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1.
Deletion of the ferric uptake regulator Fur impairs the in vitro growth and virulence of Actinobacillus pleuropneumoniae
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Jacobsen I Gerstenberger J Gruber AD Bossé JT Langford PR Hennig-Pauka I Meens J Gerlach GF 《Infection and immunity》2005,73(6):3740-3744
In order to investigate the role of the ferric uptake regulator Fur in the porcine lung pathogen Actinobacillus pleuropneumoniae, we constructed an isogenic in-frame deletion mutant, A. pleuropneumoniae Deltafur. This mutant showed constitutive expression of transferrin-binding proteins, growth deficiencies in vitro, and reduced virulence in an aerosol infection model. 相似文献
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Maren Kummerfeld Jochen Meens Ludwig Haas Wolfgang Baumgrtner Andreas Beineke 《Journal of virological methods》2009,160(1-2):185-188
The BeAn strain of Theiler's murine encephalomyelitis virus (TMEV) causes a demyelinating leukomyelitis in mice, which serves as an important animal model for multiple sclerosis in humans. The present report describes the generation and characterization of a TMEV-specific polyclonal antibody by immunization of rabbits with purified TMEV of the BeAn strain. The specificity of the antibody was confirmed by Western blotting and sequence analysis of the recognized antigen by high resolution mass spectrometry. The presence of TMEV-specific polyclonal antibodies in post-immunization sera was tested on TMEV-infected L-cells (murine lung tumor cell line) using an immunofluorescence assay. Additionally, the rabbit serum enabled virus detection in formalin-fixed and paraffin-embedded TMEV-infected BHK21 cell pellets and brain tissue of TMEV-infected mice by immunohistochemistry. Immune electron microscopy revealed colloid gold-labeled picornavirus-typical paracrystalline arrays and non-aggregated viral particles of TMEV-infected BHK21 cells. The present report demonstrates the applicability of the generated marker for investigating TMEV cell tropism and viral spread at a cellular and subcellular level in future studies. 相似文献
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Meens MJ Mattheij NJ Nelissen J Lemkens P Compeer MG Janssen BJ De Mey JG 《Hypertension》2011,58(1):99-106
Slow dissociation of endothelin 1 from its endothelin A receptors is responsible for the long-lasting vasoconstrictor effects of the peptide. We showed recently that calcitonin gene-related peptide selectively terminates long-lasting contractile responses to endothelin 1 in isolated rat mesenteric arteries. Here we assessed whether the antiendothelinergic effect of calcitonin gene-related peptide is vascular bed specific and may terminate long-lasting pressor responses to exogenous and locally produced endothelin 1 in vivo. Regional heterogeneity of the calcitonin gene-related peptide/endothelin A receptor cross-talk was explored in arteries isolated from various rat organs. Endothelin A receptor-mediated arterial contractions were terminated by calcitonin gene-related peptide in rat mesenteric, renal, and spermatic arteries but not in basilar, coronary, epigastric, gastric, splenic, and saphenous arteries. Endothelin A receptor antagonism only ended endothelin 1-induced contractions in spermatic arteries. In anesthetized rats, instrumented with Doppler flow probes to record regional blood flows, long-lasting pressor and vasoconstrictor responses to an intravenous bolus injection of endothelin 1 or big endothelin 1 were transiently reduced by sodium nitroprusside (NO donor) but terminated by intravenously administered calcitonin gene-related peptide. In conscious rats, calcitonin gene-related peptide but not sodium nitroprusside terminated prolonged (>60-minute) pressor responses to endothelin 1 but not those to intravenous infusion of phenylephrine. In conclusion, pressor responses to circulating and locally produced endothelin 1 that are resistant to endothelin receptor antagonism and NO can be terminated by a regionally selective effect of calcitonin gene-related peptide. Calcitonin gene related peptide receptor agonism may represent a novel strategy to treat endothelin 1-associated cardiovascular pathologies. 相似文献
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Use of an Actinobacillus pleuropneumoniae multiple mutant as a vaccine that allows differentiation of vaccinated and infected animals
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Vaccination against Actinobacillus pleuropneumoniae is hampered by the lack of vaccines inducing reliable cross-serotype protection. In contrast, pigs surviving natural infection are at least partially protected from clinical symptoms upon reinfection with any serotype. Thus, we set out to construct an attenuated A. pleuropneumoniae live vaccine allowing the differentiation of vaccinated from infected animals (the DIVA concept) by successively deleting virulence-associated genes. Based on an A. pleuropneumoniae serotype 2 prototype live negative marker vaccine (W. Tonpitak, N. Baltes, I. Hennig-Pauka, and G.-F. Gerlach, Infect. Immun. 70:7120-7125, 2002), genes encoding three enzymes involved in anaerobic respiration and the ferric uptake regulator Fur were deleted, resulting in a highly attenuated sixfold mutant; this mutant was still able to colonize the lower respiratory tract and induced a detectable immune response. Upon a single aerosol application, this mutant provided significant protection from clinical symptoms upon heterologous infection with an antigenically distinct A. pleuropneumoniae serotype 9 challenge strain and allowed the serological discrimination between infected and vaccinated groups. 相似文献
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Otto L.D. Cerqueira Peter Truesdell Tomas Baldassarre Santiago A. Vilella-Arias Kathleen Watt Jalna Meens Harish Chander Cynthia A.B. Osório Fernando A. Soares Eduardo M. Reis Andrew W.B. Craig 《Oncotarget》2015,6(11):9397-9408
Signaling via epidermal growth factor receptor (EGFR) and Src kinase pathways promote triple-negative breast cancer (TNBC) cell invasion and tumor metastasis. Here, we address the role of Cdc42-interacting protein-4 (CIP4) in TNBC metastasis in vivo, and profile CIP4 expression in human breast cancer patients. In human TNBC cells, CIP4 knock-down (KD) led to less sustained activation of Erk kinase and impaired cell motility compared to control cells. This correlated with significant defects in 3D invasion of surrounding extracellular matrix by CIP4 KD TNBC cells when grown as spheroid colonies. In mammary orthotopic xenograft assays using both human TNBC cells (MDA-MB-231, HCC 1806) and rat MTLn3 cells, CIP4 silencing had no overt effect on tumor growth, but significantly reduced the incidence of lung metastases in each tumor model. In human invasive breast cancers, high CIP4 levels was significantly associated with high tumor stage, TNBC and HER2 subtypes, and risk of progression to metastatic disease. Together, these results implicate CIP4 in promoting metastasis in TNBCs. 相似文献
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The relation between constitutional skin color and photosensitivity estimated from UV-induced erythema and pigmentation dose-response curves 总被引:4,自引:0,他引:4
W Westerhof O Estevez-Uscanga J Meens A Kammeyer M Durocq I Cario 《The Journal of investigative dermatology》1990,94(6):812-816
In 54 healthy volunteers we assessed predictors of sensitivity to ultraviolet (UV) light, including Fitzpatrick's sun reactive skin types and constitutional skin color, and compared these with one another and with responses of the skin to UV irradiation, as determined experimentally by a minimal erythema dose (MED), a minimal melanogenic dose (MMD), and dose-response curves for UV-induced erythema and pigmentation. For these studies, a xenon arc solar simulator was used as the source of UV irradiation, and a chromameter interfaced with a computer for objective measurement of UV-induced erythema and pigmentation was employed. The skin type did not correspond well to the constitutional skin color, as measured by a chromameter prior to UV irradiation. Within each skin type, there were large ranges of MED and MMD values and great variability in the shapes of the dose-response curves. Constitutional skin color was also not a good predictor of the measured MED and MMD values but did appear to correlate with the steepness of the dose-response curves for erythema and for pigmentation. From these studies, we propose that objectively measured constitutional skin color is a better predictor of UV responses of the skin than skin type and that steepness of dose-response curves for erythema is a better measure of the response of the skin to UV irradiation than is a MED measurement. 相似文献
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Meens MJ Mattheij NJ van Loenen PB Spijkers LJ Lemkens P Nelissen J Compeer MG Alewijnse AE De Mey JG 《British journal of pharmacology》2012,166(1):297-308