RESUMO
The DC subsets that express αE integrin (CD103) have been described to exert antagonistic functions, driving T cells towards either an inflammatory (Th1/Th17) or immunosuppressive phenotype (regulatory T cells - Treg). These functions depend on the tissue they reside and microenvironment factors or stimuli that this Antigen-presenting cell (APC) subpopulation receive. In this regard, immunoregulatory phenotype has been described in small subsets of CD103+ DCs from lung and intestinal mucosa. The function of this APC subpopulation in pulmonary Paracoccidioides brasiliensis infection is poorly described. Here, we showed that lung CD103+ DCs contribute to Treg differentiation in a pulmonary P. brasiliensis infection model, which was attributed to downregulation of costimulatory molecules analyzed in these APC subtypes 21 days post-infection. Overall, this data suggests that P. brasiliensis infection caused an immunosuppression that has also been observed in patients with the most severe form of Paracoccidioidomycosis (PCM) - a sickness caused by this fungus genus. Furthermore, these results open new perspectives for knowledge of the mechanisms that underlie the higher percentage of Treg cells found in peripheral blood of PCM patients.
Assuntos
Paracoccidioides , Paracoccidioidomicose , Animais , Antígenos CD , Diferenciação Celular , Células Dendríticas , Humanos , Cadeias alfa de Integrinas , Pulmão , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T ReguladoresRESUMO
Malaria is an infectious disease of major worldwide clinical importance that causes a variety of severe, or complicated, syndromes including cerebral malaria, which is often fatal. Leukocyte integrins are essential for host defense but also mediate physiologic responses of the innate and adaptive immune systems. We previously showed that targeted deletion of the αD subunit (αD-/-) of the αDß2 integrin, which is expressed on key leukocyte subsets in mice and humans, leads to absent expression of the integrin heterodimer on murine macrophages and reduces mortality in mice infected with Plasmodium berghei ANKA (P. berghei ANKA). To further identify mechanisms involved in the protective effect of αD deletion in this model of severe malaria we examined wild type C57BL/6 (WT) and αD-/- mice after P. berghei ANKA infection and found that vessel plugging and leukocyte infiltration were significantly decreased in the brains of αD-/- animals. Intravital microscopy demonstrated decreased rolling and adhesion of leukocytes in cerebral vessels of αD-/- mice. Flow cytometry analysis showed decreased T-lymphocyte accumulation in the brains of infected αD-/- animals. Evans blue dye exclusion assays demonstrated significantly less dye extravasation in the brains of αD-/- mice, indicating preserved blood-brain barrier integrity. WT mice that were salvaged from P. berghei ANKA infection by treatment with chloroquine had impaired aversive memory, which was not observed in αD-/- mice. We conclude that deletion of integrin αDß2 alters the natural course of experimental severe malaria, demonstrating previously unrecognized activities of a key leukocyte integrin in immune-inflammatory responses that mediate cerebral involvement.
Assuntos
Antígenos CD11/metabolismo , Cadeias alfa de Integrinas/metabolismo , Malária/fisiopatologia , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Edema Encefálico/metabolismo , Edema Encefálico/fisiopatologia , Antígenos CD11/fisiologia , Cloroquina/metabolismo , Modelos Animais de Doenças , Inflamação/metabolismo , Cadeias alfa de Integrinas/fisiologia , Integrinas/imunologia , Integrinas/metabolismo , Contagem de Leucócitos , Leucócitos/metabolismo , Leucócitos/fisiologia , Macrófagos/metabolismo , Malária/genética , Malária Cerebral/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Plasmodium berghei/metabolismoRESUMO
An important challenge in cancer immunotherapy is to expand the number of patients that benefit from immune checkpoint inhibitors (CI), a fact that has been related to the pre-existence of an efficient anti-tumor immune response. Different strategies are being proposed to promote tumor immunity and to be used in combined therapies with CI. Recently, we reported that intratumoral administration of naked poly A:U, a dsRNA mimetic empirically used in early clinical trials with some success, delays tumor growth and prolongs mice survival in several murine cancer models. Here, we show that CD103+ cDC1 and, to a much lesser extent CD11b+ cDC2, are the only populations expressing TLR3 at the tumor site, and consequently could be potential targets of poly A:U. Upon poly A:U administration these cells become activated and elicit profound changes in the composition of the tumor immune infiltrate, switching the immune suppressive tumor environment to anti-tumor immunity. The sole administration of naked poly A:U promotes striking changes within the lymphoid compartment, with all the anti-tumoral parameters being enhanced: a higher frequency of CD8+ Granzyme B+ T cells, (lower Treg/CD8+ ratio) and an important expansion of tumor-antigen specific CD8+ T cells. Also, PD1/PDL1 showed an increased expression indicating that neutralization of this axis could be exploited in combination with poly A:U. Our results shed new light to promote further assays in this dsRNA mimetic to the clinical field.
Assuntos
Antígenos CD/imunologia , Células Dendríticas/imunologia , Cadeias alfa de Integrinas/imunologia , Linfócitos do Interstício Tumoral/imunologia , Neoplasias Experimentais/imunologia , Receptor 3 Toll-Like/imunologia , Microambiente Tumoral/imunologia , Animais , Linfócitos B/imunologia , Linfócitos B/patologia , Linfócitos T CD8-Positivos/patologia , Linfócitos do Interstício Tumoral/patologia , Camundongos , Camundongos Transgênicos , Neoplasias Experimentais/patologia , Poli A-U/farmacologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologiaRESUMO
Both high fat diet (HFD) and high carbohydrate diet (HCD) modulate brain fatty acids (FA) composition. Notwithstanding, there is a lack of information on time sequence of brain FA deposition either for HFD or HCD. The changes in brain FA composition in mice fed with HFD or HCD for 7, 14, 28, or 56 days were compared with results of 0 (before starting given the diets). mRNA expressions of allograft inflammatory factor 1 (Aif1), cyclooxygenase-2 (Cox 2), F4/80, inducible nitric oxide synthase (iNOS), integrin subunit alpha m (Itgam), interleukin IL-1ß (IL-1ß), IL-6, IL-10, and tumor necrosis factor alpha (TNF-α) were measured. The HFD group had higher speed of deposition of saturated FA (SFA), monounsaturated FA (MUFA), and polyunsaturated FA (PUFA) at the beginning of the experimental period. However, on day 56, the total amount of SFA, MUFA, and PUFA were similar. mRNA expressions of F4/80 and Itgam, markers of microglia infiltration, were increased (p < 0.05) in the brain of the HCD group whereas inflammatory marker index (IMI) was higher (46%) in HFD group. In conclusion, the proportion of fat and carbohydrates in the diet modulates the speed deposition of FA and expression of inflammatory gene markers.
Assuntos
Encéfalo/metabolismo , Dieta da Carga de Carboidratos/efeitos adversos , Dieta Hiperlipídica/efeitos adversos , Carboidratos da Dieta/efeitos adversos , Gorduras na Dieta/efeitos adversos , Ácidos Graxos/metabolismo , Animais , Antígenos de Diferenciação/metabolismo , Antígeno CD11b/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Ciclo-Oxigenase 2/metabolismo , Citocinas/metabolismo , Inflamação/metabolismo , Cadeias alfa de Integrinas/metabolismo , Masculino , Camundongos , Proteínas dos Microfilamentos/metabolismo , Óxido Nítrico Sintase/metabolismo , RNA Mensageiro/metabolismoRESUMO
In transplantation, donor dendritic cells (do-DCs) initiate the alloimmune response either by direct interaction with host T cells or by transferring intact donor MHC to host DCs. However, how do-DCs can be targeted for improving allograft survival is still unclear. Here we show CD103+ DCs are the major do-DC subset involved in the acute rejection of murine skin transplants. In the absence of CD103+ do-DCs, less donor MHC-II is carried to host lymph nodes, fewer allogenic T cells are primed and allograft survival is prolonged. Incubation of skin grafts with the anti-inflammatory mycobacterial protein DnaK reduces donor MHC-II on CD103+DCs and prolongs graft survival. This effect is mediated through IL-10-induced March1, which ubiquitinates and decreases MHC-II levels. Importantly, in vitro pre-treatment of human DCs with DnaK reduces their ability to prime alloreactive T cells. Our findings demonstrate a novel therapeutic approach to dampen alloimmunity by targeting donor MHC-II on CD103+DCs.
Assuntos
Antígenos CD/metabolismo , Células Dendríticas/metabolismo , Cadeias alfa de Integrinas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Antígenos CD/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/metabolismo , Cadeias alfa de Integrinas/genética , Interleucina-10/genética , Interleucina-10/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Ubiquitina-Proteína Ligases/genéticaRESUMO
ß2 integrins are critical in host defense responses to invading pathogens and inflammation. Previously, we reported that genetic deficiency of integrin αDß2 in mice altered outcomes in experimental systemic infections including accelerated mortality in animals infected with Salmonella enterica serovar Typhimurium. Here, we show that deficiency of αDß2 results in impaired accumulation of leukocytes in response to peritoneal infection by S. Typhimurium, impaired pathogen clearance in vivo, defective bacterial elimination by cultured peritoneal macrophages, and enhanced pyroptosis, a cell death process triggered by Salmonella. Salmonella-infected animals deficient in αDß2 had increased levels of peritoneal cytokines in addition to other markers of pyroptosis, which may contribute to inflammatory injury and increased mortality in the context of impaired bacterial killing. These observations indicate important contributions of leukocyte integrins to the host response in experimental Salmonella infection and reveal previous activities of αDß2 in bacterial infection.
Assuntos
Antígenos CD11/metabolismo , Antígenos CD18/metabolismo , Cadeias alfa de Integrinas/metabolismo , Leucócitos/imunologia , Leucócitos/metabolismo , Infecções por Salmonella/imunologia , Infecções por Salmonella/metabolismo , Salmonella typhimurium/imunologia , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno/imunologia , Contagem de Leucócitos , Lipopolissacarídeos/imunologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Knockout , Piroptose/imunologia , Infecções por Salmonella/microbiologiaRESUMO
As it has been established that demethylation of lysine 27 of histone H3 by the lysine-specific demethylase JMJD3 increases immune responses and thus elicits inflammation, we hypothesize that inhibition of JMJD3 may attenuate autoimmune disorders. We found that in vivo administration of GSK-J4, a selective inhibitor of JMJD3 and UTX, ameliorates the severity of experimental autoimmune encephalomyelitis (EAE). In vitro experiments revealed that the anti-inflammatory effect of GSK-J4 was exerted through an effect on dendritic cells (DCs), promoting a tolerogenic profile characterized by reduced expression of costimulatory molecules CD80/CD86, an increased expression of tolerogenic molecules CD103 and TGF-ß1, and reduced secretion of proinflammatory cytokines IL-6, IFN-γ, and TNF. Adoptive transfer of GSK-J4-treated DCs into EAE mice reduced the clinical manifestation of the disease and decreased the extent of inflammatory CD4+ T cells infiltrating the central nervous system. Notably, Treg generation, stability, and suppressive activity were all exacerbated by GSK-J4-treated DCs without affecting Th1 and Th17 cell production. Our data show that GSK-J4-mediated modulation of inflammation is achieved by a direct effect on DCs and that systemic treatment with GSK-J4 or adoptive transfer of GSK-J4-treated DCs ex vivo may be promising approaches for the treatment of inflammatory and autoimmune disorders.
Assuntos
Benzazepinas/farmacologia , Células Dendríticas/efeitos dos fármacos , Encefalomielite Autoimune Experimental/prevenção & controle , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Pirimidinas/farmacologia , Transferência Adotiva , Animais , Antígenos CD/imunologia , Antígenos CD/metabolismo , Antígeno B7-1/imunologia , Antígeno B7-1/metabolismo , Antígeno B7-2/imunologia , Antígeno B7-2/metabolismo , Western Blotting , Linfócitos T CD4-Positivos/imunologia , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/imunologia , Expressão Gênica/efeitos dos fármacos , Tolerância Imunológica/genética , Tolerância Imunológica/imunologia , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Cadeias alfa de Integrinas/imunologia , Cadeias alfa de Integrinas/metabolismo , Histona Desmetilases com o Domínio Jumonji/imunologia , Histona Desmetilases com o Domínio Jumonji/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fenótipo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Crescimento Transformador beta1/imunologia , Fator de Crescimento Transformador beta1/metabolismoRESUMO
BACKGROUND: Malaria-associated acute respiratory distress syndrome (MA-ARDS) is a potentially lethal complication of clinical malaria. Acute lung injury in MA-ARDS shares features with ARDS triggered by other causes, including alveolar inflammation and increased alveolar-capillary permeability, leading to leak of protein-rich pulmonary oedema fluid. Mechanisms and physiologic alterations in MA-ARDS can be examined in murine models of this syndrome. Integrin αDß2 is a member of the leukocyte, or ß2 (CD18), sub-family of integrins, and emerging observations indicate that it has important activities in leukocyte adhesion, accumulation and signalling. The goal was to perform analysis of the lungs of mice wild type C57Bl/6 (a D (+/+) ) and Knockout C57Bl/6 (a D (-/-) ) with malaria-associated acute lung injury to better determine the relevancy of the murine models and investigate the mechanism of disease. METHODS: C57BL/6 wild type (a D (+/+) ) and deficient for CD11d sub-unit (a D (-/-) ) mice were monitored after infection with 10(5) Plasmodium berghei ANKA. CD11d subunit expression RNA was measured by real-time polymerase chain reaction, vascular barrier integrity by Evans blue dye (EBD) exclusion and cytokines by ELISA. Protein and leukocytes were measured in bronchoalveolar lavage fluid (BALF) samples. Tissue cellularity was measured by the point-counting technique, F4/80 and VCAM-1 expression by immunohistochemistry. Respiratory function was analysed by non-invasive BUXCO and mechanical ventilation. RESULTS: Alveolar inflammation, vascular and interstitial accumulation of monocytes and macrophages, and disrupted alveolar-capillary barrier function with exudation of protein-rich pulmonary oedema fluid were present in P. berghei-infected wild type mice and were improved in αDß2-deficient animals. Key pro-inflammatory cytokines were also decreased in lung tissue from α D (-/-) mice, providing a mechanistic explanation for reduced alveolar-capillary inflammation and leak. CONCLUSIONS: The results indicate that αDß2 is an important inflammatory effector molecule in P. berghei-induced MA-ARDS, and that leukocyte integrins regulate critical inflammatory and pathophysiologic events in this model of complicated malaria. Genetic deletion of integrin subunit αD in mice, leading to deficiency of integrin αDß2, alters lung inflammation and acute lung injury in a mouse model of MA-ARDS caused by P. berghei.
Assuntos
Antígenos CD11/metabolismo , Cadeias alfa de Integrinas/metabolismo , Malária/complicações , Síndrome do Desconforto Respiratório/patologia , Animais , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Citocinas/análise , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Azul Evans/metabolismo , Perfilação da Expressão Gênica , Imuno-Histoquímica , Contagem de Leucócitos , Pulmão/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Permeabilidade , Plasmodium berghei/crescimento & desenvolvimento , Proteínas/análise , Reação em Cadeia da Polimerase em Tempo Real , Testes de Função RespiratóriaRESUMO
The magnitude of the cellular adaptive immune response is critical for the control of Mycobacterium tuberculosis infection in the chronic phase. In addition, the genetic background is equally important for resistance or susceptibility to tuberculosis. In this study, we addressed whether lung populations of dendritic cells, obtained from genetically different hosts, would play a role in the magnitude and function of CD4(+) populations generated after M. tuberculosis infection. Thirty days post-infection, C57BL/6 mice, which generate a stronger interferon-γ (IFN-γ)-mediated immune response than BALB/c mice, exhibited a higher number and frequency of lung CD11c(+) CD11b(-) CD103(+) cells compared with BALB/c mice, which exhibited a high frequency of lung CD11c(+) CD11b(+) CD103(-) cells. CD11c(+) CD11b(-) CD103(+) cells, purified from lungs of infected C57BL/6 mice, but not from infected BALB/c mice, induced a higher frequency of IFN-γ-producing or interleukin-17 (IL-17)-producing CD4(+) cells. Moreover, CD4(+) cells also arrive at the lung of C57BL/6 mice faster than in BALB/c mice. This pattern of immune response seems to be associated with higher gene expression for CCL4, CCL19, CCL20 and CCR5 in the lungs of infected C57BL/6 mice compared with infected BALB/c mice. The results described here show that the magnitude of IFN-γ-producing or IL-17-producing CD4(+) cells is dependent on CD11c(+) CD11b(-) CD103(+) cells, and this pattern of immune response is directly associated with the host genetic background. Therefore, differences in the genetic background contribute to the identification of immunological biomarkers that can be used to design human assays to predict progression of M. tuberculosis infection.
Assuntos
Antígenos CD/imunologia , Antígeno CD11c/imunologia , Cadeias alfa de Integrinas/imunologia , Interferon gama/imunologia , Interleucina-17/imunologia , Pulmão/imunologia , Mycobacterium tuberculosis/imunologia , Células Th17/imunologia , Tuberculose Pulmonar/imunologia , Animais , Antígenos CD/metabolismo , Antígeno CD11b/imunologia , Antígeno CD11b/metabolismo , Antígeno CD11c/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/microbiologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/microbiologia , Modelos Animais de Doenças , Feminino , Genótipo , Imunidade Celular , Cadeias alfa de Integrinas/metabolismo , Interferon gama/metabolismo , Interleucina-17/metabolismo , Pulmão/metabolismo , Pulmão/microbiologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/patogenicidade , Fenótipo , Transdução de Sinais , Especificidade da Espécie , Células Th17/metabolismo , Células Th17/microbiologia , Fatores de Tempo , Tuberculose Pulmonar/genética , Tuberculose Pulmonar/metabolismo , Tuberculose Pulmonar/microbiologiaRESUMO
The homing properties of mesenchymal stromal cells (MSCs) toward tumors turn them into attractive tools for combining cell and gene therapy. The aim of this study was to select in a feasible way a human bone marrow-derived MSC subpopulation that might exhibit a selective ability to target the tumor mass. Using differential in vitro adhesive capacities during cells isolation, we selected a specific MSC subpopulation (termed MO-MSCs) that exhibited enhanced multipotent capacity and increased cell surface expression of specific integrins (integrins α2, α3, and α5), which correlated with an enhanced MO-MSCs adhesiveness toward their specific ligands. Moreover, MO-MSCs exhibited a higher migration toward conditioned media from different cancer cell lines and fresh human breast cancer samples in the presence or not of a human microendothelium monolayer. Further in vivo studies demonstrated increased tumor homing of MO-MSCs toward established 578T and MD-MBA-231 breast cancer and A375N melanoma tumor xenografts. Tumor penetration by MO-MSCs was highly dependent on metallopeptidases production as it was inhibited by the specific inhibitor 1,10 phenantroline. Finally, systemically administered MO-MSCs preloaded with an oncolytic adenovirus significantly inhibited tumor growth in mice harboring established A375N melanomas, overcoming the natural resistance of the tumor to in situ administration of the oncolytic adenovirus. In summary, this work characterizes a novel MSC subpopulation with increased tumor homing capacity that can be used to transport therapeutic compounds.
Assuntos
Adenoviridae/metabolismo , Melanoma/terapia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/citologia , Terapia Viral Oncolítica/métodos , Adenoviridae/genética , Animais , Antineoplásicos/uso terapêutico , Adesão Celular , Técnicas de Cultura de Células , Diferenciação Celular , Linhagem Celular Tumoral , Movimento Celular , Condrogênese , Meios de Cultivo Condicionados , Humanos , Cadeias alfa de Integrinas/metabolismo , Melanoma/patologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Nus , Vírus Oncolíticos/genética , Vírus Oncolíticos/metabolismo , Fenantrolinas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
The expression and function of integrin-type extracellular matrix receptors, VLA-4 and VLA-5, and laminin receptor VLA-6 on the surface of CD3(+)CD4(+) and CD3(+)CD8(+) defined T cell populations was evaluated in the blood of Duchenne muscular dystrophy (DMD) patients and healthy individuals. Both the number of CD4(+) and CD8(+) T cell subsets expressing VLA-4 or VLA-5 and the fibronectin-driven T cell migration was significantly higher in DMD patients. These data indicate that interactions of VLA-4 and/or VLA-5 with fibronectin may drive T lymphocytes to specific niches within muscle, contributing to tissue damage and fibrosis in DMD patients.
Assuntos
Regulação da Expressão Gênica/imunologia , Integrinas/biossíntese , Músculo Esquelético/imunologia , Músculo Esquelético/fisiopatologia , Distrofia Muscular de Duchenne/imunologia , Distrofia Muscular de Duchenne/fisiopatologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Adolescente , Movimento Celular/genética , Movimento Celular/imunologia , Criança , Pré-Escolar , Humanos , Imunofenotipagem , Cadeias alfa de Integrinas/biossíntese , Cadeias alfa de Integrinas/genética , Cadeias alfa de Integrinas/fisiologia , Integrina alfa5beta1/biossíntese , Integrina alfa5beta1/genética , Integrina alfa5beta1/fisiologia , Integrina alfa6beta1/biossíntese , Integrina alfa6beta1/genética , Integrina alfa6beta1/fisiologia , Integrinas/genética , Integrinas/fisiologia , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Subpopulações de Linfócitos T/patologiaRESUMO
Increasing evidence implies beneficial effects of angiotensin-converting enzyme (ACE) inhibitors beyond those of their original indications to control hypertension. One of the most attractive non-hemodynamic properties of ACE inhibitors is their ability to regulate cytokine production. The mechanism(s) underlying the role of ACE inhibitors on cytokine synthesis are not well understood but they have traditionally been attributed to the inhibition of angiotensin (Ang) II formation. In fact, it has been extensively demonstrated that ACE inhibitors decrease Ang II-induced production of proinflammatory cytokines and chemokines. However, it is not well described if inhibition of endogenous Ang II generation by ACE inhibitors modulates systemic cytokine production in mice. To verify that, in this work, we investigated the effects of treatment with the ACE inhibitors enalapril and captopril on cytokine synthesis in C57Bl/6 and Balb/c mice. Our results show that enalapril up regulates IL-10 produced by splenocytes from Balb/c and C57Bl/6 mice and captopril increased it only in Balb/c mice. Furthermore, CD4(+)CD103(+) presented increased IL-10 production after enalapril treatment. Enalapril as well as captopril short-term treatment enhanced IL-2 synthesis in Balb/c mice. Besides, enhanced IL-2 and IL-10 levels correlates with increased CD4(+)CD103(+)CD25(negative) T cells numbers in spleens from enalapril-treated mice.
Assuntos
Captopril/farmacologia , Citocinas/metabolismo , Enalapril/farmacologia , Baço/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Antígenos CD/metabolismo , Antígenos CD4/metabolismo , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Cadeias alfa de Integrinas/metabolismo , Interleucina-10/metabolismo , Interleucina-2/metabolismo , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Especificidade da Espécie , Baço/citologia , Baço/metabolismo , Linfócitos T/citologia , Linfócitos T/metabolismoRESUMO
BACKGROUND: HIV-1-infected children show changes of blood lymphocyte subpopulations. We have, therefore, investigated how highly active anti-retroviral therapy (ART) alter these subsets. Blood samples were taken from 41 HIV-1-infected children on ART who were divided into groups showing good, partial and poor responses to ART on the basis of viral load (VL) measurement in blood. The observations were compared to those seen in 20 uninfected children. METHODS: The samples were studied using 4-color flow cytometry for "naïve", central memory and effector memory cells as well as for CD38 expression as the sign of activation within both the CD4+ and the CD8+ T cell populations. HIV-1 infected children were also evaluated for the presence and the titers of antibodies induced by vaccination against childhood infections in our patients while on HAART. RESULTS: Lymphocyte counts were lower in the "poor" viral load responding (VLR) group when compared with partial and good VLRs. Poor VLRs had lower total and naïve CD4+ T cell counts. HIV-1-infected children from all three groups had high CD8+ T cell counts. Central memory CD4+ and CD8+ T cell percentages were particularly low in the poor VLR group while in the poor VLR group the percentages of effector memory CD4+ and CD8+ T cells were higher when compared with the control group. Higher cellular activation of CD8+ T cells was observed in HIV-1-infected children, particularly when analyzed for the intensity of CD38 expression in the poor VLR group. CD5 expression on B cells was higher among all HIV-1-infected children. Antibodies to tetanus, diphtheria, measles, rubella, and hepatitis B were present in a large proportion of children but the titers were similarly low for all three groups of HIV-infected children. CONCLUSIONS: Children with different levels of viral response to HAART present immune phenotype characteristics that tend to place the children with partial and good virological responses into the same group. These children are still moderately deficient in their immune responses but show better recovery than seen with children in the poor VLR group. These observations indicate that the proportions of central memory cells among the CD4+ T cells and the intensity of the expression of CD38 activation antigen on CD8+ T cells provide more informative parameters for monitoring children on HAART than the absolute numbers of CD4+ and CD8+ T cells alone.
Assuntos
Terapia Antirretroviral de Alta Atividade , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , HIV-1/imunologia , Vacinas contra a AIDS/imunologia , Anticorpos/sangue , Antígenos CD/imunologia , Linfócitos B/imunologia , Linfócitos B/patologia , Linfócitos B/virologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD4-Positivos/virologia , Antígenos CD5/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Linfócitos T CD8-Positivos/virologia , Contagem de Células , Criança , Feminino , Infecções por HIV/virologia , HIV-1/patogenicidade , Humanos , Imunofenotipagem , Cadeias alfa de Integrinas/imunologia , Células Matadoras Naturais/citologia , Células Matadoras Naturais/patologia , Células Matadoras Naturais/virologia , Leucócitos/imunologia , Leucócitos/patologia , Leucócitos/virologia , Ativação Linfocitária/imunologia , Masculino , Timo/imunologia , Timo/patologia , Timo/virologia , Carga ViralRESUMO
The long-term persistence of pathogens in a host is a hallmark of certain infectious diseases, including schistosomiasis, leishmaniasis, and paracoccidioidomycosis (PCM). Natural regulatory T (Treg) cells are involved in control of the immune responses, including response to pathogens. Because CTLA-4 is constitutively expressed in Treg cells and it acts as a negative regulator of T cell activation in patients with PCM, here we investigated the involvement of Treg cells in the control of systemic and local immune response in patients with PCM. We found that the leukocyte subsets were similar in patients and controls, except for CD11c+CD1a+ cells. However, a higher frequency of CD4+CD25+ T cells expressing CTLA-4, glucorticoid-inducible TNFR, membrane-bound TGF-beta, and forkhead-box 3 were observed in PBMC of patients. In accordance, these cells exhibited stronger suppressive activity when compared with those from controls (94.0 vs 67.5% of inhibition of allogeneic T cell proliferation). In addition, the data showed that CD4+CD25+ T cells expressing CTLA-4+, glucocorticoid-inducible TNFR positive, CD103+, CD45RO+, membrane-bound TGF-beta, forkhead-box 3 positive, and the chemokines receptors CCR4 and CCR5 accumulate in the Paracoccidioides brasiliensis-induced lesions. Indeed, the secreted CCL17 and CCL22, both associated with the migration of Treg cells to peripheral tissues, were also detected in the biopsies. Moreover, the CD4+CD25+ T cell derived from lesions, most of them TGF-beta+, also exhibited functional activity in vitro. Altogether, these data provide the first evidence that Treg cells play a role in controlling local and systemic immune response in patients with a fungal-induced granulomatous disease advancing our understanding about the immune regulation in human chronic diseases.
Assuntos
Antígenos CD4/análise , Subunidade alfa de Receptor de Interleucina-2/análise , Paracoccidioidomicose/imunologia , Linfócitos T Reguladores/imunologia , Antígenos CD/análise , Antígenos de Diferenciação/análise , Antígeno CTLA-4 , Membrana Celular/química , Membrana Celular/imunologia , Movimento Celular , Quimiocina CCL17 , Quimiocina CCL22 , Quimiocinas/metabolismo , Quimiocinas CC/metabolismo , Doença Crônica , Citocinas/metabolismo , Proteína Relacionada a TNFR Induzida por Glucocorticoide , Fator 3-gama Nuclear de Hepatócito/análise , Humanos , Cadeias alfa de Integrinas/análise , Antígenos Comuns de Leucócito/análise , Paracoccidioidomicose/patologia , Fenótipo , Receptores CCR4 , Receptores CCR5/análise , Receptores de Quimiocinas/análise , Receptores de Fator de Crescimento Neural/análise , Receptores do Fator de Necrose Tumoral/análise , Fator de Crescimento Transformador beta/análiseRESUMO
Interferons (IFNs) are a family of cytokines that have many biological functions in the cell, including regulation of cellular growth, differentiation, immunomodulation, and viral replication by inducing a set of interferon stimulated genes (ISGs). Based on their structure and biological activities IFNs are subdivided into two groups: type I IFNs, which includes IFN-alpha and IFN-beta and type II IFNs, represented by IFN-gamma. The aim of this work was to investigate whether integrin alpha 11 (ITGA-11), a novel collagen-binding integrin, is responsive to type I IFN treatment. Our findings indicated that type I IFNs were able to induce the ITGA-11 mRNA levels in T98G cells. Increased levels of ITGA-11 protein were also observed in IFN-treated cells. The in vivo induction of ITGA-11 was detected in spleen and lungs of IFN-treated BALB/c mice. T98G cells infected with Murine encephalomyocarditis virus showed increased levels of ITGA-11 mRNA and protein. We observed that the ITGA-11 promoter has binding sites for transcriptional factors regulated by IFNs and the double-stranded RNA dependent protein kinase (PKR). Therefore we investigated the role of PKR in the induction of ITGA-11 by using a PKR deficient mouse embryo fibroblast cell line (MEFs). PKR(-/-) MEFs treated with IFN did not show increased levels of ITGA-11 protein nor mRNA although that could be promptly detected in wild type MEFs. Taken together our data suggest that ITGA-11 is a new interferon stimulated gene.
Assuntos
Regulação da Expressão Gênica/fisiologia , Cadeias alfa de Integrinas/genética , Interferon Tipo I/farmacologia , Interferon-alfa/fisiologia , Interferon beta/fisiologia , Animais , Linhagem Celular Transformada , Linhagem Celular Tumoral , Humanos , Cadeias alfa de Integrinas/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Proteínas Recombinantes , eIF-2 Quinase/deficiência , eIF-2 Quinase/genéticaRESUMO
Uma das grandes controvérsias encontradas na literatura científica consiste no estabelecimento de critérios para distinção entre um folículo pericoronário espessado e um cisto dentígero incipiente. O objetivo do presente estudo consistiu em avaliar a expressãoimuno-histoquímica das integrinas Assuntos
Cisto Dentígero/etiologia
, Cisto Dentígero/patologia
, Cistos Odontogênicos/diagnóstico
, Cistos Odontogênicos/etiologia
, Cistos Odontogênicos/patologia
, Imuno-Histoquímica
, Saco Dentário/patologia
, Cadeias alfa de Integrinas/imunologia
, Cadeias beta de Integrinas/imunologia
RESUMO
Toxoplasma gondii is an obligate intracellular parasite, able to disseminate into deep tissues and cross biological barriers, reaching immunoprivileged sites such as the brain and retina. In order to investigate whether the parasite uses leukocyte trafficking to disseminate throughout the host, the adhesive potential to extracellular matrix components, the expression of adhesion molecules and the in vivo migration of murine macrophages infected with RH strain of T. gondii were investigated. Cellular adhesion to fibronectin, laminin and collagen IV decreased after 24 h of T. gondii infection. However, the decrease in adhesion of infected macrophages observed at early infection was reversed after 48 h. Moreover, decreased adhesion was dependent on active penetration, since heat-killed parasites were unable to reproduce it. Expression of integrins alphaL, alpha4 and alpha5 chains was downmodulated early postinfection, but a progressive regain of expression was observed after 12 h of infection. Expression of beta2, alphav and alpha4 integrins by peritoneal macrophages at late infection was also gradually reestablished. The assessment of in vivo migration of infected macrophages labeled with the fluorescent dye 5-chloromethylfluorescein diacetate showed a 48-h delay in migration to cervical lymph nodes when compared to LPS pre-stimulated macrophages. Furthermore, cells that migrate to distal lymph nodes were loaded with live parasites. Taken together, these results provide insights about T. gondii escape from the host immune response, placing the macrophage as a "Trojan horse", contributing to parasite dissemination and access to immunoprivileged sites.
Assuntos
Adesão Celular , Movimento Celular/fisiologia , Macrófagos/parasitologia , Toxoplasma/patogenicidade , Animais , Antígenos CD18/biossíntese , Antígenos CD18/genética , Colágeno Tipo IV/metabolismo , Fibronectinas/metabolismo , Regulação da Expressão Gênica/imunologia , Cadeias alfa de Integrinas/biossíntese , Cadeias alfa de Integrinas/genética , Laminina/metabolismo , Linfonodos/citologia , Macrófagos/fisiologia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
OBJECTIVE: To analyze integrin expression and distribution in different histological types of ameloblastoma, compared with dental germ, dental lamina and adult lining epithelium. MATERIALS AND METHODS: Three-micrometer sections from paraffin-embedded specimens were evaluated employing a streptavidin-biotin immunohistochemical method and anti-integrin alpha2, alpha3, alpha5, alphav, beta1, beta3 and beta4 antibodies. RESULTS: All integrins were present in all specimens, exhibiting different patterns. In follicular ameloblastoma, the integrin staining was stronger in the periphery while integrin alpha2 was not present in the central cells. Acanthomatous ameloblastoma showed a similar pattern, with positive staining for integrins alpha3, alpha5, alphav, beta1 and beta4 in the metaplastic cells. In the unicystic, integrin staining was uniform except for integrins alpha5 and beta3 which showed weaker staining in the upper layers. In the plexiform ameloblastoma, dental germ and lamina integrin staining was uniform. In the adult lining epithelium, staining for integrins alpha2, alpha5 and beta4 was confined to the basal layer, while integrins alphav and beta3 were present in the basal and parabasal, with integrins alpha3 and beta1 in the upper layers. CONCLUSION: Acanthomatous, follicular and unicystic ameloblastomas showed integrin staining patterns similar to the adult lining epithelium while the plexiform ameloblastoma was similar to the dental germ and lamina.
Assuntos
Ameloblastoma/patologia , Cadeias alfa de Integrinas/análise , Cadeias beta de Integrinas/análise , Mucosa Bucal/patologia , Germe de Dente/patologia , Adulto , Ameloblastoma/classificação , Anticorpos , Membrana Basal/patologia , Corantes , Epitélio/patologia , Humanos , Imuno-Histoquímica , Integrina alfa2/análise , Integrina alfa3/análise , Integrina alfa5/análise , Integrina alfaV/análise , Integrina beta1/análise , Integrina beta3/análise , Integrina beta4/análise , MetaplasiaRESUMO
The adhesion of osteoblasts to bone extracellular matrix, of which type-I collagen constitutes >85%, can modulate diverse aspects of their physiology such as growth, differentiation and mineralisation. In this study we examined the adhesion of UMR106 rat osteoblast-like cells either to a control (Col) or advanced-glycation-endproduct-modified (AGEs-Col) type I collagen matrix. We investigated the possible role of different integrin receptors in osteoblastic adhesion, by co-incubating these cells either with beta-peptide (conserved sequence 113-125 of the beta subunit of integrins) or with two other peptides, RGD (Arg-Gly-Asp) and DGEA (Asp-Gly-Glu-Ala), which are recognition sequences for the alpha-subunits of alpha(1,5)beta(1) and alpha(2)beta(1) integrins. Collagen glycation inhibited the adhesion of UMR106 osteoblasts to the matrix (40% reduction versus Col, P > 0.001). beta-Peptide showed a dose- and glycation-dependent inhibitory effect on adhesion, and at a concentration of 100 microM decreased the attachment of UMR106 cells to both matrices (42% to Col, P<0.001and 25% to AGEs-Col, P<0.01). The synthetic peptides RGD (1mM) and DGEA (5mM) inhibited the attachment of UMR106 cells to Col (30 and 20%, P > 0.01 and P< 0.001, respectively), but not to AGEs-Col. beta-Peptide induced an increase in UMR106 cell clumping and a decrease in cellular spreading, while DGEA increased spreading with cellular extensions in multiple directions. These results indicate that both alpha and beta integrin subunits participate in osteoblastic attachment to type-I collagen, probably through the alpha(1,5)beta(1) and alpha(2)beta(1) integrins. AGEs-modification of type-I collagen impairs the integrin-mediated adhesion of osteoblastic cells to the matrix, and could thus contribute to the pathogenesis of diabetic osteopenia.