RESUMO
Campylobacter jejuni is a commensal in many animals but causes diarrhea in humans. Its polysaccharide capsule contributes to host colonization and virulence in a strain- and model-specific manner. We investigated if the capsule and its heptose are important for interactions of strain NCTC 11168 with various hosts and their innate immune defenses. We determined that they support bacterial survival in Drosophila melanogaster and enhance virulence in Galleria mellonella. We showed that the capsule had limited antiphagocytic activity in human and chicken macrophages, decreased adherence to chicken macrophages, and decreased intracellular survival in both macrophages. In contrast, the heptose increased uptake by chicken macrophages and supported adherence to human macrophages and survival within them. While the capsule triggered nitric oxide production in chicken macrophages, the heptose mitigated this and protected against nitrosative assault. Finally, the C. jejuni strain NCTC 11168 elicited strong cytokine production in both macrophages but quenched ROS production independently from capsule and heptose, and while the capsule and heptose did not protect against oxidative assault, they favored growth in biofilms under oxidative stress. This study shows that the wild-type capsule with its heptose is optimized to resist innate defenses in strain NCTC 11168 often via antagonistic effects of the capsule and its heptose.
Assuntos
Infecções por Campylobacter , Campylobacter jejuni , Humanos , Animais , Drosophila melanogaster , Polissacarídeos , Heptoses , Galinhas , Infecções por Campylobacter/microbiologia , Imunidade InataRESUMO
BACKGROUND: Differences in the reference intervals between dog breeds have been recognized for many years. Due to the importance of multi-drug-resistance 1-deficient (MDR1) Collies in veterinary medicine, it is important to determine whether breed-specific reference intervals are needed for this group. OBJECTIVES: The goal of this study was to establish plasma chemistry reference intervals for adult MDR1-deficient Collies. METHODS: Plasma samples collected from 110 healthy male and female adult MDR1-deficient Collies were analyzed for 21 analytes on a Beckman AU480 clinical chemistry analyzer. Reference intervals were established using a nonparametric statistical method. RESULTS: Reference intervals were established for 21 biochemical measurands in healthy adult MDR1-deficient Collies. CONCLUSION: Plasma chemistry reference intervals for MDR1-deficient Collies were clinically similar to intervals earlier created for Beagles. Intervals for male and female MDR1-deficient Collies were very similar to each other.
Assuntos
Resistência a Múltiplos Medicamentos , Cães , Animais , Feminino , Masculino , Resistência a Múltiplos Medicamentos/genética , Valores de ReferênciaRESUMO
Murine norovirus (MNV) and mouse parvovirus (MPV) are among the most common adventitial viruses seen in laboratory mice, and infections arise in barrier facilities despite rigorous biosecurity programs. Some authors have implicated nonsterilized feed as a source of MPV in rodent facilities, but none have conclusively documented viral particles in the feed. In this study, we hypothesized that both viruses can resist the pelleting process but not subsequent irradiation or autoclaving, thus revealing a potential source of outbreaks in rodent facilities. To test this hypothesis, we contaminated powdered feed with 10-fold concentrations of MNV and MPV and fed it to both Swiss Webster (SW) and C57BL/6NTac (B6) mice to determine a 'powdered ID50' according to seroconversion over a 28-d period. We repeated the experiment by using powdered feed that we contaminated with increasing viral doses (as no. of powdered ID50) and subsequently pelleted; from these results, we determined a 'pelleted ID50.' Finally we assessed the effect of irradiation and autoclaving on contaminated pellets by using the same experimental design. The powdered ID50 was relatively low and identical in both mouse strains (2.51 × 10² pfu) for MNV but higher in B6 (copy number, 3.20 × 106) than SW (3.98 × 104 copies) for MPV. As hypothesized, mice were infected by contaminated rodent feed despite the pelleting process. Indeed, pelleting resulted in a 1- to 2-log increase in ID50 in both strains for MNV and MPV. Irradiation and autoclaving of infected pellets effectively prevented seroconversion of mice exposed to all doses of MNV, whereas a single mouse seroconverted at the highest dose of MPV (1.35 × 107 copies). These data suggest that both MNV and MPV remain infectious after conditions reproducing the rodent chow pelleting process and that nonsterilized rodent chow might be a source of viral outbreaks.
Assuntos
Ração Animal/análise , Infecções por Caliciviridae/veterinária , Norovirus , Infecções por Parvoviridae/veterinária , Parvovirus , Doenças dos Roedores/prevenção & controle , Animais , Infecções por Caliciviridae/prevenção & controle , Manipulação de Alimentos , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Parvoviridae/prevenção & controle , RoedoresRESUMO
We report the identification, pathogenesis, and transmission of a novel polyomavirus in severe combined immunodeficient F344 rats with null Prkdc and interleukin 2 receptor gamma genes. Infected rats experienced weight loss, decreased fecundity, and mortality. Large basophilic intranuclear inclusions were observed in epithelium of the respiratory tract, salivary and lacrimal glands, uterus, and prostate gland. Unbiased viral metagenomic sequencing of lesioned tissues identified a novel polyomavirus, provisionally named Rattus norvegicus polyomavirus 2 (RatPyV2), which clustered with Washington University (WU) polyomavirus in the Wuki clade of the Betapolyomavirus genus. In situ hybridization analyses and quantitative polymerase chain reaction (PCR) results demonstrated viral nucleic acids in epithelium of respiratory, glandular, and reproductive tissues. Polyomaviral disease was reproduced in Foxn1rnu nude rats cohoused with infected rats or experimentally inoculated with virus. After development of RatPyV2-specific diagnostic assays, a survey of immune-competent rats from North American research institutions revealed detection of RatPyV2 in 7 of 1,000 fecal samples by PCR and anti-RatPyV2 antibodies in 480 of 1,500 serum samples. These findings suggest widespread infection in laboratory rat populations, which may have profound implications for established models of respiratory injury. Additionally, RatPyV2 infection studies may provide an important system to investigate the pathogenesis of WU polyomavirus diseases of man.
Assuntos
Infecções por Polyomavirus , Polyomavirus , Infecções Tumorais por Vírus , Animais , Feminino , Pulmão/virologia , Masculino , Metagenômica , Polyomavirus/genética , Polyomavirus/isolamento & purificação , Polyomavirus/patogenicidade , Infecções por Polyomavirus/complicações , Infecções por Polyomavirus/genética , Infecções por Polyomavirus/transmissão , Infecções por Polyomavirus/virologia , Ratos , Análise de Sequência de DNA , Imunodeficiência Combinada Severa/complicações , Distribuição Tecidual , Infecções Tumorais por Vírus/complicações , Infecções Tumorais por Vírus/genética , Infecções Tumorais por Vírus/transmissão , Infecções Tumorais por Vírus/virologia , Carga Viral/genéticaRESUMO
Sampling of bedding debris within the exhaust systems of ventilated racks may be a mechanism for detecting murine pathogens in colony animals. This study examined the effectiveness of detecting pathogens by PCR analysis of exhaust debris samples collected from ventilated racks of 2 different rack designs, one with unfiltered air flow from within the cage to the air-exhaust pathway, and the other had a filter between the cage and the air-exhaust pathway. For 12 wk, racks were populated with either 1 or 5 cages of mice (3 mice per cage) infected with one of the following pathogens: mouse norovirus (MNV), mouse parvovirus (MPV), mouse hepatitis virus (MHV), Helicobacter spp., Pasteurella pneumotropica, pinworms, Entamoeba muris, Tritrichomonas muris, and fur mites. Pathogen shedding by infected mice was monitored throughout the study. In the filter-containing rack, PCR testing of exhaust plenums yielded negative results for all pathogens at all time points of the study. In the rack with open air flow, pathogens detected by PCR analysis of exhaust debris included MHV, Helicobacter spp., P. pneumotropica, pinworms, enteric protozoa, and fur mites; these pathogens were detected in racks housing either 1 or 5 cages of infected mice. Neither MPV nor MNV was detected in exhaust debris, even though prolonged viral shedding was confirmed. These results demonstrate that testing rack exhaust debris from racks with unfiltered air flow detected MHV, enteric bacteria and parasites, and fur mites. However, this method failed to reliably detect MNV or MPV infection of colony animals.
Assuntos
Filtros de Ar/microbiologia , Filtros de Ar/parasitologia , Abrigo para Animais , Infecções/veterinária , Doenças dos Roedores/microbiologia , Doenças dos Roedores/parasitologia , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Infecções/microbiologia , Infecções/parasitologia , Infecções/virologia , Camundongos , Parasitos/classificação , Parasitos/isolamento & purificação , Reação em Cadeia da Polimerase , Doenças dos Roedores/virologia , Vírus/classificação , Vírus/isolamento & purificaçãoRESUMO
Helicobacter spp. are some of the most prevalent bacterial contaminants of laboratory mice. Although abundant data regarding the diseases associated with H. hepaticus infection are available, little is known about the pathogenicity of H. ganmani, which was first isolated in 2001 from the intestines of laboratory mice. The objective of this study was to evaluate the host response to H. ganmani colonization in H. hepaticus disease-resistant C57BL/6 and disease-susceptible A/J and IL10-deficient mice. Mice were inoculated with H. ganmani, H. hepaticus, or Brucella broth. Cecal lesion scores, cecal gene expression, and Helicobacter load were measured at 4 and 90 d after inoculation. At both time points, mice inoculated with H. ganmani had similar or significantly more copies of cecum-associated Helicobacter DNA than did mice inoculated with H. hepaticus. When compared with those of sham-inoculated control mice, cecal lesion scores at 4 and 90 d after inoculation were not significantly greater in H. ganmani-inoculated A/J, C57BL/6, or IL10-deficient mice. Analysis of cecal gene expression demonstrated that H. ganmani infection failed to cause significant elevations of IFNγ in A/J, C57BL/6, or IL10-deficient mice. However, in IL10-deficient mice, H. ganmani infection was associated with a significant increase in the expression of the proinflammatory cytokine IL12/23p40. Although H. ganmani infection in this study failed to induce the typhlitis that is the hallmark of H. hepaticus infection, infection with H. ganmani was associated with alterations in inflammatory cytokines in IL10-deficient mice.
Assuntos
Resistência à Doença/imunologia , Suscetibilidade a Doenças/microbiologia , Regulação da Expressão Gênica/imunologia , Infecções por Helicobacter/imunologia , Infecções por Helicobacter/microbiologia , Interações Hospedeiro-Patógeno/fisiologia , Animais , Carga Bacteriana , Ceco/microbiologia , Ceco/patologia , Infecções por Helicobacter/patologia , Camundongos , Especificidade da EspécieRESUMO
The pathogenesis of inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis, is due in part to interactions between the immune system, genetics, the environment, and endogenous microbiota. Gonadal sex hormones (GSH), such as estrogen, are thought to be involved in the development of IBD as variations in disease severity occur during pregnancy, menopause, or oral contraceptives use. In certain strains of mice, infection with Helicobacter hepaticus triggers IBD-like mucosal inflammation that is more severe in female mice than in males, suggesting a role for GSH in this model. To determine the role of estrogen signaling in microbiota-induced intestinal inflammation, estrogen receptor (ER) α and ß knock-out (KO) mice, ER agonists, and adoptive transfers were utilized. We demonstrate that, when signaling is limited to ERß on a non-CD4+ cell subset, disease is less severe and this correlates with decreased expression of pro-inflammatory mediators.
Assuntos
Estrogênios/metabolismo , Helicobacter/fisiologia , Doenças Inflamatórias Intestinais/microbiologia , Doenças Inflamatórias Intestinais/patologia , Transdução de Sinais , Animais , Modelos Animais de Doenças , Receptor alfa de Estrogênio/deficiência , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/deficiência , Receptor beta de Estrogênio/genética , Feminino , Técnicas de Inativação de Genes , Doenças Inflamatórias Intestinais/genética , CamundongosRESUMO
Commercially available diagnostic tools for the detection of lactate dehydrogenase elevating virus (LDV) infection have been restricted to measurement of serum lactate dehydrogenase (LDH) activity levels and detection of the viral genome by RT-PCR assays. Serologic diagnosis of LDV infection has not been widely adopted due to the belief that the formation of antigen-antibody complexes and B-cell polyclonal activation may confound interpretation of results. In the current study, we inoculated BALB/c, C57BL/6, and Swiss Webster mice with LDV to compare the diagnostic reliability of a commercially available multiplex fluorescent immunoassay for the detection of antiLDV antibodies with that of the LDH enzyme assay. The serologic assay was vastly more sensitive and specific than was the LDH enzyme assay. Moreover, the serologic assay detected antiviral antibodies throughout the 3-mo time course of this study. These results suggest that antigen-antibody complex formation and polyclonal B-cell activation had little effect on assay performance.
Assuntos
Anticorpos Antivirais/sangue , Infecções por Arterivirus/veterinária , Imunoensaio/métodos , Vírus Elevador do Lactato Desidrogenase/isolamento & purificação , Doenças dos Roedores/virologia , Animais , Animais não Endogâmicos , Complexo Antígeno-Anticorpo/imunologia , Infecções por Arterivirus/virologia , Linfócitos B/imunologia , Ensaios Enzimáticos/métodos , Feminino , L-Lactato Desidrogenase/análise , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Reprodutibilidade dos TestesRESUMO
Idiopathic lung lesions characterized by dense perivascular cuffs of lymphocytes and a lymphohistiocytic interstitial pneumonia have been noted in research rats since the 1990s. Although the etiology of this disease has remained elusive, a putative viral etiology was suspected and the term 'rat respiratory virus' (RRV) has been used in reference to this disease agent. The purpose of this study was to determine whether Pneumocystis carinii infection in immunocompetent rats can cause idiopathic lung lesions previously attributed to RRV. In archived paraffin-embedded lungs (n = 43), a significant association was seen between idiopathic lung lesions and Pneumocystis DNA detected by PCR. In experimental studies, lung lesions of RRV developed in 9 of 10 CD rats 5 wk after intratracheal inoculation with P. carinii. No lung lesions developed in CD rats (n = 10) dosed with a 0.22-µm filtrate of the P. carinii inoculum, thus ruling out viral etiologies, or in sham-inoculated rats (n = 6). Moreover, 13 of 16 CD rats cohoused with immunosuppressed rats inoculated with P. carinii developed characteristic lung lesions from 3 to 7 wk after cohousing, whereas no lesions developed in rats cohoused with immunosuppressed sham-inoculated rats (n = 7). Both experimental infection studies revealed a statistically significant association between lung lesion development and exposure to P. carinii. These data strongly support the conclusion that P. carinii infection in rats causes lung lesions that previously have been attributed to RRV.
Assuntos
Pulmão/microbiologia , Pneumocystis carinii , Pneumonia por Pneumocystis/veterinária , Ratos , Doenças dos Roedores/microbiologia , Viroses/veterinária , Animais , Diagnóstico Diferencial , Feminino , Pulmão/patologia , Pulmão/virologia , Pneumonia por Pneumocystis/patologia , Doenças dos Roedores/patologia , Doenças dos Roedores/virologia , Viroses/patologiaRESUMO
Rat theilovirus (RTV) is a cardiovirus related to Theiler's murine encephalomyelitis virus. While RTV is a prevalent viral pathogen of rats used in biomedical research, the pathogenesis and characterization of RTV infections is not well understood. In the studies reported herein, we used immunohistochemistry to identify viral antigens in enterocytes of the small intestines of Sprague-Dawley (SD) rats. Fecal viral shedding in immunocompromised and immunocompetent rats following oral gavage with RTV1 was high for the first 2 weeks of infection with persistent shedding of high viral loads being observed in immunocompromised nude rats but not in immunocompetent rats. RTV was also detected in mesenteric lymph nodes and spleen of immunocompromised rats but not immunocompetent rats. In addition, the magnitude of serum antibody responses differed between immunocompetent rat strains with Brown Norway and SD rats having a significantly higher antibody response than CD or Fischer 344 rats. These data suggest that RTV1 has a tropism for the epithelial cells of the small intestine, immunocompetent rats have differing serum antibody responses to RTV infection, and sustained fecal shedding and extraintestinal dissemination of RTV1 occurs in rats deficient in T cell-dependent adaptive immunity. RTV infection in immunocompromised and immunocompetent rats has merit as a model for further studies of theilovirus pathogenesis following oral viral exposure.
Assuntos
Infecções por Cardiovirus/imunologia , Infecções por Cardiovirus/virologia , Theilovirus/patogenicidade , Tropismo Viral , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/análise , Infecções por Cardiovirus/patologia , Modelos Animais de Doenças , Enterócitos/virologia , Fezes/virologia , Feminino , Hospedeiro Imunocomprometido , Imuno-Histoquímica , Intestino Delgado/virologia , Linfonodos/virologia , Masculino , Ratos , Ratos Endogâmicos F344 , Ratos Sprague-Dawley , Doenças dos Roedores/imunologia , Doenças dos Roedores/virologia , Baço/virologia , Theilovirus/crescimento & desenvolvimento , Theilovirus/imunologia , Eliminação de Partículas ViraisRESUMO
Col1a2-deficient (oim) mice synthesize homotrimeric type I collagen due to nonfunctional proα2(I) collagen chains. Our previous studies revealed a postnatal, progressive type I collagen glomerulopathy in this mouse model, but the mechanism of the sclerotic collagen accumulation within the renal mesangium remains unclear. The recent demonstration of the resistance of homotrimeric type I collagen to cleavage by matrix metalloproteinases (MMPs), led us to investigate the role of MMP-resistance in the glomerulosclerosis of Col1a2-deficient mice. We measured the pre- and post-translational expression of type I collagen and MMPs in glomeruli from heterozygous and homozygous animals. Both the heterotrimeric and homotrimeric isotypes of type I collagen were equally present in whole kidneys of heterozygous mice by immunohistochemistry and biochemical analysis, but the sclerotic glomerular collagen was at least 95-98% homotrimeric, suggesting homotrimeric type I collagen is the pathogenic isotype of type I collagen in glomerular disease. Although steady-state MMP and Col1a1 mRNA levels increased with the disease progression, we found these changes to be a secondary response to the deficient clearance of MMP-resistant homotrimers. Increased renal MMP expression was not sufficient to prevent homotrimeric type I collagen accumulation.
Assuntos
Colágeno Tipo I/deficiência , Colágeno Tipo I/metabolismo , Glomérulos Renais/patologia , Metaloproteases/metabolismo , Osteogênese Imperfeita/metabolismo , Animais , Compostos Azo , Colágeno Tipo I/genética , Primers do DNA/genética , Técnicas Histológicas , Imuno-Histoquímica , Glomérulos Renais/crescimento & desenvolvimento , Glomérulos Renais/metabolismo , Camundongos , Camundongos Mutantes , Osteogênese Imperfeita/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Inflammatory bowel diseases (IBDs) are complex disorders caused by a combination of environmental, microbial, and genetic factors. Genome-wide association studies in humans have successfully identified multiple genes and loci associated with disease susceptibility, but the mechanisms by which these loci interact with each other and/or with environmental factors (i.e., intestinal microbiota) to cause disease are poorly understood. Helicobacter hepaticus-induced intestinal inflammation in mice is an ideal model system for elucidating the genetic basis of IBD susceptibility in a bacterially induced system, as there are significant differences in H. hepaticus-induced disease susceptibility among inbred mouse strains. Infected A/J mice develop acute overexpression of proinflammatory cytokines followed 2-3 months later by chronic cecal inflammation, whereas infected C57BL/6 mice fail to develop cecal inflammation or increased cytokine expression. The goal of this project was to use quantitative trait locus (QTL) mapping to evaluate genetic factors that contribute to the differential disease susceptibility between these two mouse strains. Using acute cecal IL-12/23p40 expression as a biomarker for disease susceptibility, QTL analysis of H. hepaticus-infected F(2) mice revealed involvement of multiple loci. The loci with the strongest association were located on Chromosome 3 and Chromosome 17, with logarithm of odds (LOD) scores of 6.89 and 3.09, respectively. Cecal expression of IL-12/23p40 in H. hepaticus-infected C57BL/6J-Chr3(A/J)/NaJ chromosome substitution mice had an intermediate phenotype, significantly higher than in resistant C57BL/6 but lower than in susceptible A/J mice, confirming the importance of this locus to the immune response to H. hepaticus infection.
Assuntos
Infecções por Helicobacter/genética , Infecções por Helicobacter/imunologia , Helicobacter hepaticus , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/imunologia , Locos de Características Quantitativas , Alelos , Animais , Ceco/imunologia , Ceco/metabolismo , Cromossomos de Mamíferos , Modelos Animais de Doenças , Feminino , Predisposição Genética para Doença , Doenças Inflamatórias Intestinais/microbiologia , Interleucina-12/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fatores SexuaisRESUMO
Helicobacter bilis-infected Smad3(-/-) mice represent an attractive model of inflammation-associated colon cancer. Most infected mice develop mucinous adenocarcinoma (MUC) by 6 weeks post inoculation (PI); however, approximately one third do not progress to MUC. The ability to predict the development of MUC in mice used in therapeutic studies would confer a considerable saving of time and money. In addition, the inadvertent use of mice without MUC may confound therapeutic studies by making treatments seem falsely efficacious. We assessed both magnetic resonance imaging (MRI) and fecal biomarkers in Helicobacter- and sham-inoculated mice as methods of noninvasively detecting MUC before the predicted onset of disease. Non-contrast-enhanced MRI was able to detect lesions in 58% of mice with histologically confirmed MUC; however, serial imaging sessions produced inconsistent results. MRI was also a labor- and time-intensive technique requiring anesthesia. Alternatively, inflammatory biomarkers isolated from feces at early time points were correlated to later histologic lesions. Fecal expression of interleukin 1ß, macrophage inflammatory protein 1α, and regulated on activation, normal T-cell expressed, and secreted at 3 weeks PI correlated significantly with lesion severity at 9 weeks PI. For each biomarker, receiver-operator characteristic curves were also generated, and all three biomarkers performed well at 1 to 3 weeks PI, indicating that the development of MUC can be predicted based on the early expression of certain inflammatory mediators in feces.
Assuntos
Adenocarcinoma Mucinoso/diagnóstico , Neoplasias do Colo/diagnóstico , Fezes/química , Helicobacter/patogenicidade , Proteína Smad3/genética , Adenocarcinoma Mucinoso/imunologia , Animais , Sequência de Bases , Biomarcadores/análise , Quimiocina CCL3/análise , Quimiocina CCL3/genética , Neoplasias do Colo/imunologia , Modelos Animais de Doenças , Fezes/microbiologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/patologia , Inflamação/microbiologia , Interleucina-1beta/análise , Interleucina-1beta/genética , Imageamento por Ressonância Magnética , Camundongos , Prognóstico , RNA/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteína Smad3/deficiênciaRESUMO
Mice used in biomedical research typically are tested for the presence of Helicobacter spp., including Helicobacter hepaticus. Here we evaluated the ability of a commercially available colorimetric Helicobacter dipstick assay to detect H. hepaticus in experimentally and naturally infected mice, with use of a Helicobacter PCR assay as the 'gold standard' test. None of the fecal samples from experimentally infected A/JCr mice (n = 12) tested positive for Helicobacter by the colorimetric dipstick test. In naturally infected A/JCr and C57BL/6 mice, 11% (1 of 9) and 30% (3 of 10) of fecal samples, respectively, tested positive for Helicobacter by the colorimetric dipstick assay. In these 3 groups of H. hepaticus-infected mice, statistically fewer mice tested positive by the colorimetric dipstick test than by PCR. The colorimetric Helicobacter dipstick assay had an overall diagnostic sensitivity of 13%, diagnostic specificity of 94%, and analytical sensitivity of 10(8) H. hepaticus cfu/mL. As currently formulated, the colorimetric dipstick assay had high specificity but lacked sensitivity for detecting H. hepaticus infections in 2 strains of mice commonly used in research, thereby limiting its utility as a diagnostic screening test for H. hepaticus infections in research mice.
Assuntos
Infecções por Helicobacter/veterinária , Camundongos Endogâmicos/microbiologia , Doenças dos Roedores/diagnóstico , Animais , Colorimetria , Fezes/microbiologia , Helicobacter/isolamento & purificação , Infecções por Helicobacter/diagnóstico , Camundongos , Reação em Cadeia da Polimerase , Doenças dos Roedores/microbiologia , Sensibilidade e EspecificidadeRESUMO
Pasteurella pneumotropica can cause inflammation and abscess formation in a variety of tissues. Most commonly, P. pneumotropica produces clinical disease in immunodeficient mice or those concurrently infected with other pathogens. Because clinical disease is infrequent in immunocompetent mice harboring P. pneumotropica, some scientists consider it an opportunistic pathogen with little clinical relevance to biomedical research. However, other infectious agents, including mouse parvoviruses, mouse rotavirus, and Helicobacter spp. alter physiologic or biologic responses without causing clinical signs of illness. We investigated the potential for P. pneumotropica to modulate the transcription of cytokine genes in immunocompetent mice. In C57BL/6 mice inoculated oronasally with a minimal colonizing dose of P. pneumotropica, modest but statistically significant elevations of IL1beta, TNFalpha, CCL3, CXCL1, and CXCL2 mRNA were detected in mandibular and superficial cervical lymph nodes at 7 d after inoculation, and upregulation of IL1beta mRNA was detected 28 d after inoculation. These perturbations were not present in C57/BL6 mice inoculated with heat killed-P. pneumotropica or the related bacterium Actinobacillus muris. Nasal mucosal cytokine transcription did not vary significantly in C57BL/6 mice given a high dose of P. pneumotropica. These data indicate that slight and transient experimental perturbations are possible in immunocompetent mice colonized with P. pneumotropica. Knowing the full health status of experimental mice is paramount to avoid unwanted experimental variables, especially when using exquisitely sensitive testing methodologies such as those for quantification of gene expression.
Assuntos
Citocinas/genética , Regulação da Expressão Gênica/fisiologia , Pasteurella pneumotropica/fisiologia , Animais , Sequência de Bases , Primers do DNA , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência com Séries de Oligonucleotídeos , Projetos Piloto , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Infections with a variety of Helicobacter species have been documented in rodent research facilities, with variable effects on rodent health. Helicobacter typhlonius has been reported to cause enteric disease in immunodeficient and IL10(-/-) mice, whereas H. rodentium has only been reported to cause disease in immunodeficient mice coinfected with other Helicobacter species. The effect of Helicobacter infections on murine reproduction has not been well studied. The reproductive performance of C57BL/6 IL10(-/-) female mice intentionally infected with H. typhlonius, H. rodentium, or both was compared with that of age-matched uninfected controls or similarly infected mice that received antihelicobacter therapy. The presence of Helicobacter organisms in stool and relevant tissues was detected by PCR assays. Helicobacter infection of IL10(-/-) female mice markedly decreased pregnancy rates and pup survival. The number of pups surviving to weaning was greatest in noninfected mice and decreased for H. rodentium > H. typhlonius >> H. rodentium and H. typhlonius coinfected mice. Helicobacter organisms were detected by semiquantitative real-time PCR in the reproductive organs of a subset of infected mice. Treatment of infected mice with a 4-drug regimen consisting of amoxicillin, clarithromycin, metronidazole, and omeprazole increased pregnancy rates, and pup survival and dam fecundity improved. We conclude that infection with H. typhlonius, H. rodentium, or both decreased the reproductive performance of IL10(-/-) mice. In addition, antihelicobacter therapy improved fecundity and enhanced pup survival.
Assuntos
Infecções por Helicobacter/fisiopatologia , Helicobacter/isolamento & purificação , Interleucina-10/metabolismo , Reprodução , Doenças dos Roedores/fisiopatologia , Animais , Antibacterianos/uso terapêutico , DNA Bacteriano/isolamento & purificação , Feminino , Fertilidade , Helicobacter/genética , Helicobacter/patogenicidade , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/transmissão , Infecções por Helicobacter/veterinária , Transmissão Vertical de Doenças Infecciosas , Interleucina-10/deficiência , Interleucina-10/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ovário/microbiologia , Ovário/fisiopatologia , Gravidez , Reprodução/efeitos dos fármacos , Doenças dos Roedores/tratamento farmacológico , Doenças dos Roedores/microbiologia , Útero/microbiologia , Útero/fisiopatologiaRESUMO
Infection with Helicobacter species is endemic in many animal facilities and may alter the penetrance of inflammatory bowel disease (IBD) phenotypes. However, little is known about the relative pathogenicity of H. typhlonius, H. rodentium, and combined infection in IBD models. We infected adult and neonatal IL10-/- mice with H. typhlonius, H. rodentium, or both bacteria. The severity of IBD and incidence of inflammation-associated colonic neoplasia were assessed in the presence and absence of antiHelicobacter therapy. Infected IL10-/- mice developed IBD with severity of noninfected (minimal to no inflammation) < H. rodentium < H. typhlonius Assuntos
Neoplasias do Colo/etiologia
, Infecções por Helicobacter/complicações
, Helicobacter/patogenicidade
, Doenças Inflamatórias Intestinais/etiologia
, Interleucina-10/deficiência
, Animais
, Animais Recém-Nascidos
, Antibacterianos/uso terapêutico
, Neoplasias do Colo/imunologia
, Modelos Animais de Doenças
, Feminino
, Helicobacter/classificação
, Infecções por Helicobacter/tratamento farmacológico
, Infecções por Helicobacter/imunologia
, Infecções por Helicobacter/patologia
, Doenças Inflamatórias Intestinais/tratamento farmacológico
, Doenças Inflamatórias Intestinais/imunologia
, Doenças Inflamatórias Intestinais/patologia
, Interleucina-10/genética
, Masculino
, Camundongos
, Camundongos Endogâmicos C57BL
, Camundongos Knockout
, Especificidade da Espécie
RESUMO
BACKGROUND: A/JCr mice develop typhlitis in response to Helicobacter hepaticus infection, whereas C57BL/6 mice coexist with this bacterium in a "commensal" relationship and do not develop disease even during prolonged colonization. METHODS: To determine mechanisms that control this balance between responsiveness and nonresponsiveness, the mucosal response of A/JCr and C57BL/6 mice to acute H. hepaticus colonization was evaluated using genome-wide profiling. Transcription levels for a subset of gene discoveries were then evaluated longitudinally by semiquantitative real-time reverse-transcriptase polymerase chain reaction (RT-PCR) to identify changes in gene expression that occur during progression from the acute to chronic phase of colonization. To determine whether chronic mucosal inflammation in A/JCr mice was mediated through a Th1 mechanism, as was inferred from the gene expression data, mice with typhlitis were treated with neutralizing antibody targeting IL-12/23p40 or IFN-gamma and the response to treatment was determined by cecal lesion severity and transcription of disease-related genes. RESULTS: A/JCr mice had a biphasic expression of proinflammatory genes that corresponded with the acute and chronic phases of disease. In contrast, C57BL/6 mice exhibited a less robust acute transcriptional response that waned by day 30 postinoculation. Sustained upregulation of proinflammatory signals and responsiveness to anti-IL-12/23p40 and anti-IFN-gamma antibody suggests that inflammation in A/JCr mice was mediated through a Th1 mechanism. Prolonged upregulation of SOCS3 during the acute response to colonization suggests that C57BL/6 mice maintain mucosal homeostasis, at least in part by attenuating responsiveness to cytokine signaling. CONCLUSIONS: Collectively, these findings provide a foundation for understanding the immunological mechanisms that confer resistance or susceptibility to H. hepaticus-induced typhlitis.
Assuntos
Ceco/metabolismo , Regulação da Expressão Gênica , Células Th1/imunologia , Tiflite/genética , Animais , Anticorpos Monoclonais , Ceco/imunologia , Ceco/patologia , Doença de Crohn/genética , Doença de Crohn/imunologia , Doença de Crohn/microbiologia , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Genoma , Infecções por Helicobacter/complicações , Helicobacter hepaticus , Imunidade nas Mucosas/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/biossíntese , Proteínas Supressoras da Sinalização de Citocina/genética , Tiflite/imunologia , Tiflite/microbiologia , Tiflite/patologiaRESUMO
Helicobacter rodentium was first recognized as a potential pathogen when it was isolated, along with Helicobacter bilis, from a colony of scid/Trp53 knockout mice with diarrhea. Clinical disease in these mice was more severe than that previously reported in mice infected with H. bilis alone, thus suggesting that H. rodentium contributed to the pathogenesis of enteritis. The purpose of the study reported here was to address two questions: is H. rodentium pathogenic in mice, and when co-infection with a pathogenic helicobacter occurs, does H. rodentium augment disease? To this end, A/JCr and C.B-17/IcrCrl-scidBr mice were inoculated with H. rodentium and/or H. hepaticus. Twelve weeks after inoculation, mice were euthanized. The cecum and liver were evaluated microscopically for evidence of disease. Cecal interferon-inducible protein 10 (IP-10), macrophage inflammatory protein 1alpha (MIP-1alpha), interleukin 10 (IL-10), and interferon gamma (IFN-gamma) mRNA values were measured as an indicator of mucosal immune response. Hepatic lesions were not identified in mice mono-infected with H. rodentium; likewise, cecal lesion scores were not significantly different from those of uninfected controls. With the exception of an increased IL-10 mRNA value in SCID mice, mean immune-related gene expression in H. rodentium mono-infected and uninfected control mice was not significantly different. In contrast, all mice infected with H. hepaticus developed moderate to severe hepatitis, significant increase in cecal lesion scores, and increased immune-related gene expression. The C.B-17/IcrCrl-scidBr mice co-infected with H. hepaticus and H. rodentium had liquid cecal contents and low terminal body weight. Further, compared with mice infected with H. hepaticus alone, co-infection was associated with significant increases of IL-10, MIP-1alpha, and IP-10 mRNA values in C.B-17/IcrCrl-scidBr and IFN-gamma and MIP-1alpha mRNA values in A/JCr mice. These results suggested that H. rodentium alone does not cause hepatitis or enteritis in A/JCr or C.B-17/IcrCrl-scidBr mice; however, co-infection with H. hepaticus and H. rodentium was associated with augmented cecal gene expression and clinical manifestation of disease in immunodeficient mice.
Assuntos
Infecções por Helicobacter/veterinária , Helicobacter/patogenicidade , Doenças dos Roedores/microbiologia , Animais , Ceco/metabolismo , Ceco/microbiologia , Ceco/patologia , Quimiocina CCL3 , Quimiocina CCL4 , Quimiocina CXCL10 , Quimiocinas CXC/genética , Quimiocinas CXC/metabolismo , Feminino , Expressão Gênica , Helicobacter/classificação , Helicobacter/isolamento & purificação , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Imunocompetência , Hospedeiro Imunocomprometido , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-10/genética , Interleucina-10/metabolismo , Fígado/metabolismo , Fígado/microbiologia , Fígado/patologia , Proteínas Inflamatórias de Macrófagos/genética , Proteínas Inflamatórias de Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos A , Camundongos SCID , RNA Mensageiro/metabolismo , Doenças dos Roedores/patologia , VirulênciaRESUMO
The inflammatory bowel diseases, Crohn's disease and ulcerative colitis, are chronic inflammatory disorders of the gastrointestinal tract. The causes of these diseases remain unknown; however, prevailing theories suggest that chronic intestinal inflammation results from a dysregulated immune response to ubiquitous bacterial antigens. While a substantial body of data has been amassed describing the role of the adaptive immune system in perpetuating and sustaining inflammation, very little is known about the early signals, prior to the development of inflammation, that initiate and direct the abnormal immune response. To this end, we characterized the gene expression profile of A/JCr mice with Helicobacter hepaticus-induced typhlitis at month 1 of infection, prior to the onset of histologic disease, and month 3 of infection, after chronic inflammation is fully established. Analysis of the gene expression in ceca of H. hepaticus infected mice revealed 25 up-regulated and 3 down-regulated genes in the month-1 postinoculation group and 31 up-regulated and 2 down-regulated genes in the month-3 postinoculation group. Among these was a subset of immune-related genes, including interferon-inducible protein 10, monokine induced by gamma interferon, macrophage-induced protein 1 alpha, and serum amyloid A1. Semiquantitative real-time reverse transcriptase PCR confirmed the increased expression levels of these genes, as well as elevated expression of gamma interferon. To our knowledge, this is the first report profiling cecal gene expression in H. hepaticus-infected A/JCr mice. The findings of altered gene expression prior to the development of any features of pathology and the ensuing chronic disease course make this an attractive model for studying early host response to microbe-induced inflammatory bowel disease.