Differential gene expression in chicken primary B cells infected ex vivo with attenuated and very virulent strains of infectious bursal disease virus (IBDV).

Infectious bursal disease virus (IBDV) belongs to the family Birnaviridae and is economically important to the poultry industry worldwide. IBDV infects B cells in the bursa of Fabricius (BF), causing immunosuppression and morbidity in young chickens. In addition to strains that cause classical Gumboro disease, the so-called 'very virulent' (vv) strain, also in circulation, causes more severe disease and increased mortality. IBDV has traditionally been controlled through the use of live attenuated vaccines, with attenuation resulting from serial passage in non-lymphoid cells. However, the factors that contribute to the vv or attenuated phenotypes are poorly understood. In order to address this, we aimed to investigate host cell-IBDV interactions using a recently described chicken primary B-cell model, where chicken B cells are harvested from the BF and cultured ex vivo in the presence of chicken CD40L. We demonstrated that these cells could support the replication of IBDV when infected ex vivo in the laboratory. Furthermore, we evaluated the gene expression profiles of B cells infected with an attenuated strain (D78) and a very virulent strain (UK661) by microarray. We found that key genes involved in B-cell activation and signalling (TNFSF13B, CD72 and GRAP) were down-regulated following infection relative to mock, which we speculate could contribute to IBDV-mediated immunosuppression. Moreover, cells responded to infection by expressing antiviral type I IFNs and IFN-stimulated genes, but the induction was far less pronounced upon infection with UK661, which we speculate could contribute to its virulence

Intercultural ethics: questions of methods in language and intercultural communication

This paper explores how questions of ethics and questions of method are intertwined and unavoidable in any serious study of language and intercultural communication. It argues that the focus on difference and solution orientations to intercultural conflict has been a fundamental driver for theory, data collection and methods in the field. These approaches, the paper argues, have created a considerable consciousness raising industry, with methods, trainings and ‘critical incidents’, which ultimately focus intellectual energy in areas which may be productive in terms of courses and publications but which have a problematic basis in their ethical terrain. Dieser Artikel untersucht wie ethische und methodische Fragen nicht nur ineinander greifen, sondern in keiner ernstzunehmenden Studie ueber Sprache und interkulturelle Kommunikation ausgelassen werden duerfen. Es wird hier argumentiert, dass der Schwerpunkt auf Verschiedenheit und Problemorientierung im interkulturellen Konflikt einen wesentlichen Einfluss auf theoretische Entwicklungen, Datenerhebung und Methoden in diesem Bereich hatte. Dieser Artikel legt auch dar, wie diese Ansaetze eine betraechtliche ‘Bewusstseinsbildungs – Branche' erzeugt haben, mit Methoden, Trainings, und ‘kritischen Interaktionssituationen’, welche letztendlich allen intellektuellen Arbeitseifer auf Bereiche konzentriert hat, die zwar ertragreich sind in Bezug auf Kurse und Publikationen, jedoch eine problematische Grundlage im ethischen Bereich aufweisen

College of Radiology, Academy of Medicine of Malaysia position on whole body screening CT scans in healthy asymptomatic individuals (2008)

To date, the College of Radiology (CoR) does not see any clear benefit in performing whole body screening computed tomography (CT) examinations in healthy asymptomatic individuals. There are radiation risk issues in CT and principles of screening should be adhered to. There may be a role for targeted cardiac screening CT that derives calcium score, especially for asymptomatic medium-risk individuals and CT colonography when used as part of a strategic programme for colorectal cancer screening in those 50 years and older. However, population based screening CT examinations may become appropriate when evidence emerges regarding a clear benefit for the patient outweighing the associated radiation risks

Multiband tight-binding theory of disordered ABC semiconductor quantum dots: Application to the optical properties of alloyed CdZnSe nanocrystals

Zero-dimensional nanocrystals, as obtained by chemical synthesis, offer a broad range of applications, as their spectrum and thus their excitation gap can be tailored by variation of their size. Additionally, nanocrystals of the type ABC can be realized by alloying of two pure compound semiconductor materials AC and BC, which allows for a continuous tuning of their absorption and emission spectrum with the concentration x. We use the single-particle energies and wave functions calculated from a multiband sp^3 empirical tight-binding model in combination with the configuration interaction scheme to calculate the optical properties of CdZnSe nanocrystals with a spherical shape. In contrast to common mean-field approaches like the virtual crystal approximation (VCA), we treat the disorder on a microscopic level by taking into account a finite number of realizations for each size and concentration. We then compare the results for the optical properties with recent experimental data and calculate the optical bowing coefficient for further sizes

Brugia malayi Microfilariae Induce a Regulatory Monocyte/Macrophage Phenotype That Suppresses Innate and Adaptive Immune Responses

Background Monocytes and macrophages contribute to the dysfunction of immune responses in human filariasis. During patent infection monocytes encounter microfilariae in the blood, an event that occurs in asymptomatically infected filariasis patients that are immunologically hyporeactive. Aim To determine whether blood microfilariae directly act on blood monocytes and in vitro generated macrophages to induce a regulatory phenotype that interferes with innate and adaptive responses. Methodology and principal findings Monocytes and in vitro generated macrophages from filaria non-endemic normal donors were stimulated in vitro with Brugia malayi microfilarial (Mf) lysate. We could show that monocytes stimulated with Mf lysate develop a defined regulatory phenotype, characterised by expression of the immunoregulatory markers IL-10 and PD-L1. Significantly, this regulatory phenotype was recapitulated in monocytes from Wuchereria bancrofti asymptomatically infected patients but not patients with pathology or endemic normals. Monocytes from non-endemic donors stimulated with Mf lysate directly inhibited CD4+ T cell proliferation and cytokine production (IFN-γ, IL-13 and IL-10). IFN-γ responses were restored by neutralising IL-10 or PD-1. Furthermore, macrophages stimulated with Mf lysate expressed high levels of IL-10 and had suppressed phagocytic abilities. Finally Mf lysate applied during the differentiation of macrophages in vitro interfered with macrophage abilities to respond to subsequent LPS stimulation in a selective manner. Conclusions and significance Conclusively, our study demonstrates that Mf lysate stimulation of monocytes from healthy donors in vitro induces a regulatory phenotype, characterized by expression of PD-L1 and IL-10. This phenotype is directly reflected in monocytes from filarial patients with asymptomatic infection but not patients with pathology or endemic normals. We suggest that suppression of T cell functions typically seen in lymphatic filariasis is caused by microfilaria-modulated monocytes in an IL-10-dependent manner. Together with suppression of macrophage innate responses, this may contribute to the overall down-regulation of immune responses observed in asymptomatically infected patients

A direct comparison of strategies for combinatorial RNA interference

<p>Abstract</p> <p>Background</p> <p>Combinatorial RNA interference (co-RNAi) is a valuable tool for highly effective gene suppression of single and multiple-genes targets, and can be used to prevent the escape of mutation-prone transcripts. There are currently three main approaches used to achieve co-RNAi in animal cells; multiple promoter/shRNA cassettes, long hairpin RNAs (lhRNA) and miRNA-embedded shRNAs, however, the relative effectiveness of each is not known. The current study directly compares the ability of each co-RNAi method to deliver pre-validated siRNA molecules to the same gene targets.</p> <p>Results</p> <p>Double-shRNA expression vectors were generated for each co-RNAi platform and their ability to suppress both single and double-gene reporter targets were compared. The most reliable and effective gene silencing was achieved from the multiple promoter/shRNA approach, as this method induced additive suppression of single-gene targets and equally effective knockdown of double-gene targets. Although both lhRNA and microRNA-embedded strategies provided efficient gene knockdown, suppression levels were inconsistent and activity varied greatly for different siRNAs tested. Furthermore, it appeared that not only the position of siRNAs within these multi-shRNA constructs impacted upon silencing activity, but also local properties of each individual molecule. In addition, it was also found that the insertion of up to five promoter/shRNA cassettes into a single construct did not negatively affect the efficacy of each individual shRNA.</p> <p>Conclusions</p> <p>By directly comparing the ability of shRNAs delivered from different co-RNA platforms to initiate knockdown of the same gene targets, we found that multiple U6/shRNA cassettes offered the most reliable and predictable suppression of both single and multiple-gene targets. These results highlight some important strengths and pitfalls of the currently used methods for multiple shRNA delivery, and provide valuable insights for the design and application of reliable co-RNAi.</p

Critical Role of the Virus-Encoded MicroRNA-155 Ortholog in the Induction of Marek's Disease Lymphomas

Notwithstanding the well-characterised roles of a number of oncogenes in neoplastic transformation, microRNAs (miRNAs) are increasingly implicated in several human cancers. Discovery of miRNAs in several oncogenic herpesviruses such as KSHV has further highlighted the potential of virus-encoded miRNAs to contribute to their oncogenic capabilities. Nevertheless, despite the identification of several possible cancer-related genes as their targets, the direct in vivo role of virus-encoded miRNAs in neoplastic diseases such as those induced by KSHV is difficult to demonstrate in the absence of suitable models. However, excellent natural disease models of rapid-onset Marek's disease (MD) lymphomas in chickens allow examination of the oncogenic potential of virus-encoded miRNAs. Using viruses modified by reverse genetics of the infectious BAC clone of the oncogenic RB-1B strain of MDV, we show that the deletion of the six-miRNA cluster 1 from the viral genome abolished the oncogenicity of the virus. This loss of oncogenicity appeared to be primarily due to the single miRNA within the cluster, miR-M4, the ortholog of cellular miR-155, since its deletion or a 2-nucleotide mutation within its seed region was sufficient to inhibit the induction of lymphomas. The definitive role of this miR-155 ortholog in oncogenicity was further confirmed by the rescue of oncogenic phenotype by revertant viruses that expressed either the miR-M4 or the cellular homolog gga-miR-155. This is the first demonstration of the direct in vivo role of a virus-encoded miRNA in inducing tumors in a natural infection model. Furthermore, the use of viruses deleted in miRNAs as effective vaccines against virulent MDV challenge, enables the prospects of generating genetically defined attenuated vaccines

Genetic Control of a Central Pattern Generator: Rhythmic Oromotor Movement in Mice Is Controlled by a Major Locus near Atp1a2

Fluid licking in mice is a rhythmic behavior that is controlled by a central pattern generator (CPG) located in a complex of brainstem nuclei. C57BL/6J (B6) and DBA/2J (D2) strains differ significantly in water-restricted licking, with a highly heritable difference in rates (h2≥0.62) and a corresponding 20% difference in interlick interval (mean ± SEM = 116.3±1 vs 95.4±1.1 ms). We systematically quantified motor output in these strains, their F1 hybrids, and a set of 64 BXD progeny strains. The mean primary interlick interval (MPI) varied continuously among progeny strains. We detected a significant quantitative trait locus (QTL) for a CPG controlling lick rate on Chr 1 (Lick1), and a suggestive locus on Chr 10 (Lick10). Linkage was verified by testing of B6.D2-1D congenic stock in which a segment of Chr 1 of the D2 strain was introgressed onto the B6 parent. The Lick1 interval on distal Chr 1 contains several strong candidate genes. One of these is a sodium/potassium pump subunit (Atp1a2) with widespread expression in astrocytes, as well as in a restricted population of neurons. Both this subunit and the entire Na+/K+-ATPase molecule have been implicated in rhythmogenesis for respiration and locomotion. Sequence variants in or near Apt1a2 strongly modulate expression of the cognate mRNA in multiple brain regions. This gene region has recently been sequenced exhaustively and we have cataloged over 300 non-coding and synonymous mutations segregating among BXD strains, one or more of which is likely to contribute to differences in central pattern generator tempo