Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
J Biol Regul Homeost Agents ; 33(5): 1395-1403, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31507154

RESUMO

Nitric oxide (NO) plays a key role in inflammation. It is partly produced by three forms of NOS: eNOS of inflammatory cells, nNOS of neural cells and iNOS (inducible isoform). Estrogens can cause an anti-inflammatory effect, although it is not yet clear through which NOS isoforms. The aim of this study was to evaluate the role of the different NOS isoforms, as well as estrogen receptors (ERs) α and ß, on the anti-inflammatory effects of estrogens. To avoid the influence of endogenous glucocorticoids or sexual hormones, male rats were hypophysectomized. Animals were segregated into two control groups (no-treatment control group and SHAM-operated animals) and three hypophysectomized groups (no-hormonal treatment, with estradiol-17ß, or with testosterone replacement treatment). Freund's complete adjuvant (1 mg) was administered to the footpad of all animals. Measurements were made based on footpad inflammation (with a plethysmometer) such as eNOS, nNOS, iNOS and ER α and ß protein expression (by immunohistochemistry principle/method) on days 1, 7 and 14. Only estradiol decreased inflammation, accompanied by increased levels of eNOS and nNOS and differential expression of ERs α and ß in the inflammatory infiltrate. The higher levels of estradiol-induced eNOS and nNOS ocurred perhaps through the activation of ER ß.


Assuntos
Estradiol/farmacologia , Receptor beta de Estrogênio/metabolismo , Inflamação/tratamento farmacológico , Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Animais , Estrogênios , Masculino , Ratos
2.
Parasite Immunol ; 40(3)2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29243267

RESUMO

We investigated whether intranasal immunization with amoebic lysates plus cholera toxin modified the populations of T and B lymphocytes, macrophages and dendritic cells by flow cytometry from nose-associated lymphoid tissue (NALT), cervical lymph nodes (CN), nasal passages (NP) and spleen (SP). In all immunized groups, the percentage of CD4 was higher than CD8 cells. CD45 was increased in B cells from mice immunized. We observed IgA antibody-forming cell (IgA-AFC) response, mainly in NALT and NP. Macrophages from NP and CN expressed the highest levels of CD80 and CD86 in N. fowleri lysates with either CT or CT alone immunized mice, whereas dendritic cells expressed high levels of CD80 and CD86 in all compartment from immunized mice. These were lower than those expressed by macrophages. Only in SP from CT-immunized mice, these costimulatory molecules were increased. These results suggest that N. fowleri and CT antigens are taking by APCs, and therefore, protective immunity depends on interactions between APCs and T cells from NP and CN. Consequently, CD4 cells stimulate the differentiation from B lymphocytes to AFC IgA-positive; antibody that we previously found interacting with trophozoites in the nasal lumen avoiding the N. fowleri attachment to nasal epithelium.


Assuntos
Administração Intranasal , Antígenos de Protozoários/administração & dosagem , Naegleria fowleri/fisiologia , Mucosa Nasal/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Antígenos de Protozoários/imunologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Toxina da Cólera/administração & dosagem , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Naegleria fowleri/crescimento & desenvolvimento , Naegleria fowleri/imunologia , Mucosa Nasal/citologia
3.
Parasite Immunol ; 38(8): 481-95, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27189133

RESUMO

Naegleria fowleri infects humans through the nasal mucosa causing a disease in the central nervous system known as primary amoebic meningoencephalitis (PAM). Polymorphonuclear cells (PMNs) play a critical role in the early phase of N. fowleri infection. Recently, a new biological defence mechanism called neutrophil extracellular traps (NETs) has been attracting attention. NETs are composed of nuclear DNA combined with histones and antibacterial proteins, and these structures are released from the cell to direct its antimicrobial attack. In this work, we evaluate the capacity of N. fowleri to induce the liberation of NETs by human PMN cells. Neutrophils were cocultured with unopsonized or IgG-opsonized N. fowleri trophozoites. DNA, histone, myeloperoxidase (MPO) and neutrophil elastase (NE) were stained, and the formation of NETs was evaluated by confocal microscopy and by quantifying the levels of extracellular DNA. Our results showed N. fowleri induce the liberation of NETs including release of MPO and NE by human PMN cells as exposure interaction time is increased, but N. fowleri trophozoites evaded killing. However, when trophozoites were opsonized, they were susceptible to the neutrophils activity. Therefore, our study suggests that antibody-mediated PMNs activation through NET formation may be crucial for antimicrobial responses against N. fowleri.


Assuntos
Anticorpos Antiprotozoários/imunologia , Armadilhas Extracelulares/imunologia , Imunoglobulina G/imunologia , Naegleria fowleri/imunologia , Ativação de Neutrófilo/imunologia , Neutrófilos/imunologia , Trofozoítos/imunologia , Animais , Técnicas de Cocultura , DNA/metabolismo , Histonas/metabolismo , Humanos , Elastase de Leucócito/metabolismo , Meningoencefalite/imunologia , Meningoencefalite/parasitologia , Microscopia Confocal , Mucosa Nasal/parasitologia , Peroxidase/metabolismo , Fagocitose/imunologia
4.
Parasite Immunol ; 38(8): 503-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27138813

RESUMO

Entamoeba histolytica invades the intestine and other organs during the pathogenesis of amoebiasis. In the early stages, the host organism responds with an inflammatory infiltrate composed mostly of neutrophils. It has been reported that these immune cells, activated by E. histolytica, exert a protective role by releasing proteolytic enzymes and generating reactive oxygen/nitrogen species (ROS/RNS) and antimicrobial peptides. It is now known that neutrophils also produce neutrophil extracellular traps (NETs), which are able to damage and kill pathogens. Studies have shown that intracellular protozoan pathogens, including Toxoplasma gondi, Plasmodium falciparum and Leishmania spp, induce neutrophils to release NETs and are damaged by them. However, the action of this mechanism has not been explored in relation to E. histolytica trophozoites. Through scanning electron, epifluorescence microscopy and viability assays, we show for first time that during in vitro interaction with E. histolytica trophozoites, human neutrophils released NETs that covered amoebas and reduced amoebic viability. These NETs presented histones, myeloperoxidase and decondensed chromatin. The results suggest that NETs participate in the elimination of the parasite.


Assuntos
Entamoeba histolytica/imunologia , Armadilhas Extracelulares/imunologia , Interações Hospedeiro-Parasita/imunologia , Neutrófilos/imunologia , Trofozoítos/imunologia , Amebíase/imunologia , Amebíase/parasitologia , Células Cultivadas , Cromatina/metabolismo , Histonas/metabolismo , Humanos , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Peroxidase/metabolismo , Fagocitose/imunologia
5.
Int J Sports Med ; 37(1): 63-70, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26528943

RESUMO

Moderate exercise enhances resistance to pathogen-associated infections. However, its influence on intestinal IgA levels and resistance to Salmonella typhimurium in mice has not been reported. The aim of this study was to assess the impact of moderate exercise on bacterial resistance and the intestinal-IgA response in a murine typhoid model. Sedentary and exercised (under a protocol of moderate swimming) BALB/c mice were orally infected with Salmonella typhimurium and sacrificed on days 7 or 14 post-infection (n=5 per group). Compared with infected sedentary mice, infected exercised animals had i) lower intestinal and systemic bacterial loads; ii) higher total and specific intestinal-IgA levels, iii) a higher percentage of IgA plasma cells in lamina propria; iv) a higher level on day 7 and lower level on day 14 of intestinal α- and J-chain mRNA and plasma corticosterone, v) unchanged mRNA expression of intestinal pIgR, and vi) a higher mRNA expression of liver pIgR, α-chain and J-chain on day 7. Hence, it is likely that an increase in corticosterone levels (stress response) induced by moderate exercise increased intestinal IgA levels by enabling greater liver expression of pIgR mRNA, leading to a rise in IgA transcytosis from the liver to intestine. The overall effect of these changes is an enhanced resistance to infection.


Assuntos
Resistência à Doença/fisiologia , Imunoglobulina A/metabolismo , Mucosa Intestinal/metabolismo , Condicionamento Físico Animal/fisiologia , Infecções por Salmonella/prevenção & controle , Salmonella typhimurium , Animais , Carga Bacteriana , Corticosterona/sangue , Modelos Animais de Doenças , Cadeias J de Imunoglobulina/metabolismo , Cadeias alfa de Imunoglobulina/metabolismo , Intestinos/microbiologia , Fígado/metabolismo , Masculino , Camundongos Endogâmicos BALB C , RNA Mensageiro/metabolismo , Receptores de Imunoglobulina Polimérica/metabolismo , Natação/fisiologia
6.
Biomed Res Int ; 2015: 458470, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26634209

RESUMO

Although diet and exercise clearly have an influence on immune function, studies are scarce on the effect caused by exercise and the consumption of a carbohydrate-rich or fat-rich diet on the peripheral immune system. The aim of the present study was to evaluate the effect of exercise and the two aforementioned unbalanced diets on young Balb/c mice, especially in relation to BMI, the level of glucose, and the percentage of lymphocyte subpopulations in peripheral blood. The changes found were then related to the synthesis of leptin and adiponectin as well as the production of oxidative stress. The increase in BMI found with the carbohydrate-rich and fat-rich diets showed correlation with the levels of leptin and adiponectin. An increase in leptin and a decrease in adiponectin directly correlated with an increase in total lymphocytes and CD4+ cells and with a decrease in B cells. The increase in leptin also correlated with an increase in CD8+ cells. Glycemia and oxidative stress increased with the two unbalanced diets, negatively affecting the proliferation of total lymphocytes and the percentage of B cells, apparently by causing alterations in proteins through carbonylation. These alterations caused by an unbalanced diet were not modified by moderate exercise.


Assuntos
Glicemia/imunologia , Índice de Massa Corporal , Dieta/métodos , Ingestão de Alimentos/imunologia , Imunidade Inata/imunologia , Atividade Motora/imunologia , Animais , Citocinas/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Condicionamento Físico Animal/métodos
7.
Int. j. morphol ; 33(1): 213-221, Mar. 2015. ilus
Artigo em Inglês | LILACS | ID: lil-743788

RESUMO

All organs of the immune system are innervated and almost all neurotransmitter receptors are present on immune cells. We studied the effects of sympathetic innervation in the development of amebic liver abscess (ALA) in rats. Our results showed that lack of sympathetic innervation promote a decrease in size of ALA. We found scarce amoebas, increased the number of neutrophils and a few collagen fibers surrounding the abscess, meanwhile in control group, we observed abscesses areas with typical necrosis including trophozoites and neutrophils. Macrophages were differentially distributed surrounding abscess area in control and vehicle groups, but equally located in and outside of the abscesses in sympathectomized rat. No significant differences were observed on NK cells in analysed groups. In cytokines quantification studies, we observed down-expression of IFN-g and TNF-a, moreover, we found overexpression of IL-10 in sympathectomized and ALA group. In conclusion, our results suggest that elimination of sympathetic nerve fibers in a model rat of amebic liver abscess induces reduction of the innate immune response and presence of amebas through the liver at seven days post-inoculation.


Todos los órganos del sistema inmune están inervados y casi todos los receptores para neurotransmisores están presentes en las células de la respuesta inmune. Nosotros estudiamos el efecto de la inervación simpática en el desarrollo del Absceso Hepático Amebiano (AHA) en ratas. Nuestros resultados muestran que la inervación simpática promueve una disminución en el tamaño del AHA. Nosotros encontramos áreas fibróticas bien definidas con algunas amibas, mayor número de neutrófilos y pocas fibras de colágena rodeando el área de daño, mientras que en el grupo control, nosotros observamos áreas con necrosis, trofozoítos y pocos neutrófilos en el área fibrótica. Los macrófagos se observaron distribuidos en el área fibrótica en los animales simpatectomizados, mientras que en los controles encontramos a los macrófagos distribuidos en la periferia del absceso. No se encontró diferencia significativa en la distribución y cantidad de células NK. En el estudio de citocinas nosotros observamos una disminución de IFN-g y TNF-a y un incremento de IL-10 en animales simpatectomizados. En conclusión, nuestros resultados sugieren que la eliminación de las fibras del sistema nervioso simpático en el modelo de AHA en rata, reduce la respuesta inmune innata y persisten amebas en el tejido dañados a los 7 días post-inoculación.


Assuntos
Animais , Masculino , Ratos , Abscesso Hepático Amebiano/imunologia , Sistema Nervoso Simpático/imunologia , Sistema Nervoso Simpático/metabolismo , Entamoeba histolytica , Imunidade Inata , Imuno-Histoquímica , Abscesso Hepático Amebiano/metabolismo , Microscopia Eletrônica de Transmissão , Neurotransmissores/imunologia , Ratos Wistar , Simpatectomia Química
8.
Scand J Immunol ; 79(5): 315-24, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24612255

RESUMO

The impact of intermittent fasting versus ad libitum feeding during Salmonella typhimurium infection was evaluated in terms of duodenum IgA levels, bacterial clearance and intestinal and extra-intestinal infection susceptibility. Mice that were intermittently fasted for 12 weeks or fed ad libitum were infected with S. typhimurium and assessed at 7 and 14 days post-infection. Next, we evaluated bacterial load in the faeces, Peyer's patches, spleen and liver by plate counting, as well as total and specific intestinal IgA and plasmatic corticosterone levels (by immunoenzymatic assay) and lamina propria IgA levels in plasma cells (by cytofluorometry). Polymeric immunoglobulin receptor, α- and J-chains, Pax-5 factor, pro-inflammatory cytokine (tumour necrosis factor-α and interferon-γ) and anti-inflammatory cytokine (transforming growth factor-ß) mRNA levels were assessed in mucosal and liver samples (by real-time PCR). Compared with the infected ad libitum mice, the intermittently fasted infected animals had (1) lower intestinal and systemic bacterial loads; (2) higher SIgA and IgA plasma cell levels; (3) higher mRNA expression of most intestinal parameters; and (4) increased or decreased corticosterone levels on day 7 and 14 post-infection, respectively. No contribution of liver IgA was observed at the intestinal level. Apparently, the changes following metabolic stress induced by intermittent fasting during food deprivation days increased the resistance to S. typhimurium infection by triggering intestinal IgA production and presumably, pathogen elimination by phagocytic inflammatory cells.


Assuntos
Duodeno/imunologia , Jejum , Imunoglobulina A/imunologia , Plasmócitos/imunologia , Infecções por Salmonella/imunologia , Salmonella typhimurium/imunologia , Estresse Fisiológico/imunologia , Animais , Carga Bacteriana , Corticosterona/sangue , Citocinas/genética , Citocinas/metabolismo , Duodeno/microbiologia , Fezes/microbiologia , Regulação da Expressão Gênica , Imunidade nas Mucosas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/metabolismo
9.
Immunol Res ; 56(1): 44-60, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23371837

RESUMO

The neuraminidase (NA) epitope from the Mexican AH1N1 influenza virus was identified by using sequences registered at the GenBank during the peak of a pandemic (from April 2009 to October 2010). First, NA protein sequences were submitted for multiple alignment analysis, and their three-dimensional models (3-D) were then built by using homology modeling. The most common sequence (denominated wild-type) and its mutants were submitted to linear and nonlinear epitope predictors, which included the major histocompatibility complex type II (MHC II) and B-cell peptides. The epitope prediction was in accordance with evolutionary behavior and some protein structural properties. The latter included a low NA mutation rate, NA 3-D surface exposure, and the presence of high hindrance side chain residues. After selecting the epitope, docking studies and molecular dynamics (MD) simulations were used to explore interactions between the epitope and MHC II. Afterward, several experimental assays were performed to validate the theoretical study by using antibodies from humans (infected by pandemic H1N1) and rabbits (epitope vaccination). The results show 119 complete sequences that were grouped into 28 protein sequences according to their identity (one wild-type and 27 representative mutants (1-5 mutations)). The predictors yielded several epitopes, with the best fit being the one located in the C-terminal region. Theoretical methods demonstrated that the selected epitope reached the P4, P6, P7, and P9 pockets of MHC II, whereas the experimental evidence indicates that the epitope is recognized by human antibodies and also by rabbit antibodies immunized with the peptide.


Assuntos
Mapeamento de Epitopos/métodos , Epitopos de Linfócito B/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/imunologia , Neuraminidase/metabolismo , Infecções por Orthomyxoviridae/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/metabolismo , Biologia Computacional , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Influenza Humana/diagnóstico , México , Modelos Animais , Dados de Sequência Molecular , Mutação/genética , Neuraminidase/genética , Neuraminidase/imunologia , Ligação Proteica , Conformação Proteica , Coelhos , Vacinação
10.
J Sports Med Phys Fitness ; 52(6): 674-81, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23187332

RESUMO

AIM: The aim of this paper was to evaluate the effect of a treatment with glycophosphopeptide on Olympic high platform divers during training and competition by measuring lymphocytes and cortisol in peripheral blood, and secretory immunoglobin A in saliva (sIgA). METHODS: Two groups of 8 divers were given a 14-day treatment of capsules (Gp or placebo) three times per day. Measurements of the peripheral blood lymphocytes (TCD3+, TCD4+ and T CD8+), plasma cortisol and IgA levels in saliva were made on day 0, 21 and 150. RESULTS: There was no significant difference found between the Gp- and placebo-treated groups regarding the increase in IgA between basal and first, or first and second measurements. The fact that there was a significant increase in S-IgA (9.89 ± 0.44 to 10.59±0.55, P=0.001) and B CD19+ (345.13±108.24 to 484.75±120.54, P=0.025) in the Gp- and not in the placebo-treated group between the basal and first measurement was due to the variation among the athletes of the latter group, and not the increase itself, indicating that Gp acted as an immunomodulator. It was apparently the exercise and not the Gp treatment that caused the increase in S-IgA and B CD19+ at the first and second measurements. CONCLUSION: The current study reports that with athletes who practiced moderately intense exercise, which stimulated the immune response, a Gp treatment of two weeks seems to have acted only as an immunomodulator that reduced the variation in the increased levels of IgA and B CD19+.


Assuntos
Adjuvantes Imunológicos/farmacologia , Mergulho/fisiologia , Exercício Físico/fisiologia , Imunidade Inata/efeitos dos fármacos , Imunoglobulina A Secretora/metabolismo , Saliva/metabolismo , Linfócitos T/efeitos dos fármacos , Adolescente , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Contagem de Linfócitos , Masculino , Estudos Prospectivos , Infecções Respiratórias/imunologia , Infecções Respiratórias/metabolismo , Infecções Respiratórias/prevenção & controle
11.
Int J Sports Med ; 33(12): 1020-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22706946

RESUMO

The immune-suppression caused by acute stress can be reduced by a regular practice of moderate exercise which is known to modulate the expression of secretory-IgA. This antibody is essential for protection against infections and maintenance of homeostasis at the mucosal level. In order to explore the effects of moderate exercise on secretory-IgA production in ileum of the small intestine, 2 groups of mice were submitted to this protocol for 6 months, an exercise group and a sedentary group. After sacrifice, levels of secretory-IgA in intestinal fluid and levels of adrenal hormones in serum were determined by enzyme immunoenzymatic assay. IgA-plasma cells in lamina propria were evaluated by flow cytometry. Transcriptional mRNA expression in mucosa of alpha-chain, J-chain, pIgR and cytokines (Interleukin-2, -4, -6, -10, transforming growth factor-beta, interferon-gamma and tumor necrosis factor) were determined by RT-PCR. In comparison with sedentary mice, moderate exercised mice displayed an up-regulating effect on the production of secretory-IgA and IgA-plasma cells, on the expression of all mRNA transcripts from secretory-IgA associated proteins, and on all cytokines tested. However, serum levels of adrenal hormones were not altered. Future studies on secretory-IgA production are necessary to support the substantive effect of moderate exercise on protection and homeostasis at the intestinal level.


Assuntos
Íleo/imunologia , Imunoglobulina A Secretora/imunologia , Condicionamento Físico Animal/fisiologia , Esforço Físico/imunologia , Animais , Íleo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Esforço Físico/fisiologia
12.
Parasitol Res ; 111(3): 1401-5, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22453500

RESUMO

Genome analysis of Entamoeba histolytica predicts the presence of acetyl-CoA carboxylase. Using Western blot, histochemistry, and confocal microscopy, we demonstrated the presence of a biotin-containing protein in the cytoplasm of E. histolytica, with a molecular weight of 136 kDa and biotin-carboxylase activity. This protein probably corresponds to a transcarboxylase that catalyzes the rate-limiting reaction leading to fatty acid elongation.


Assuntos
Carboxil e Carbamoil Transferases/metabolismo , Entamoeba histolytica/enzimologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Proteínas de Protozoários/metabolismo , Animais , Carboxil e Carbamoil Transferases/genética , Entamoeba histolytica/genética , Entamoeba histolytica/metabolismo , Genoma de Protozoário , Proteínas de Protozoários/genética
13.
Parasite Immunol ; 33(5): 255-64, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21204853

RESUMO

During amebic invasion, neutrophils are a key component in either protecting against invading trophozoites or contributing to tissue damage. Upon degranulating or being lysed, neutrophils release toxic substances that can kill amebas as well as damage host tissue. In a previous study we identified a protein from nonspecifically stimulated peritoneal exudates of hamster that has peroxidase and marked amebicidal activity. In the current study we analyzed the in vitro amebicidal effect of purified hamster myeloperoxidase (MPO). The results demonstrate that MPO must bind directly to the surface of Entamoeba histolytica trophozoites in order to carry out amebicidal activity by using the H(2) O(2) produced by the amebas themselves. Myeloperoxidase-incubated amebas showed important morphological and ultrastructural alterations that increased with incubation time. Changes included an increase of vacuoles in the cytoplasm, a decrease of glycogen, alterations of nuclear morphology and disturbances in the plasma membrane culminating in complete ameba destruction.


Assuntos
Antiprotozoários/farmacologia , Entamoeba histolytica/efeitos dos fármacos , Neutrófilos/enzimologia , Peroxidase/farmacologia , Trofozoítos/efeitos dos fármacos , Animais , Antiprotozoários/isolamento & purificação , Antiprotozoários/metabolismo , Sobrevivência Celular , Cricetinae , Entamoeba histolytica/citologia , Masculino , Mesocricetus , Peroxidase/isolamento & purificação , Peroxidase/metabolismo , Ligação Proteica , Trofozoítos/citologia
14.
Parasite Immunol ; 33(1): 65-72, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21189654

RESUMO

The neuro-immune network, in which the vagus nerve is involved, provides feedback between its afferent branches for signalling central nervous system from sites of injury through cytokines and its efferent branches, which release acetylcholine, an anti-inflammatory neurotransmitter. For gain insight into the parasympathetic mechanisms participating in the inflammatory response in the liver, we studied the effects of a vagotomy on the innate immune response in hamsters with amoebic liver abscess. At 7 days post-infection, compared to the control, liver parasympathectomy resulted in a larger abscess size, a greater production of collagen fibres, fewer trophozoites, increased serum levels of IL-10 and IFN-γ and increased numbers of IL-10 and IFN-γ-positive cells in situ, with no change in the number of macrophages and NK cells. Data indicate that the vagotomy disrupted the inflammatory response, causing an increase in the response against infection, then could favour the innervation of the liver by the sympathetic nervous system and would then take the control of the immune response by stimulating the conversion of macrophages to epithelioid cells; and through increased IL-10 production would induce the hepatic stellar cells to become myofibroblast collagen producer cells, thus forming a barrier of collagen and blocking trophozoite migration.


Assuntos
Interferon gama/imunologia , Interleucina-10/imunologia , Células Matadoras Naturais/imunologia , Abscesso Hepático Amebiano/imunologia , Abscesso Hepático Amebiano/fisiopatologia , Fígado/imunologia , Fígado/fisiopatologia , Macrófagos/imunologia , Miofibroblastos/imunologia , Neuroimunomodulação , Fator de Necrose Tumoral alfa/imunologia , Vagotomia , Nervo Vago/imunologia , Nervo Vago/fisiopatologia , Nervo Vago/cirurgia , Animais , Cricetinae , Ensaio de Imunoadsorção Enzimática , Imuno-Histoquímica , Células Matadoras Naturais/parasitologia , Fígado/parasitologia , Fígado/ultraestrutura , Abscesso Hepático Amebiano/parasitologia , Macrófagos/parasitologia , Masculino , Miofibroblastos/parasitologia , Neuroimunomodulação/fisiologia
15.
J Physiol Biochem ; 66(1): 7-13, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20407859

RESUMO

In rats, hypophysectomy (HYPOX) or neurointermediate pituitary lobectomy (NIL) reduce humoral and cell-mediated immune responses. However, to our knowledge, the differences in the effects of anterior versus posterior pituitary hormones on the immune responses have not been studied to date. We compared in rats, the effects of sham surgery (SHAM), HYPOX, and NIL on humoral immune responses to T cell-independent (TI) type 1 antigen DNP-LPS and to TI type 2 antigen DNP-FICOLL, as well as to T cell-dependent (TD) antigens ovalbumin (OVA) and bovine serum albumin (BSA). The results showed that: (1) both HYPOX and NIL induced a similar and significant decrease in IgM responses towards TI-1 antigens, (2) NIL but not HYPOX induced a decreased IgM response to TI-2 antigens, and (3) both HYPOX and NIL induced similar and significant decrease in IgG responses to TI-2 antigens. Compared with the SHAM group, IgM responses to both TD antigens did not change in HYPOX and NIL animals, whereas the IgG responses to OVA and BSA significantly decreased in HYPOX and NIL animals. These results indicate that hormones of the anterior and posterior pituitary play their own role in the regulation of humoral immune responses.


Assuntos
Antígenos T-Independentes/imunologia , Imunidade Humoral , Hipófise/imunologia , Linfócitos T/imunologia , Animais , Hipofisectomia , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Imunoglobulina M/imunologia , Imunoglobulina M/metabolismo , Masculino , Ovalbumina/imunologia , Hipófise/cirurgia , Ratos , Soroalbumina Bovina/imunologia
16.
J. physiol. biochem ; 66(1): 7-13, mar. 2010.
Artigo em Inglês | IBECS | ID: ibc-122844

RESUMO

No disponible


In rats, hypophysectomy (HYPOX) or neurointermediate pituitary lobectomy (NIL) reduce humoral and cell-mediated immune responses. However, to our knowledge, the differences in the effects of anterior versus posterior pituitary hormones on the immune responses have not been studied to date. We compared in rats, the effects of sham surgery (SHAM), HYPOX, and NIL on humoral immune responses to T cell-independent (TI) type 1 antigen DNP-LPS and to TI type 2 antigen DNP-FICOLL, as well as to T cell-dependent (TD) antigens ovalbumin (OVA) and bovine serum albumin(BSA). The results showed that: (1) both HYPOX and NIL induced a similar and significant decrease in IgM responses towards TI-1 antigens, (2) NIL but not HYPOX induced a decreased IgM response to TI-2 antigens, and (3) both HYPOX and NIL induced similar and significant decrease in IgG responses to TI-2 antigens. Compared with the SHAM group, IgM responses to both TD antigens did not change in HYPOX and NIL animals, whereas the IgG responses to OVA and BSA significantly decreased in HYPOX and NIL animals. These results indicate that hormones of the anterior and posterior pituitary play their own role in the regulation of humoral immune responses (AU)


Assuntos
Animais , Ratos , Hipofisectomia , Antígenos de Histocompatibilidade Classe II/análise , Hormônios Adeno-Hipofisários , Hormônios Neuro-Hipofisários , Ovalbumina/farmacocinética , Soroalbumina Bovina/farmacocinética
17.
Parasite Immunol ; 31(7): 384-91, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19527454

RESUMO

Human fulminant amoebic colitis (FAC) is characterized by ulceration and inflammation of the colon. The specific mixture of pro-inflammatory and anti-inflammatory cytokines may participate in either the host defense or in the pathogenesis of amoebic colitis. Therefore, we studied the expression of IL-8, IL-10, IL-4, TGF-beta and IFN-gamma in human FAC patients and controls through immunohistochemistry analysis. The number of cells expressing IL-8, IL-4 and IL-10 was significantly enhanced in all FAC samples compared to the control samples. However, the expression of TGF- beta in patients was low in the colonic mucosa and high in the lamina propria compared with the control. No expression of IFN-gamma was found in the controls or FAC samples. The production of IL-8 by intestinal epithelial cells may play a role in the pathogenesis of amoebic infection, because this cytokine attracts neutrophils, which lead to an inflammatory reaction that results in tissue damage. The predominant expression of the macrophage down-regulating cytokines, IL-4, IL-10 and TGF-beta, or the Th2-type immune response could inhibit a cell-mediated immune response, which in turn would facilitate parasite invasion in these tissues.


Assuntos
Colo/imunologia , Colo/parasitologia , Citocinas/biossíntese , Disenteria Amebiana/imunologia , Mucosa Intestinal/imunologia , Colo/patologia , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica/métodos , Mucosa Intestinal/patologia
18.
Parasitol Res ; 104(4): 821-6, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19018568

RESUMO

In vitro studies have proved the presence of epitopes of CD59 in the surface of trophozoites of Entamoeba histolytica (E. histolytica). However, it has not been proved if CD59 molecules are expressed in the surface during the trophozoites' tissue invasion. The aim of the present study was to determine whether the complement-regulatory protein CD59 is present on trophozoites of E. histolytica in human colon. Eleven specimens of amoebic colitis were studied by immunohistochemistry and electron microscopy techniques with a monoclonal antibody against human CD59 molecule. Our results show that a CD59-like molecule is expressed in trophozoites of E. histolytica found in colonic amebic lesions. Also, a CD59-like molecule was detected by western blot analysis in whole lysate of E. histolytica as well as on the plasma membrane by immunocytochemistry. These results suggest that E. histolytica can use CD59-like protein against the lytic action of membrane attack complex.


Assuntos
Antígenos CD59/metabolismo , Colite/parasitologia , Colo/parasitologia , Entamoeba histolytica/patogenicidade , Proteínas de Protozoários/metabolismo , Trofozoítos/metabolismo , Animais , Western Blotting , Colo/metabolismo , Entamoeba histolytica/crescimento & desenvolvimento , Entamoeba histolytica/metabolismo , Entamebíase/parasitologia , Humanos , Imuno-Histoquímica , Microscopia Eletrônica , Trofozoítos/crescimento & desenvolvimento , Trofozoítos/ultraestrutura
19.
Parasite Immunol ; 30(1): 31-8, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18086014

RESUMO

According to previous reports, intranasal administration of the Cry1Ac protein alone or with amoebic lysates increases protection against Naegleria fowleri meningoencephalitis in mice, apparently by eliciting IgA responses in the nasal mucosa. In the current study, we performed an immunohistochemical analysis of IgA in the nasal mucosa of mice immunized intranasally with Cry1Ac, and amoebic lysates or a combination of both. The animals were sacrificed 24 h after the last immunization or after an intranasal lethal challenge with N. fowleri. Our results indicate that all of the intranasal immunizations provoked an increase in areas with metaplasia in the olfactory epithelium, allowing for secretion of IgA. As a result, IgA antibodies were found interacting with trophozoites in the nasal lumen, and there was a marked increase of IgA in the metaplasic epithelium. On the other hand in nonimmunized mice trophozoites were observed invading the nasal mucosa, which was not the case for immunized mice. Our results suggest that intranasal immunization provokes cellular changes in the olfactory epithelium, leading to greater protection against N. fowleri that is probably caused by an increased secretion of IgA. The increased IgA response induced in the nasal mucosa by immunization probably impedes both amoebic adhesion and subsequent invasion of the parasite to the nasal epithelium.


Assuntos
Amebíase/imunologia , Proteínas de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Endotoxinas/imunologia , Proteínas Hemolisinas/imunologia , Imunização , Imunoglobulina A Secretora/análise , Meningoencefalite/imunologia , Naegleria fowleri/imunologia , Mucosa Olfatória/imunologia , Adjuvantes Imunológicos , Administração Intranasal , Amebíase/parasitologia , Animais , Anticorpos Antiprotozoários/análise , Antígenos de Protozoários/imunologia , Masculino , Meningoencefalite/parasitologia , Metaplasia , Camundongos , Camundongos Endogâmicos BALB C , Mucosa Nasal/imunologia , Mucosa Nasal/parasitologia , Proteínas Recombinantes/imunologia
20.
Parasite Immunol ; 29(4): 201-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17371457

RESUMO

In cases of fulminant amoebic colitis we have determined the interactions between Entamoeba histolytica trophozoites and immune cells in order to better understand the pathophysiology of amoebic colitis. Eleven specimens of amoebic colitis and five specimens of colon without amoebic lesions were studied. Trophozoites and immune cells were located by topographic stains, histochemistry and immunohistochemistry. Trophozoites were seen in both damaged and undamaged areas of the colonic mucosa. Specimens of fulminant amoebic colitis showed: (a) an increase in IgA+, IgG+ B cells and neutrophils; (b) a reduction in IgM+ B cells, CD8+ T cells, macrophages, eosinophils and mast cells; and (c) no change in the number of NK and CD4+ T cells. The cellular infiltrate in amoebic colitis may represent the combined effects of amoebic monocyte locomotion inhibitory factor and switching of IgM+ B cells to IgG+ and IgA+ plasma cells, induced by amoebic antigens. Tissue damage in the absence of trophozoites may result from ischaemia or host immune responses.


Assuntos
Colo , Disenteria Amebiana/imunologia , Disenteria Amebiana/patologia , Entamoeba histolytica/patogenicidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Pré-Escolar , Colo/imunologia , Colo/parasitologia , Colo/patologia , Disenteria Amebiana/parasitologia , Entamoeba histolytica/crescimento & desenvolvimento , Feminino , Humanos , Imuno-Histoquímica/métodos , Mucosa Intestinal/imunologia , Mucosa Intestinal/parasitologia , Mucosa Intestinal/patologia , Leucócitos/imunologia , Macrófagos/imunologia , Masculino , Mastócitos/imunologia , Pessoa de Meia-Idade , Trofozoítos/crescimento & desenvolvimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA