Molecular immunophenotyping of lungs and spleens in naive and vaccinated chickens early after pulmonary avian influenza A (H9N2) virus infection

In a respiratory-infection-model with the avian influenza A H9N2 virus we studied lung and splenic immune reactions in chickens using a recently developed 5K chicken immuno-microarray. Groups of chickens were either mock-immunized (referred to as non-immune), vaccinated with inactivated viral antigen only (immune) or with viral antigen in a water-in-oil (W/O) immunopotentiator (immune potentiated). Three weeks after vaccination all animals were given a respiratory infection. Immune potentiated birds developed inhibitory antiviral antibodies, showed minimal lung histopathology and no detectable viral sequences, while non-immune animals showed microscopic immunopathology and detectable virus. Immune birds, receiving antigen in saline only, showed minimal microscopic histopathology, and intermediate levels of virus detection. These classical features in the different groups were mirrored by overlapping or specific mRNA gene expression profiles in lungs and spleen using microarray analysis. To our knowledge this is the first study demonstrating pneumonia-associated lung pathology of the low pathogenic avian influenza H9N2 virus. Our data provide insights into the molecular interaction of this virus with its natural host when naive or primed by vaccination

Strong Electron-Phonon Coupling in Superconducting MgB2_2: A Specific Heat Study

We report on measurements of the specific heat of the recently discovered superconductor MgB$_2$ in the temperature range between 3 and 220 K. Based on a modified Debye-Einstein model, we have achieved a rather accurate account of the lattice contribution to the specific heat, which allows us to separate the electronic contribution from the total measured specific heat. From our result for the electronic specific heat, we estimate the electron-phonon coupling constant $\lambda$ to be of the order of 2, significantly enhanced compared to common weak-coupling values $\leq 0.4$. Our data also indicate that the electronic specific heat in the superconducting state of MgB$_2$ can be accounted for by a conventional, s-wave type BCS-model.Comment: 4 pages, 4 figure

Rubisco activation by wheat Rubisco activase isoform 2β is insensitive to inhibition by ADP

Rubisco activase (Rca) is a catalytic chaperone that remodels the active site, promotes the release of inhibitors and restores catalytic competence to Rubisco. Rca activity and its consequent effect on Rubisco activation and photosynthesis are modulated by changes to the chloroplast environment induced by fluctuations in light levels that reach the leaf, including redox status and adenosine diphosphate (ADP)/adenosine triphosphate (ATP) ratio. The Triticum aestivum (wheat) genome encodes for three Rca protein isoforms: 1β (42.7 kDa), 2β (42.2 kDa) and 2α (46.0 kDa). The regulatory properties of these isoforms were characterised by measuring rates of Rubisco activation and ATP hydrolysis by purified recombinant Rca proteins in the presence of physiological ADP/ATP ratios. ATP hydrolysis by all three isoforms was sensitive to inhibition by increasing amounts of ADP in the assay. In contrast, Rubisco activation activity of Rca 2β was insensitive to ADP inhibition, while Rca 1β and 2α were inhibited. Two double and one quadruple site-directed mutants were designed to elucidate if differences in the amino acid sequences between Rca 1β and 2β could explain the differences in ADP sensitivity. Changing two amino acids in Rca 2β to the corresponding residues in 1β (T358K & Q362E) resulted in significant inhibition of Rubisco activation in presence of ADP. The results show that the wheat Rca isoforms differ in their regulatory properties and that amino acid changes in the C domain influence ADP sensitivity. Advances in the understanding of Rubisco regulation will aid efforts to improve the efficiency of photosynthetic CO2 assimilation

Development of a chicken 5 K microarray targeted towards immune function

<p>Abstract</p> <p>Background</p> <p>The development of microarray resources for the chicken is an important step in being able to profile gene expression changes occurring in birds in response to different challenges and stimuli. The creation of an immune-related array is highly valuable in determining the host immune response in relation to infection with a wide variety of bacterial and viral diseases.</p> <p>Results</p> <p>Here we report the development of chicken immune-related cDNA libraries and the subsequent construction of a microarray containing 5190 elements (in duplicate). Clones on the array originate from tissues known to contain high levels of cells related to the immune system, namely Bursa, Peyers patch, thymus and spleen. Represented on the array are genes that are known to cluster with existing chicken ESTs as well as genes that are unique to our libraries. Some of these genes have no known homologies and represent novel genes in the chicken collection. A series of reference genes (ie. genes of known immune function) are also present on the array. Functional annotation data is also provided for as many of the genes on the array as is possible.</p> <p>Conclusion</p> <p>Six new chicken immune cDNA libraries have been created and nearly 10,000 sequences submitted to GenBank [GenBank: <ext-link ext-link-type="gen" ext-link-id="AM063043">AM063043</ext-link>-<ext-link ext-link-type="gen" ext-link-id="AM071350">AM071350</ext-link>; <ext-link ext-link-type="gen" ext-link-id="AM071520">AM071520</ext-link>-<ext-link ext-link-type="gen" ext-link-id="AM072286">AM072286</ext-link>; <ext-link ext-link-type="gen" ext-link-id="AM075249">AM075249</ext-link>-<ext-link ext-link-type="gen" ext-link-id="AM075607">AM075607</ext-link>]. A 5 K immune-related array has been developed from these libraries. Individual clones and arrays are available from the ARK-Genomics resource centre.</p

Stationary shapes of deformable particles moving at low Reynolds numbers

Lecture Notes of the Summer School ``Microswimmers -- From Single Particle Motion to Collective Behaviour'', organised by the DFG Priority Programme SPP 1726 (Forschungszentrum J{\"{u}}lich, 2015).Comment: Pages C7.1-16 of G. Gompper et al. (ed.), Microswimmers - From Single Particle Motion to Collective Behaviour, Lecture Notes of the DFG SPP 1726 Summer School 2015, Forschungszentrum J\"ulich GmbH, Schriften des Forschungszentrums J\"ulich, Reihe Key Technologies, Vol 110, ISBN 978-3-95806-083-

A robust, scanning quantum system for nanoscale sensing and imaging

Controllable atomic-scale quantum systems hold great potential as sensitive tools for nanoscale imaging and metrology. Possible applications range from nanoscale electric and magnetic field sensing to single photon microscopy, quantum information processing, and bioimaging. At the heart of such schemes is the ability to scan and accurately position a robust sensor within a few nanometers of a sample of interest, while preserving the sensor's quantum coherence and readout fidelity. These combined requirements remain a challenge for all existing approaches that rely on direct grafting of individual solid state quantum systems or single molecules onto scanning-probe tips. Here, we demonstrate the fabrication and room temperature operation of a robust and isolated atomic-scale quantum sensor for scanning probe microscopy. Specifically, we employ a high-purity, single-crystalline diamond nanopillar probe containing a single Nitrogen-Vacancy (NV) color center. We illustrate the versatility and performance of our scanning NV sensor by conducting quantitative nanoscale magnetic field imaging and near-field single-photon fluorescence quenching microscopy. In both cases, we obtain imaging resolution in the range of 20 nm and sensitivity unprecedented in scanning quantum probe microscopy

ANALYSIS OF CYTOARCHITECTONICS OF TLR2⁺ AND TLR4⁺ LYMPHOCYTES AND TRANSCRIPTIONAL ACTIVITY OF THE GENES <i>Gp2, Spi-B, Nf-kB1, с-REL, TNFα</i> AND <i>TNFr</i> IN GALT OF RATS IN EXPERIMENTAL DIABETES MELLITUS AND AFTER PENTOXIFYLLINE ADMINISTRATION

Summary.Changes in the state of gut-associated lymphoid tissue (GALT) and the composition of the intestinal microbiome, both in experimental STZ-induced diabetes and in development of type 1 diabetes in humans as well as chronic inflammation due to stimulation of innate immunity are crucially important in the development of type 1 diabetes mellitus. One of the most important mediators for interactions between the intestinal microbiome and GALT are specialized M cells of the follicle-associated epithelium, providing transcytotic delivery of antigens to the underlying lymphoid structures. TNFα-signaling also plays a supporting role in the formation of M cells. Therefore, the aim of our work was to study some features of TLRs expression and transcriptional activity of the Gp2, Spi-B, Nf-kB1, c-Rel, TNFα and TNFr genes in GALT in experimental diabetes mellitus (EDM), and after pentoxifylline administration. To identify TLR2+ cells and TLR4+ cells, an immunofluorescence method was used with monoclonal antibodies to corresponding pattern-recognizing receptors. To study the transcriptional activity of genes, the method of real-time reverse transcription polymerase chain reaction (RT-PCR) was used. In the course of developing experimental pathology, at the terms of 2 and 4 weeks, a decrease in the total density of TLR2+ and TLR4+ lymphocytes was observed in lamina propria of villus (villus) and subepithelial zone isolated lymphoid follicles (ILF) of rat ileum. At the same time, the density of TLR2 on the membrane of immunopositive cells was increased for small lymphocytes, and TLR4 density has became higher in medium and small lymphocytes. The pentoxifylline administration to diabetic rats resulted in a decrease in the total density of TLR2+ cells at the 2nd week of development of the pathology, and an increase in this index at the 4th week. The total density of TLR4+ cells showed changing growth rates only in villus at the 2nd week of EDM development in the presence of pentoxifylline. Changes in the density of TLR2 and TLR4 on the surface of lymphocytes were multidirectional. The development of diabetes is also reflected in the transcriptional induction of genes of the key transcription factors NF-kB1 and c-Rel in GALT cells at both the 2nd and 4th week of the development of EDM. Meanwhile, administration of pentoxifylline resulted in a significantly reduced level of normalized expression of NF-kB1 mRNA during the entire observation period and increased this indicator for c-Rel mRNA at the 2nd week. The growth of normalized expression of markers of M cells Gp2 and Spi-B was observed both on the 2nd and on the 4th week of the development of experimental pathology. Administration of pentoxifylline to diabetic animals was largely reflected in the change in the intensity of mRNA expression of the mature M cell Gp2 marker. This parameter was increased during the 2nd week of developing pathology, and on the 4th week, a downward trend was shown. The development of EDM led to a significantly increased level of near-normalized expression of proinflammatory TNFα cytokine and its receptor TNFr, and demonstrated a trend towards their decrease following pentoxifylline administration in diabetic animals