RESUMO
BACKGROUND: Eosinophils are multifunctional, polymorphonuclear leucocytes that secrete proteins within cytoplasmic granules, such as cytokines, chemokines, metalloproteinases (MMPs) and metalloproteinases tissue inhibitors (TIMPs). Although eosinophilia is a hallmark of atopic dermatitis (AD), several functional aspects of eosinophils remain unknown. OBJECTIVE: We aimed to evaluate the phenotype and functional response of eosinophils under staphylococcal enterotoxin B (SEB) and Toll-like receptor (TLR)-2/6 (FSL-1) stimulation in the secretion of CCL5, MMPs and TIMPs in adults with AD. METHODS: Forty-one adult patients with AD and 45 healthy controls enrolled for the study. Phenotype of eosinophils from granulocytes of peripheral blood was analysed by flow cytometry. We performed evaluation of CCL5 (cytometric bead array), MMP and TIMP (ELISA) secretion, in culture supernatants of purified eosinophils stimulated with SEB or TLR2/6 agonist (FSL-1). RESULTS: We found a higher frequency of LIN1- CCR3+ eosinophils, and decreased expression of CD23 and CD62L receptors in eosinophils of AD patients. There was no difference in MMP and TIMP serum levels between the evaluated groups. However, we detected decreased basal levels of TIMP-1, TIMP-2 and CCL5 in culture supernatants from purified, unstimulated eosinophils from AD patients. CONCLUSION: In adults with AD, phenotypical features of eosinophils reveal decreased expression of early activation and L-selectin receptors. Regarding the functional profile of purified eosinophils related to tissue remodelling in atopic dermatitis, innate immune stimulation (TLR2/6 agonist and SEB) did not affect the ratio of MMP/TIMPs secretion in AD. Our findings reinforce the potential breakdown in tissue remodelling process mediated by eosinophils in AD.
Assuntos
Dermatite Atópica/imunologia , Eosinófilos/metabolismo , Selectina L/imunologia , Receptores de IgE/imunologia , Inibidores Teciduais de Metaloproteinases/metabolismo , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Imunoglobulina E/sangue , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Ouabain (OUA) is a steroid hormone capable of inhibiting the protein Na+K+ATPase present in the plasma membrane of cells. Ouabain was initially extracted from the roots of African trees such as Acocanthera ouabaio and Strophantus gratus seeds and later described as an endogenous component found in higher mammals. The adrenal gland is the main site of synthesis of ouabain and it is released in stressful situations, conditions similar to those where there is secretion of corticosteroids. Immunological functions have been shown to be regulated by ouabain. In order to understand the effects of ouabain on B lymphocyte populations in different lymphoid organs, mice received intraperitoneal injections of ouabain for 3 consecutive days. Twenty-four hours after the last injection, cells were analyzed by flow cytometry. In the spleen, ouabain modulated especially follicular B cells, inducing a significant decrease in the percentage and absolute numbers of those cells. Ouabain also reduced the absolute number of marginal zone B lymphocytes. No difference in the percentage or absolute number of B lymphocytes in the spleen forty-eight hours after the last injection was observed. An increase in the number of B cells was seen in mesenteric lymph nodes and this retention appears to be directly related to increased expression of CXCR5 chemokine receptor and reduction of CD62L, which also explains the observed reduction of B cells in the spleen. Our results indicate that ouabain regulates the dynamics of B lymphocytes in peripheral organs but production of total IgM and IgG in the serum of animals treated in vivo with ouabain was not affected.
Assuntos
Subpopulações de Linfócitos B/efeitos dos fármacos , Cardiotônicos/farmacologia , Linfonodos/efeitos dos fármacos , Ouabaína/farmacologia , Baço/efeitos dos fármacos , Animais , Subpopulações de Linfócitos B/citologia , Subpopulações de Linfócitos B/imunologia , Feminino , Regulação da Expressão Gênica , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Imunofenotipagem , Injeções Intraperitoneais , Selectina L/genética , Selectina L/imunologia , Linfonodos/citologia , Linfonodos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Receptores CXCR5/genética , Receptores CXCR5/imunologia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/imunologia , Baço/citologia , Baço/imunologiaRESUMO
Although much is described about the molecules involved in neutrophil migration from circulation into tissues, less is known about the molecular mechanisms that regulate neutrophil entry into lymph nodes (LNs) draining a local inflammatory site. In this study, we investigated neutrophil migration toward LNs in a context of inflammation induced by immunization of BALB/c mice with OVA emulsified in CFA. We demonstrated that neutrophils can enter LNs of OVA/CFA-immunized mice not only via lymphatic vessels but also from blood, across high endothelial venules. By adoptive transfer experiments, we showed that this influx was dependent on an inflammatory-state condition and previous neutrophil stimulation with OVA/anti-OVA immune complexes. Importantly, we have demonstrated that, in the migratory pattern to LNs, neutrophils used L-selectin and P-selectin glycoprotein ligand-1, macrophage-1 Ag and LFA-1 integrins, and CXCR4 to get access across high endothelial venules, whereas macrophage-1 Ag, LFA-1, and CXCR4 were involved in their trafficking through afferent lymphatics. Strikingly, we found that stimulation with immune complexes significantly upregulated the expression of sphingosine-1-phosphate receptor 4 on neutrophils, and that treatment with the sphingosine-1-phosphate agonist FTY720 altered neutrophil LN-homing ability. These findings summarized in this article disclose the molecular pattern that controls neutrophil recruitment to LNs.
Assuntos
Complexo Antígeno-Anticorpo/imunologia , Doenças do Sistema Imunitário/imunologia , Transtornos Leucocíticos/imunologia , Linfonodos/imunologia , Neutrófilos/imunologia , Transferência Adotiva , Animais , Movimento Celular/imunologia , Feminino , Cloridrato de Fingolimode , Imunossupressores/farmacologia , Inflamação/imunologia , Selectina L/imunologia , Linfonodos/citologia , Vasos Linfáticos/imunologia , Antígeno-1 Associado à Função Linfocitária/imunologia , Lisofosfolipídeos/agonistas , Antígeno de Macrófago 1/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Neutrófilos/transplante , Selectina-P/imunologia , Propilenoglicóis/farmacologia , Receptores CXCR4/imunologia , Receptores de Lisoesfingolipídeo/metabolismo , Esfingosina/agonistas , Esfingosina/análogos & derivados , Esfingosina/farmacologiaRESUMO
Corynebacterium bovis is one of the most commonly isolated bacteria from aseptically collected bovine milk samples. The objective of the current study was to characterize the bovine innate immune response by evaluating milk polymorphonuclear neutrophilic leukocytes (PMNL) in mammary glands infected with C. bovis. Twenty quarters infected with C. bovis and 28 culture-negative quarters (with milk somatic cell count <1×10(5) cells/mL) were used. The percentages of milk PMNL and the PMNL expression of L-selectin (CD62L), ß2-integrin (CD11b), and one of the endothelial-selectin ligands (CD44), as well as the levels of intracellular reactive oxygen species (ROS) and the phagocytosis of Staphylococcus aureus, were evaluated by flow cytometry. The apoptosis and necrosis rates of the PMNL were quantified using dual-color flow cytometry with fluorescein-labeled annexin and propidium iodide. The present study revealed a higher percentage of PMNL in the milk from C. bovis-infected quarters, although no significant differences were found in levels of CD44, CD62L, or CD11b expression among the PMNL. A lower percentage of apoptotic PMNL was observed in C. bovis-infected quarters, as well as higher percentages of viable PMNL and of PMNL that produced intracellular ROS. However, no alterations were observed in phagocytosis of Staph. aureus by the PMNL or in intensity of intracellular ROS production by PMNL. Thus, results from this investigation of the PMNL function support, at least in part, the fact that intramammary infections by C. bovis may offer protection against intramammary infections by other bacteria.
Assuntos
Infecções por Corynebacterium/imunologia , Corynebacterium/imunologia , Mastite Bovina/imunologia , Mastite Bovina/microbiologia , Leite/imunologia , Neutrófilos/imunologia , Animais , Antígeno CD11b/imunologia , Bovinos , Separação Celular/veterinária , Corynebacterium/isolamento & purificação , Feminino , Receptores de Hialuronatos/imunologia , Selectina L/imunologia , Leite/citologia , Leite/microbiologia , Neutrófilos/citologia , Fagocitose , Espécies Reativas de Oxigênio/metabolismoRESUMO
The D-mannose binding lectin ArtinM from Artocarpus integrifolia, previously known as KM+ and artocarpin, is considered a stimulant of Th1-type immunity, which is able to confer resistance to some intracellular pathogens. In addition, ArtinM induces neutrophil migration by haptotaxis through simultaneous interactions of its carbohydrate recognition domains (CRDs) with glycans expressed on the extracellular matrix and the neutrophil surface. In the present study, we have expanded the characterization of ArtinM as a neutrophil activator. Exposure of neutrophils to ArtinM for 15 min resulted in tyrosine phosphorylation of intracellular proteins, a process that was selectively inhibited by d-mannose or mannotriose. Shortly after stimulation, neutrophils secreted high levels of LTB(4) and underwent shedding of L-selectin from their surface. Exposure to ArtinM enhanced neutrophil functions, such as respiratory burst and zymozan and Listeria monocytogenes phagocytosis. In addition, ArtinM-stimulated neutrophils displayed increased CXCL-8 secretion and TLR2 gene transcription. These results demonstrate that ArtinM is able to induce potent neutrophil activation, a feature that should be strongly considered in the assessment of the lectin capacity to confer resistance against infections.
Assuntos
Movimento Celular , Lectinas de Ligação a Manose/farmacologia , Ativação de Neutrófilo , Neutrófilos/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Humanos , Interleucina-8/biossíntese , Interleucina-8/imunologia , Interleucina-8/farmacologia , Selectina L/efeitos dos fármacos , Selectina L/imunologia , Selectina L/metabolismo , Leucotrieno B4/biossíntese , Leucotrieno B4/imunologia , Neutrófilos/imunologia , Fagocitose/imunologia , Receptor 2 Toll-Like/efeitos dos fármacos , Receptor 2 Toll-Like/imunologia , Receptor 2 Toll-Like/metabolismoRESUMO
The ability of leukocytes to leave the circulation and migrate into tissues is a critical feature of the immune response. L-selectin (CD62L), the leukocyte selectin, mediates the binding of lymphocytes to high endothelial venules of peripheral lymph nodes and is also involved in lymphocyte, neutrophil and monocyte attachment to vascular endothelium at sites of inflammation. In this study L-selectin expression on peripheral T cells and neutrophils was evaluated in 25 HIV infected children, who had not received antiretroviral therapy, and 25 healthy controls. The expression level of L-selectin on T cells was also evaluated in 10 out 25 patients after 6 months of antiretroviral therapy. L-selectin expression on CD3+, CD4+ and CD8+ T cells were significantly lower in HIV infected children than in the control group. The percentage of neutrophils expressing CD62L was significantly reduced in patients with severe immunologic suppression. A positive correlation between the number of CD4+ T cells and the percentage of neutrophils CD62L+ was found. L-selectin expression on both CD4+ and CD8+ T cells did not significantly vary after 6 months of treatment. Altered leukocyte functions such as migration and homing resulting from reduced expression of CD62L may be an important contributor of the progressive dysfunction of the immune system in HIV infected children.
Assuntos
Infecções por HIV/sangue , Selectina L/sangue , Neutrófilos/imunologia , Linfócitos T/imunologia , Criança , Pré-Escolar , Feminino , Infecções por HIV/imunologia , Humanos , Lactente , Selectina L/imunologia , MasculinoRESUMO
La capacidad de los leucócitos de abandonar la circulación y migrar hacia los tejidos es un paso crítica de la respuesta inmune. La L-selectina, selectina leucocitaria (CD62L), media la unión de linfócitos a las vênulas endoteliales altas de los ganglios linfáticos periféricos, y también participa en la adhesión de linfócitos, neutrófilos y monócitos al endotelio vascular activado en los sítios de inflamación. En este trabajo se estudiaron los niveles de expresión de L- selectina sobre los linfócitos T y polimorfonucleares neutrófilos en 25 niños HIV (+) sin tratamiento antirretroviral y 25 niños sanos HIV (-), avaluando además su comportamiento en 10 de los pacientes, luego de 6 meses de iniciada la terapéutica específica para el HIV. El número de linfócitos TCD3+, CD4+ y CD8+ que expresan CD62L se encontró significativamente disminuido en los niños HIV(+) con respecto al grupo control. El porcentaje de neutrófilos que expresan CD62L se encontro significativamente disminuido en los pacientes con mayor compromiso inmunológico. Se observó una correlación positiva entre los niveles de LTCD4+ y el porcentaje de neutrófilos que expresan CD62L. Luego de 6 meses de tratamiento antirretroviral no hubo câmbios significatios en los niveles de expresión de CD62L sobre LTCD4+ y LTCD8+ . La reducción en los niveles de expresión de L-selectina en estos tipos celulares sugiere que durante la infección por HIV las funciones leucocitarias tales como la migración y el asentamiento linfocitario son anormales, contribuyendo al progresivo deterioro inmune.
Assuntos
Lactente , Pré-Escolar , Criança , Humanos , Masculino , Feminino , Infecções por HIV/sangue , Selectina L/sangue , Neutrófilos/imunologia , Linfócitos T/imunologia , Infecções por HIV/imunologia , Selectina L/imunologiaRESUMO
La capacidad de los leucócitos de abandonar la circulación y migrar hacia los tejidos es un paso crítica de la respuesta inmune. La L-selectina, selectina leucocitaria (CD62L), media la unión de linfócitos a las vÛnulas endoteliales altas de los ganglios linfáticos periféricos, y también participa en la adhesión de linfócitos, neutrófilos y monócitos al endotelio vascular activado en los sítios de inflamación. En este trabajo se estudiaron los niveles de expresión de L- selectina sobre los linfócitos T y polimorfonucleares neutrófilos en 25 niños HIV (+) sin tratamiento antirretroviral y 25 niños sanos HIV (-), avaluando además su comportamiento en 10 de los pacientes, luego de 6 meses de iniciada la terapéutica específica para el HIV. El número de linfócitos TCD3+, CD4+ y CD8+ que expresan CD62L se encontró significativamente disminuido en los niños HIV(+) con respecto al grupo control. El porcentaje de neutrófilos que expresan CD62L se encontro significativamente disminuido en los pacientes con mayor compromiso inmunológico. Se observó una correlación positiva entre los niveles de LTCD4+ y el porcentaje de neutrófilos que expresan CD62L. Luego de 6 meses de tratamiento antirretroviral no hubo cÔmbios significatios en los niveles de expresión de CD62L sobre LTCD4+ y LTCD8+ . La reducción en los niveles de expresión de L-selectina en estos tipos celulares sugiere que durante la infección por HIV las funciones leucocitarias tales como la migración y el asentamiento linfocitario son anormales, contribuyendo al progresivo deterioro inmune. (AU)
Assuntos
Lactente , Pré-Escolar , Criança , Humanos , Masculino , Feminino , Selectina L/sangue , Linfócitos T/imunologia , Neutrófilos/imunologia , Infecções por HIV/sangue , Selectina L/imunologia , Infecções por HIV/imunologiaRESUMO
L-selectin is an adhesion molecule that is responsible for the initial attachment of leukocytes to endothelium. After leukocyte activation L-selectin is endoproteolytically released from the cell surface. In order to analyze the relationship between soluble L-selectin (sL-selectin) and parameters of immune activation and disease progression, 51 HIV infected children and 15 healthy controls were studied. Serum L-selectin concentrations were significantly higher in HIV infected children than in the control group. Levels of sL-selectin were higher in HIV infected patients with severe immunologic suppression than in those with moderate or no evidence of suppression. A positive correlation between sL-selectin levels and LTCD8 counts, sL-selectin and soluble intercellular adhesion molecule-1 (sICAM-1) and immunogobulin A (IgA) levels was detected. On the contrary sL-selectin concentration did not correlate with plasmatic viral load. The correlation with parameters of immune activation may implicate involvement of sL-selectin in the immunopathogenesis of HIV infection.
Assuntos
Infecções por HIV/metabolismo , HIV/imunologia , Selectina L/sangue , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Criança , Pré-Escolar , Feminino , Infecções por HIV/imunologia , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina A/metabolismo , Lactente , Molécula 1 de Adesão Intercelular/sangue , Molécula 1 de Adesão Intercelular/imunologia , Molécula 1 de Adesão Intercelular/metabolismo , Selectina L/imunologia , Selectina L/metabolismo , Masculino , Solubilidade , Carga ViralRESUMO
La L-selectina es una molécula de adhesión responsable de la adhesión inicial de los leucocitos al endotelio. Esta molécula es liberada desde la superficie celular por clivaje proteolítico después de la activación leucocitaria. Se midieron los niveles séricos de la forma soluble de la L-selectina (sL-selectina) en 51 niños HIV(+) y en 15 controles sanos HIV(-). Estos valores se compararon con parámetros de activación inmune y de progresión de enfermedad. La concentración de sL-selectina se encontró significativamente aumentada en el grupo de pacientes HIV(+). Dichos niveles eran más altos en los pacientes con mayor inmunosupresión. Se encontró una correlación positiva entre los niveles de sL-selectina y el número relativo de LTCD8, y entre sL-selectina y los niveles de la forma soluble de la molécula de adhesión intercelular-1(sICAM-1) y la inmunoglobulina A(IgA). No se obtuvo correlación significativa entre sL-selectina y los valores de la carga viral (CV) plasmática. El aumento en los niveles de sL-selectina sería otro componente entre las múltiples alteraciones inmunológicas producidas por el HIV
Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Infecções por HIV/metabolismo , HIV/imunologia , Selectina L/sangue , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Infecções por HIV/imunologia , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina A/metabolismo , Molécula 1 de Adesão Intercelular/sangue , Molécula 1 de Adesão Intercelular/imunologia , Molécula 1 de Adesão Intercelular/metabolismo , Selectina L/imunologia , Selectina L/metabolismo , Solubilidade , Carga ViralRESUMO
La L-selectina es una molécula de adhesión responsable de la adhesión inicial de los leucocitos al endotelio. Esta molécula es liberada desde la superficie celular por clivaje proteolítico después de la activación leucocitaria. Se midieron los niveles séricos de la forma soluble de la L-selectina (sL-selectina) en 51 niños HIV(+) y en 15 controles sanos HIV(-). Estos valores se compararon con parámetros de activación inmune y de progresión de enfermedad. La concentración de sL-selectina se encontró significativamente aumentada en el grupo de pacientes HIV(+). Dichos niveles eran más altos en los pacientes con mayor inmunosupresión. Se encontró una correlación positiva entre los niveles de sL-selectina y el número relativo de LTCD8, y entre sL-selectina y los niveles de la forma soluble de la molécula de adhesión intercelular-1(sICAM-1) y la inmunoglobulina A(IgA). No se obtuvo correlación significativa entre sL-selectina y los valores de la carga viral (CV) plasmática. El aumento en los niveles de sL-selectina sería otro componente entre las múltiples alteraciones inmunológicas producidas por el HIV