Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
2.
Leuk Lymphoma ; 62(4): 801-809, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33284055

RESUMO

Previous studies demonstrated that the majority of Hodgkin lymphoma (HL) patients achieve response after treatment, while 5% become refractory. Studies analyzing the role of lymphocyte subsets in peripheral blood are limited. This investigation sought to evaluate peripheral blood lymphocyte subsets and soluble MHC class I chain-related proteins A and B (sMIC-A/B) and their correlation with survival in patients with newly diagnosed HL. The study recruited 36 patients and 72 healthy donors. HL patients showed a decrease in CD4, B, monocytes, NK, and NKT cells; and an increase in γ-δ T cells and soluble MIC-A serum levels. Higher values of s-MIC-A  >100 ng/mL and NKT cells >40 µL correlated with poor overall survival (OS). In conclusion, in HL peripheral blood CD4 T and B cells, monocytes, NK, and NKT cells were decreased, while s-MIC-A and γ-δ T cells increased. Higher values of s-MIC-A and NKT cells correlated with poor survival.


Assuntos
Doença de Hodgkin , Células T Matadoras Naturais , Humanos , Contagem de Linfócitos , Subpopulações de Linfócitos , Subpopulações de Linfócitos T
3.
Clin Microbiol Rev ; 34(2)2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33361143

RESUMO

The immune system must work in an orchestrated way to achieve an optimal response upon detection of antigens. The cells comprising the immune response are traditionally divided into two major subsets, innate and adaptive, with particular characteristics for each type. Type I natural killer T (iNKT) cells are defined as innate-like T cells sharing features with both traditional adaptive and innate cells, such as the expression of an invariant T cell receptor (TCR) and several NK receptors. The invariant TCR in iNKT cells interacts with CD1d, a major histocompatibility complex class I (MHC-I)-like molecule. CD1d can bind and present antigens of lipid nature and induce the activation of iNKT cells, leading to the secretion of various cytokines, such as gamma interferon (IFN-γ) and interleukin 4 (IL-4). These cytokines will aid in the activation of other immune cells following stimulation of iNKT cells. Several molecules with the capacity to bind to CD1d have been discovered, including α-galactosylceramide. Likewise, several molecules have been synthesized that are capable of polarizing iNKT cells into different profiles, either pro- or anti-inflammatory. This versatility allows NKT cells to either aid or impair the clearance of pathogens or to even control or increase the symptoms associated with pathogenic infections. Such diverse contributions of NKT cells to infectious diseases are supported by several publications showing either a beneficial or detrimental role of these cells during diseases. In this article, we discuss current data relative to iNKT cells and their features, with an emphasis on their driving role in diseases produced by pathogenic agents in an organ-oriented fashion.


Assuntos
Doenças Transmissíveis , Células T Matadoras Naturais , Citocinas , Humanos , Imunidade Inata
4.
Inflamm Bowel Dis ; 26(5): 697-708, 2020 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-31819985

RESUMO

BACKGROUND: The gut microbiota is a key element to support host homeostasis and the development of the immune system. The relationship between the microbiota and immunity is a 2-way road, in which the microbiota contributes to the development/function of immune cells and immunity can affect the composition of microbes. In this context, natural killer T cells (NKT cells) are distinct T lymphocytes that play a role in gut immunity and are influenced by gut microbes. In our work, we investigated the involvement of invariant NKT cells (iNKT) in intestinal homeostasis. RESULTS: We found that iNKT-deficient mice (iNKT-KO) had reduced levels of fecal IgA and an altered composition of the gut microbiota, with increased Bacteroidetes. The absence of iNKT cells also affected TGF-ß1 levels and plasma cells, which were significantly reduced in knockout (KO) mice. In addition, when submitted to dextran sodium sulfate colitis, iNKT-KO mice had worsening of colitis when compared with wild-type (WT) mice. To further address iNKT cell contribution to intestinal homeostasis, we adoptively transferred iNKT cells to KO mice, and they were submitted to colitis. Transfer of iNKT cells improved colitis and restored fecal IgA levels and gut microbiota. CONCLUSIONS: Our results indicate that intestinal NKT cells are important modulators of intestinal homeostasis and that gut microbiota composition may be a potential target in the management of inflammatory bowel diseases.


Assuntos
Microbioma Gastrointestinal/imunologia , Homeostase/imunologia , Imunoglobulina A/análise , Intestinos/imunologia , Células T Matadoras Naturais/imunologia , Animais , Colite/induzido quimicamente , Colite/imunologia , Colite/microbiologia , Sulfato de Dextrana , Modelos Animais de Doenças , Fezes/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
5.
Int Rev Immunol ; 36(6): 315-337, 2017 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-28933579

RESUMO

Modulation of the immune system has been widely targeted for the treatment of several immune-related diseases, such as autoimmune disorders and cancer, due to its crucial role in these pathologies. Current available therapies focus mainly on symptomatic treatment and are often associated with undesirable secondary effects. For several years, remission of disease and subsequently recovery of immune homeostasis has been a major goal for immunotherapy. Most current immunotherapeutic strategies are aimed to inhibit or potentiate directly the adaptive immune response by modulating antibody production and B cell memory, as well as the effector potential and memory of T cells. Although these immunomodulatory approaches have shown some success in the clinic with promising therapeutic potential, they have some limitations related to their effectiveness in disease models and clinical trials, as well as elevated costs. In the recent years, a renewed interest has emerged on targeting innate immune cells for immunotherapy, due to their high plasticity and ability to exert a potent and extremely rapid response, which can influence the outcome of the adaptive immune response. In this review, we discuss the immunomodulatory potential of several innate immune cells, as well as they use for immunotherapy, especially in autoimmunity and cancer.


Assuntos
Doenças Autoimunes/terapia , Células Dendríticas/imunologia , Imunidade Inata , Imunoterapia Adotiva/métodos , Células T Matadoras Naturais/imunologia , Neoplasias/terapia , Animais , Doenças Autoimunes/imunologia , Plasticidade Celular , Humanos , Imunidade , Células T Matadoras Naturais/transplante , Neoplasias/imunologia
6.
Microbes Infect ; 19(11): 527-535, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28943322

RESUMO

Mycobacterium avium is a facultative intracellular opportunistic pathogen especially relevant in cases of people living with AIDS. The aim of this study was to evaluate the role of intercellular adhesion molecule 1 (ICAM-1) in the inflammatory response against M. avium infection. Mice deficient for ICAM-1 (ICAM KO) and infected with M. avium presented increased bacterial load in the spleen, liver and lungs compared to C57BL/6. Moreover, ICAM deficient mice presented reduced granuloma area in liver at 30 days post-infection with reduced numbers of lymphocytes and granulocytes. The assessment of in vitro cytokine production by ICAM KO spleen cells showed lower levels of IFN-γ compared to C57BL/6, whereas TNF-α remained unaltered. Additionally, the production of IFN-γ in liver and spleen tissues was also diminished in ICAM-1 KO mice. Interestingly, a persistent reduction in IFN-γ production was observed in CD3+NK1.1+ cells of ICAM-1 deficient mice compared to wild-type animals. Together, these results demonstrate the importance of ICAM-1 in the efficient control of M. avium infection and granuloma formation and highlights its role on CD3+NK1.1+ cell population as important for IFN-γ production during infection.


Assuntos
Molécula 1 de Adesão Intercelular/fisiologia , Mycobacterium avium , Tuberculose/metabolismo , Animais , Citometria de Fluxo , Interferon gama/metabolismo , Fígado/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Baço/patologia , Tuberculose/microbiologia
7.
Parasit Vectors ; 10(1): 219, 2017 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-28468680

RESUMO

BACKGROUND: Cutaneous leishmaniasis (CL) is caused by Leishmania (Viannia) braziliensis, which infects dermal macrophages and dendritic cells, causing an intense immune-mediated-tissue inflammation and a skin ulcer with elevated borders that can heal spontaneously or after antimonial therapy. The resolution of lesions depends on an adaptive immune response, and cytotoxic cells seem to have a fundamental role in this process. The aim of this study is to better understand the role of cytotoxicity mediated mechanisms that occur during the immune response in the CL lesion milieu, considering distinct cytotoxic-related CD107a+ cells, such as CD8+, CD4+, CD4neg CD8neg (double-negative, DN) and CD4+CD8+ (double-positive, DP) T lymphocytes, as well as NK and NKT cells. METHODS: Lesion derived cells were assessed for T cell subpopulations and NK cells, as well as CD107a expression by flow cytometry. In addition, cytometric bead array (CBA) was used to quantify cytokines and granzyme B concentrations in supernatants from macerated lesions. RESULTS: Flow cytometry analyses revealed that NKT cells are the major CD107a-expressing cell population committed to cytotoxicity in CL lesion, although we also observed high frequencies of CD4+ and DN T cells expressing CD107a. Analysing the pool of CD107a+-cell populations, we found a higher distribution of DN T cells (44%), followed by approximately 25% of NKT cells. Interestingly, NK and CD8+ T cells represented only 3 and 4% of the total-CD107a+-cell pool, respectively. CONCLUSIONS: The cytotoxicity activity that occurs in the lesion milieu of CL patients seems to be dominated by DN T and NKT cells. These findings suggest the need for a reevaluation of the role of classical-cytotoxic NK and CD8+ T cells in the pathogenesis of CL, implicating an important role for other T cell subpopulations.


Assuntos
Citotoxicidade Imunológica , Leishmaniose Cutânea/imunologia , Proteína 1 de Membrana Associada ao Lisossomo/imunologia , Células T Matadoras Naturais/imunologia , Subpopulações de Linfócitos T/imunologia , Adulto , Antígenos de Protozoários/imunologia , Biópsia , Brasil/epidemiologia , Citocinas/biossíntese , Citocinas/genética , Feminino , Citometria de Fluxo , Granzimas/análise , Humanos , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/epidemiologia , Proteína 1 de Membrana Associada ao Lisossomo/genética , Masculino , Pessoa de Meia-Idade , Pele/imunologia , Pele/parasitologia , Pele/patologia
8.
Parasite Immunol ; 38(4): 244-54, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26928901

RESUMO

Cutaneous leishmaniasis (CL) is an important public health issue worldwide. The control of Leishmania infection depends on cellular immune mechanisms, and the inflammatory response may contribute to pathogenesis. A beneficial role of CD8(+) T lymphocytes has been proposed; nevertheless, other studies suggest a cytotoxic role of CD8(+) T lymphocytes involved in tissue damage, showing controversial role of these cells. The goal of the current study was to understand the immunopathology of CL and determine the profile of cytotoxic cells--such as CD4(+) T, natural killer and natural killer T cells--that might be involved in triggering immunological mechanisms, and may lead to cure or disease progression. The frequencies of cytotoxic cell populations in peripheral blood, obtained from patients with active disease, during treatment and after clinical healing, were assessed by flow cytometry. Cytotoxicity could not be related to a deleterious role in Leishmania braziliensis infection, as patients with active CL showed similar percentages of degranulation to healthy individuals (HI). Cured patients exhibited a lower percentage of degranulating cells, which may be due to a downregulation of the immune response. The understanding of the immunopathological mechanisms involved in CL and the commitment of cytotoxic cells enables improvements in therapeutic strategies.


Assuntos
Leishmaniose Cutânea/imunologia , Adulto , Antiprotozoários/uso terapêutico , Contagem de Linfócito CD4 , Degranulação Celular , Células Cultivadas , Citotoxicidade Imunológica , Feminino , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/parasitologia , Leishmania braziliensis/imunologia , Leishmaniose Cutânea/tratamento farmacológico , Masculino , Meglumina/uso terapêutico , Antimoniato de Meglumina , Pessoa de Meia-Idade , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/parasitologia , Compostos Organometálicos/uso terapêutico , Adulto Jovem
9.
Immunobiology ; 220(11): 1210-8, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26101139

RESUMO

After Candida albicans arrival to the liver, the local production of proinflammatory cytokines and the expanded intrahepatic lymphocytes (IHL) can be either beneficial or detrimental to the host. Herein we explored the balance between protective inflammatory reaction and liver damage, focusing our study on the contribution of TNF-α and Fas-Fas-L pathways in the hepatocellular apoptosis associated to C. albicans infection. A robust tissue reaction and a progressive increase of IL-1ß, IL-6 and TNF-α were observed in infected animals. Blocking the biological activity of TNF-α did not modify the number of apoptotic cells observed in C. albicans infected animals. Fas-L molecule was up regulated on purified hepatic mononuclear cells and its expression progressed with the infection. In the IHL compartment, the absolute number of Fas-L+ NK and NKT cells increased on days 1 and 3 of the infection. C. albicans was also able to up regulate Fas-L expression in normal liver NK and NKT cells after in vitro contact. The innate receptor TLR2 was involved in this phenomenon. In the interplay between host factors and evasion strategies exploited by pathogens, the mechanism supported here could represent an additional way that allows this fungus to circumvent protective immune responses in the liver.


Assuntos
Candida albicans/imunologia , Proteína Ligante Fas/genética , Regulação da Expressão Gênica , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Animais , Apoptose , Quimiocinas/genética , Quimiocinas/metabolismo , Citocinas/genética , Citocinas/metabolismo , Feminino , Hepatócitos/imunologia , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/microbiologia , Inflamação/patologia , Fígado/imunologia , Fígado/metabolismo , Fígado/microbiologia , Fígado/patologia , Ratos , Transdução de Sinais , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA