Measles virus glycoprotein-based lentiviral targeting vectors that avoid neutralizing antibodies

Lentiviral vectors (LVs) are potent gene transfer vehicles frequently applied in research and recently also in clinical trials. Retargeting LV entry to cell types of interest is a key issue to improve gene transfer safety and efficacy. Recently, we have developed a targeting method for LVs by incorporating engineered measles virus (MV) glycoproteins, the hemagglutinin (H), responsible for receptor recognition, and the fusion protein into their envelope. The H protein displays a single-chain antibody (scFv) specific for the target receptor and is ablated for recognition of the MV receptors CD46 and SLAM by point mutations in its ectodomain. A potential hindrance to systemic administration in humans is pre-existing MV-specific immunity due to vaccination or natural infection. We compared transduction of targeting vectors and non-targeting vectors pseudotyped with MV glycoproteins unmodified in their ectodomains (MV-LV) in presence of α-MV antibody-positive human plasma. At plasma dilution 1:160 MV-LV was almost completely neutralized, whereas targeting vectors showed relative transduction efficiencies from 60% to 90%. Furthermore, at plasma dilution 1:80 an at least 4-times higher multiplicity of infection (MOI) of MV-LV had to be applied to obtain similar transduction efficiencies as with targeting vectors. Also when the vectors were normalized to their p24 values, targeting vectors showed partial protection against α-MV antibodies in human plasma. Furthermore, the monoclonal neutralizing antibody K71 with a putative epitope close to the receptor binding sites of H, did not neutralize the targeting vectors, but did neutralize MV-LV. The observed escape from neutralization may be due to the point mutations in the H ectodomain that might have destroyed antibody binding sites. Furthermore, scFv mediated cell entry via the target receptor may proceed in presence of α-MV antibodies interfering with entry via the natural MV receptors. These results are promising for in vivo applications of targeting vectors in humans

Teaching Landeskunde within the Framework of Korean as a Foreign Language

2007In the era of globalization and internationalisation, it has become more and more common that well-qualified students both in Germany and in Korea have better job opportunities if they gain not only specific knowledge in their major subject, but also competence in one or more foreign languages as well as intercultural competence. In the case of foreign language education scientists are assigned to develop and to provide teaching methods for foreign language teachers, who are nowadays required to promote aforementioned competences. Therefore foreign language teachers are especially entailed to teach and mediate foreign languages and cultures

Vegetation complexity and nesting resource availability predict bee diversity and functional traits in community gardens

Urban gardens can support diverse bee communities through resource provision in resource poor environments. Yet the effects of local habitat and landscape factors on wild bee communities in cities is still insufficiently understood, nor is how this information could be applied to urban wildlife conservation. Here we investigate how taxonomic and functional diversity of wild bees and their traits in urban community gardens are related to garden factors and surrounding landscape factors (e.g., plant diversity, amount of bare ground, amount of nesting resources, amount of landscape imperviousness). Using active and passive methods in 18 community gardens in Berlin, Germany, we documented 26 genera and 102 species of bees. We found that higher plant species richness and plant diversity as well as higher amounts of deadwood in gardens leads to higher numbers of wild bee species and bee (functional) diversity. Furthermore, higher landscape imperviousness surrounding gardens correlates with more cavity nesting bees, whereas a higher amount of bare ground correlates with more ground‐nesting bees. Pollen specialization was positively associated with plant diversity, but no factors strongly predicted the proportion of endangered bees. Our results suggest that, aside from foraging resources, nesting resources should be implemented in management for more pollinator‐friendly gardens. If designed and managed using such evidence‐based strategies, urban gardens can create valuable foraging and nesting habitats for taxonomically and functionally diverse bee communities in cities

Composition-Dependent Structural and Transport Properties of Amorphous Transparent Conducting Oxides

Structural properties of amorphous In-based oxides, In-X-O with X=Zn, Ga, Sn, or Ge, are investigated using ab initio molecular dynamics liquid-quench simulations. The results reveal that indium retains its average coordination of 5.0 upon 20% X fractional substitution for In, whereas X cations satisfy their natural coordination with oxygen atoms. This finding suggests that the carrier generation is primarily governed by In atoms, in accord with the observed carrier concentration in amorphous In-O and In-X-O. At the same time, the presence of X affects the number of six-coordinated In atoms as well as the oxygen sharing between the InO6 polyhedra. Based on the obtained interconnectivity and spatial distribution of the InO6 and XOx polyhedra in amorphous In-X-O, composition-dependent structural models of the amorphous oxides are derived. The results help explain our Hall mobility measurements in In-X-O thin films grown by pulsed-laser deposition and highlight the importance of long-range structural correlations in the formation of amorphous oxides and their transport properties

Fusoselect: cell-cell fusion activity engineered by directed evolution of a retroviral glycoprotein

Membrane fusion plays a key role in many biological processes including vesicle trafficking, synaptic transmission, fertilization or cell entry of enveloped viruses. As a common feature the fusion process is mediated by distinct membrane proteins. We describe here ‘Fusoselect', a universal procedure allowing the identification and engineering of molecular determinants for cell-cell fusion-activity by directed evolution. The system couples cell-cell fusion with the release of retroviral particles, but can principally be applied to membrane proteins of non-viral origin as well. As a model system, we chose a γ-retroviral envelope protein, which naturally becomes fusion-active through proteolytic processing by the viral protease. The selection process evolved variants that, in contrast to the parental protein, mediated cell-cell fusion in absence of the viral protease. Detailed analysis of the variants revealed molecular determinants for fusion competence in the cytoplasmic tail (CT) of retroviral Env proteins and demonstrated the power of Fusoselec

Fusoselect: cell–cell fusion activity engineered by directed evolution of a retroviral glycoprotein

Membrane fusion plays a key role in many biological processes including vesicle trafficking, synaptic transmission, fertilization or cell entry of enveloped viruses. As a common feature the fusion process is mediated by distinct membrane proteins. We describe here ‘Fusoselect’, a universal procedure allowing the identification and engineering of molecular determinants for cell–cell fusion-activity by directed evolution. The system couples cell–cell fusion with the release of retroviral particles, but can principally be applied to membrane proteins of non-viral origin as well. As a model system, we chose a γ-retroviral envelope protein, which naturally becomes fusion-active through proteolytic processing by the viral protease. The selection process evolved variants that, in contrast to the parental protein, mediated cell–cell fusion in absence of the viral protease. Detailed analysis of the variants revealed molecular determinants for fusion competence in the cytoplasmic tail (CT) of retroviral Env proteins and demonstrated the power of Fusoselect

Gauge-invariant charged, monopole and dyon fields in gauge theories

We propose explicit recipes to construct the euclidean Green functions of gauge-invariant charged, monopole and dyon fields in four-dimensional gauge theories whose phase diagram contains phases with deconfined electric and/or magnetic charges. In theories with only either abelian electric or magnetic charges, our construction is an euclidean version of Dirac's original proposal, the magnetic dual of his proposal, respectively. Rigorous mathematical control is achieved for a class of abelian lattice theories. In theories where electric and magnetic charges coexist, our construction of Green functions of electrically or magnetically charged fields involves taking an average over Mandelstam strings or the dual magnetic flux tubes, in accordance with Dirac's flux quantization condition. We apply our construction to 't Hooft-Polyakov monopoles and Julia-Zee dyons. Connections between our construction and the semiclassical approach are discussed

Evaluation of Ki-67 expression in feline non-ocular melanocytic tumours

Fifty tumours located in skin (n = 33) and mucosae (n = 17) were included. Forty-eight percent and 95% of amelanotic tumours (n = 21) stained positive for Melan A and S100, respectively. Most achromic tumours were mucosal (P  5, Ki-67 > 20% and lack of treatment administration. On multivariable analysis, only tumour histotype and treatment retained prognostic significance. Conclusions Although the majority of feline NOMs behave aggressively, Ki-67 index, together with other parameters, may contribute to prognostic assessment. Prospective studies on homogeneous populations are warranted to identify reliable threshold values for this marker

Differing marine animal biomass shifts under 21st century climate change between Canada's three ocean

Identificadors digitals: Digital object identifier for the 'European Research Council' (http://dx.doi.org/10.13039/501100000781) and Digital object identifier for 'Horizon 2020' (http://dx.doi.org/10.13039/501100007601)Unidad de excelencia María de Maeztu CEX2019-000940-MUnder climate change, species composition and abundances in high-latitude waters are expected to substantially reconfigure with consequences for trophic relationships and ecosystem services. Outcomes are challenging to project at national scales, despite their importance for management decisions. Using an ensemble of six global marine ecosystem models we analyzed marine ecosystem responses to climate change from 1971 to 2099 in Canada's Exclusive Economic Zone (EEZ) under four standardized emissions scenarios. By 2099, under business-as-usual emissions (RCP8.5) projected marine animal biomass declined by an average of −7.7% (±29.5%) within the Canadian EEZ, dominated by declines in the Pacific (−24% ± 24.5%) and Atlantic (−25.5% ± 9.5%) areas; these were partially compensated by increases in the Canadian Arctic (+26.2% ± 38.4%). Lower emissions scenarios projected successively smaller biomass changes, highlighting the benefits of stronger mitigation targets. Individual model projections were most consistent in the Atlantic and Pacific, but highly variable in the Arctic due to model uncertainties in polar regions. Different trajectories of future marine biomass changes will require regional-specific responses in conservation and management strategies, such as adaptive planning of marine protected areas and species-specific management plans, to enhance resilience and rebuilding of Canada's marine ecosystems and commercial fish stocks

Iron Oxide Nanoparticles for Visualization of Prostate Cancer in MRI

Prostate cancer (PCa) is one of the most common cancers in men. For detection and diagnosis of PCa, non-invasive methods, including magnetic resonance imaging (MRI), can reduce the risk potential of surgical intervention. To explore the molecular characteristics of the tumor, we investigated the applicability of ferumoxytol in PCa in a xenograft mouse model in two different tumor volumes, 500 mm3 and 1000 mm3. Macrophages play a key role in tumor progression, and they are able to internalize iron-oxide particles, such as ferumoxytol. When evaluating T2*-weighted sequences on MRI, a significant decrease of signal intensity between pre- and post-contrast images for each tumor volume (n = 14; p < 0.001) was measured. We, furthermore, observed a higher signal loss for a tumor volume of 500 mm3 than for 1000 mm3. These findings were confirmed by histological examinations and laser ablation inductively coupled plasma-mass spectrometry. The 500 mm3 tumors had 1.5% iron content (n = 14; σ = 1.1), while the 1000 mm3 tumors contained only 0.4% iron (n = 14; σ = 0.2). In vivo MRI data demonstrated a correlation with the ex vivo data (R2 = 0.75). The results of elemental analysis by inductively coupled plasma-mass spectrometry correlated strongly with the MRI data (R2 = 0.83) (n = 4). Due to its long retention time in the blood, biodegradability, and low toxicity to patients, ferumoxytol has great potential as a contrast agent for visualization PCa.SonderforschungsbereichDeutsche ForschungsgemeinschaftPeer Reviewe