RESUMEN

BACKGROUND: Peritoneal fibrosis (PF) represents a long-term complication of peritoneal dialysis (PD), affecting peritoneal membrane (PM) integrity and function. Understanding the mechanisms underlying PF development in an uremic environment aiming alternative therapeutic strategies for treating this process is of great interest. The aim of this study was to analyze the effects of tamoxifen (TAM) and recombinant BMP7 (rBMP7) in an experimental model of PF developed in uremic rats. METHODS: To mimic the clinical situation of patients on long-term PD, a combo model, characterized by the combination of PF and CKD with severe uremia, was developed in Wistar rats. PF was induced by intraperitoneal (IP) injections of chlorhexidine gluconate (CG), and CKD was induced by an adenine-rich diet. Uremia was confirmed by severe hypertension, increased blood urea nitrogen (BUN> 120 mg/dL) and serum creatinine levels (> 2 mg/dL). Uremic rats with PF were treated with TAM (10 mg/Kg by gavage) or BMP7 (30 µg/Kg, IP). Animals were followed up for 30 days. RESULTS: CG administration in uremic rats induced a striking increase in PM thickness, neoangiogenesis, demonstrated by increased capillary density, and failure of ultrafiltration capacity. These morphological and functional changes were blocked by TAM or rBMP7 treatment. In parallel, TAM and rBMP7 significantly ameliorated the PM fibrotic response by reducing α-SMA, extracellular matrix proteins and TGF-ß expression. TAM or rBMP7 administration significantly inhibited peritoneal Smad3 expression in uremic rats with PF, prevented Smad3 phosphorylation, and induced a remarkable up-regulation of Smad7, an intracellular inhibitor of TGFß/Smad signaling, contributing to a negative modulation of profibrotic genes. Both treatments were also effective in reducing local inflammation, possibly by upregulating IκB-α expression in the PM of uremic rats with PF. In vitro experiments using primary peritoneal fibroblasts activated by TGF-ß confirmed the capacity of TAM or rBMP7 in blocking inflammatory mediators, such as IL-1ß expression. CONCLUSIONS: In conclusion, these findings indicate important roles of TGF-ß/Smad signaling in PF aggravated by uremia, providing data regarding potential therapeutic approaches with TAM or rBMP7 to block this process.

Asunto(s)

Proteína Morfogenética Ósea 7/farmacología , Inflamación/metabolismo , Fibrosis Peritoneal/metabolismo , Tamoxifeno/farmacología , Uremia/metabolismo , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Masculino , Peritoneo/citología , Peritoneo/efectos de los fármacos , Ratas , Ratas Wistar , Proteínas Recombinantes/farmacología , Insuficiencia Renal Crónica , Proteína smad7 , Factor de Crecimiento Transformador beta/metabolismo

RESUMEN

The peritoneal cavity has a microenvironment capable of promoting proliferation, differentiation, and activation of the resident cells and recruitment of blood cells through the capillary network involved in the peritoneum. Among the cells found in the peritoneal cavity, B-1 cells are a particular cell type that contains features that are not very well defined. These cells differ from conventional B lymphocytes (B-2) by phenotypic, functional, and molecular characteristics. B-1 cells can produce natural antibodies, migrate to the inflammatory focus, and have the ability to phagocytose pathogens. However, the role of B-1 cells in immunity against parasites is still not completely understood. Several experimental models have demonstrated that B-1 cells can affect the susceptibility or resistance to parasite infections depending on the model and species. Here, we review the literature to provide information on the peculiarities of B-1 lymphocytes as well as their interaction with parasites.

Asunto(s)

Subgrupos de Linfocitos B/inmunología , Helmintiasis/inmunología , Helmintos/inmunología , Inmunidad Humoral/inmunología , Parásitos/inmunología , Cavidad Peritoneal/citología , Infecciones por Protozoos/inmunología , Animales , Citocinas/biosíntesis , Citocinas/inmunología , Helmintiasis/parasitología , Humanos , Ratones , Peritoneo/citología , Peritoneo/inmunología , Infecciones por Protozoos/parasitología

RESUMEN

OBJECTIVE: The aim of this study was to investigate the influence of aging on the internalization and the production of nitric oxide (NO) by peritoneal adherent cells (PAC), in response to Candida albicans (C. albicans). MATERIAL AND METHODS: PAC obtained from young and aged mice were challenged with dead or viable C. albicans by using predetermined proportions (cells:yeast) for 30 and 120 minutes. Phagocytosis was analyzed by acridine orange dye, and NO production by the Griess reaction. RESULTS: C. albicans phagocytosis by PAC from aged mice was similar to that of young mice, although the cells from older mice cells present more internalized fungi compared with matched control. In addition, a tendency towards impaired NO production by peritoneal mononuclear phagocytes from aged mice was observed. CONCLUSIONS: PAC from aged mice may capture and store many fungi, which in turn may mean that these cells are effectively unable to eliminate fungi, probably due to impaired NO production. Therefore, considering the important role of C. albicans overgrowth in the pathogenesis of DS and the aspects observed in this study, aging may favor the onset and severity of local candidosis such as DS and its systemic forms.

Asunto(s)

Envejecimiento/fisiología , Candida albicans/patogenicidad , Adhesión Celular/fisiología , Óxido Nítrico/biosíntesis , Fagocitosis/fisiología , Estomatitis Subprotética/metabolismo , Estomatitis Subprotética/microbiología , Factores de Edad , Animales , Candida albicans/aislamiento & purificación , Candidiasis/microbiología , Masculino , Ratones Endogámicos C57BL , Óxido Nítrico/análisis , Peritoneo/citología , Valores de Referencia , Factores de Tiempo

RESUMEN

Abstract Elderly denture wearers are commonly affected by Candida-associated denture stomatitis (DS), an inflammatory process of the oral mucosa strongly associated with Candida spp and other microorganisms, as well as local and systemic factors. The impaired immune response against pathogens is among the inherent host factors that have been also associated with the pathogenesis of DS. Mononuclear phagocytes respond to the pathogens through phagocytosis followed by the production of several substances inside the phagosomes, among them are the reactive nitrogen species (RNS). A failure in these mechanisms may contribute to the DS development. Objective The aim of this study was to investigate the influence of aging on the internalization and the production of nitric oxide (NO) by peritoneal adherent cells (PAC), in response to Candida albicans (C. albicans). Material and methods PAC obtained from young and aged mice were challenged with dead or viable C. albicans by using predetermined proportions (cells:yeast) for 30 and 120 minutes. Phagocytosis was analyzed by acridine orange dye, and NO production by the Griess reaction. Results C. albicans phagocytosis by PAC from aged mice was similar to that of young mice, although the cells from older mice cells present more internalized fungi compared with matched control. In addition, a tendency towards impaired NO production by peritoneal mononuclear phagocytes from aged mice was observed. Conclusions PAC from aged mice may capture and store many fungi, which in turn may mean that these cells are effectively unable to eliminate fungi, probably due to impaired NO production. Therefore, considering the important role of C. albicans overgrowth in the pathogenesis of DS and the aspects observed in this study, aging may favor the onset and severity of local candidosis such as DS and its systemic forms.

Asunto(s)

Animales , Masculino , Fagocitosis/fisiología , Estomatitis Subprotética/metabolismo , Estomatitis Subprotética/microbiología , Candida albicans/patogenicidad , Envejecimiento/fisiología , Adhesión Celular/fisiología , Óxido Nítrico/biosíntesis , Peritoneo/citología , Valores de Referencia , Factores de Tiempo , Candida albicans/aislamiento & purificación , Candidiasis/microbiología , Factores de Edad , Ratones Endogámicos C57BL , Óxido Nítrico/análisis

RESUMEN

Tissue macrophages are a heterogeneous cell population residing in all body tissues that contribute to the maintenance of homeostasis and trigger immune activation in response to injurious stimuli. This heterogeneity may be associated with tissue-specific functions; however, the presence of distinct macrophage populations within the same microenvironment indicates that macrophage heterogeneity may also be influenced outside of tissue specialization. The F4/80 molecule was established as a unique marker of murine macrophages when a monoclonal antibody was found to recognize an antigen exclusively expressed by these cells. However, recent research has shown that F4/80 is expressed by other immune cells and is not equivalently expressed across tissue-specific macrophage lineages, including those residing in the same microenvironment, such as the peritoneum and spleen. In this context, two murine macrophage subtypes with distinct F4/80 expression patterns were recently found to coexist in the peritoneum, termed large peritoneal macrophages (LPMs) and small peritoneal macrophages (SPMs). However, the presence of phenotypic and functional heterogeneous macrophage subpopulations in the spleen was already known. Thus, although F4/80 surface expression continues to be the best method to identify tissue macrophages, additional molecules must also be examined to distinguish these cells from other immune cells.

Asunto(s)

Antígenos de Diferenciación/biosíntesis , Biomarcadores/metabolismo , Macrófagos Peritoneales/citología , Bazo/citología , Animales , Humanos , Macrófagos/citología , Macrófagos/metabolismo , Macrófagos Peritoneales/metabolismo , Ratones , Peritoneo/citología

RESUMEN

CONTEXT: Plants of the Piperaceae family produce piplartine that was used to synthesize the cinnamides. OBJECTIVE: To assess the effects of piplartine (1) and cinnamides (2-5) against the protozoa responsible for malaria and leishmaniasis, and peritoneal cells of Swiss mice. MATERIALS AND METHODS: Cultures of Leishmania amazonensis, Plasmodium falciparum-infected erythrocytes, and peritoneal cells were incubated, in triplicate, with different concentrations of the compounds (0 to 256 µg/mL). The inhibitory concentration (IC50) in L. amazonensis and cytotoxic concentration (CC50) in peritoneal cell were assessed by the MTT method after 6 h of incubation, while the IC50 for P. falciparum-infected erythrocytes was determined by optical microscopy after 48 or 72 h of incubation; the Selectivity Index (SI) was calculated by CC50/IC50. RESULTS: All compounds inhibited the growth of microorganisms, being more effective against P. falciparum after 72 h of incubation, especially for the compounds 1 (IC50 = 3.2 µg/mL) and 5 (IC50 = 6.6 µg/mL), than to L. amazonensis (compound 1 = 179.0 µg/mL; compound 5 = 106.0 µg/mL). Despite all compounds reducing the viability of peritoneal cells, the SI were <10 to L. amazonensis, whereas in the cultures of P. falciparum the SI >10 for the piplartine (>37.4) and cinnamides 4 (>10.7) and 5 (= 38.4). DISCUSSION AND CONCLUSION: The potential of piplartine and cinnamides 4 and 5 in the treatment of malaria suggest further pre-clinical studies to evaluate their effects in murine malaria and to determine their mechanisms in cells of the immune system.

Asunto(s)

Cinamatos/farmacología , Leishmania/efectos de los fármacos , Piperidonas/farmacología , Plasmodium falciparum/efectos de los fármacos , Animales , Supervivencia Celular/efectos de los fármacos , Cinamatos/administración & dosificación , Cinamatos/química , Relación Dosis-Respuesta a Droga , Eritrocitos/parasitología , Femenino , Humanos , Concentración 50 Inhibidora , Masculino , Ratones , Peritoneo/citología , Peritoneo/efectos de los fármacos , Piperaceae/química , Piperidonas/administración & dosificación , Piperidonas/aislamiento & purificación , Factores de Tiempo

RESUMEN

Protein malnutrition (PM) is a major public health problem in developing countries, affecting the inflammatory response and increasing susceptibility to opportunistic infections. For this reason, an adequate nutritional intervention can improve the quality of life of patients. Glutamine (GLN) is a nonessential amino acid, but can be considered "conditionally essential" for macrophage function in stress situations, in which it plays a role in the improvement of the inflammatory response. Concerning this issue, in the current study, it was of interest to evaluate some biological aspects of peritoneal cells from a protein malnutrition (PM) mouse model challenged with lipopolysaccharide (LPS) and treated intravenously with GLN. Two-month-old male Balb/c mice were subjected to a low-protein diet (2 % protein) and stimulated intravenously with LPS 1 h prior to the injection of 0.75 mg/kg GLN. Malnourished animals showed a reduced number of total peritoneal cells. Malnourished animals stimulated with LPS or LPS plus GLN did not show differences in peritoneal cell counts; however, the control group showed increased cellularity after LPS stimulus, which was reversed after GLN injection. Further, in the animals from both groups stimulated with LPS, GLN decreased the circulating levels of TNF-α and the levels of TNF-α produced by peritoneal cells; additionally, GLN decreased the IL-10 circulating levels in the malnourished animals stimulated with LPS. In addition, peritoneal cells of the control and malnourished groups stimulated with LPS showed a negative modulation of the NFkB signaling pathway after GLN injection. In conclusion, this study shows that GLN has the capacity to reduce TNF-α synthesis as well as to act as a negative regulator of NFkB phosphorylation, leading to a positive outcome in the control of TNF-α production.

Asunto(s)

Glutamina/administración & dosificación , Desnutrición Proteico-Calórica/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Modelos Animales de Enfermedad , Glutamina/uso terapéutico , Interleucina-10/sangre , Ratones , Ratones Endogámicos BALB C , FN-kappa B/metabolismo , Peritoneo/citología , Fosforilación/efectos de los fármacos , Desnutrición Proteico-Calórica/tratamiento farmacológico , Factor de Necrosis Tumoral alfa/análisis

RESUMEN

AIM: To evaluate alterations in tight junction (TJ) proteins and glucose transporters in rat peritoneal mesothelial cells (RPMC) from diabetic rats and after treatment with peritoneal dialysis solutions (PDS) in vitro. METHODS: Diabetes was induced in female Wistar rats by streptozotocin (STZ)-injection. Twenty-one days after STZ-injection, peritoneal thickness and mesothelial cell morphology were studied by light microscopy and microvilli length and density by atomic force microscopy. RPMC were obtained from healthy and diabetic rats. Mesothelial phenotype, evaluated by cytokeratin and pan-cadherin, epithelial to mesenchymal transition (EMT), evaluated by alpha-smooth muscle action (α-SMA) and vimentin, TJ proteins, claudins-1 and -2, and occludin, and glucose transporters, sodium and glucose co-transporters (SGLT) -1 and -2 and facilitative glucose transporters (GLUT) -1 and -2 were analyzed. Also, transepithelial electrical resistance (TER) was measured. Oxidative stress was estimated by measuring reactive oxygen species production, and protein carbonylation, receptor for advanced glycation end products (RAGE), nuclear factor erythroid related factor-2 (Nrf-2), and expression of antioxidant enzymes. KEY FINDINGS: Peritoneal damage was present 21days after STZ-injection. Diabetes induced changes in TJ and glucose transporters in RPMC together with decreased TER. RPMC from diabetic rats showed oxidative stress, which was enhanced by exposure to PDS. In addition, RPMC from diabetic rats showed early EMT. SIGNIFICANCE: To our knowledge, this is the first study that shows changes in TJ proteins and glucose transporters of RPMC from diabetic rats. All these alterations might explain the increased peritoneal permeability observed in diabetic patients undergoing peritoneal dialysis.

Asunto(s)

Proteínas Facilitadoras del Transporte de la Glucosa/metabolismo , Proteínas de Uniones Estrechas/metabolismo , Animales , Antioxidantes/metabolismo , Soluciones para Diálisis , Transición Epitelial-Mesenquimal , Femenino , Microscopía de Fuerza Atómica , Diálisis Peritoneal , Peritoneo/citología , Peritoneo/metabolismo , Ratas , Ratas Wistar

RESUMEN

Galectin-3 is a ß-galactoside-binding protein with an inhibitory role in B cell differentiation into plasma cells in distinct lymphoid tissues. We use a model of chronic schistosomiasis, a well-characterized experimental disease hallmarked by polyclonal B cell activation, in order to investigate the role of galectin-3 in controlling IgA production through peritoneal B1 cells. Chronically infected, galectin-3-deficient mice (Lgals3(-/-)) display peritoneal fluid hypercellularity, increased numbers of atypical peritoneal IgM(+)/IgA(+) B1a and B1b lymphocytes and histological disturbances in plasma cell niches when compared with Lgals3(+/+) mice. Similar to our infection model, peritoneal B1 cells from uninfected Lgals3(-/-) mice show enhanced switching to IgA after in vitro treatment with interleukin-5 plus transforming growth factor-ß (IL-5 + TGF-ß1). A higher number of IgA(+) B1a lymphocytes was found in the peritoneal cavity of Lgals3(-/-)-uninfected mice at 1 week after i.p. injection of IL-5 + TGF-ß1; this correlates with the increased levels of secreted IgA detected in the peritoneal fluid of these mice after cytokine treatment. Interestingly, a higher number of degranulated mast cells is present in the peritoneal cavity of uninfected and Schistosoma mansoni-infected Lgals3(-/-) mice, indicating that, at least in part, mast cells account for the enhanced differentiation of B1 into IgA-producing B cells found in the absence of galectin-3. Thus, a novel role is revealed for galectin-3 in controlling the expression of surface IgA by peritoneal B1 lymphocytes; this might have important implications for manipulating the mucosal immune response.

Asunto(s)

Linfocitos B/citología , Linfocitos B/metabolismo , Diferenciación Celular , Galectina 3/deficiencia , Inmunoglobulina A/metabolismo , Peritoneo/citología , Regulación hacia Arriba , Animales , Recuento de Células , Degranulación de la Célula , Proliferación Celular , Forma de la Célula , Enfermedad Crónica , Galectina 3/metabolismo , Inmunoglobulina A/sangre , Cambio de Clase de Inmunoglobulina , Inmunoglobulina M/sangre , Interleucina-5 , Mastocitos/fisiología , Mesenterio/metabolismo , Ratones Endogámicos C57BL , Epiplón/metabolismo , Fenotipo , Células Plasmáticas/metabolismo , Esquistosomiasis/sangre , Esquistosomiasis/inmunología , Esquistosomiasis/parasitología , Esquistosomiasis/patología , Factor de Crecimiento Transformador beta1/metabolismo

RESUMEN

There are no studies investigating the role of nutritional status and immunity associated with Jorge Lobo's disease. The objective of this study was to evaluate the effects of protein-calorie malnutrition on the immune response of BALB/c mice inoculated with Lacazia loboi. In this study,the animals were divided into four groups: G1: inoculated with restricted diet, G2: not inoculated with restricted diet, G3: inoculated with regular diet, G4: not inoculated with regular diet. The animals of groups G1 and G2 were submitted to malnutrition for 20 days and once installed the animals were inoculated intradermally into the footpad. After 4 months, they were euthanised for the isolation of peritoneal lavage cells and removal of the footpad. The production of IL-2, IL-4, IL-10, IL-12, IFN-γ, TNF-α, H2 O2 and nitric oxide (NO) was evaluated in the peritoneal lavage cells. The footpad was evaluated regarding the size of macroscopic lesions, number of fungi and viability index. The results showed that the infection did not exert great influence on the body weight of the mice and previous malnutrition was an unfavourable factor for viability index, number of fungi, macroscopic lesion size in the footpad and production of H2 O2 , NO, IL-12, IL-10 and IFN-γ, suggesting that malnutrition significantly altered fungal activity and peritoneal cells. The results suggest considerable interaction between nutrition and immunity in Jorge Lobo's disease.

Asunto(s)

Lacazia , Lobomicosis/inmunología , Lobomicosis/microbiología , Desnutrición/complicaciones , Estado Nutricional , Animales , Peso Corporal , Citocinas/metabolismo , Modelos Animales de Enfermedad , Interleucina-12/metabolismo , Interleucina-2/metabolismo , Lacazia/inmunología , Lobomicosis/complicaciones , Ratones , Ratones Endogámicos BALB C , Lavado Peritoneal , Peritoneo/citología , Peritoneo/inmunología , Factor de Necrosis Tumoral alfa/metabolismo

RESUMEN

Mast cells (MCs) are versatile effector and regulatory cells in various physiologic, immunologic, and pathologic processes. In addition to the well-characterized IgE/FcεRI-mediated degranulation, a variety of biological substances can induce MCs activation and release of their granule content. Sex steroids, mainly estradiol and progesterone, have been demonstrated to elicit MCs activation. Most published studies have been conducted on MCs lines or freshly isolated peritoneal and bone marrow-derived MC without addressing gender impact on MC response. Our goal was to investigate if the effect of estradiol, progesterone, testosterone, and dihydrotestosterone (DHT) on MCs may differ depending on whether female or male rats are used as MCs donors. Our results demonstrated that effect of sex steroids on MCs histamine release is dose- and gender-dependent and can be direct, synergistic, or inhibitory depending on whether hormones are used alone or to pretreat MCs followed by substance P-stimulation or upon IgE-mediated stimulation. In contrast, sex steroids did not have effect on the MC expression of the IgE high affinity receptor, FcεRI, no matter female or male rats were used. In conclusion, MCs degranulation is modulated by sex hormones in a gender-selective fashion, with MC from females being more susceptible than MC from males to the effects of sex steroids.

Asunto(s)

Hormonas Esteroides Gonadales/farmacología , Liberación de Histamina/efectos de los fármacos , Mastocitos/inmunología , Peritoneo/citología , Receptores de IgE/biosíntesis , Animales , Degranulación de la Célula/inmunología , Células Cultivadas , Dihidrotestosterona/farmacología , Estradiol/farmacología , Femenino , Inmunoglobulina E/inmunología , Masculino , Mastocitos/citología , Progesterona/farmacología , Ratas , Ratas Sprague-Dawley , Factores Sexuales , Sustancia P/metabolismo , Testosterona/farmacología

RESUMEN

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) that is a major public health problem. The vaccine used for TB prevention is Mycobacterium bovis bacillus Calmette-Guérin (BCG), which provides variable efficacy in protecting against pulmonary TB among adults. Consequently, several groups have pursued the development of a new vaccine with a superior protective capacity to that of BCG. Here we constructed a new recombinant BCG (rBCG) vaccine expressing a fusion protein (CMX) composed of immune dominant epitopes from Ag85C, MPT51, and HspX and evaluated its immunogenicity and protection in a murine model of infection. The stability of the vaccine in vivo was maintained for up to 20 days post-vaccination. rBCG-CMX was efficiently phagocytized by peritoneal macrophages and induced nitric oxide (NO) production. Following mouse immunization, this vaccine induced a specific immune response in cells from lungs and spleen to the fusion protein and to each of the component recombinant proteins by themselves. Vaccinated mice presented higher amounts of Th1, Th17, and polyfunctional specific T cells. rBCG-CMX vaccination reduced the extension of lung lesions caused by challenge with Mtb as well as the lung bacterial load. In addition, when this vaccine was used in a prime-boost strategy together with rCMX, the lung bacterial load was lower than the result observed by BCG vaccination. This study describes the creation of a new promising vaccine for TB that we hope will be used in further studies to address its safety before proceeding to clinical trials.

Asunto(s)

Vacuna BCG/inmunología , Células TH1/inmunología , Células Th17/inmunología , Tuberculosis/prevención & control , Animales , Antígenos Bacterianos/genética , Antígenos Bacterianos/metabolismo , Carga Bacteriana/inmunología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/inmunología , Citocinas/metabolismo , Epítopos/inmunología , Femenino , Pulmón/metabolismo , Pulmón/microbiología , Pulmón/patología , Macrófagos/citología , Macrófagos/inmunología , Ratones , Ratones Endogámicos BALB C , Mycobacterium tuberculosis/inmunología , Mycobacterium tuberculosis/metabolismo , Mycobacterium tuberculosis/patogenicidad , Óxido Nítrico/metabolismo , Peritoneo/citología , Fagocitosis , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Bazo/inmunología , Bazo/metabolismo , Células TH1/citología , Células Th17/citología , Tuberculosis/inmunología

RESUMEN

The peritoneum is a thin membrane that covers most of the abdominal organs, composed of a monolayer of mesothelial cells and subjacent submesothelial loose connective tissue. Cells from the peritoneal wall are correlated with peritoneal fibrosis and epithelial-to-mesenchymal transition. However, the distinct involvement of mesothelial or submesothelial cells in such phenomena is still not clear. Here, we propose a new strategy to obtain stromal cells from anterior peritoneal wall explant cultures. These cells migrated from peritoneal tissues and proliferated in vitro for 4 weeks as adherent fibroblast-like cells. Optical and electronic microscopy analyses of the fragments revealed a significant submesothelial disorganization. The obtained cells were characterized as cytokeratin- vimentin+ laminin+ α-smooth muscle actin+, suggesting a connective tissue origin. Moreover, at the third passage, these stromal cells were CD90+CD73+CD29+Flk-1+CD45-, a phenotype normally attributed to cells of mesenchymal origin. These cells were able to support hematopoiesis, expressing genes involved in myelopoiesis (SCF, G-CSF, GM-CSF, IL-7 and CXCL-12), and differentiated into osteogenic and adipogenic cell lineages. The methodology demonstrated in this work can be considered an excellent experimental model to understand the physiology of the peritoneal wall in healthy and pathological processes. Moreover, this work shows for the first time that submesothelial stromal cells have properties similar to those of mesenchymal cells from other origins.

Asunto(s)

Adipogénesis , Linaje de la Célula , Epitelio/metabolismo , Hematopoyesis , Osteogénesis , Peritoneo/citología , Animales , Movimiento Celular , Separación Celular , Técnicas de Cocultivo , Citometría de Flujo , Cinética , Masculino , Ratones Endogámicos BALB C , Mielopoyesis , Peritoneo/ultraestructura , Fenotipo , Células del Estroma/citología , Células del Estroma/metabolismo

RESUMEN

Purinergic signaling has been established as an important feature of inflammation and homeostasis. The expression of a number of P2 receptor subtypes in the gut has been reported. In this study, using a well-known permeabilization method that is assessed by flow cytometry, we show that lymphocytes and macrophages from the mesenteric lymph nodes (MLN) and the peritoneal cavity exhibit different sensitivities to extracellular ATP. Compared with the macrophages, the lymphocytes are more sensitive to ATP in the MLN compartment, whereas in the peritoneal cavity the macrophages are more sensitive to ATP than the lymphocytes. In addition, we have shown that the epithelial cells from the small bowel are more resistant to the ATP effects than the cells from the colon. These cells, however, become susceptible after exposure to IFN-γ. Furthermore, by examining parameters such as pH manipulation, the exposure to divalent cations and the P2X7 antagonist Brilliant Blue G, and the use of cells from P2X7(-/-) mice, we have shown that the P2X7 receptors are the ATP-activated receptors responsible for the permeabilization phenomenon. In addition, using Western blot analysis, we have demonstrated the changes in the P2X7 receptor expression in immune cells isolated from different sites in the gut and in the gut-associated lymphoid tissues. Our findings suggest the existence of the site-specific modulation of P2X7 receptors on epithelial and immune cells, and we define purinergic signaling as a new regulatory element in the control of inflammation and cell fate in the gut and in the gut-associated lymphoid tissues.

Asunto(s)

Adenosina Trifosfato/farmacología , Células Epiteliales/metabolismo , Tracto Gastrointestinal/metabolismo , Linfocitos/metabolismo , Macrófagos/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Colon/citología , Colon/metabolismo , Células Epiteliales/efectos de los fármacos , Femenino , Tracto Gastrointestinal/citología , Intestino Delgado/citología , Intestino Delgado/metabolismo , Ganglios Linfáticos/citología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Linfocitos/efectos de los fármacos , Linfocitos/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Masculino , Mesenterio/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Peritoneo/citología , Peritoneo/inmunología , Peritoneo/metabolismo , Transducción de Señal/efectos de los fármacos

RESUMEN

Trypanosoma cruzi is a protozoan parasite that infects vertebrates, causing in humans a pathological condition known as Chagas' disease. The infection of host cells by T. cruzi involves a vast collection of molecules, including a family of 85 kDa GPI-anchored glycoproteins belonging to the gp85/trans-sialidase superfamily, which contains a conserved cell-binding sequence (VTVXNVFLYNR) known as FLY, for short. Herein, it is shown that BALB/c mice administered with a single dose (1 µg/animal, intraperitoneally) of FLY-synthetic peptide are more susceptible to infection by T. cruzi, with increased systemic parasitaemia (2-fold) and mortality. Higher tissue parasitism was observed in bladder (7·6-fold), heart (3-fold) and small intestine (3·6-fold). Moreover, an intense inflammatory response and increment of CD4+ T cells (1·7-fold) were detected in the heart of FLY-primed and infected animals, with a 5-fold relative increase of CD4+CD25+FoxP3+ T (Treg) cells. Mice treated with anti-CD25 antibodies prior to infection, showed a decrease in parasitaemia in the FLY model employed. In conclusion, the results suggest that FLY facilitates in vivo infection by T. cruzi and concurs with other factors to improve parasite survival to such an extent that might influence the progression of pathology in Chagas' disease.

Asunto(s)

Enfermedad de Chagas/inmunología , Glicoproteínas/química , Neuraminidasa/química , Péptidos/administración & dosificación , Trypanosoma cruzi/patogenicidad , Secuencia de Aminoácidos , Animales , Linfocitos T CD4-Positivos/inmunología , Enfermedad de Chagas/parasitología , Secuencia Conservada , Femenino , Factores de Transcripción Forkhead/inmunología , Glicoproteínas/inmunología , Humanos , Subunidad alfa del Receptor de Interleucina-2/inmunología , Ratones , Ratones Endogámicos BALB C , Neuraminidasa/inmunología , Parasitemia/inmunología , Parasitemia/parasitología , Péptidos/síntesis química , Péptidos/química , Peritoneo/citología , Linfocitos T Reguladores/inmunología , Trypanosoma cruzi/enzimología , Trypanosoma cruzi/inmunología , Virulencia

RESUMEN

Humoral immunity during experimental Chagas disease has been considered a double-edge sword, critical to control Trypanosoma cruzi spreading but also associated to tissue damage. Peritoneal B-1 cells have been linked to the pathogenesis of Chagas disease; however, they may also help to control the infection by providing a fast wave of antibodies. In the present work, we determined that peritoneal B-cell response to T. cruzi is characterized by a marked reduction of CD19(+) B cells due to plasma cell differentiation rather than to cell death. Both peritoneal B-2 and B-1 cells decrease after parasite infection, but with different kinetics. Thus, the reduction in B-2 cell number can be detected from day 4 postinfection while the number of B-1 cells decreases only after 15 days of infection. Differentiation of peritoneal B-1 and B-2 cells into IgM-secreting cells was triggered by parasites but not by cytokines produced by peritoneal cells. Electron microscopy studies showed that peritoneum of infected mice lodges plasma cells with typical morphology as well as atypical plasma cells named 'Mott-like cells' containing high number of cytoplasmatic Ig(+) granules. The plasma cells induced during the infection showed a phenotype that may allow their persistence in peritoneum and they may contribute to the high levels of antibodies exhibited at the chronic phase of infection. We also showed that the peritoneal B-cell response is scarcely specific for the invading pathogen and rather constitute an important source of non-parasite-specific IgM and IgG in the infected host.

Asunto(s)

Anticuerpos/inmunología , Enfermedad de Chagas/inmunología , Peritoneo/citología , Peritoneo/inmunología , Células Plasmáticas/citología , Células Plasmáticas/inmunología , Trypanosoma cruzi/inmunología , Animales , Antígenos CD19/inmunología , Diferenciación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Cinética , Ratones , Ratones Endogámicos BALB C , Células Plasmáticas/metabolismo , Sindecano-1/análisis , Factores de Transcripción/genética , Factores de Transcripción/inmunología , Trypanosoma cruzi/aislamiento & purificación

RESUMEN

Proteinase-activated receptors (PAR) are widely recognized for their modulatory properties in inflammatory and immune responses; however, their direct role on phagocyte effector functions remains unknown. S100A9, a protein secreted during inflammatory responses, deactivates activated peritoneal macrophages, and its C-terminal portion inhibits spreading and phagocytosis of adherent peritoneal cells. Herein, the effect of PAR1 and PAR2 agonists was investigated on spreading and phagocytosis by adherent peritoneal cells, as well as the ability of murine C-terminal of S100A9 peptide (mS100A9p) to modulate this effect. Adherent peritoneal cells obtained from mouse abdominal cavity were incubated with PAR1 and PAR2 agonists and spreading and phagocytosis of Candida albicans particles were evaluated. PAR1 agonists increased both the spreading and the phagocytic activity, but PAR2 agonists only increased the spreading index. mS100A9p reverted both the increased spreading and phagocytosis induced by PAR1 agonists, but no interference in the increased spreading induced by PAR2 agonists was noticed. The shorter homologue peptide to the C-terminal of mS100A9p, corresponding to the H(92)-E(97) region, also reverted the increased spreading and phagocytosis induced by PAR1 agonists. These findings show that proteinase-activated receptors have an important role for spreading and phagocytosis of adherent peritoneal cells, and that the peptide corresponding to the C-terminal of S100A9 protein is a remarkable candidate for use as a novel compound to modulate PAR1 function.

Asunto(s)

Calgranulina B/química , Forma de la Célula/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Peritoneo/citología , Fagocitosis/efectos de los fármacos , Receptor PAR-1/metabolismo , Receptor PAR-2/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Calgranulina B/metabolismo , Bovinos , Adhesión Celular , Tamaño de la Célula/efectos de los fármacos , Masculino , Ratones , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Peritoneo/metabolismo , Receptor PAR-1/agonistas , Receptor PAR-1/química , Receptor PAR-2/agonistas , Receptor PAR-2/química , Homología de Secuencia de Aminoácido , Zinc/metabolismo

RESUMEN

Lipopolysaccharide (LPS) from gram-negative bacteria activates B cells, enabling them to proliferate and differentiate into plasma cells. This response is critically dependent on the expression of TLR4; but other genes, such as RP105 and MHC class II, have also been shown to contribute to B cell LPS response. Here, we have evaluated the role of genetic control of the B cell response to LPS at the single cell level. We compared the response to LPS of peritoneal cavity (PEC) and splenic B cells on the BALB/c genetic background (LPS-low responder) to those on the C57BL/6J background (LPS-high responder) and their F1 progeny (CB6F1). Both PEC and splenic B cells from B6 exhibited 100% clonal growth in the presence of LPS; whereas, BALB/c PEC and splenic B cells achieved only 50% and 23% clonal growth, respectively. Adding CpG to the LPS stimulus pushed PEC B cell clonal growth in the low responder strain BALB/c up to 90%, showing that the nonresponse to LPS is a specific effect. Surprisingly, PEC B cells on the F1 background behaved as high responders, while splenic B cells behaved as low responders to LPS. The data presented here reveals a previous unsuspected behavior in the genetic control of the B cell response to LPS with an opposing impact in splenic versus peritoneal cavity B cells. These results suggest the existence of an, as yet, unidentified genetic factor exclusively expressed by coelomic B cells that contributes to the control of the LPS signaling pathway in the B lymphocyte.

Asunto(s)

Linfocitos B/inmunología , Regulación de la Expresión Génica , Lipopolisacáridos/inmunología , Peritoneo/inmunología , Bazo/citología , Animales , Linfocitos B/metabolismo , Cruzamientos Genéticos , Femenino , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Peritoneo/citología , Bazo/inmunología

RESUMEN

This study describes the first days of Taenia crassiceps infection in BALB/c substrains, BALB/cAnN and BALB/cJ, using two stocks of the same strains which were kept in different animal facilities, conventional and pathogen-free conditions, respectively. This study shows that parasite growth restriction shown by conventional BALB/cJ mice changed to parasite growth permissiveness when pathogen-free BALB/cJ mice were used. In addition, the higher number of macrophages, NK cells and intraperitoneal level of IFN-gamma found in the conventional restrictive BALB/cJ substrain vanished when the permissiveness to the parasite growth increased. No differences were found in DNA sequences of parasites collected before and after the change in the permissiveness to parasite growth which favors the possibility that the observed modifications could be due to changes in the murine strains and/or their maintenance conditions.

Asunto(s)

Cisticercosis/inmunología , Cysticercus/crecimiento & desarrollo , Animales , Cisticercosis/parasitología , Cysticercus/genética , Cysticercus/inmunología , ADN de Helmintos/química , ADN Intergénico/química , Femenino , Citometría de Flujo , Interferón gamma/metabolismo , Ratones , Ratones Endogámicos BALB C , Peritoneo/citología , Peritoneo/inmunología , Polimorfismo Genético , Organismos Libres de Patógenos Específicos

RESUMEN

Extracellular galectin-3 participates in the control of B2 lymphocyte migration and adhesion and of their differentiation into plasma cells. Here, we analyzed the role of galectin-3 in B1-cell physiology and the balance between B1a and B1b lymphocytes in the peritoneal cavity. In galectin-3(-/-) mice, the total number of B1a lymphocytes was lower, while B1b lymphocyte number was higher as compared to wild-type mice. The differentiation of B1a cells into plasma cells was associated with their abnormal adhesion and location on the mesentery. The B220 and CD43, constitutively expressed by B1 lymphocytes, were respectively up- and downregulated in galectin-3(-/-) mice. Mononuclear cells were strongly adhered to the mesenteric membranes of both CD43(-/-) and galectin-3(-/-) mice, but in contrast to CD43(-/-) mice, the accumulation of B1 cells in peritoneal membranes in galectin-3(-/-) mice was accompanied by their functional differentiation into plasma cells. We have shown that in the absence of galectin-3, B1-cell differentiation into plasma cells is favored and the dynamic equilibrium of B1-cell populations in the peritoneum is maintained through a compensatory increase in B1b lymphocytes.

Asunto(s)

Diferenciación Celular , Galectina 3/metabolismo , Peritoneo/citología , Células Plasmáticas/citología , Células Plasmáticas/metabolismo , Animales , Galectina 3/deficiencia , Ratones , Ratones Noqueados