Publications

The Pirbright Institute publication directory contains details of selected publications written by our researchers.

There were a total of 2259 results for your search.

Abstract

The host adaptation of influenza virus is partly dependent on the sialic acid (SA) isoform bound by the viral hemagglutinin (HA). Avian influenza viruses preferentially bind the alpha-2,3 SA and human influenza viruses the alpha-2,6 isoform. Each isoform is predominantly associated with different surface epithelial cell types of the human upper airway. Using recombinant HAs and human tracheal airway epithelial cells in vitro and ex vivo, we show that many avian HA subtypes do not adhere to this canonical view of SA specificity. The propensity of avian viruses to adapt to human receptors may thus be more widespread than previously supposed.
Sherwood K, Head M, Walker R, Smith C, Ironside J W, Fazakerley J K (2011)

A new index of agonal state for neurological disease

Neuropathology and Applied Neurobiology 37 (6), 672-675

Abstract

Aims: To determine premortem and post mortem factors affecting quality and yield of RNA isolated from the unique archived brain material in the UK National Creutzfeldt-Jakob Disease Surveillance Unit Brain and Tissue Bank and to compare this to control brain tissue with no neurological disease. Methods: In parallel and in replicate, RNA was prepared from the frontal parasagittal or subfrontal cortex of samples dissected from half brains (frozen intact) or from brain samples snap frozen or placed in RNALater. A total of 350 RNA samples from 78 human autopsy cases, 21 variant Creutzfeldt-Jakob disease, 26 other neurological diseases and 31 non-neurological diseases were studied. Results: There was no difference in the quality or yield of RNA isolated from variant Creutzfeldt-Jakob disease, other neurological disease and non-neurological disease brains. RNA preparations from archived frozen half brains or snap frozen autopsy samples were generally of poor quality (RNA integrity number 5). Age at death, gender, post mortem interval and freezer storage time had no effect on RNA quality. Conclusion: Reasonable-quality RNA can be isolated from samples dissected from archived frozen human half brains but repeated sampling results in RNA degradation. Better-quality RNA is obtained from samples placed in RNALater than from snap frozen samples. The quality and yield of RNA are not affected by age at death, gender, post mortem interval of > 6 h or freezer storage time.

Abstract

Throughout the 21st century, livestock diseases will impact upon the productivity of domesticated livestock and compromise the ability to feed a growing global population. The focus of the present review is to outline how the recent rapid expansion of genetic sequence data available for both pathogens and hosts can be exploited to develop new tools to improve the ways in which livestock diseases can be controlled. In the post-genomics era of the future, there will be a more intimate understanding of the way in which pathogens interact with their hosts and the key molecules that define host pathogen relationships; knowledge that can be utilized to generate novel diagnostics and vaccination strategies. However, experience from the global rinderpest eradication programme highlights that effective disease control is a multifactorial process. Clearly, appropriate new therapeutic and diagnostic tools can play a critical role in our ability to monitor and limit the spread of diseases. However, adequate resources are also required: these are principally financial and also include the availability of trained personnel and veterinary infrastructure; international cooperation, transparency between different countries and sharing of epidemiological data and ownership of disease; acceptance of the difference in perception of importance of diseases in the developed world v. the developing world.
Simmons G S, McKemey A R, Morrison N I, O'Connell S, Tabashnik B E, Claus J, Fu G, Tang G, Sledge M, Walker A S, Phillips C E, Miller E D, Rose R I, Staten R T, Donnelly C A, Alphey L (2011)

Field performance of a genetically engineered strain of pink bollworm

PLoS One 6 (9), e24110

Abstract

Pest insects harm crops, livestock and human health, either directly or by acting as vectors of disease. The Sterile Insect Technique (SIT) - mass-release of sterile insects to mate with, and thereby control, their wild counterparts - has been used successfully for decades to control several pest species, including pink bollworm, a lepidopteran pest of cotton. Although it has been suggested that genetic engineering of pest insects provides potential improvements, there is uncertainty regarding its impact on their field performance. Discrimination between released and wild moths caught in monitoring traps is essential for estimating wild population levels. To address concerns about the reliability of current marking methods, we developed a genetically engineered strain of pink bollworm with a heritable fluorescent marker, to improve discrimination of sterile from wild moths. Here, we report the results of field trials showing that this engineered strain performed well under field conditions. Our data show that attributes critical to SIT in the field - ability to find a mate and to initiate copulation, as well as dispersal and persistence in the release area - were comparable between the genetically engineered strain and a standard strain. To our knowledge, these represent the first open-field experiments with a genetically engineered insect. The results described here provide encouragement for the genetic control of insect pests.

Abstract

Leukotoxin (LKT) is a virulence factor for Mannheimia haemolytica. In this study, bovine alveolar macrophages (BAMs) were challenged with wild type (wt) and LKT deficient (lkt?) M. haemolytica at a concentration of 1 bacterium/BAM and the cytokine response was quantified by ELISA and real-time reverse transcriptase-PCR. Significant increases in protein concentrations of tumor necrosis factor (TNF)-? and interleukin (IL)-10 were observed in supernatants obtained from BAMs challenged with the lkt? strain of M. haemolytica compared with wt challenged BAMs. There were no significant differences in mRNA expression of TNF?, IL-1ß, IL-6, IL-8 or IL-10 between BAMs challenged with the lkt? strain of M. haemolytica compared with wt challenged BAMs. BAMs challenged with the wt strain exhibited, on average, 43% more cytotoxicity than lkt? challenged BAMs (P

Abstract

Actin-based motility of the melioidosis pathogen Burkholderia pseudomallei requires BimA (Burkholderia intracellular motility A). The mechanism by which BimA mediates actin assembly at the bacterial pole is ill-defined. Toward an understanding of the regions of B. pseudomallei BimA required for intracellular motility and the binding and polymerization of actin, we constructed plasmid-borne bimA variants and glutathione-S-transferase fusion proteins with in-frame deletions of specific motifs. A 13-amino-acid direct repeat and IP7 proline-rich motif were dispensable for actin binding and assembly in vitro, and expression of the mutated proteins in a B. pseudomallei bimA mutant restored actin-based motility in J774.2 murine macrophage-like cells. However, two WASP homology 2 (WH2) domains were found to be required for actin binding, actin assembly, and plaque formation. A tract of five PDASX direct repeats influenced the polymerization of pyrene-actin monomers in vitro and was required for actin-based motility and intercellular spread, but not actin binding. None of the mutations impaired surface expression or polar targeting of BimA. The number of PDASX repeats varied in natural isolates from two to seven. Such repeats acted additively to promote pyrene-actin polymerization in vitro, with stepwise increases in the rate of polymerization as the number of repeats was increased. No differences in the efficiency of actin tail formation could be discerned between strains expressing BimA variants with two, five, or seven PDASX repeats. The data provide valuable new insights into the role of conserved and variable motifs of BimA in actin-based motility and intercellular spread of B. pseudomallei.

Abstract

RNA interference (RNAi) is an important mosquito defense mechanism against arbovirus infection. In this paper we study the processes underlying antiviral RNAi in Aedes albopictus-derived U4.4 mosquito cells infected with Semliki Forest virus (SFV) (Togaviridae; Alphavirus). The production of virus-derived small interfering RNAs (viRNAs) from viral double-stranded RNA (dsRNA) is a key event in this host response. dsRNA could be formed by RNA replication intermediates, by secondary structures in RNA genomes or antigenomes, or by both. Which of these dsRNAs is the substrate for the generation of viRNAs is a fundamental question. Here we used deep sequencing of viRNAs and bioinformatic analysis of RNA secondary structures to gain insights into the characteristics and origins of viRNAs. An asymmetric distribution of SFV-derived viRNAs with notable areas of high-level viRNA production (hot spots) and no or a low frequency of viRNA production (cold spots) along the length of the viral genome with a slight bias toward the production of genome-derived viRNAs over antigenome-derived viRNAs was observed. Bioinformatic analysis suggests that hot spots of viRNA production are rarely but not generally associated with putative secondary structures in the SFV genome, suggesting that most viRNAs are derived from replicative dsRNA. A pattern of viRNAs almost identical to those of A. albopictus cells was observed for Aedes aegypti-derived Aag2 cells, suggesting common mechanisms that lead to viRNA production. Hot-spot viRNAs were found to be significantly less efficient at mediating antiviral RNAi than cold-spot viRNAs, pointing toward a nucleic acid-based viral decoy mechanism to evade the RNAi response.

Abstract

Marek's disease virus (MDV) is a highly contagious oncogenic alphaherpesvirus that causes disease that is both a cancer model and a continuing threat to the world's poultry industry. This comprehensive gene expression study analyzes the host response to infection in both resistant and susceptible lines of chickens and inherent expression differences between the two lines following the infection of the host. A novel pathogenicity mechanism, involving the downregulation of genes containing HIC1 transcription factor binding sites as early as 4 days postinfection, was suggested from this analysis. HIC1 drives antitumor mechanisms, suggesting that MDV infection switches off genes involved in antitumor regulation several days before the expression of the MDV oncogene meq. The comparison of the gene expression data to previous QTL data identified several genes as candidates for involvement in resistance to MD. One of these genes, IRG1, was confirmed by single nucleotide polymorphism analysis to be involved in susceptibility. Its precise mechanism remains to be elucidated, although the analysis of gene expression data suggests it has a role in apoptosis. Understanding which genes are involved in susceptibility/resistance to MD and defining the pathological mechanisms of the disease gives us a much greater ability to try to reduce the incidence of this virus, which is costly to the poultry industry in terms of both animal welfare and economics.

Abstract

Bacterial artificial chromosome (BAC) vectors containing the full-length genomes of several herpesviruses have been used widely as tools to enable functional studies of viral genes. Marek's disease viruses (MDVs) are highly oncogenic alphaherpesviruses that induce rapid-onset T-cell lymphomas in chickens. Oncogenic strains of MDV reconstituted from BAC clones have been used to examine the role of viral genes in inducing tumours. Past studies have demonstrated continuous increase in virulence of MDV strains. We have previously reported on the UK isolate C12/130 that showed increased virulence features including lymphoid organ atrophy and enhanced tropism for the central nervous system. Here we report the construction of the BAC clones (pC12/130) of this strain. Chickens were infected with viruses reconstituted from the pC12/130 clones along with the wild-type virus for the comparison of the pathogenic properties. Our studies show that BAC-derived viruses induced disease similar to the wild-type virus, though there were differences in the levels of pathogenicity between individual viruses. Generation of BAC clones that differ in the potential to induce cytolytic disease provide the opportunity to identify the molecular determinants of increased virulence by direct sequence analysis as well as by using reverse genetics approaches on the infectious BAC clones.

Pages

Filter Publications

Trim content

® The Pirbright Institute 2021 | A company limited by guarantee, registered in England no. 559784. The Institute is also a registered charity.