RESUMEN

Angiostrongylus cantonensis is the main cause of human eosinophilic meningitis. Humans are accidental hosts, becoming infected due to ingestion of raw intermediate (snails and slugs) or paratenic hosts. Once ingested, the larvae migrate towards the brain where they die, causing the disease. To develop better mollusk control strategies, it is important to first understand what happens in the snail during infection, therefore our purpose was to characterize proteomic, metabolic and immunologic changes in Biomphalaria glabrata 24 h after infection with A. cantonensis. For this purpose, proteins were extracted from infected and uninfected snails and analyzed through mass spectrometry. Hemolymph was also collected, the number of hemocytes was counted and urea, nitric oxide, calcium, glycogen levels as well as alanine and aspartate aminotransferases activities were assessed. The cephalopodal region and gonad-digestive gland complex were dissected and their glycogen content was measured. After infection with A. cantonensis, we observed an increase of hemocytes and granulocytes as well as an increase in hemoglobin type 2 proteins. Temptin-like protein was also found up-regulated in infected snails. Several proteins with structural function (such as myosin heavy chain - striated muscle - like and protein LOC106059779 with ADAM/reprosolin domain) were also differentially expressed, suggesting loss/damage of internal tissues. Increase in phosphoglycerate mutase indicates an increase in glycolysis, possible to compensate the increase in energetic needs. Consequently, there is a decrease in glycogen reserves, particularly in the gonad - digestive gland complex.

Asunto(s)

Biomphalaria/parasitología , Proteómica/métodos , Infecciones por Strongylida/metabolismo , Animales , Hemolinfa/química , Interacciones Huésped-Parásitos , Humanos , Ratas , Ratas Wistar

RESUMEN

Background: It has been shown that dietary protein supplementation during lactation boosts immunity in Nippostrongylus brasiliensis-infected periparturient rats. It is not known whether body protein reserves accumulated during gestation have a similar effect during lactation. Objective: This study aimed to quantify the impact of body protein reserves and dietary protein supplementation on maternal performance and immune responses to N. brasiliensis during lactation. Methods: Multiparous female Sprague-Dawley rats were administered a primary infection of N. brasiliensis before mating and were restriction-fed either 60 g [low-protein diet gestation (Lge)] or 210 g [high-protein diet gestation (Hge)] crude protein (CP) per kilogram of dry matter (DM) until parturition. From parturition onward, dams were restriction-fed either 100 g [low-protein diet lactation (Lla)] or 300 g [high-protein diet lactation (Hla)] CP per kilogram of DM, generating 4 different dietary treatments. A subset of rats was sampled before parturition; postparturition, dams were secondarily infected with N. brasiliensis and samples were collected at days 5 and 11 postparturition. Results: Maternal performance until parturition, as measured by pup weight, was better in Hge rats than in Lge rats [Lge: 4.84 g; Hge: 6.15 g; standard error of the difference (SED): 0.19]. On day 11, pup weights of dams with reduced protein reserves fed protein during lactation (Lge-Hla; 20.28 g) were higher than their counterparts from Hge-Lla dams (17.88 g; SED: 0.92). Worm counts were significantly different between Lge-Lla-fed (253; 95% CI: 124, 382) and Hge-Hla-fed (87; 95% CI: 22, 104) dams on day 11 (P = 0.024). The expression of splenic interleukin 13 (Il13) and arachidonate 15-lipoxygenase (Alox15) was significantly higher (P < 0.05) in Hge-Hla dams compared with Lge-Lla dams on day 5. Conclusions: Although protein reserves were adequate to maintain maternal performance in the early stage of lactation in dams infected with N. brasiliensis, they were not adequate to maintain maternal performance and effective immune responses at later stages. Dietary protein supplementation was required to achieve this.

Asunto(s)

Animales Recién Nacidos/crecimiento & desarrollo , Proteínas en la Dieta/metabolismo , Inmunidad , Lactancia , Fenómenos Fisiologicos Nutricionales Maternos , Nippostrongylus/crecimiento & desarrollo , Infecciones por Strongylida/metabolismo , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Araquidonato 15-Lipooxigenasa/metabolismo , Peso Corporal/efectos de los fármacos , Dieta con Restricción de Proteínas , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/farmacología , Suplementos Dietéticos , Femenino , Interleucina-13/metabolismo , Fenómenos Fisiologicos Nutricionales Maternos/inmunología , Embarazo , Ratas Sprague-Dawley , Bazo/efectos de los fármacos , Bazo/metabolismo

RESUMEN

Despite increased appreciation for the role of nicotinic receptors in the modulation of and response to inflammation, the contribution of muscarinic receptors to mucosal homeostasis, clearance of enteric pathogens, and modulation of immune cell function remains relatively undefined. Uninfected and Nippostrongylus brasiliensis-infected wild-type and type 3 muscarinic receptor (M3R)-deficient (Chrm3(-/-)) mice were studied to determine the contribution of M3R to mucosal homeostasis as well as host defense against the TH2-eliciting enteric nematode N. brasiliensis Intestinal permeability and expression of TH1/TH17 cytokines were increased in uninfected Chrm3(-/-) small intestine. Notably, in Chrm3(-/-) mice infected with N. brasiliensis, small intestinal upregulation of TH2 cytokines was attenuated and nematode clearance was delayed. In Chrm3(-/-) mice, TH2-dependent changes in small intestinal function including smooth muscle hypercontractility, increased epithelial permeability, decreased epithelial secretion and absorption, and goblet cell expansion were absent despite N. brasiliensis infection. These findings identify an important role for M3R in host defense and clearance of N. brasiliensis, and support the expanding role of cholinergic muscarinic receptors in maintaining mucosal homeostasis.

Asunto(s)

Citocinas/metabolismo , Inmunidad Mucosa , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Nippostrongylus/patogenicidad , Receptor Muscarínico M3/metabolismo , Infecciones por Strongylida/metabolismo , Células Th2/metabolismo , Animales , Células Cultivadas , Citocinas/inmunología , Modelos Animales de Enfermedad , Predisposición Genética a la Enfermedad , Homeostasis , Interacciones Huésped-Patógeno , Mucosa Intestinal/inmunología , Mucosa Intestinal/parasitología , Intestino Delgado/inmunología , Intestino Delgado/parasitología , Activación de Macrófagos , Macrófagos/inmunología , Macrófagos/metabolismo , Macrófagos/parasitología , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Noqueados , Nippostrongylus/inmunología , Fenotipo , Receptor Muscarínico M3/deficiencia , Receptor Muscarínico M3/genética , Infecciones por Strongylida/genética , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/parasitología , Células Th2/inmunología , Células Th2/parasitología , Factores de Tiempo

RESUMEN

IL-13 driven Th2 immunity is indispensable for host protection against infection with the gastrointestinal nematode Nippostronglus brasiliensis. Disruption of CD28 mediated costimulation impairs development of adequate Th2 immunity, showing an importance for CD28 during the initiation of an immune response against this pathogen. In this study, we used global CD28⁻/⁻ mice and a recently established mouse model that allows for inducible deletion of the cd28 gene by oral administration of tamoxifen (CD28(-/lox)Cre⁺/⁻+TM) to resolve the controversy surrounding the requirement of CD28 costimulation for recall of protective memory responses against pathogenic infections. Following primary infection with N. brasiliensis, CD28⁻/⁻ mice had delayed expulsion of adult worms in the small intestine compared to wild-type C57BL/6 mice that cleared the infection by day 9 post-infection. Delayed expulsion was associated with reduced production of IL-13 and reduced serum levels of antigen specific IgG1 and total IgE. Interestingly, abrogation of CD28 costimulation in CD28(-/lox)Cre⁺/⁻ mice by oral administration of tamoxifen prior to secondary infection with N. brasiliensis resulted in impaired worm expulsion, similarly to infected CD28⁻/⁻ mice. This was associated with reduced production of the Th2 cytokines IL-13 and IL-4, diminished serum titres of antigen specific IgG1 and total IgE and a reduced CXCR5⁺ T(FH) cell population. Furthermore, total number of CD4⁺ T cells and B220⁺ B cells secreting Th1 and Th2 cytokines were significantly reduced in CD28⁻/⁻ mice and tamoxifen treated CD28(-/lox)Cre⁺/⁻ mice compared to C57BL/6 mice. Importantly, interfering with CD28 costimulatory signalling before re-infection impaired the recruitment and/or expansion of central and effector memory CD4⁺ T cells and follicular B cells to the draining lymph node of tamoxifen treated CD28(-/lox)Cre⁺/⁻ mice. Therefore, it can be concluded that CD28 costimulation is essential for conferring host protection during secondary N. brasiliensis infection.

Asunto(s)

Antígenos CD28/inmunología , Linfocitos T CD4-Positivos/inmunología , Nippostrongylus , Infecciones por Strongylida/inmunología , Animales , Antígenos CD28/metabolismo , Citometría de Flujo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Infecciones por Strongylida/metabolismo

RESUMEN

Immunity to Nippostrongylus brasiliensis reinfection requires pulmonary CD4⁺ T-cell responses. We examined whether secondary lymphoid recruited or pre-existing lung CD4⁺ T-cell populations coordinated this immunity. To do this, we blocked T-cell egress from lymph nodes using Fingolimod (FTY720). This impaired host ability to resolve a primary infection but did not change effectiveness of recall immunity. Associated with this effective recall immunity was the expansion and T helper type 2 polarization of a pre-existing pulmonary CD4⁺ T-cell population. LTßR-Ig (lymphotoxin beta-receptor fusion protein)-mediated disruption of stromal cell organization of immune cells did not disrupt this recall immunity, suggesting that protection was mediated by a pulmonary interstitial residing CD4⁺ T-cell population. Adoptive transfer of N. brasiliensis-experienced pulmonary CD4⁺ T cells from FTY720-treated wild-type or T-cell interleukin (IL)-4Rα-deficient mice demonstrated protection to be IL-4Rα dependent. These results show that pre-existing CD4⁺ T cells can drive effective recall immunity to N. brasiliensis infection independently of T-cell recruitment from secondary lymphoid organs.

Asunto(s)

Linfocitos T CD4-Positivos/inmunología , Memoria Inmunológica , Subunidad alfa del Receptor de Interleucina-4/metabolismo , Pulmón/inmunología , Pulmón/metabolismo , Nippostrongylus/inmunología , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/metabolismo , Animales , Linfocitos T CD4-Positivos/metabolismo , Movimiento Celular/genética , Movimiento Celular/inmunología , Modelos Animales de Enfermedad , Expresión Génica , Subunidad alfa del Receptor de Interleucina-4/genética , Pulmón/parasitología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Ratones , Ratones Noqueados , Infecciones por Strongylida/genética , Infecciones por Strongylida/parasitología

RESUMEN

Angiostrongylus cantonensis meningitis was first reported in Cuba in 1981, and it was recently reported in South America. The aim of this paper is to evaluate the intrathecal immunoglobulin synthesis patterns from Cuba's and Ecuador's patients with angiostrongyliasis; 8 Ecuadorian patients from two different outbreaks and 28 Cuban patients were studied. Simultaneous blood and cerebrospinal fluid samples were taken. Immunoglobulin (Ig) A, IgM, IgG, and albumin were quantified by radial immunodiffusion. Corresponding Reibergrams were applied. A three-Ig pattern was the most frequent in the two groups, but IgM was presented in all Ecuadorian young mature patients; however, in the Cuban children, only 12 of 28 patients had intrathecal IgM, but about 90% had an IgA and IgG synthesis at time of later puncture. This indicates that, with a larger amount of parasites ingested, clinical symptoms are more severe, and a higher frequency of intrathecal IgM synthesis could be observed. This is discussed as a similarity with the intrathecal IgM synthesis in African trypanosomiasis.

Asunto(s)

Inmunoglobulinas/líquido cefalorraquídeo , Meningitis/líquido cefalorraquídeo , Meningitis/parasitología , Niño , Preescolar , Cuba/epidemiología , Ecuador/epidemiología , Humanos , Inmunoglobulinas/metabolismo , Meningitis/epidemiología , Meningitis/inmunología , Infecciones por Strongylida/líquido cefalorraquídeo , Infecciones por Strongylida/epidemiología , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/metabolismo , Adulto Joven

RESUMEN

Infections with the parasitic helminth, Nippostrongylus brasiliensis, cause changes in rat small intestinal goblet cell mucin, particularly in the peripheral sugar residues of oligosaccharide. These changes may correlate with expulsion. In this study, we examined changes in mucin oligosaccharides caused by primary infection and reinfection with N. brasiliensis, using two monoclonal antibodies, HCM31 and PGM34, that react with sialomucin and sulfomucin, respectively. Enzyme-linked immunosorbent assay of jejunal mucins showed that the relative reactivity of mucins with HCM31, but not PGM34, increased up to 16 days after primary infection and 6 days after reinfection, the times when the worms were expelled from the rats. Immunohistochemical studies confirmed that goblet cells stained with HCM31 greatly increased at the time of worm expulsion. These results indicate that the marked increase observed in HCM31-reactive sialomucins may be related to expulsion of the worms.

Asunto(s)

Parasitosis Intestinales/metabolismo , Yeyuno/metabolismo , Nippostrongylus/fisiología , Sialomucinas/metabolismo , Infecciones por Strongylida/metabolismo , Animales , Anticuerpos Monoclonales/inmunología , Ensayo de Inmunoadsorción Enzimática , Heces/parasitología , Células Caliciformes/metabolismo , Inmunidad Mucosa , Inmunohistoquímica , Parasitosis Intestinales/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/parasitología , Yeyuno/parasitología , Cinética , Lectinas , Masculino , Nippostrongylus/inmunología , Recuento de Huevos de Parásitos , Ratas , Ratas Wistar , Sialomucinas/inmunología , Infecciones por Strongylida/inmunología

RESUMEN

BACKGROUND & AIMS: Visceral hypersensitivity, a hallmark of irritable bowel syndrome, is generally considered to be mechanosensitive in nature and mediated via spinal afferents. Both stress and inflammation are implicated in visceral hypersensitivity, but the underlying molecular mechanisms of visceral hypersensitivity are unknown. METHODS: Mice were infected with Nippostrongylus brasiliensis (Nb) larvae, exposed to environmental stress and the following separate studies performed 3-4 weeks later. Mesenteric afferent nerve activity was recorded in response to either ramp balloon distention (60 mm Hg), or to an intraluminal perfusion of hydrochloric acid (50 mmol/L), or to octreotide administration (2 micromol/L). Intraperitoneal injection of cholera toxin B-488 identified neurons projecting to the abdominal viscera. Fluorescent neurons in dorsal root and nodose ganglia were isolated using laser-capture microdissection. RNA was hybridized to Affymetrix Mouse whole genome arrays for analysis to evaluate the effects of stress and infection. RESULTS: In mice previously infected with Nb, there was no change in intestinal afferent mechanosensitivity, but there was an increase in chemosensitive responses to intraluminal hydrochloric acid when compared with control animals. Gene expression profiles in vagal but not spinal visceral sensory neurons were significantly altered in stressed Nb-infected mice. Decreased afferent responses to somatostatin receptor 2 stimulation correlated with lower expression of vagal somatostatin receptor 2 in stressed Nb-infected mice, confirming a link between molecular data and functional sequelae. CONCLUSIONS: Alterations in the intestinal brain-gut axis, in chemosensitivity but not mechanosensitivity, and through vagal rather than spinal pathways, are implicated in stress-induced postinflammatory visceral hypersensitivity.

Asunto(s)

Encéfalo/fisiología , Intestinos/inervación , Mesenterio/inervación , Nippostrongylus/patogenicidad , Infecciones por Strongylida/metabolismo , Aferentes Viscerales/efectos de los fármacos , Adyuvantes Inmunológicos/farmacología , Animales , Toxina del Cólera/farmacología , Modelos Animales de Enfermedad , Femenino , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/metabolismo , Ganglios Espinales/fisiopatología , Expresión Génica/efectos de los fármacos , Ácido Clorhídrico/farmacología , Mucosa Intestinal/metabolismo , Mesenterio/efectos de los fármacos , Mesenterio/metabolismo , Ratones , Ratones Endogámicos BALB C , Ganglio Nudoso/efectos de los fármacos , Ganglio Nudoso/metabolismo , Ganglio Nudoso/fisiopatología , Octreótido/farmacología , Reacción en Cadena de la Polimerasa , ARN/genética , Receptores de Somatostatina/biosíntesis , Receptores de Somatostatina/genética , Infecciones por Strongylida/parasitología , Infecciones por Strongylida/patología , Nervio Vago/efectos de los fármacos , Nervio Vago/metabolismo , Nervio Vago/fisiopatología , Aferentes Viscerales/metabolismo

RESUMEN

Elimination of the helminth parasite Nippostrongylus brasiliensis from infected mice is mediated by IL-4 or IL-13 and dependent on the IL-4Ralpha chain and the transcription factor Stat6 in non-hematopoietic cells. However, it is not clear which Stat6-dependent effector molecules mediate worm expulsion. We identified intelectin-1 and -2 as Stat6-dependent genes that are induced during infection. Intelectins can bind galactofuranose, a sugar present only in microorganisms and might therefore serve as microbial pattern element. To analyze whether constitutive expression of intelectin-1 or -2 leads to accelerated pathogen clearance, transgenic mice were generated which express high levels of these genes selectively in the lung. Infection with N. brasiliensis or Mycobacterium tuberculosis did not result in accelerated pathogen clearance in transgenic as compared to wild-type mice. Further, no significant modulation of the immune response in lung or lymph nodes was observed. Thus, under these conditions, intelectins did not enhance pathogen clearance.

Asunto(s)

Citocinas/genética , Lectinas/genética , Nippostrongylus/genética , Factor de Transcripción STAT6/fisiología , Infecciones por Strongylida/genética , Animales , Citocinas/biosíntesis , Citocinas/inmunología , Citometría de Flujo , Proteínas Ligadas a GPI , Expresión Génica , Mucosa Intestinal/metabolismo , Lectinas/biosíntesis , Lectinas/inmunología , Pulmón/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , Nippostrongylus/inmunología , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/metabolismo

RESUMEN

Intestinal nematode infection induces marked goblet cell hyperplasia and mucus secretion, but the mechanisms of regulation of the changes still remain to be elucidated. In the present study, epithelial cells were isolated from the rat small intestine at various times after Nippostrongylus brasiliensis infection, and the levels of expression of goblet cell- and mucin glycosylation-related genes were estimated by semi-quantitative reverse transcription (RT)-PCR. Among the genes investigated, mucin core peptide (MUC) 2, sialyltransferase (Siat) 4c and trefoil factor family (TFF) 3 were upregulated as early as 2-4 days post-infection, suggesting that they are associated with an early innate protective response. Seven days post-infection and thereafter, when the nematodes reached maturity, significant upregulation of MUC3, MUC4, resistin-like molecule beta (Relmbeta) and 3O-sulfotransferase (3ST)1 was observed, while 3ST2 expression levels increased after the majority of the worms were expelled from the intestine. Similar alterations of glycosylation-related gene expression were also observed in mast-cell-deficient Ws/Ws rats, suggesting that mast cells in the epithelium are not relevant to the upregulation of these genes. The present finding that the expression level of each goblet cell- or glycosylation-related gene was altered differently during the time course of infection indicates the progression of sequential qualitative changes in the mucus layer after infection.

Asunto(s)

Regulación de la Expresión Génica , Células Caliciformes/parasitología , Parasitosis Intestinales/veterinaria , Mucosa Intestinal/parasitología , Mucinas/metabolismo , Nippostrongylus , Enfermedades de los Roedores/genética , Infecciones por Strongylida/veterinaria , Animales , Glicosilación , Células Caliciformes/metabolismo , Hormonas Ectópicas/genética , Parasitosis Intestinales/genética , Parasitosis Intestinales/metabolismo , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , Intestino Delgado/parasitología , Mucina 2 , Mucina 4 , Mucinas/genética , Neuropéptidos/genética , Ratas , Enfermedades de los Roedores/metabolismo , Sialiltransferasas/genética , Infecciones por Strongylida/genética , Infecciones por Strongylida/metabolismo , Sulfotransferasas/genética , Factor Trefoil-3 , Regulación hacia Arriba , beta-Galactosida alfa-2,3-Sialiltransferasa

RESUMEN

Infection with gastrointestinal nematodes exerts profound effects on both immune and physiological responses of the host. Helminth infection induces a hypercontractility of intestinal smooth muscle that is dependent on the Th2 cytokines, IL-4 and IL-13, and may contribute to worm expulsion. Protease-activated receptors (PARs) are expressed throughout the gut, and activation of PAR-1 was observed in asthma, a Th2-driven pathology. In the current study we investigated the physiologic and immunologic regulation of PAR-1 in the murine small intestine, specifically 1) the effect of PAR-1 agonists on small intestinal smooth muscle contractility, 2) the effects of Nippostrongylus brasiliensis infection on PAR-1 responses, 3) the roles of IL-13 and IL-4 in N. brasiliensis infection-induced alterations in PAR-1 responses, and 4) the STAT6 dependence of these responses. We demonstrate that PAR-1 activation induces contraction of murine intestinal smooth muscle that is enhanced during helminth infection. This hypercontractility is associated with an elevated expression of PAR-1 mRNA and protein. N. brasiliensis-induced changes in PAR-1 function and expression were seen in IL-4-deficient mice, but not in IL-13- or STAT6-deficient mice, indicating the dependence of IL-13 on the STAT6 signaling pathway independent of IL-4.

Asunto(s)

Yeyuno/inmunología , Yeyuno/metabolismo , Nippostrongylus/inmunología , Receptor PAR-1/biosíntesis , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/metabolismo , Animales , Relación Dosis-Respuesta a Droga , Femenino , Interleucina-13/administración & dosificación , Interleucina-13/deficiencia , Interleucina-13/fisiología , Interleucina-4/deficiencia , Interleucina-4/genética , Interleucina-4/fisiología , Yeyuno/efectos de los fármacos , Yeyuno/parasitología , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Oligopéptidos/farmacología , Receptor PAR-1/agonistas , Receptor PAR-1/metabolismo , Factor de Transcripción STAT6/deficiencia , Factor de Transcripción STAT6/genética , Factor de Transcripción STAT6/fisiología , Regulación hacia Arriba/inmunología

RESUMEN

Infection with the nematode Nippostrongylus brasiliensis induces various types of cytological alterations in the intestinal villus epithelium. The aim of this study was to analyse the expression of hexose, peptide and amino acid transporters in the small intestinal epithelium after infection. Brown-Norway rats were infected with 2000 N. brasiliensis L3 larvae and villus epithelial cells were isolated at various time points after infection. Expression of hexose transporters Na(+)/glucose cotransporter SGLT1 and glucose transporter GLUT-1, -2 and -5, a peptide transporter (PepT1) and an amino acid transporter (LAT2) was examined by reverse transcription-PCR, Western blotting or immunohistochemistry. Semi-quantitative reverse transcription-PCR studies of separated jejunal epithelial cells showed that expression levels of GLUT5, PepT1 and LAT2 were significantly decreased 7 and 14 days after infection, while these changes were not observed in the ileal epithelium. Although the apical surface glucose transporter SGLT1 showed no significant alteration in mRNA expression, Western blotting analyses of jejunal epithelial cell lysate showed a marked decrease. Contrary to SGLT1, GLUT5, PepT1 and LAT2, expression of GLUT1, which is essential in maintaining high rates of glucose influx, was significantly up-regulated in the jejunal epithelium 7 and 14 days after infection in reverse transcription-PCR as in Western blotting analyses. Immunohistochemical studies showed that GLUT1 immunoreactivity was localised to the basolateral membrane of intestinal epithelial cells 7 days after infection. These results show that N. brasiliensis infection results in an increase in GLUT1 and a decrease in various hexose, amino acid and peptide transporter expression in jejunal epithelial cells. Up-regulation of GLUT1 might be a compensatory response in injured epithelial cells.

Asunto(s)

Sistema de Transporte de Aminoácidos y+ , Proteínas Portadoras/análisis , Células Epiteliales/metabolismo , Células Epiteliales/parasitología , Intestino Delgado/parasitología , Nippostrongylus , Infecciones por Strongylida/metabolismo , Simportadores , Actinas/análisis , Actinas/genética , Animales , Western Blotting/métodos , Proteínas Portadoras/genética , Cadenas Ligeras de la Proteína-1 Reguladora de Fusión/análisis , Cadenas Ligeras de la Proteína-1 Reguladora de Fusión/genética , Transportador de Glucosa de Tipo 1 , Transportador de Glucosa de Tipo 2 , Transportador de Glucosa de Tipo 5 , Íleon/metabolismo , Íleon/parasitología , Inmunohistoquímica/métodos , Intestino Delgado/metabolismo , Yeyuno/metabolismo , Yeyuno/parasitología , Masculino , Glicoproteínas de Membrana/análisis , Glicoproteínas de Membrana/genética , Proteínas de Transporte de Monosacáridos/análisis , Proteínas de Transporte de Monosacáridos/genética , Transportador de Péptidos 1 , ARN Mensajero/análisis , Ratas , Ratas Endogámicas BN , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transportador 1 de Sodio-Glucosa , ATPasa Intercambiadora de Sodio-Potasio/análisis , ATPasa Intercambiadora de Sodio-Potasio/genética , Timidina Quinasa/análisis , Timidina Quinasa/genética

RESUMEN

Substance P (SP) and its receptors NK1 and NK2 are widely expressed in the intestinal wall by neurones, interstitial cells of Cajal (ICC) and smooth muscle cells. Changes in SP and/or its NK receptors have been documented during experimental inflammation in animals or inflammatory bowel diseases in humans, but the data concern the acute phase of the inflammatory process. We determined immunohistochemically whether NK receptors and SP were altered in the muscle coat during jejunal inflammation induced by the nematode Nippostrongylus brasiliensis and whether these alterations persisted when inflammation had spontaneously resolved 30 days postinfection. An ultrastructural analysis was also conducted on ICC, nerves and muscle. At day 14, when inflammation peaked, there was a reduction in NK1 receptors in myenteric neurones and in SP-immunoreactive nerve endings. There were also ultrastructural anomalies in synaptic vesicles and NK2 receptor loss in the circular muscle layer. The SP decrease persisted at day 30, whereas neurones and circular muscle cells re-expressed NK1 and NK2 receptors, respectively. The ICC at the deep muscular plexus, located near to the inflammatory site, underwent alterations leading to their complete loss at day 30. These morphological changes are probably associated with impairment in tachykinergic control of jejunal functions leading to the alterations of motility and sensitivity to distension already described in these animals.

Asunto(s)

Yeyuno/patología , Nippostrongylus , Receptores de Neuroquinina-1/ultraestructura , Receptores de Neuroquinina-2/ultraestructura , Infecciones por Strongylida/metabolismo , Infecciones por Strongylida/patología , Animales , Células del Tejido Conectivo/metabolismo , Células del Tejido Conectivo/ultraestructura , Inmunohistoquímica , Inflamación/metabolismo , Inflamación/parasitología , Inflamación/patología , Yeyuno/inervación , Yeyuno/metabolismo , Yeyuno/ultraestructura , Masculino , Músculo Liso/inervación , Músculo Liso/metabolismo , Músculo Liso/ultraestructura , Peroxidasa/metabolismo , Ratas , Ratas Wistar , Infecciones por Strongylida/parasitología , Sustancia P/análisis

RESUMEN

The glycosylation alterations of mouse small intestinal mucins during a 12-day infectious cycle caused by the parasite Nippostrongylus brasiliensis have been studied. The guanidinium chloride insoluble mucins were isolated at day 0 to 12 from the small intestine of infected and non-infected C57BL/6 mice. The O-linked oligosaccharides were released by reductive beta-elimination from the mucins and separated into neutral, sialylated and sulfated fractions. All fractions were analyzed by monosaccharide composition analysis and the neutral oligosaccharides were structurally characterized by gas chromatography/mass spectrometry. Two oligosaccharides containing blood group H-type epitopes (Fucalpha1-2Gal-) were transiently expressed with a maximum at day 6. Additional oligosaccharides with the common structure HexNAc-Gal-3GalNAcol were transiently induced with a maximum at day 10. Northern blot analysis on total RNA showed a transient expression at day 4-6 of the Fut2 gene encoding a Fucalpha1-2 fucosyltransferase, probably responsible for the detected blood group H-type epitopes. Comparisons with the corresponding infection in rat studied previously, revealed structurally different alterations, although occurring as transient events in both species. Both showed an induced blood group-type transferase halfway through the infection (a blood group A transferase in rat) and an induced transferase adding a terminal GalNAc (to a sialic acid- containing epitope in rat) towards the end of the infection. These differences between closely related species suggest rapid evolutionary alterations in glycosyltransferase expression.

Asunto(s)

Mucosa Intestinal/metabolismo , Intestinos/parasitología , Mucinas/metabolismo , Nippostrongylus/fisiología , Infecciones por Strongylida/metabolismo , Animales , Secuencia de Carbohidratos , Fucosiltransferasas/genética , Fucosiltransferasas/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Glicosilación , Ratones , Datos de Secuencia Molecular , Mucinas/química , Ácido N-Acetilneuramínico/metabolismo , Oligosacáridos/química , Oligosacáridos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Infecciones por Strongylida/parasitología , Sulfatos/metabolismo

RESUMEN

The sialylation of the oligosaccharides from small-intestinal mucins during a 13-day infectious cycle was studied in Sprague-Dawley rats with the parasite Nippostrongylus brasiliensis. Sialic acid analysis and release, permethylation and analysis by GC-MS of the sialylated oligosaccharides isolated from the 'insoluble' mucin complex revealed a relative decrease (4-7-fold) of N-glycolylneuraminic acid compared with N-acetylneuraminic acid just before parasite expulsion. Northern blots showed that this effect was due to the decreased expression of a hydroxylase converting CMP-N-acetylneuraminic acid into CMP-N-glycolylneuraminic acid. Analysis of other rat strains showed that this parasite infection also caused the same effect in these animals. Detailed analysis of infected Sprague-Dawley rats revealed four sialylated oligosaccharides not found in the uninfected animals. These new oligosaccharides were characterized in detail and all shown to contain the trisaccharide epitope NeuAc/NeuGcalpha2-3(GalNAcbeta1-4)Galbeta1 (where NeuGc is N-glycolyl neuraminic acid). This epitope is similar to the Sd(a)- and Cad-type blood-group antigens and suggests that the infection causes the induction of a GalNAcbeta1-4 glycosyltransferase. This model for an intestinal infection suggests that the glycosylation of intestinal mucins is a dynamic process being modulated by the expression of specific enzymes during an infection process.

Asunto(s)

Mucinas/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Nippostrongylus/fisiología , Oligosacáridos/metabolismo , Infecciones por Strongylida/metabolismo , Animales , Secuencia de Carbohidratos , Cromatografía de Gases y Espectrometría de Masas , Glicosilación , Oxigenasas de Función Mixta/antagonistas & inhibidores , Datos de Secuencia Molecular , Mucina 2 , Ratas , Ratas Sprague-Dawley

RESUMEN

To study the kinetics and the phenotype of the mast cells (MC) arising during infection with the nematode Nippostrongylus brasiliensis, monospecific cDNA probes for nine different MC proteases were used in a Northern blot analysis of RNA from the small intestine of infected rats. The expression was analyzed at four individual time points during infection, day 0 (before infection), and days 7, 12 and 16 post infection. A dramatic increase in mRNA for rat mast cell protease (RMCP)-2, the major mucosal MC protease in the rat, was observed, beginning around day 7 after infection and peaking around day 12. At day 16 the expression was already beginning to decline. An almost identical pattern of mRNA expression was detected for the RMCP-8 subfamily of rat MC proteases (RMCP-8, -9 and -10) and for two additional rat serine proteases, the chymases RMCP-3 and -4. No simultaneous increase in the proteases known to be expressed preferentially by mature connective tissue MC (RMCP-1, -6 and -7) was observed. This is consistent with our finding that the expansion of MC in the intestines of parasite-infected animals was limited, almost exclusively, to the mucosal MC population. However, a minor increase in RMCP-5 and MC carboxypeptidase A (CPA) mRNA was detected at day 12 after infection, suggesting a derivation of mucosal MC from an expanding RMCP-5- and CPA-positive population of MC precursors.

Asunto(s)

Mucosa Intestinal/metabolismo , Nippostrongylus , ARN Mensajero/análisis , Serina Endopeptidasas/genética , Infecciones por Strongylida/metabolismo , Animales , Carboxipeptidasas/genética , Carboxipeptidasas A , Quimasas , Cinética , Masculino , Reacción en Cadena de la Polimerasa , Ratas , Ratas Sprague-Dawley , Triptasas

RESUMEN

Several studies have documented the opiate effects of parasitic infection on experimental animals. The current study examined the relationships between infection with the intestinal nematode, Nippostrongylus brasiliensis with analgesia and activity levels. Male white mice infected with N. brasiliensis displayed a significant increase in thermal latency thresholds that rose through the duration of infection and subsided with its termination. Analgesia first became apparent on day three-post infection but did not reach statistical significance (p < 0.05) until day 7 post infection. The maximum analgesia was reached on day 8-post infection and gradually declined. By day 15 post infection, there was no significant difference in the latency times between control and infected mice. The initial significant difference in latency roughly corresponded with the onset of egg production by the parasite. The peak difference in latency times and their subsequent decline also parallels peak egg production and the decline in egg production as the infection subsided. Both naloxone and naltrindole significantly reduced the latency times (p < 0.05) of infected mice. There was also a significant difference in total ambulatory activity levels between infected and control mice. Activity levels began to decline on the second day post infection but did not reach a statistically significant difference (p < 0.05) from the controls until 9th day post infection. Infected mice that were injected with either naloxone or naltrindole had a significantly higher activity level than the infected mice injected with saline.

Asunto(s)

Conducta Animal/fisiología , Nippostrongylus , Receptores Opioides/fisiología , Infecciones por Strongylida/metabolismo , Infecciones por Strongylida/psicología , Animales , Inyecciones Intraperitoneales , Masculino , Ratones , Ratones Endogámicos ICR , Actividad Motora/fisiología , Naloxona/administración & dosificación , Naloxona/farmacología , Naltrexona/administración & dosificación , Naltrexona/análogos & derivados , Naltrexona/farmacología , Antagonistas de Narcóticos/administración & dosificación , Antagonistas de Narcóticos/farmacología , Tiempo de Reacción/efectos de los fármacos , Receptores Opioides mu/antagonistas & inhibidores , Receptores sigma/antagonistas & inhibidores

RESUMEN

Ws/Ws rats are deficient in both mucosal- and connective tissue-type mast cells. To study the role of mast cells in active anaphylaxis, changes in vascular permeability in the trachea upon intravenous antigen challenge with Evans blue dye were examined in Ws/Ws, heterogenic Ws/+, and normal +/ + rats sensitized with the nematode Nippostrongylus brasiliensis. Antigen challenge resulted in fatal anaphylactic shock in some +/+ and Ws/+ rats, but not in Ws/Ws rats. Marked dye leakage developed within 30 min in the trachea of +/+ and Ws/+ rats, while Ws/Ws rats showed no substantial increases in the levels of vascular permeability. Ex vivo stimulation of sensitized lung fragments from +/+ animals with specific antigen induced significant releases of histamine and leukotriene (LT) C4, while sensitized Ws/Ws rat-lung fragments did not. In Ws/Ws rats, levels of nematode-specific IgE, IgG1 and IgG2a antibodies as well as levels of lung eosinophilia were not significantly different from those in +/+ rats. These results show that mast cell-deficient Ws/Ws rats fail to develop active anaphylaxis, and this is mediated probably by the lack of mast cell-derived mediators required for initiation of the reaction.

Asunto(s)

Anafilaxia/inmunología , Anafilaxia/parasitología , Pulmón/inmunología , Pulmón/parasitología , Mastocitos/inmunología , Mastocitos/parasitología , Nippostrongylus/inmunología , Animales , Anticuerpos Antihelmínticos/biosíntesis , Anticuerpos Antihelmínticos/sangre , Antígenos Helmínticos/inmunología , Permeabilidad Capilar , Recuento de Células , Liberación de Histamina , Inmunización , Leucotrieno C4/metabolismo , Pulmón/metabolismo , Pulmón/patología , Mastocitos/patología , Ratas , Ratas Mutantes , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/metabolismo , Infecciones por Strongylida/patología , Tráquea/irrigación sanguínea

RESUMEN

The influence of parasitism on host biogenic amine levels was investigated in Nippostrongylus brasiliensis infected rats. Amine levels were estimated in tissues surrounding Nematods in their biological environment: the lung and intestinal mucus. D0 being the day of infestation, tissues were obtained at 24, 30 and 45 hrs, and every day between D4 and D14 (when the rat was completely deparasited by the self-cure phenomenon). Biogenic amines belonging to the serotoninergic pathway were quantified by HPLC with electrochemical detection. In the lungs and mucus, parasitism resulted in an important decrease in serotonine (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) levels, as opposed to the immediate 5-HT precursor, the 5-hydroxy-tryptophane (5-HTP). Host response to parasitism is translated by serotoninergic pathway levels. This leads to two hypotheses: 5-HT turn-over may be accelerated, but the inhibition of 5-HT synthetic enzyme, 5-hydroxytryptophane hydroxylase, by the parasite present in the host seems more probable.

Asunto(s)

Mucosa Intestinal/metabolismo , Pulmón/metabolismo , Nippostrongylus , Serotonina/metabolismo , Infecciones por Strongylida/metabolismo , Animales , Ácido Hidroxiindolacético/metabolismo , Masculino , Ratas , Ratas Wistar

RESUMEN

The effects of a parasitic infection with the nematode Nippostrongylus brasiliensis on the degradation rates of cytoplasmic tRNA, rRNA and mRNA in rats have been investigated by measuring the renal excretion rates of the modified RNA catabolites N6-threoninocarbonyladenosine, pseudouridine and 7-methylguanine. Between days 9 and 13 post-infection when the expulsion of N. brasiliensis is usually the most pronounced, the degradation rates of the different RNA classes were significantly higher than in the control rats (P < 0.05) by, on average, +24% (tRNA), +34% (rRNA) and +26% (mRNA). We suspect that the elevated degradation rates of RNA are related to an increased production of reactive oxygen species by the host during the expulsion of N. brasiliensis.

Asunto(s)

Nippostrongylus/fisiología , ARN Mensajero/metabolismo , ARN Ribosómico/metabolismo , ARN de Transferencia/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Infecciones por Strongylida/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Interacciones Huésped-Parásitos , Masculino , ARN Mensajero/orina , ARN Ribosómico/orina , ARN de Transferencia/orina , Ratas , Ratas Wistar , Estadísticas no Paramétricas , Infecciones por Strongylida/genética , Infecciones por Strongylida/parasitología , Infecciones por Strongylida/orina