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81.
Susana Romao Nathalie Gasser Andrea C. Becker Bruno Guhl Milica Bajagic Danusia Vanoaica Urs Ziegler Joachim Roesler J?rn Dengjel Janine Reichenbach Christian Münz 《The Journal of cell biology》2013,203(5):757-766
Antigen preservation for presentation is a hallmark of potent antigen-presenting cells. In this paper, we report that in human macrophages and dendritic cells, a subset of phagosomes gets coated with Atg8/LC3, a component of the molecular machinery of macroautophagy, and maintains phagocytosed antigens for prolonged presentation on major histocompatibility complex class II molecules. These Atg8/LC3-positive phagosomes are formed around the antigen with TLR2 agonists and require reactive oxygen species production by NOX2 for their generation. A deficiency in the NOX2-dependent formation of these antigen storage phagosomes could contribute to compromise antifungal immune control in chronic granulomatous disease patients. 相似文献
82.
Jovana Čukuranović Kokoris Ivan Jovanović Vukica Pantović Miljan Krstić Milica Stanojković Verica Milošević Slađana Ugrenović Vesna Stojanović 《Tissue & cell》2017,49(1):78-85
The aim of this research was to quantify the changes in the morphology and density of the anterior pituitary folliculostellate (FS) and luteinizing hormone (LH) cells. Material was tissue of the pituitary gland of the 14 male cadavers. Tissue slices were immunohistochemically stained with monoclonal anti-LH antibody and polyclonal anti-S100 antibody for the detection of LH and FS cells, respectively. Digital images of the stained slices were afterwards morphometrically analyzed by ImageJ. Results of the morphometric analysis showed significant increase of the FS cells volume density in cases older than 70 years. Volume density of the LH cells did not significantly change, whereas their area significantly increased with age. Nucleocytoplasmic ratio of the LH cells gradually decreased and became significant after the age of 70. Finally, volume density of the FS cell significantly correlated with LH cells area and nucleocytoplasmic ratio. From all above cited, we concluded that in men, density and size of the FS cells increase with age. Long-term hypertrophy of the LH cells results in their functional decline after the age of 70. Strong correlation between FS cells and LH cells morphometric parameters might point to age-related interaction between these two cell groups. 相似文献
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84.
Jovanka Lukic Ivana Strahinic Marina Milenkovic Milica Nikolic Maja Tolinacki Milan Kojic Jelena Begovic 《Microbial ecology》2014,68(3):633-644
Modern research in the area of probiotics is largely devoted to discovering factors that promote the adherence of probiotic candidates to host mucosal surfaces. The aim of the present study was to test the role of aggregation factor (AggL) and mucin-binding protein (MbpL) from Lactococcus sp. in adhesion to gastrointestinal mucosa. In vitro, ex vivo, and in vivo experiments in rats were used to assess the adhesive potential of these two proteins expressed in heterologous host Lactobacillus salivarius BGHO1. Although there was no influence of MbpL protein expression on BGHO1 adhesion to gut mucosa, expression of AggL had a negative effect on BGHO1 binding to ileal and colonic rat mucosa, as well as to human HT29-MTX cells and porcine gastric mucin in vitro. Because AggL did not decrease the adhesion of bacteria to intestinal fragments in ex vivo tests, where peristaltic simulation conditions were missing, we propose that intestinal motility could be a crucial force for eliminating aggregation-factor-bearing bacteria. Bacterial strains expressing aggregation factor could facilitate the removal of pathogens through the coaggregation mechanism, thus balancing gut microbial ecosystems in people affected by intestinal bacteria overgrowth. 相似文献
85.
Eleanor C. Saunders William W. Ng Joachim Kloehn Jennifer M. Chambers Milica Ng Malcolm J. McConville 《PLoS pathogens》2014,10(1)
Leishmania parasites alternate between extracellular promastigote stages in the insect vector and an obligate intracellular amastigote stage that proliferates within the phagolysosomal compartment of macrophages in the mammalian host. Most enzymes involved in Leishmania central carbon metabolism are constitutively expressed and stage-specific changes in energy metabolism remain poorly defined. Using 13C-stable isotope resolved metabolomics and 2H2O labelling, we show that amastigote differentiation is associated with reduction in growth rate and induction of a distinct stringent metabolic state. This state is characterized by a global decrease in the uptake and utilization of glucose and amino acids, a reduced secretion of organic acids and increased fatty acid β-oxidation. Isotopomer analysis showed that catabolism of hexose and fatty acids provide C4 dicarboxylic acids (succinate/malate) and acetyl-CoA for the synthesis of glutamate via a compartmentalized mitochondrial tricarboxylic acid (TCA) cycle. In vitro cultivated and intracellular amastigotes are acutely sensitive to inhibitors of mitochondrial aconitase and glutamine synthetase, indicating that these anabolic pathways are essential for intracellular growth and virulence. Lesion-derived amastigotes exhibit a similar metabolism to in vitro differentiated amastigotes, indicating that this stringent response is coupled to differentiation signals rather than exogenous nutrient levels. Induction of a stringent metabolic response may facilitate amastigote survival in a nutrient-poor intracellular niche and underlie the increased dependence of this stage on hexose and mitochondrial metabolism. 相似文献
86.
Production of glycosylated thermostable Providencia rettgeri penicillin G amidase in Pichia pastoris
Penicillin G amidase from Providencia rettgeri is a heterodimer of 92 kDa. We have previously expressed the Pr. rettgeri pac gene coding for this enzyme in Saccharomyces cerevisiae, and now we report the expression and characterization in the methylotrophic yeast Pichia pastoris. The recombinant catalytically active enzyme (rPAC(Pr)) was secreted from shake flask-grown P. pastoris cells into the medium at a level of approximately 0.18 U ml(-1). This yield of rPAC(Pr) was higher, by two orders of magnitude, than that obtained using a single-copy expression plasmid in S. cerevisiae. In addition, the secreted recombinant enzyme was entirely N-glycosylated. The recombinant PAC(Pr) was further characterized in terms of specific activity, kinetic parameters and thermostability. Except the significantly higher thermostability of the glycosylated rPAC(Pr) produced in P. pastoris, the other parameters were very similar to those of the corresponding non-glycosylated enzymes produced in bacteria or in S. cerevisiae. The higher thermostability of this recombinant enzyme has a clear industrial advantage. 相似文献
87.
Warren L. Grayson Timothy P. Martens George M. Eng Milica Radisic Gordana Vunjak-Novakovic 《Seminars in cell & developmental biology》2009,20(6):665-673
The overall goal of tissue engineering is to create functional tissue grafts that can regenerate or replace our defective or worn out tissues and organs. Examples of grafts that are now in pre-clinical studies or clinical use include engineered skin, cartilage, bone, blood vessels, skeletal muscle, bladder, trachea, and myocardium. Engineered tissues are also finding applications as platforms for pharmacological and physiological studies in vitro. To fully mobilize the cell's biological potential, a new generation of tissue engineering systems is now being developed to more closely recapitulate the native developmental milieu, and mimic the physiologic mechanisms of transport and signaling. We discuss the interactions between regenerative biology and engineering, in the context of (i) creation of functional tissue grafts for regenerative medicine (where biological input is critical), and (ii) studies of stem cells, development and disease (where engineered tissues can serve as advanced 3D models). 相似文献
88.
Djukić-Cosić D Ninković M Malicević Z Plamenac-Bulat Z Matović V 《Biological trace element research》2006,114(1-3):281-291
In this report, we present the results of our investigations on the effect of Mg pretreatment on Cd and bioelements (Cu and
Zn) contents in kidney of mice exposed to acute and subacute Cd intoxication. Acute intoxication was performed on male Swiss
mice given a single oral dose of 20 mg Cd/kg body weight and mice given the same dose of Cd but pretreated with 40 mg Mg/kg
body weight. For subacute intoxication one group of mice was given 10 mg Cd/kg body weight every day, for 2 wk, and the other
one received the same dose of Cd after oral Mg intake of 20 mg/kg body weight. Cd, Cu, and Zn content was determined in kidney
by atomic absorption spectrophotometry. In acute Cd intoxication, Mg pretreatment resulted in significant decrease of Cd in
kidney after 4 and 6 h, compared with animals given only Cd. Under the condition of subacute Cd intoxication, Mg supplementation
reduced Cd kidney content after 2 wk for about 30%, compared with animals treated with Cd only. The effect of Mg on Cu and
Zn kidney content was also beneficial. 相似文献
89.
Igor S. Mačinković Mohamed Abughren Ivan Mrkic Milica M. Grozdanović Radivoje Prodanović Marija Gavrović-Jankulović 《Journal of biotechnology》2013
High levels of recombinant protein expression can lead to the formation of insoluble inclusion bodies. These complex aggregates are commonly solubilized in strong denaturants, such as 6–8 M urea, although, if possible, solubilization under milder conditions could facilitate subsequent refolding and purification of bioactive proteins. Commercially available GST-tag assays are designed for quantitative measurement of GST activity under native conditions. GST fusion proteins accumulated in inclusion bodies are considered to be undetectable by such assays. In this work, solubilization of recombinantly produced proteins was performed in 4 M urea. The activity of rGST was assayed in 2 M urea and it was shown that rGST preserves 85% of its activity under such denaturing conditions. A colorimetric GST activity assay with 1-chloro-2, 4-dinitrobenzene (CDNB) was examined for use in rapid detection of expression targeted to inclusion bodies and for the identification of inclusion body proteins which can be solubilized in low concentrations of chaotropic agents. Applicability of the assay was evaluated by tracking protein expression of two GST-fused allergens of biopharmaceutical value in E. coli, GST-Der p 2 and GST-Mus a 5, both targeted to inclusion bodies. 相似文献
90.