RESUMEN
Burkholderia mallei is a gram-negative obligate animal pathogen that causes glanders, a highly contagious and potentially fatal disease of solipeds including horses, mules, and donkeys. Humans are also susceptible, and exposure can result in a wide range of clinical forms, i.e., subclinical infection, chronic forms with remission and exacerbation, or acute and potentially lethal septicemia and/or pneumonia. Due to intrinsic antibiotic resistance and the ability of the organisms to survive intracellularly, current treatment regimens are protracted and complicated; and no vaccine is available. As a consequence of these issues, and since B. mallei is infectious by the aerosol route, B. mallei is regarded as a major potential biothreat agent. To develop optimal medical countermeasures and diagnostic tests, well characterized animal models of human glanders are needed. The goal of this study was to perform a head-to-head comparison of models employing three commonly used nonhuman primate (NHP) species, the African green monkey (AGM), Rhesus macaque, and the Cynomolgus macaque. The natural history of infection and in vitro clinical, histopathological, immunochemical, and bacteriological parameters were examined. The AGMs were the most susceptible NHP to B. mallei; five of six expired within 14 days. Although none of the Rhesus or Cynomolgus macaques succumbed, the Rhesus monkeys exhibited abnormal signs and clinical findings associated with B. mallei infection; and the latter may be useful for modeling chronic B. mallei infection. Based on the disease progression observations, gross and histochemical pathology, and humoral and cellular immune response findings, the AGM appears to be the optimal model of acute, lethal glanders infection. AGM models of infection by B. pseudomallei, the etiologic agent of melioidosis, have been characterized recently. Thus, the selection of the AGM species provides the research community with a single NHP model for investigations on acute, severe, inhalational melioidosis and glanders.
Asunto(s)
Burkholderia mallei , Burkholderia pseudomallei , Muermo , Melioidosis , Aerosoles , Animales , Chlorocebus aethiops , Modelos Animales de Enfermedad , Muermo/diagnóstico , Caballos , Macaca mulattaRESUMEN
Th17 cells have been described as short lived, but this view is at odds with their capacity to trigger protracted damage to normal and transformed tissues. We report that Th17 cells, despite displaying low expression of CD27 and other phenotypic markers of terminal differentiation, efficiently eradicated tumors and caused autoimmunity, were long lived, and maintained a core molecular signature resembling early memory CD8(+) cells with stem cell-like properties. In addition, we found that Th17 cells had high expression of Tcf7, a direct target of the Wnt and ß-catenin signaling axis, and accumulated ß-catenin, a feature observed in stem cells. In vivo, Th17 cells gave rise to Th1-like effector cell progeny and also self-renewed and persisted as IL-17A-secreting cells. Multipotency was required for Th17 cell-mediated tumor eradication because effector cells deficient in IFN-γ or IL-17A had impaired activity. Thus, Th17 cells are not always short lived and are a less-differentiated subset capable of superior persistence and functionality.
Asunto(s)
Células Madre/metabolismo , Células Th17/inmunología , Animales , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Supervivencia Celular/genética , Perfilación de la Expresión Génica , Interleucina-17/biosíntesis , Ratones , Ratones Transgénicos , Neoplasias/inmunología , Células Madre/citología , Subgrupos de Linfocitos T/citología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Células TH1/citología , Células TH1/inmunología , Células Th17/citología , Células Th17/metabolismo , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/genética , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/metabolismoRESUMEN
BACKGROUND: Licensed antiviral therapeutics and vaccines to protect against eastern equine encephalitis virus (EEEV) in humans currently do not exist. Animal models that faithfully recapitulate the clinical characteristics of human EEEV encephalitic disease, including fever, drowsiness, anorexia, and neurological signs such as seizures, are needed to satisfy requirements of the Food and Drug Administration (FDA) for clinical product licensing under the Animal Rule. METHODS: In an effort to meet this requirement, we estimated the median lethal dose and described the pathogenesis of aerosolized EEEV in the common marmoset (Callithrix jacchus). Five marmosets were exposed to aerosolized EEEV FL93-939 in doses ranging from 2.4 × 101 PFU to 7.95 × 105 PFU. RESULTS: The median lethal dose was estimated to be 2.05 × 102 PFU. Lethality was observed as early as day 4 post-exposure in the highest-dosed marmoset but animals at lower inhaled doses had a protracted disease course where humane study endpoint was not met until as late as day 19 post-exposure. Clinical signs were observed as early as 3 to 4 days post-exposure, including fever, ruffled fur, decreased grooming, and leukocytosis. Clinical signs increased in severity as disease progressed to include decreased body weight, subdued behavior, tremors, and lack of balance. Fever was observed as early as day 2-3 post-exposure in the highest dose groups and hypothermia was observed in several cases as animals became moribund. Infectious virus was found in several key tissues, including brain, liver, kidney, and several lymph nodes. Clinical hematology results included early neutrophilia, lymphopenia, and thrombocytopenia. Key pathological changes included meningoencephalitis and retinitis. Immunohistochemical staining for viral antigen was positive in the brain, retina, and lymph nodes. More intense and widespread IHC labeling occurred with increased aerosol dose. CONCLUSION: We have estimated the medial lethal dose of aerosolized EEEV and described the pathology of clinical disease in the marmoset model. The results demonstrate that the marmoset is an animal model suitable for emulation of human EEEV disease in the development of medical countermeasures.
Asunto(s)
Aerosoles , Callithrix/virología , Modelos Animales de Enfermedad , Virus de la Encefalitis Equina del Este/patogenicidad , Encefalomielitis Equina Oriental/veterinaria , Encefalomielitis Equina Oriental/virología , Animales , Análisis Químico de la Sangre , Encéfalo/patología , Encéfalo/virología , Encefalomielitis Equina Oriental/patología , Encefalomielitis Equina Oriental/fisiopatología , Femenino , Inmunidad , Inmunohistoquímica , Riñón/virología , Dosificación Letal Mediana , Hígado/virología , Ganglios Linfáticos/virología , Masculino , ARN Viral/análisis , ARN Viral/aislamiento & purificación , Análisis de Supervivencia , Carga Viral , Ensayo de Placa ViralRESUMEN
BACKGROUND: Cell-free hemoglobin (Hb) in the vasculature leads to vasoconstriction and injury. Proposed mechanisms have been based on nitric oxide (NO) scavenging by oxyhemoglobin (oxyHb) or processes mediated by oxidative reactions of methemoglobin (metHb). To clarify this, we tested the vascular effect and fate of oxyHb or metHb infusions. STUDY DESIGN AND METHODS: Twenty beagles were challenged with 1-hour similar infusions of (200 µmol/L) metHb (n = 5), oxyHb (n = 5), albumin (n = 5), or saline (n = 5). Measurements were taken over 3 hours. RESULTS: Infusions of the two pure Hb species resulted in increases in mean arterial blood pressure (MAP), systemic vascular resistance index, and NO consumption capacity of plasma (all p < 0.05) with the effects of oxyHb being greater than that from metHb (MAP; increase 0 to 3 hr; 27 ± 6% vs. 7 ± 2%, respectively; all p < 0.05). The significant vasoconstrictive response of metHb (vs. albumin and saline controls) was related to in vivo autoreduction of metHb to oxyHb, and the vasoactive Hb species that significantly correlated with MAP was always oxyHb, either from direct infusion or after in vivo reduction from metHb. Clearance of total Hb from plasma was faster after metHb than oxyHb infusion (p < 0.0001). CONCLUSION: These findings indicate that greater NO consumption capacity makes oxyHb more vasoactive than metHb. Additionally, metHb is reduced to oxyHb after infusion and cleared faster or is less stable than oxyHb. Although we found no direct evidence that metHb itself is involved in acute vascular effects, in aggregate, these studies suggest that metHb is not inert and its mechanism of vasoconstriction is due to its delayed conversion to oxyHb by plasma-reducing agents.
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Metahemoglobina/farmacología , Oxihemoglobinas/farmacología , Vasoconstricción/efectos de los fármacos , Albúminas/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Perros , Metahemoglobina/metabolismo , Óxido Nítrico/metabolismo , Oxihemoglobinas/metabolismo , Distribución AleatoriaRESUMEN
Effector cells derived from central memory CD8(+) T cells were reported to engraft and survive better than those derived from effector memory populations, suggesting that they are superior for use in adoptive immunotherapy studies. However, previous studies did not evaluate the relative efficacy of effector cells derived from naïve T cells. We sought to investigate the efficacy of tumor-specific effector cells derived from naïve or central memory T-cell subsets using transgenic or retrovirally transduced T cells engineered to express a tumor-specific T-cell receptor. We found that naïve, rather than central memory T cells, gave rise to an effector population that mediated superior antitumor immunity upon adoptive transfer. Effector cells developed from naïve T cells lost the expression of CD62L more rapidly than those derived from central memory T cells, but did not acquire the expression of KLRG-1, a marker for terminal differentiation and replicative senescence. Consistent with this KLRG-1(-) phenotype, naïve-derived cells were capable of a greater proliferative burst and had enhanced cytokine production after adoptive transfer. These results indicate that insertion of genes that confer antitumor specificity into naïve rather than central memory CD8(+) T cells may allow superior efficacy upon adoptive transfer.
Asunto(s)
Traslado Adoptivo , Linfocitos T CD8-positivos/inmunología , Memoria Inmunológica , Inmunoterapia Adoptiva/métodos , Neoplasias/inmunología , Animales , Animales Modificados Genéticamente , Autoantígenos/inmunología , Humanos , Inmunofenotipificación , Neoplasias Experimentales/inmunología , Primates/inmunología , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/inmunología , Tasa de SupervivenciaRESUMEN
OBJECTIVE: Evidence supports an antilipotoxic role for leptin in preventing inappropriate peripheral tissue lipid deposition. Obese, leptin-deficient mice develop left ventricular (LV) hypertrophy and myocardial steatosis with increased apoptosis and decreased longevity. Here we investigated the cardiac effects of caloric restriction versus leptin repletion in obese leptin-deficient (ob/ob) mice. METHODS: Echocardiography was performed on 7 mo old C57BL/6 wild-type mice (WT) and ob/ob mice fed ad libitum, leptin-repleted (LR-ob/ob), or calorie-restricted (CR-ob/ob) for 4 wk. Ventricular tissue was examined by electron microscopy (EM), triglyceride (TAG) content, oil red O staining, mitochondrial coupling assay, and microarray expression profiling. RESULTS: LR and CR-ob/ob mice showed decreased body and heart weight, and LV wall thickness compared with ad libitum ob/ob mice. LV fractional shortening was decreased in ad libitum ob/ob mice, but restored to WT in LR and CR groups. However, myocardial lipid content by EM and TAG analysis revealed persistent cardiac steatosis in the CR-ob/ob group. Although CR restored mitochondrial coupling to WT levels, PPARα was suppressed and genes associated with oxidative stress and cell death were upregulated in CR-ob/ob animals. In contrast, LR eliminated cardiac steatosis, normalized mitochondrial coupling, and restored PGC1α and PPARα expression, while inducing core genes involved in glycerolipid/free fatty acid (GL/FFA) cycling, a thermogenic pathway that can reduce intracellular lipids. CONCLUSIONS: Thus, CR in the absence of leptin fails to normalize cardiac steatosis. GL/FFA cycling may be, at least in part, leptin-dependent and a key pathway that protects the heart from lipid accumulation.
Asunto(s)
Restricción Calórica/métodos , Hipertrofia Ventricular Izquierda/patología , Leptina/deficiencia , Lípidos/análisis , Miocardio/química , PPAR alfa/metabolismo , Análisis de Varianza , Animales , Apoptosis/genética , Peso Corporal , Ecocardiografía , Perfilación de la Expresión Génica , Hipertrofia Ventricular Izquierda/etiología , Leptina/administración & dosificación , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Análisis por Micromatrices , Microscopía Electrónica , Miocardio/patología , Estrés Oxidativo/genéticaRESUMEN
We hypothesized that invasive pulmonary aspergillosis (IPA) may generate a distinctive proteomic signature in plasma and bronchoalveolar lavage (BAL). Proteins in plasma and BAL from two neutropenic rabbit models of IPA and Pseudomonas pneumonia were analyzed by SELDI-TOF MS. Hierarchical clustering analysis of plasma time course spectra demonstrated two clusters of peaks that were differentially regulated between IPA and Pseudomonas pneumonia (57 and 34 peaks, respectively, p<0.001). PCA of plasma proteins demonstrated a time-dependent separation of the two infections. A random forest analysis that ranked the top 30 spectral points distinguished between late Aspergillus and Pseudomonas pneumonias with 100% sensitivity and specificity. Based on spectral data analysis, three proteins were identified using SDS-PAGE and LC/MS and quantified using reverse phase arrays. Differences in the temporal sequence of plasma haptoglobin (p<0.001), apolipoprotein A1 (p<0.001) and transthyretin (p<0.038) were observed between IPA and Pseudomonas pneumonia, as was C-reactive protein (p<0.001). In summary, proteomic analysis of plasma and BAL proteins of experimental Aspergillus and Pseudomonas pneumonias demonstrates unique protein profiles with principal components and spectral regions that are shared in early infection and diverge at later stages of infection. Haptoglobin, apolipoprotein A1, transthyretin, and C-reactive protein are differentially expressed in these infections suggesting important contributions to host defense against IPA.
Asunto(s)
Aspergilosis Pulmonar Invasiva/diagnóstico , Neumonía Bacteriana/diagnóstico , Proteoma/análisis , Infecciones por Pseudomonas/diagnóstico , Animales , Aspergillus fumigatus , Biomarcadores/análisis , Líquido del Lavado Bronquioalveolar/química , Análisis por Conglomerados , Femenino , Aspergilosis Pulmonar Invasiva/microbiología , Neumonía Bacteriana/microbiología , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa , ConejosRESUMEN
CONTEXT: Sepsis bundles have been developed to improve patient outcomes by combining component therapies. Valid bundles require effective components with additive benefits. Proponents encourage evaluation of bundles, both as a whole and based on the performance of each component. OBJECTIVE: Assess the association between outcome and the utilization of component therapies in studies of sepsis bundles. DATA SOURCE: Database searches (January 1980 to July 2008) of PubMed, Embase, and the Cochrane Library, using the terms sepsis, bundles, guidelines, and early goal directed therapy. DATA EXTRACTION: Inclusion required comparison of septic adults who received bundled care vs. nonprotocolized care. Survival and use rates for individual interventions were abstracted. MAIN RESULTS: Eight unblinded trials, one randomized and seven with historical controls, were identified. Sepsis bundles were associated with a consistent (I2 = 0%, p = .87) and significant increase in survival (odds ratio, 1.91; 95% confidence interval, 1.49-2.45; p < .0001). For all studies reporting such data, there were consistent (I2 = 0%, p > or = .64) decreases in time to antibiotics, and increases in the appropriateness of antibiotics (p < or = .0002 for both). In contrast, significant heterogeneity was seen across trials for all other treatments (antibiotic use within a specified time period; administration of fluids, vasopressors, inotropes, and packed red blood cells titrated to hemodynamic goals; corticosteroids and human recombinant activated protein C use) (all I2 > or = 67%, p < .002). Except for antibiotics, sepsis bundle components are still being investigated for efficacy in randomized controlled trials. CONCLUSION: Bundle use was associated with consistent and significant improvement in survival and antibiotic use. Use of other bundle components changed heterogeneously across studies, making their impact on survival uncertain. However, this analysis should be interpreted cautiously as these studies were unblinded, and only one was randomized.
Asunto(s)
Guías de Práctica Clínica como Asunto , Choque Séptico/terapia , Antibacterianos/uso terapéutico , Intervalos de Confianza , Adhesión a Directriz , Humanos , Oportunidad Relativa , Choque Séptico/tratamiento farmacológico , Choque Séptico/mortalidad , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
BACKGROUND: The expression levels of many genes show wide natural variation among strains or populations. This study investigated the potential for animal strain-related genotypic differences to confound gene expression profiles in acute cellular rejection (ACR). Using a rat heart transplant model and 2 different rat strains (Dark Agouti, and Brown Norway), microarrays were performed on native hearts, transplanted hearts, and peripheral blood mononuclear cells (PBMC). RESULTS: In heart tissue, strain alone affected the expression of only 33 probesets while rejection affected the expression of 1368 probesets (FDR 10% and FC > o= 3). Only 13 genes were affected by both strain and rejection, which was < 1% (13/1368) of all probesets differentially expressed in ACR. However, for PBMC, strain alone affected 265 probesets (FDR 10% and FC > or = 3) and the addition of ACR had little further effect. Pathway analysis of these differentially expressed strain effect genes connected them with immune response, cell motility and cell death, functional themes that overlap with those related to ACR. After accounting for animal strain, additional analysis identified 30 PBMC candidate genes potentially associated with ACR. CONCLUSION: In ACR, genetic background has a large impact on the transcriptome of immune cells, but not heart tissue. Gene expression studies of ACR should avoid study designs that require cross strain comparisons between leukocytes.
Asunto(s)
Perfilación de la Expresión Génica , Rechazo de Injerto/genética , Leucocitos Mononucleares/metabolismo , Miocardio/metabolismo , Animales , Modelos Animales de Enfermedad , Expresión Génica , Rechazo de Injerto/metabolismo , Rechazo de Injerto/patología , Trasplante de Corazón , Miocardio/patología , Análisis de Secuencia por Matrices de Oligonucleótidos , Análisis de Componente Principal , Ratas , Trasplante Homólogo , Trasplante IsogénicoRESUMEN
CONTEXT: Hemoglobin-based blood substitutes (HBBSs) are infusible oxygen-carrying liquids that have long shelf lives, have no need for refrigeration or cross-matching, and are ideal for treating hemorrhagic shock in remote settings. Some trials of HBBSs during the last decade have reported increased risks without clinical benefit. OBJECTIVE: To assess the safety of HBBSs in surgical, stroke, and trauma patients. DATA SOURCES: PubMed, EMBASE, and Cochrane Library searches for articles using hemoglobin and blood substitutes from 1980 through March 25, 2008; reviews of Food and Drug Administration (FDA) advisory committee meeting materials; and Internet searches for company press releases. STUDY SELECTION: Randomized controlled trials including patients aged 19 years and older receiving HBBSs therapeutically. The database searches yielded 70 trials of which 13 met these criteria; in addition, data from 2 other trials were reported in 2 press releases, and additional data were included in 1 relevant FDA review. DATA EXTRACTION: Data on death and myocardial infarction (MI) as outcome variables. RESULTS: Sixteen trials involving 5 different products and 3711 patients in varied patient populations were identified. A test for heterogeneity of the results of these trials was not significant for either mortality or MI (for both, I2 = 0%, P > or = .60), and data were combined using a fixed-effects model. Overall, there was a statistically significant increase in the risk of death (164 deaths in the HBBS-treated groups and 123 deaths in the control groups; relative risk [RR], 1.30; 95% confidence interval [CI], 1.05-1.61) and risk of MI (59 MIs in the HBBS-treated groups and 16 MIs in the control groups; RR, 2.71; 95% CI, 1.67-4.40) with these HBBSs. Subgroup analysis of these trials indicated the increased risk was not restricted to a particular HBBS or clinical indication. CONCLUSION: Based on the available data, use of HBBSs is associated with a significantly increased risk of death and MI.
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Sustitutos Sanguíneos/efectos adversos , Hemoglobinas , Hemoglobinas/efectos adversos , Humanos , Mortalidad , Infarto del Miocardio/epidemiología , Rafinosa/efectos adversos , Rafinosa/análogos & derivados , RiesgoRESUMEN
Mouse models have been essential to generate supporting data for the research of infectious diseases. Burkholderia pseudomallei, the etiological agent of melioidosis, has been studied using mouse models to investigate pathogenesis and efficacy of novel medical countermeasures to include both vaccines and therapeutics. Previous characterization of mouse models of melioidosis have demonstrated that BALB/c mice present with an acute infection, whereas C57BL/6 mice have shown a tendency to be more resistant to infection and may model chronic disease. In this study, either BALB/c or C57BL/6 mice were exposed to aerosolized human clinical isolates of B. pseudomallei. The bacterial strains included HBPUB10134a (virulent isolate from Thailand), MSHR5855 (virulent isolate from Australia), and 1106a (relatively attenuated isolate from Thailand). The LD50 values were calculated and serial sample collections were performed in order to examine the bacterial burdens in tissues, histopathological features of disease, and the immune response mounted by the mice after exposure to aerosolized B. pseudomallei. These data will be important when utilizing these models for testing novel medical countermeasures. Additionally, by comparing highly virulent strains with attenuated isolates, we hope to better understand the complex disease pathogenesis associated with this bacterium.
Asunto(s)
Burkholderia pseudomallei/fisiología , Melioidosis/patología , Animales , Formación de Anticuerpos , Australia/epidemiología , Bronquios/inmunología , Bronquios/microbiología , Bronquios/patología , Burkholderia pseudomallei/patogenicidad , Citocinas/sangre , Citocinas/inmunología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Melioidosis/sangre , Melioidosis/epidemiología , Melioidosis/inmunología , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Tailandia/epidemiología , VirulenciaRESUMEN
BACKGROUND: Meta-analyses of N-acetylcysteine (NAC) for preventing contrast-induced nephrotoxicity (CIN) have led to disparate conclusions. Here we examine and attempt to resolve the heterogeneity evident among these trials. METHODS: Two reviewers independently extracted and graded the data. Limiting studies to randomized, controlled trials with adequate outcome data yielded 22 reports with 2746 patients. RESULTS: Significant heterogeneity was detected among these trials (I2 = 37%; p = 0.04). Meta-regression analysis failed to identify significant sources of heterogeneity. A modified L'Abbé plot that substituted groupwise changes in serum creatinine for nephrotoxicity rates, followed by model-based, unsupervised clustering resolved trials into two distinct, significantly different (p < 0.0001) and homogeneous populations (I2 = 0 and p > 0.5, for both). Cluster 1 studies (n = 18; 2445 patients) showed no benefit (relative risk (RR) = 0.87; 95% confidence interval (CI) 0.68-1.12, p = 0.28), while cluster 2 studies (n = 4; 301 patients) indicated that NAC was highly beneficial (RR = 0.15; 95% CI 0.07-0.33, p < 0.0001). Benefit in cluster 2 was unexpectedly associated with NAC-induced decreases in creatinine from baseline (p = 0.07). Cluster 2 studies were relatively early, small and of lower quality compared with cluster 1 studies (p = 0.01 for the three factors combined). Dialysis use across all studies (five control, eight treatment; p = 0.42) did not suggest that NAC is beneficial. CONCLUSION: This meta-analysis does not support the efficacy of NAC to prevent CIN.
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Acetilcisteína/farmacología , Medios de Contraste/efectos adversos , Enfermedades Renales/inducido químicamente , Enfermedades Renales/prevención & control , Anciano , Análisis por Conglomerados , Creatinina/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Biológicos , Sesgo de Publicación , Ensayos Clínicos Controlados Aleatorios como Asunto , Análisis de Regresión , Diálisis Renal , Factores de Riesgo , Sensibilidad y EspecificidadRESUMEN
Jacket use in NHP is a common practice and is often considered a form of refinement during experiments necessitating extended periods of catheterization. An important consideration when using jackets is the physiologic effects that jacketing has on NHP and its potential to confound research. Several studies have evaluated the stress response and habituation of NHP to various forms of restraint, but none have looked directly at the timeframe necessary for the habituation of rhesus macaques (Macaca mulatta) to jackets. We set out to determine whether 3 d was a sufficient timeframe for this species to become habituated to a jacket, with or without an undershirt, by evaluating 2 major physiologic parameters. After jacket placement, we measured food consumption and collected fecal samples to measure fecal corticosterone metabolites (FCM) daily for 2 wk. FCM measurements for NHP without undershirts were significantly increased for days 2 and 3 after jacketing before returning to baseline levels. FCM measurements for NHP with undershirts were significantly increased for only 1 d after jacketing, suggesting that the undershirt has a positive effect on jacket habituation. There were no measurable differences in food consumption during the jacket habituation period. Furthermore, no significant differences were noted between sexes. These findings suggest that FCM levels return to baseline 3 d after jacketing and could be a useful predictor of jacket habituation in rhesus macaques.
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Crianza de Animales Domésticos , Bienestar del Animal , Macaca mulatta/fisiología , Crianza de Animales Domésticos/instrumentación , Animales , Cateterismo/veterinaria , Corticosterona/análisis , Heces/químicaRESUMEN
Burkholderia pseudomallei, the etiologic agent of melioidosis, is a gram-negative facultative intracellular bacterium. This bacterium is endemic in Southeast Asia and Northern Australia and can infect humans and animals by several routes. It has also been estimated to present a considerable risk as a potential biothreat agent. There are currently no effective vaccines for B. pseudomallei, and antibiotic treatment can be hampered by nonspecific symptomology, the high incidence of naturally occurring antibiotic resistant strains, and disease chronicity. Accordingly, there is a concerted effort to better characterize B. pseudomallei and its associated disease. Before novel vaccines and therapeutics can be tested in vivo, a well characterized animal model is essential. Previous work has indicated that mice may be a useful animal model. In order to develop standardized animal models of melioidosis, different strains of bacteria must be isolated, propagated, and characterized. Using a murine intraperitoneal (IP) infection model, we tested the virulence of 11 B. pseudomallei strains. The IP route offers a reproducible way to rank virulence that can be readily reproduced by other laboratories. This infection route is also useful in distinguishing significant differences in strain virulence that may be masked by the exquisite susceptibility associated with other routes of infection (e.g., inhalational). Additionally, there were several pathologic lesions observed in mice following IP infection. These included varisized abscesses in the spleen, liver, and haired skin. This model indicated that commonly used laboratory strains of B. pseudomallei (i.e., K96243 and 1026b) were significantly less virulent as compared to more recently acquired clinical isolates. Additionally, we characterized in vitro strain-associated differences in virulence for macrophages and described a potential inverse relationship between virulence in the IP mouse model of some strains and in the macrophage phagocytosis assay. Strains which were more virulent for mice (e.g., HBPU10304a) were often less virulent in the macrophage assays, as determined by several parameters such as intracellular bacterial replication and host cell cytotoxicity.
Asunto(s)
Burkholderia pseudomallei/inmunología , Macrófagos/inmunología , Macrófagos/microbiología , Melioidosis/inmunología , Melioidosis/microbiología , Absceso/inmunología , Absceso/microbiología , Absceso/patología , Animales , Burkholderia pseudomallei/patogenicidad , Modelos Animales de Enfermedad , Lipopolisacáridos/inmunología , Lipopolisacáridos/metabolismo , Melioidosis/metabolismo , Melioidosis/patología , Ratones , FenotipoRESUMEN
Recent experimentation with the variants of the Ebola virus that differ in the glycoprotein's poly-uridine site, which dictates the form of glycoprotein produced through a transcriptional stutter, has resulted in questions regarding the pathogenicity and lethality of the stocks used to develop products currently undergoing human clinical trials to combat the disease. In order to address these concerns and prevent the delay of these critical research programs, we designed an experiment that permitted us to intramuscularly challenge statistically significant numbers of naïve and vaccinated cynomolgus macaques with either a 7U or 8U variant of the Ebola virus, Kikwit isolate. In naïve animals, no difference in survivorship was observed; however, there was a significant delay in the disease course between the two groups. Significant differences were also observed in time-of-fever, serum chemistry, and hematology. In vaccinated animals, there was no statistical difference in survivorship between either challenge groups, with two succumbing in the 7U group compared to 1 in the 8U challenge group. In summary, survivorship was not affected, but the Ebola virus disease course in nonhuman primates is temporally influenced by glycoprotein poly-U editing site populations.
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Fiebre Hemorrágica Ebola/patología , Fiebre Hemorrágica Ebola/virología , Poli U/análisis , Proteínas del Envoltorio Viral/química , Factores de Virulencia/química , Animales , Modelos Animales de Enfermedad , Inyecciones Intramusculares , Macaca fascicularis , Análisis de Supervivencia , Proteínas del Envoltorio Viral/metabolismo , Factores de Virulencia/metabolismoRESUMEN
Jacketing of nonhuman primates (NHP) is a commonly used practice in the laboratory animal setting to support data collection with reduced direct human-to-animal interaction. NHP often wear jackets for several weeks, potentially leading to the formation of dermal lesions ranging from mild alopecia to severe full-thickness ulceration. We sought to evaluate the addition of a commercially available undershirt for primates as a possible refinement practice for our jacketed rhesus macaques. In this study, we compared the lesion count, location, and severity and differences in rectal body temperature between jacketed NHP with undershirts with those wearing the jackets alone. In both groups, most lesions (75%) were located at either the underarm or shoulder. The percentages of total lesions in the back and neck were lower in jacketed NHP that wore undershirts than in those that did not. In addition, the estimated odds of increased severity scores in jacketed NHP without undershirts was 1.80 times that for NHP that wore both jackets and undershirts. Both groups of NHP showed a significant decrease in dermal scores with time, indicating adaptation to the jackets with or without undershirts. However, there was no statistically significant decrease in lesion count, severity, or location in jacketed NHP that wore undershirts compared with those that did not.
Asunto(s)
Animales de Laboratorio , Macaca mulatta , Ropa de Protección , Telemetría/veterinaria , Animales , Temperatura Corporal , Femenino , MasculinoRESUMEN
Infection by the Gram-negative pathogen Burkholderia pseudomallei results in the disease melioidosis, acquired from the environment in parts of southeast Asia and northern Australia. Clinical symptoms of melioidosis range from acute (fever, pneumonia, septicemia, and localized infection) to chronic (abscesses in various organs and tissues, most commonly occurring in the lungs, liver, spleen, kidney, prostate and skeletal muscle), and persistent infections in humans are difficult to cure. Understanding the basic biology and genomics of B. pseudomallei is imperative for the development of new vaccines and therapeutic interventions. This formidable task is becoming more tractable due to the increasing number of B. pseudomallei genomes that are being sequenced and compared. Here, we compared three B. pseudomallei genomes, from strains MSHR668, K96243 and 1106a, to identify features that might explain why MSHR668 is more virulent than K96243 and 1106a in a mouse model of B. pseudomallei infection. Our analyses focused on metabolic, virulence and regulatory genes that were present in MSHR668 but absent from both K96243 and 1106a. We also noted features present in K96243 and 1106a but absent from MSHR668, and identified genomic differences that may contribute to variations in virulence noted among the three B. pseudomallei isolates. While this work contributes to our understanding of B. pseudomallei genomics, more detailed experiments are necessary to characterize the relevance of specific genomic features to B. pseudomallei metabolism and virulence. Functional analyses of metabolic networks, virulence and regulation shows promise for examining the effects of B. pseudomallei on host cell metabolism and will lay a foundation for future prediction of the virulence of emerging strains. Continued emphasis in this area will be critical for protection against melioidosis, as a better understanding of what constitutes a fully virulent Burkholderia isolate may provide for better diagnostic and medical countermeasure strategies.
Asunto(s)
Burkholderia pseudomallei/genética , Melioidosis/microbiología , Animales , Burkholderia pseudomallei/metabolismo , Burkholderia pseudomallei/patogenicidad , Cromosomas Bacterianos , Genoma Bacteriano , Humanos , Redes y Vías Metabólicas , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , VirulenciaRESUMEN
Bacterial proteins destined for the Tat pathway are folded before crossing the inner membrane and are typically identified by an N-terminal signal peptide containing a twin arginine motif. Translocation by the Tat pathway is dependent on the products of genes which encode proteins possessing the binding site of the signal peptide and mediating the actual translocation event. In the fully virulent CO92 strain of Yersinia pestis, the tatA gene was deleted. The mutant was assayed for loss of virulence through various in vitro and in vivo assays. Deletion of the tatA gene resulted in several consequences for the mutant as compared to wild-type. Cell morphology of the mutant bacteria was altered and demonstrated a more elongated form. In addition, while cultures of the mutant strain were able to produce a biofilm, we observed a loss of adhesion of the mutant biofilm structure compared to the biofilm produced by the wild-type strain. Immuno-electron microscopy revealed a partial disruption of the F1 antigen on the surface of the mutant. The virulence of the ΔtatA mutant was assessed in various murine models of plague. The mutant was severely attenuated in the bubonic model with full virulence restored by complementation with the native gene. After small-particle aerosol challenge in a pneumonic model of infection, the mutant was also shown to be attenuated. In contrast, when mice were challenged intranasally with the mutant, very little difference in the LD50 was observed between wild-type and mutant strains. However, an increased time-to-death and delay in bacterial dissemination was observed in mice infected with the ΔtatA mutant as compared to the parent strain. Collectively, these findings demonstrate an essential role for the Tat pathway in the virulence of Y. pestis in bubonic and small-aerosol pneumonic infection but less important role for intranasal challenge.