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771.
Gisela Adrienne Weiss Thomas Grabinger Jesus Glaus Garzon Tobias Hasler Anna Greppi Christophe Lacroix Nikolay Khanzhin Thierry Hennet 《Cellular microbiology》2021,23(1)
Endogenous carbohydrates released from the intestinal mucus represent a constant source of nutrients to the intestinal microbiota. Mucus‐derived carbohydrates can also be used as building blocks in the biosynthesis of bacterial cell wall components, thereby influencing host mucosal immunity. To assess the uptake of endogenous carbohydrates by gut microbes in healthy mice and during intestinal inflammation, we applied azido‐monosaccharides that can be tracked on bacterial cell walls after conjugation with fluorophores. In interleukin‐10 deficient mice, changes in the gut microbiota were accompanied by decreased carbohydrate hydrolase activities and increased lumenal concentrations of host glycan‐derived monosaccharides. Tracking of the monosaccharide N‐azidoacetylglucosamine (GlcNAz) in caecum bacteria revealed a preferential incorporation of this carbohydrate by Xanthomonadaceae in healthy mice and by Bacteroidaceae in interleukin‐10 deficient mice. These GlcNAz‐positive Bacteroidaceae fractions mainly belonged to the species B. acidifaciens and B. vulgatus. Growth of Bacteroides species in the presence of specific monosaccharides changed their stimulatory activity toward CD11c+ dendritic cells. Expression of activation markers and cytokine production was highest after stimulation of dendritic cells with B. vulgatus. The variable incorporation of monosaccharides by related Bacteroides species underline the necessity to investigate intestinal bacteria down to the species level when addressing microbiota‐host interactions. 相似文献
772.
Dong J Sereno A Snyder WB Miller BR Tamraz S Doern A Favis M Wu X Tran H Langley E Joseph I Boccia A Kelly R Wortham K Wang Q Berquist L Huang F Gao SX Zhang Y Lugovskoy A Martin S Gouvis H Berkowitz S Chiang G Reff M Glaser SM Hariharan K Demarest SJ 《The Journal of biological chemistry》2011,286(6):4703-4717
Bispecific antibodies (BsAbs) target multiple epitopes on the same molecular target or different targets. Although interest in BsAbs has persisted for decades, production of stable and active BsAbs has hindered their clinical evaluation. Here, we describe the production and characterization of tetravalent IgG-like BsAbs that combine the activities of allosteric and competitive inhibitors of the type-I insulin-like growth factor receptor (IGF-1R). The BsAbs, which were engineered for thermal stability, express well, demonstrate favorable biophysical properties, and recognize both epitopes on IGF-1R. Only one BsAb with a unique geometry, denoted BIIB4-5scFv, was capable of engaging all four of its binding arms simultaneously. All the BsAbs (especially BIIB4-5scFv) demonstrated enhanced ligand blocking over the single monoclonal antibodies (mAbs), particularly at high ligand concentrations. The pharmacokinetic profiles of two IgG-like BsAbs were tested in nude mice and shown to be comparable with that of the parental mAbs. The BsAbs, especially BIIB4-5scFv, demonstrated an improved ability to reduce the growth of multiple tumor cell lines and to inhibit ligand-induced IGF-1R signaling in tumor cells over the parental mAbs. BIIB4-5scFv also led to superior tumor growth inhibition over its parental mAbs in vivo. In summary, BsAbs that bridge multiple inhibitory mechanisms against a single target may generally represent a more effective strategy for intervention in oncology or other indications compared with traditional mAb therapy. 相似文献
773.
Bacteriophage T4 genome. 总被引:2,自引:0,他引:2
Eric S Miller Elizabeth Kutter Gisela Mosig Fumio Arisaka Takashi Kunisawa Wolfgang Rüger 《Microbiology and molecular biology reviews》2003,67(1):86-156, table of contents
774.
Coca M Bortolotti C Rufat M Peñas G Eritja R Tharreau D del Pozo AM Messeguer J San Segundo B 《Plant molecular biology》2004,54(2):245-259
The Aspergillus giganteus antifungal protein (AFP), encoded by the afp gene, has been reported to possess in vitro antifungal activity against various economically important fungal pathogens, including the rice blast fungus Magnaporthe grisea. In this study, transgenic rice ( Oryza sativa ) constitutively expressing the afp gene was generated by Agrobacterium -mediated transformation. Two different DNA constructs containing either the afp cDNA sequence from Aspergillus or a chemically synthesized codon-optimized afp gene were introduced into rice plants. In both cases, the DNA region encoding the signal sequence from the tobacco AP24 gene was N-terminally fused to the coding sequence of the mature AFP protein. Transgenic rice plants showed stable integration and inheritance of the transgene. No effect on plant morphology was observed in the afp -expressing rice lines. The inhibitory activity of protein extracts prepared from leaves of afp plants on the in vitro growth of M. grisea indicated that the AFP protein produced by the trangenic rice plants was biologically active. Several of the T(2) homozygous afp lines were challenged with M. grisea in a detached leaf infection assay. Transformants exhibited resistance to rice blast at various levels. Altogether, the results presented here indicate that AFP can be functionally expressed in rice plants for protection against the rice blast fungus M. grisea. 相似文献
775.
Else Eising Sjoerd M. H. Huisman Ahmed Mahfouz Lisanne S. Vijfhuizen Verneri Anttila Bendik S. Winsvold Tobias Kurth M. Arfan Ikram Tobias Freilinger Jaakko Kaprio Dorret I. Boomsma Cornelia M. van Duijn Marjo-Riitta R. Järvelin John-Anker Zwart Lydia Quaye David P. Strachan Christian Kubisch Martin Dichgans George Davey Smith Kari Stefansson Aarno Palotie Daniel I. Chasman Michel D. Ferrari Gisela M. Terwindt Boukje de Vries Dale R. Nyholt Boudewijn P. F. Lelieveldt Arn M. J. M. van den Maagdenberg Marcel J. T. Reinders 《Human genetics》2016,135(4):425-439
776.
The arbuscular mycorrhizal fungal (AMF) communities associated with cacao in Venezuela were studied. The species of AMF spores present in sixteen cacao plantations and in one nursery were isolated and identified when possible. The spore densities, species richness, diversity, Shannon-Wiener diversity index and dominance concentration index for the AMF communities were calculated. Acaulospora scrobiculata was associated with cacao plants in all study sites. No Scutellospora spp. were found in the analyzed soils. The spore number found in cacao plantations was relatively lower as compared with other tropical crops (38 spores 100 g–1 soil up to 1674). Soils that were cultivated with cacao for more than 40 years showed the lowest spore numbers. Species richness and diversity of AMF communities associated with cacao, were negatively correlated with available P in soils. The Shannon-Wiener diversity index was positively correlated with soil organic matter. These results indicate that the traditional cacao cultivation practices used in Venezuela, maintain mycorrhizal infection on cacao plants. The diversity of the AMF community is similar to that found in natural undisturbed ecosystems from Venezuela. 相似文献
777.
Juan M. Fernández Gisela Di Giusto Maia Kalstein Luciana Melamud Valeria Rivarola Paula Ford Claudia Capurro 《PloS one》2013,8(2)
Müller cells are mainly involved in controlling extracellular homeostasis in the retina, where intense neural activity alters ion concentrations and osmotic gradients, thus favoring cell swelling. This increase in cell volume is followed by a regulatory volume decrease response (RVD), which is known to be partially mediated by the activation of K+ and anion channels. However, the precise mechanisms underlying osmotic swelling and subsequent cell volume regulation in Müller cells have been evaluated by only a few studies. Although the activation of ion channels during the RVD response may alter transmembrane potential (Vm), no studies have actually addressed this issue in Müller cells. The aim of the present work is to evaluate RVD using a retinal Müller cell line (MIO-M1) under different extracellular ionic conditions, and to study a possible association between RVD and changes in Vm. Cell volume and Vm changes were evaluated using fluorescent probe techniques and a mathematical model. Results show that cell swelling and subsequent RVD were accompanied by Vm depolarization followed by repolarization. This response depended on the composition of extracellular media. Cells exposed to a hypoosmotic solution with reduced ionic strength underwent maximum RVD and had a larger repolarization. Both of these responses were reduced by K+ or Cl− channel blockers. In contrast, cells facing a hypoosmotic solution with the same ionic strength as the isoosmotic solution showed a lower RVD and a smaller repolarization and were not affected by blockers. Together, experimental and simulated data led us to propose that the efficiency of the RVD process in Müller glia depends not only on the activation of ion channels, but is also strongly modulated by concurrent changes in the membrane potential. The relationship between ionic fluxes, changes in ion permeabilities and ion concentrations –all leading to changes in Vm– define the success of RVD. 相似文献
778.
779.
Katherine Muñoz Mario Vega Gisela Rios Rolf Geisen Gisela H. Degen 《Mycotoxin Research》2011,27(4):239-247
Ochratoxin A (OTA) is one of the most widespread mycotoxins, and is produced by several Aspergillus or Penicillium species. Human exposure to OTA is mainly by intake of contaminated food, with cereal products, followed by coffee and red
wine as the main sources of OTA. In this study, the OTA production of four ochratoxigenic fungi (two Aspergillus and two Penicillium species) was investigated in four different media, i.e. wheat and coffee model media as food-based media and two standard laboratory media (malt extract glucose agar, MEA and yeast
extract sucrose agar, YES). Colony growth was documented and OTA concentrations in cultures were determined at day 2, 4 and
8 of incubation at 25°C by high-performance thin-layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC).
OTA production clearly depended upon time of incubation, fungal species, and medium composition. On coffee based medium, moderate
OTA levels were produced by A. ochraceus BFE635 (9.8 μg/g) and by A. niger BFE632 (10.6 μg/g) on day 8 of incubation. In wheat-based medium, these strains produced much more OTA than in coffee. The
highest OTA concentration (83.8 μg/g on day 8) was formed by A. ochraceus BFE635 followed by the other Aspergillus niger BFE632 (49 μg/g). Lower OTA levels were produced by P. verrucosum BFE550 and P. nordicum BFE487, in both wheat and in YES medium, whilst OTA was hardly detectable in coffee and in MEA in case of P. nordicum. Colony growth of the tested strains on different media was not indicative of OTA production. Guttation droplets developed
on wheat-based medium with the Aspergillus strains within a week, and this phenomenon coincided with the high OTA amounts formed by these species. Results from this
study add to our knowledge on the behaviour of ochratoxigenic fungal species when cultured on food based media. 相似文献
780.
Gisela Mosig 《Genetics》1968,59(2):137-151