RESUMEN
Cytokines are typically single gene products, except for the heterodimeric interleukin (IL)-12 family. The two subunits (IL-12p40 and IL-12p35) of the prototype IL-12 are known to be simultaneously co-expressed in activated myeloid cells, which secrete the fully active heterodimer to promote interferon (IFN)γ production in innate and adaptive cells. We find that chimeric mice containing mixtures of cells that can only express either IL-12p40 or IL-12p35, but not both together, generate functional IL-12. This alternate two-cell pathway requires IL-12p40 from hematopoietic cells to extracellularly associate with IL-12p35 from radiation-resistant cells. The two-cell mechanism is sufficient to propel local T cell differentiation in sites distal to the initial infection and helps control systemic dissemination of a pathogen, although not parasite burden, at the site of infection. Broadly, this suggests that early secretion of IL-12p40 monomers by sentinel cells at the infection site may help prepare distal host tissues for potential pathogen arrival.
Asunto(s)
Células Dendríticas/metabolismo , Subunidad p35 de la Interleucina-12/metabolismo , Subunidad p40 de la Interleucina-12/metabolismo , Leishmania major/patogenicidad , Leishmaniasis Cutánea/metabolismo , Células del Estroma/metabolismo , Linfocitos T/metabolismo , Animales , Comunicación Celular , Células Dendríticas/inmunología , Células Dendríticas/parasitología , Modelos Animales de Enfermedad , Femenino , Interacciones Huésped-Parásitos , Interferón gamma/metabolismo , Subunidad p35 de la Interleucina-12/genética , Subunidad p40 de la Interleucina-12/genética , Leishmania major/inmunología , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/parasitología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Multimerización de Proteína , Transducción de Señal , Células del Estroma/inmunología , Células del Estroma/parasitología , Linfocitos T/inmunología , Linfocitos T/parasitologíaRESUMEN
After infection with Trypanosoma cruzi, the etiologic agent of Chagas disease, immunosuppression, and apoptosis of mature lymphocytes contribute to the establishment of the parasite in the host and thereby to persistence and pathology in the chronic stage of infection. In a systemic mouse model of experimental Chagas disease, we have demonstrated a strong depletion of mature B cells in the spleen during the first 2 weeks of infection. Remarkably, the decrease in this cell population commenced already in the bone marrow from infected mice and was a concomitant of an increased apoptosis in pro- and pre-B cell populations. Pro- and pre-B cells in the bone marrow showed a significant reduction accompanied by a functional disturbance of bone marrow-derived stromal cells resulting in diminished levels of IL-7, an essential factor for the development of B cell precursors. Ex vivo, stromal cells isolated from the bone marrow of infected mice had a strikingly impaired capacity to maintain the development of pro- and pre-B cells obtained from uninfected animals. Together, the reduction of an active humoral immune response during acute Chagas disease suggests to be an initial immune evasion mechanism of the parasite to establish persistent infection. Therefore, prevention of B cell depletion by rescuing the stromal cells during this early phase, could give rise to new therapeutic approaches.
Asunto(s)
Células de la Médula Ósea/inmunología , Enfermedad de Chagas/inmunología , Tolerancia Inmunológica , Trypanosoma cruzi/inmunología , Enfermedad Aguda , Animales , Apoptosis/inmunología , Células de la Médula Ósea/parasitología , Células de la Médula Ósea/patología , Enfermedad de Chagas/parasitología , Enfermedad de Chagas/patología , Enfermedad Crónica , Interleucina-7/inmunología , Ratones , Células Precursoras de Linfocitos B/inmunología , Células Precursoras de Linfocitos B/parasitología , Células Precursoras de Linfocitos B/patología , Bazo/inmunología , Bazo/parasitología , Bazo/patología , Células del Estroma/inmunología , Células del Estroma/parasitología , Células del Estroma/patologíaRESUMEN
Gender-associated differences in the outcome of infections are well known. Apart from behavior-released differences in their incidence, immunological factors also contribute to disease outcome. The underlying mechanisms are often unknown. Here, we show that in murine experimental leishmaniasis, female mice develop larger skin lesions that harbor significantly more parasites, exhibit increased parasite dissemination to visceral organs associated with a shift towards T helper (Th) 2 immunity with increased levels of IL-4. Antigen presenting cells (APC) responsible for T cell priming, such as macrophages or dendritic cells, were not involved in the process. Additionally, in adoptive transfer experiments, we show that differences in the lymphoid lineage are also not critical for mediating these gender-dependent effects. In summary, neither myeloid nor lymphoid cells contribute to disease outcome against this important human pathogen, but stromal cells influenced by e.g. hormonal effects in addition to other parts of the immune system might play a role.
Asunto(s)
Hormonas/metabolismo , Leishmaniasis Cutánea/inmunología , Sexo , Células del Estroma/inmunología , Células Th2/inmunología , Animales , Diferenciación Celular , Linaje de la Célula , Células Cultivadas , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Susceptibilidad a Enfermedades , Femenino , Humanos , Interleucina-4/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Células Mieloides/inmunología , Células Mieloides/parasitología , Células del Estroma/parasitología , Balance Th1 - Th2 , Células Th2/parasitologíaRESUMEN
While Trichomonas vaginalis, a cause of sexually transmitted infection, is known as a surface-dwelling protozoa, trichomonads have been detected in prostatic tissue from benign prostatic hyperplasia and prostatitis by immunoperoxidase assay or PCR. However, the immune response of prostate stromal cells infected with T. vaginalis has not been investigated. Our objective was to investigate whether T. vaginalis could induce an inflammatory response in prostate stromal cells. Incubation of a human prostate stromal myofibroblast cells (WPMY-1) with live T. vaginalis T016 increased expression of the inflammatory chemokines CXCL8 and CCL2. In addition, TLR4, ROS, MAPK and NF-κB expression increased, while inhibitors of TLR4, ROS, MAPKs and NF-κB reduced CXCL8 and CCL2 production. Medium conditioned by incubation of WPMY-1 cells with T. vaginalis stimulated the migration of human neutrophils and monocytes (THP-1 cells). We conclude that T. vaginalis increases CXCL8 and CCL2 production by human prostate stromal cells by activating TLR4, ROS, MAPKs and NF-κB, and this in turn attracts neutrophils and monocytes and leads to an inflammatory response. This study is the first attempt to demonstrate an inflammatory reaction in prostate stromal cells caused by T. vaginalis.
Asunto(s)
Próstata/patología , Trichomonas vaginalis/inmunología , Línea Celular , Movimiento Celular , Quimiocina CCL2/biosíntesis , Femenino , Humanos , Mediadores de Inflamación/metabolismo , Interleucina-8/biosíntesis , Masculino , Miofibroblastos/inmunología , Miofibroblastos/metabolismo , Miofibroblastos/parasitología , FN-kappa B/metabolismo , Neutrófilos/fisiología , Próstata/inmunología , Próstata/parasitología , Especies Reactivas de Oxígeno/metabolismo , Células del Estroma/metabolismo , Células del Estroma/parasitología , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismo , Tricomoniasis/inmunología , Tricomoniasis/parasitologíaRESUMEN
Cellular culture infection with Trypanosoma cruzi is a tool used to dissect the biological mechanisms behind Chagas disease as well as to screen potential trypanocidal compounds. Data on these models are highly heterogeneous, which represents a challenge when attempting to compare different studies. The purpose of this review is to provide an overview of the cell culture infectivity assays performed to date. Scientific journal databases were searched for articles in which cultured cells were infected with any Trypanosoma cruzi strain or isolate regardless of the study's goal. From these articles the cell type, parasite genotype, culture conditions and infectivity results were extracted. This review represents an initial step toward the unification of infectivity model data. Important differences were detected when comparing the pathophysiology of Chagas disease with the experimental conditions used in the analyzed studies. While Trypanosoma cruzi preferentially infects stromal cells in vivo, most of the assays employ epithelial cell lines. Furthermore, the most commonly used parasite strain (Tulahuen-TcVI) is associated with chagasic cardiomyopathy only in the Southern Cone of South America. Suggestions to overcome these discrepancies include the use of stromal cell lines and parasite genotypes associated with the known characteristics of the natural history of Chagas disease.
Asunto(s)
Células Cultivadas/parasitología , Enfermedad de Chagas/parasitología , Parasitología/métodos , Trypanosoma cruzi/crecimiento & desarrollo , Animales , Bovinos , Técnicas de Cultivo de Célula , Cardiomiopatía Chagásica/parasitología , Células Epiteliales/parasitología , Genotipo , Haplorrinos , Humanos , Riñón/citología , Mamíferos , Células del Estroma/parasitología , Trypanosoma cruzi/genética , Trypanosoma cruzi/patogenicidadRESUMEN
CD4(+) Th2 cytokine responses promote the development of allergic inflammation and are critical for immunity to parasitic helminth infection. Recent studies highlighted that basophils can promote Th2 cytokine-mediated inflammation and that phenotypic and functional heterogeneity exists between classical IL-3-elicited basophils and thymic stromal lymphopoietin (TSLP)-elicited basophils. However, whether distinct basophil populations develop after helminth infection and their relative contributions to anti-helminth immune responses remain to be defined. After Trichinella spiralis infection of mice, we show that basophil responses are rapidly induced in multiple tissue compartments, including intestinal-draining lymph nodes. Trichinella-induced basophil responses were IL-3-IL-3R independent but critically dependent on TSLP-TSLPR interactions. Selective depletion of basophils after Trichinella infection impaired infection-induced CD4(+) Th2 cytokine responses, suggesting that TSLP-dependent basophils augment Th2 cytokine responses after helminth infection. The identification and functional classification of TSLP-dependent basophils in a helminth infection model, coupled with their recently described role in promoting atopic dermatitis, suggests that these cells may be a critical population in promoting Th2 cytokine-associated inflammation in a variety of inflammatory or infectious settings. Collectively, these data suggest that the TSLP-basophil pathway may represent a new target in the design of therapeutic intervention strategies to promote or limit Th2 cytokine-dependent immunity and inflammation.
Asunto(s)
Basófilos/inmunología , Citocinas/biosíntesis , Mucosa Intestinal/inmunología , Células Th2/inmunología , Timo/inmunología , Trichinella spiralis/inmunología , Triquinelosis/inmunología , Animales , Basófilos/parasitología , Basófilos/patología , Citocinas/fisiología , Inflamación/inmunología , Inflamación/metabolismo , Inflamación/parasitología , Mucosa Intestinal/parasitología , Mucosa Intestinal/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Células del Estroma/inmunología , Células del Estroma/parasitología , Células del Estroma/patología , Células Th2/parasitología , Células Th2/patología , Timo/parasitología , Timo/patología , Triquinelosis/metabolismo , Triquinelosis/patología , Linfopoyetina del Estroma TímicoRESUMEN
Inflammation alters hematopoiesis, often by decreasing erythropoiesis and enhancing myeloid output. The mechanisms behind these changes and how the BM stroma contributes to this process are active areas of research. In this study, we examine these questions in the setting of murine Toxoplasma gondii infection. Our data reveal that infection alters early myeloerythroid differentiation, blocking erythroid development beyond the Pre MegE stage, while expanding the GMP population. IL-6 was found to be a critical mediator of these differences, independent of hepcidin-induced iron restriction. Comparing the BM with the spleen showed that the hematopoietic response was driven by the local microenvironment, and BM chimeras demonstrated that radioresistant cells were the relevant source of IL-6 in vivo. Finally, direct ex vivo sorting revealed that VCAM(+)CD146(lo) BM stromal fibroblasts significantly increase IL-6 secretion after infection. These data suggest that BMSCs regulate the hematopoietic changes during inflammation via IL-6.
Asunto(s)
Células Precursoras Eritroides/efectos de los fármacos , Interleucina-6/farmacología , Células Progenitoras Mieloides/efectos de los fármacos , Células del Estroma/efectos de los fármacos , Toxoplasma/efectos de los fármacos , Toxoplasmosis/tratamiento farmacológico , Animales , Médula Ósea/efectos de los fármacos , Médula Ósea/parasitología , Médula Ósea/patología , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Ensayo de Unidades Formadoras de Colonias , Células Precursoras Eritroides/parasitología , Células Precursoras Eritroides/patología , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/parasitología , Hematopoyesis/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/parasitología , Células Madre Hematopoyéticas/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Células Progenitoras Mieloides/parasitología , Células Progenitoras Mieloides/patología , Células del Estroma/parasitología , Células del Estroma/patología , Toxoplasma/patogenicidad , Toxoplasmosis/parasitología , Toxoplasmosis/patologíaRESUMEN
In the immune system, stromal cells provide specialized niches that control hematopoiesis by coordinating the production of chemokines, adhesion molecules, and growth factors. Stromal cells also have anti-inflammatory effects, including support for the differentiation of hematopoietic progenitors into dendritic cells (DCs) with immune regulatory properties. Together, these observations suggest that the alterations in hematopoiesis commonly seen in infectious disease models, such as experimental visceral leishmaniasis in mice, might result from altered stromal cell function. We report in this study that the stromal cell-derived chemokines CXCL12 and CCL8 cooperate to attract hematopoietic progenitors with the potential to differentiate into regulatory DCs. We also show that infection of murine bone marrow stromal cells by Leishmania donovani enhanced their capacity to support the development of regulatory DCs, as well as their capacity to produce CCL8. Likewise, in experimental visceral leishmaniasis, CCL8 production was induced in splenic stromal cells, leading to an enhanced capacity to attract hematopoietic progenitor cells. Thus, intracellular parasitism of stromal cells modifies their capacity to recruit and support hematopoietic progenitor differentiation into regulatory DCs, and aberrant expression of CCL8 by diseased stromal tissue may be involved in the switch from resolving to persistent infection.
Asunto(s)
Quimiocina CCL8/metabolismo , Quimiocina CXCL12/metabolismo , Células Dendríticas/metabolismo , Células del Estroma/metabolismo , Animales , Diferenciación Celular , Línea Celular , Células Cultivadas , Quimiocina CCL8/genética , Quimiocina CXCL12/genética , Análisis por Conglomerados , Técnicas de Cocultivo , Cricetinae , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Perfilación de la Expresión Génica , Células Madre Hematopoyéticas/metabolismo , Interacciones Huésped-Patógeno , Leishmania donovani/fisiología , Leishmaniasis Visceral/genética , Leishmaniasis Visceral/metabolismo , Macrófagos/metabolismo , Macrófagos/parasitología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células del Estroma/parasitologíaRESUMEN
Endosymbiotic Wolbachia bacteria are abundant in the filarial nematodes that cause onchocerciasis (river blindness), including the larvae (microfilariae) that migrate into the cornea. Using a mouse model of ocular onchocerciasis, we recently demonstrated that it is these endosymbiotic bacteria rather than the nematodes per se that induce neutrophil infiltration to the corneal stroma and loss of corneal clarity (Saint Andre et al., Science 295:1892-1895, 2002). To better understand the role of Wolbachia organisms in the pathogenesis of this disease, we examined the fate of these bacteria in the cornea by immunoelectron microscopy. Microfilariae harboring Wolbachia organisms were injected into mouse corneas, and bacteria were detected with antibody to Wolbachia surface protein. Within 18 h of injection, neutrophils completely surrounded the nematodes and were in close proximity to Wolbachia organisms. Wolbachia surface protein labeling was also prominent in neutrophil phagosomes, indicating neutrophil ingestion of Wolbachia organisms. Furthermore, the presence of numerous electron-dense granules around the phagosomes indicated that neutrophils were activated. To determine if Wolbachia organisms directly activate neutrophils, peritoneal neutrophils were incubated with either parasite extracts containing Wolbachia organisms, parasite extracts depleted of Wolbachia organisms (by antibiotic treatment of worms), or Wolbachia organisms isolated from filarial nematodes. After 18 h of incubation, we found that isolated Wolbachia organisms stimulated production of tumor necrosis factor alpha and CXC chemokines macrophage inflammatory protein 2 and KC by neutrophils in a dose-dependent manner. Similarly, these cytokines were induced by filarial extracts containing Wolbachia organisms but not by Wolbachia-depleted extracts. Taken together, these findings indicate that neutrophil activation is an important mechanism by which Wolbachia organisms contribute to the pathogenesis of ocular onchocerciasis.
Asunto(s)
Modelos Animales de Enfermedad , Filarioidea/microbiología , Activación Neutrófila , Neutrófilos/inmunología , Neutrófilos/microbiología , Oncocercosis Ocular/inmunología , Wolbachia/inmunología , Animales , Extractos Celulares , Quimiocinas/biosíntesis , Quimiocinas/inmunología , Córnea/inmunología , Córnea/microbiología , Córnea/parasitología , Córnea/patología , Citocinas/biosíntesis , Citocinas/inmunología , Filarioidea/fisiología , Ratones , Neutrófilos/citología , Oncocercosis Ocular/microbiología , Oncocercosis Ocular/parasitología , Oncocercosis Ocular/patología , Fagocitosis , Células del Estroma/inmunología , Células del Estroma/microbiología , Células del Estroma/parasitología , Vacuolas/microbiología , Wolbachia/aislamiento & purificaciónRESUMEN
Infiltration of neutrophils and eosinophils into the mammalian cornea can result in loss of corneal clarity and severe visual impairment. To identify mediators of granulocyte recruitment to the corneal stroma, we determined the relative contribution of chemokine receptors CXC chemokine receptor (CXCR)-2 (IL-8R homologue) and CCR1 using a murine model of ocular onchocerciasis (river blindness) in which neutrophils and eosinophils migrate from peripheral vessels to the central cornea. CXCR2(-/-) and CCR1(-/-) mice were immunized s.c. and injected into the corneal stroma with Ags from the parasitic helminth Onchocerca volvulus. We found that production of macrophage-inflammatory protein (MIP)-2, KC, and MIP-1 alpha was localized to the corneal stroma, rather than to the epithelium, which was consistent with the location of neutrophils in the cornea. CCR1 deficiency did not inhibit neutrophil or eosinophil infiltration to the cornea or development of corneal opacification. In marked contrast, neutrophil recruitment to the corneas of CXCR2(-/-) mice was significantly impaired (p < 0.0001 compared with control, BALB/c mice) with only occasional neutrophils detected in the central cornea. Furthermore, CXCR2(-/-) mice developed only mild corneal opacification compared with BALB/c mice. These differences were not due to impaired KC and MIP-2 production in the corneal stroma of CXCR2(-/-) mice, which was similar to BALB/c mice. Furthermore, although MIP-1 alpha production was lower in CXCR2(-/-) mice than BALB/c mice, eosinophil recruitment to the cornea was not impaired. These observations demonstrate the critical role for CXCR2 expression in neutrophil infiltration to the cornea and may indicate a target for immune intervention in neutrophil-mediated corneal inflammation.
Asunto(s)
Quimiocinas CC/metabolismo , Córnea/inmunología , Queratitis/inmunología , Infiltración Neutrófila/inmunología , Onchocerca volvulus/inmunología , Oncocercosis Ocular/inmunología , Receptores de Quimiocina/biosíntesis , Receptores de Interleucina-8B/biosíntesis , Animales , Anticuerpos Antihelmínticos/biosíntesis , Movimiento Celular/genética , Movimiento Celular/inmunología , Quimiocina CCL4 , Quimiocina CXCL1 , Quimiocina CXCL2 , Quimiocinas/biosíntesis , Quimiocinas CC/biosíntesis , Quimiocinas CXC , Córnea/metabolismo , Córnea/parasitología , Córnea/patología , Opacidad de la Córnea/genética , Opacidad de la Córnea/inmunología , Opacidad de la Córnea/parasitología , Citocinas/biosíntesis , Eosinófilos/inmunología , Eosinófilos/metabolismo , Epitelio Corneal/inmunología , Epitelio Corneal/metabolismo , Epitelio Corneal/parasitología , Inmunoglobulina G/biosíntesis , Queratitis/genética , Queratitis/parasitología , Queratitis/patología , Proteínas Inflamatorias de Macrófagos/biosíntesis , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Oncocercosis Ocular/genética , Oncocercosis Ocular/patología , Receptores CCR1 , Receptores de Quimiocina/deficiencia , Receptores de Quimiocina/genética , Receptores de Interleucina-8B/deficiencia , Receptores de Interleucina-8B/genética , Receptores de Interleucina-8B/fisiología , Células del Estroma/inmunología , Células del Estroma/metabolismo , Células del Estroma/parasitologíaRESUMEN
With the aim of developing an appropriate in vitro model of the sequestration of developing Plasmodium falciparum sexual-stage parasites, we have investigated the cytoadherence of gametocytes to human bone marrow cells of stromal and endothelial origin. Developing stage III and IV gametocytes, but not mature stage V gametocytes, adhere to bone marrow cells in significantly higher densities than do asexual-stage parasites, although these adhesion densities are severalfold lower than those encountered in classical CD36-dependent assays of P. falciparum cytoadherence. This implies that developing gametocytes undergo a transition from high-avidity, CD36-mediated adhesion during stages I and II to a lower-avidity adhesion during stages III and IV. We show that this adhesion is CD36 independent, fixation sensitive, stimulated by tumor necrosis factor alpha, and dependent on divalent cations and serum components. These data suggest that gametocytes and asexual parasites utilize distinct sets of receptors for adhesion during development in their respective sequestered niches. To identify receptors for gametocyte-specific adhesion of infected erythrocytes to bone marrow cells, we tested a large panel of antibodies for the ability to inhibit cytoadherence. Our results implicate ICAM-1, CD49c, CD166, and CD164 as candidate bone marrow cell receptors for gametocyte adhesion.
Asunto(s)
Células de la Médula Ósea/parasitología , Adhesión Celular , Eritrocitos/parasitología , Plasmodium falciparum/crecimiento & desarrollo , Receptores de Superficie Celular/aislamiento & purificación , Animales , Endotelio Vascular/parasitología , Humanos , Reproducción , Células del Estroma/parasitologíaRESUMEN
Alterations in hematopoiesis are common in experimental infectious disease. However, few studies have addressed the mechanisms underlying changes in hematopoietic function or assessed the direct impact of infectious agents on the cells that regulate these processes. In experimental visceral leishmaniasis, caused by infection with the protozoan parasite Leishmania donovani, parasites persist in the spleen and bone marrow, and their expansion in these sites is associated with increases in local hematopoietic activity. The results of this study show that L donovani targets bone marrow stromal macrophages in vivo and can infect and multiply in stromal cell lines of macrophage, but not other lineages in vitro. Infection of stromal macrophages increases their capacity to support myelopoiesis in vitro, an effect mediated mainly through the induction of granulocyte macrophage-colony stimulating factor and tumor necrosis factor-alpha. These data are the first to directly demonstrate that intracellular parasitism of a stromal cell population may modify its capacity to regulate hematopoiesis during infectious disease. (Blood. 2000;95:1642-1651)