, macrophages from Rap1a null mice exhibited increased haptotaxis on fibronectin and vitronectin matrices that correlated with decreased adhesion. Chemotaxis of lymphoid and myeloid cells in response to CXCL12 or CCL21 was significantly reduced. In contrast, an increase in FcR-mediated phagocytosis was observed. Because Rap1a was previously copurified with the human neutrophil NADPH oxidase, we addressed whether GTPase loss affected superoxide production. Neutrophils from Rap1a-/- mice had reduced fMLP-stimulated superoxide production as well as a weaker initial response to phorbol ester. These results suggest that, despite 95% amino acid sequence identity, similar intracellular distribution, and broad tissue distribution, Rap1a and 1b are not functionally redundant but rather differentially regulate certain cellular events.


Assuntos
Quimiotaxia/genética , Células Mieloides/imunologia , Proteínas rap de Ligação ao GTP/fisiologia , Proteínas rap1 de Ligação ao GTP/fisiologia , Sequência de Aminoácidos , Animais , Linfócitos B/imunologia , Quimiocina CCL21/farmacologia , Quimiocina CXCL12/farmacologia , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Camundongos , Camundongos Knockout , Células Mieloides/efeitos dos fármacos , Neutrófilos/imunologia , Fagocitose , Ésteres de Forbol/farmacologia , Explosão Respiratória , Superóxidos/metabolismo , Proteínas rap1 de Ligação ao GTP/genética
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