Publications

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

There were a total of 1926 results for your search.
Tchilian E Z, Wallace D L, Imami N, Liao H X, Burton C, Gotch F, Martinson J, Haynes B F, Beverley P C L (2001)

The Exon A (C77G) mutation is a common cause of abnormal CD45 splicing in humans

Journal of Immunology 166 (10), 6144-6148

Abstract

The leukocyte common (CD45) Ag is essential for normal T lymphocyte function and alternative splicing at the N terminus of the gene is associated with changes in T cell maturation and differentiation. Recently, a statistically significant association was reported in a large series of human thymus samples between phenotypically abnormal CD45 splicing and the presence of the CC chemokine receptor 5 deletion 32 (CCR5del32) allele, which confers resistance to HIV infection in homozygotes. We show here that abnormal splicing in these thymus samples is associated with the presence of the only established cause of CD45 abnormal splicing, a C77G transversion in exon A. In addition we have examined 227 DNA samples from peripheral blood of healthy donors and find no association between the exon A (C77G) and CCR5del32 mutations. Among 135 PBMC samples, tested by flow cytometric analysis, all those exhibiting abnormal splicing of CD45 also showed the exon A C77G transversion. We conclude that the exon A (C77G) mutation is a common cause of abnormal CD45 splicing and that further disease association studies of this mutation are warranted.
Graham S P, Trees A J, Collins R A, Moore D M, Guy F M, Taylor M J, Bianco A E (2001)

Down-regulated lymphoproliferation coincides with parasite maturation and with the collapse of both gamma interferon and interleukin-4 responses in a bovine model of onchocerciasis

Infection and Immunity 69 (7), 4313-9

Abstract

Onchocerciasis is a debilitating parasitic infection caused by the filarial nematode Onchocerca volvulus. Infections are chronic, and persistence of the parasites for several years argues for highly adapted mechanisms of immune evasion. Due to the restricted host repertoire of O. volvulus, we have used the cattle parasite Onchocerca ochengi to investigate the nature of immunomodulation underpinning these long-term infections. Cattle were infected with a single inoculation of 350 infective-stage larvae under laboratory conditions (n = 6). Intradermal nodules containing immature adult worms were detected from 110 days postinfection, and microfilariae in skin were detected from day 280 postinfection. Parasite-specific responses during early infection were nonpolarized with respect to the major Th cytokines (interleukin-4 [IL-4], IL-2, and gamma interferon [IFN-gamma]) produced by antigen-stimulated peripheral blood mononuclear cells (PBMC) or serum antibody isotypes. Antigen-induced proliferation of PBMC peaked shortly after exposure and remained high during the prepatent infection. As the parasites matured and animals developed patent infections, there was a profound down-regulation of lymphoproliferation, accompanied by sharp falls in the expression of both IL-4 and IFN-gamma and a gradual decline in IL-2. Levels of immunoglobulin G2 (IgG2) fell, while those of IgG1 remained high. We conclude that neither a classical Th2 response nor a simple Th1-to-Th2 switch is sufficient to explain the immunomodulation associated with patent Onchocerca infections. Instead, there is an initial Th0 response, which matures into a response with some, but not all of the features of a Th2 response. The natural host-parasite relationship of O. ochengi in cattle may be useful as both a descriptive and predictive tool to test more refined models of immunomodulation in onchocerciasis.
Charleston B, Hope J C, Carr B V, Howard C J (2001)

Masking of two in vitro immunological assays for Mycobacterium bovis (BCG) in calves acutely infected with non-cytopathic bovine viral diarrhoea virus

Veterinary Record 149, 481-484

Abstract

Acute infection of calves, previously vaccinated with bacille Calmette-Guerin (BCG), with non-cytopathic viral diarrhoea virus (BVDV) resulted in the temporary suppression of two in vitro assays used to monitor Mycobacterium bovis infection. Lymphocyte proliferation and interferon-gamma production by whole blood cultures containing purified protein derivatives prepared from Mycobacterium avium (PPD-A) and M bovis (PPD-B) were markedly suppressed. The implication is that acute infections of cattle with non-cytopathic BVDV may temporarily compromise diagnostic tests for M bovis infections and result in a failure to identify cattle with tuberculosis.
Tchilian E Z, Wallace D L, Wells R S, Flower D R, Morgan G, Beverley P C L (2001)

A deletion in the gene encoding the CD45 antigen in a patient with SCID

Journal of Immunology 166 (2), 1308-1313

Abstract

SCID is a heterogeneous group of hereditary diseases. Mutations in the common gamma -chain (gamma (c)) of cytokine receptors, including those for IL-2, IL-4, IL-7, IL-9, and IL-15, are responsible for an X-linked form of the disease, while mutations of several other genes, including Janus-associated kinase-3, may cause autosomal recessive forms of SCID. We investigated the first SCID patient to be described with minimal cell surface expression of the leukocyte common (CD45) Ag. CD45 is an abundant transmembrane tyrosine phosphatase, expressed on all leukocytes, and is required for efficient lymphocyte signaling. CD45-deficient mice are severely immunodeficient and have very few peripheral T lymphocytes. We report here that a homozygous 6-bp deletion in the gene encoding CD45 (PTPRC, gene map locus 1q31-32), which results in a loss of glutamic acid 339 and tyrosine 340 in the first fibronectin type III module of the extracellular domain of CD45, is associated with failure of surface expression of CD45 and SCID. Molecular modeling suggests that tyrosine 340 is crucial for the structural integrity of CD45 protein. This is the second description of a clinically relevant CD45 mutation, provides direct evidence for the importance of CD45 in immune function in humans, and suggests that abnormalities in CD45 expression are a possible cause of SCID in humans.
Hiscox J A, Wurm T, Wilson L, Britton P, Cavanagh D, Brooks G (2001)

The coronavirus infectious bronchitis virus nucleoprotein localizes to the nucleolus

Journal of Virology 75, 506-512

Abstract

The coronavirus nucleoprotein (N) has been reported to be involved in various aspects of virus replication. We examined by confocal microscopy the subcellular localization of the avian infectious bronchitis virus N protein both in the absence and in the context of an infected cell and found that N protein localizes both to the cytoplasmic and nucleolar compartments.
Chernukhin I V, Seago J E, Newbury S F (2001)

Drosophila 5′ → 3′-exoribonuclease Pacman

Methods in Enzymology: Ribonucleases, Pt B edited by A. W. Nicholson 342, 293-302

Abstract

This chapter concentrates on the methods used to express a Drosophila recombinat 5? ? 3?-exoribonuclease, purify the protein, and analyze its activity in vitro. Analysis of early development in Drosophila has shown that RNA localization, control of translation, and mRNA stability are intimately linked. Generally, translational repression leads to degradation of an RNA, and failure of an RNA to localize correctly also leads to its degradation. Work on the yeast Saccharomyces cerevisiae has identified many ribonucleases and associated factors that control mRNA decay, RNA splicing, and rRNA processing. In yeast, it has been shown that 3? ? 5? degradation/processing of RNA requires the exosome, which is a complex of at least 10 proteins. Degradation of RNA in a 5? ? 3? direction occurs by initial decapping of the mRNA, followed by 5? ? 3? degradation of the RNA by Xrn1p. The two decapping proteins (Dcp1p and Dcp2p) and Xrnlp have been shown to be complexed to seven Lsm proteins, which are likely to form a ring encircling the RNA. To understand the role of RNA stability in development, a number of approaches can be used. Once the genes encoding particular ribonucleases or associated factors have been identified, then expression of the RNA during development can be determined. These techniques have been used to show that the 5? ? 3?-exoribonuclease Pacman is differentially expressed during development.

Beard P M, Rhind S M, Sinclair M C, Wildblood L A, Stevenson K, McKendrick I J, Sharp J M, Jones D G (2000)

Modulation of gamma delta T cells and CD1 in Mycobacterium avium subsp paratuberculosis infection

Veterinary Immunology and Immunopathology 77 (3-4), 311-319

Abstract

M.a. paratuberculosis is the causal agent of paratuberculosis (Johne's disease). Recent work has suggested that gamma delta T cells may play an important role in the early immunological response to mycobacterial diseases, and that CD1 may act as a non-classical MHC molecule in antigen presentation to these gamma delta T cells. Experimental infection of neonatal lambs with M.a. paratuberculosis was used to investigate the changes in gamma delta T cells and CD1 molecules in the gut associated lymphoid tissue 4 weeks after inoculation. Immunohistochemistry was used to label the gamma delta lymphocytes and CD1 molecules. An increase in the number of gamma delta T cells was noted in both the jejunal and ileal Peyer's patches in the gut of infected lambs, but no statistically significant change was found in the mesenteric lymph nodes. There were no obvious changes in the CD1 molecules in any tissue. This work suggests that gamma delta T cells may play a role in the initial immunological events of paratuberculosis infection.

Tait S W G, Reid E B, Greaves D R, Wileman T E, Powell P P (2000)

Mechanism of inactivation of NF-κB by a viral homologue of IκBα: signal-induced release of IκBα results in binding of the viral homologue to NF-κB

Journal of Biological Chemistry 275 (44), 34656-34664

Abstract

Activation of the nuclear factor κB plays a key role in viral pathogenesis, resulting in inflammation and modulation of the immune response. We have previously shown that A238L, an open reading frame from African swine fever virus (ASFV), encoding a protein with 40% homology to porcine IκBα exerts a potent anti-inflammatory effect in host macrophages, where it down-regulates NF-κB-dependent gene transcription and proinflammatory cytokine production. This paper reveals the mechanism of suppression of NF-κB activity by A238Lp. A238Lp is synthesized throughout infection as two molecular mass forms of 28 and 32 kDa, and vaccinia-mediated expression of A238L demonstrated that both proteins are produced from a single gene. Significantly, the higher 32-kDa form of A238L, but not the 28-kDa form, interacts directly with RelA, the 65-kDa subunit of NF-κB, indicating that the binding is dependent on a post-translational modification. Immunoprecipitation analysis shows the NF-κB p65-A238L p32 heterodimer is a separate complex from NF-κB-IκBα, and it resides in the cytoplasm. Moreover, we show that ASFV infection stimulates the NFκB signal transduction pathway, which results in the rapid degradation of endogenous IκBα, although both forms of A238Lp are resistant to stimulus-induced degradation. Using the proteasome inhibitor MG132, we show that when degradation of IκBα is inhibited, A238Lp binding to NF-κB p65 is reduced. The results suggest that the virus exploits its activation of the NF-κB pathway to enable its own IκB homologue to bind to NF-κB p65. Last, we show that synthesis of IκBα is increased during ASFV infection, indicating RelA-independent transcription of the IκBα gene.

Stirrups K, Shaw K, Evans S, Dalton K, Cavanagh D, Britton P (2000)

Leader switching occurs during the rescue of defective RNAs by heterologous strains of the coronavirus infectious bronchitis virus

Journal of General Virology 81, 791-801

Abstract

A defective RNA (D-RNA), CD-61, derived from the Beaudette strain of the avian coronavirus infectious bronchitis virus (IBV), was rescued (replicated and packaged) using four heterologous strains of IBV as helper virus. Sequence analysis of the genomic RNA from the four heterologous IBV strains (M41, H120, HV10 and D207) identified nucleotide differences of up to 17% within the leader sequence and up to 4.3% within the whole of the adjacent 5' untranslated region (UTR). Analysis of the 5' ends of the rescued D-RNAs showed that the Beaudette leader sequence, present on the initial CD-61, had been replaced with the corresponding leader sequence from the helper IBV strain but the adjacent 5' UTR sequence of the rescued D-RNAs corresponded to the original CD-61 Beaudette sequence. These results demonstrated that the phenomenon of leader switching previously identified for the coronaviruses murine hepatitis virus and bovine coronavirus (BCoV) also occurred during the replication of IBV D-RNAs. Three predicted stem-loop structures were identified within the 5' UTR of IBV. Stem-loop I showed a high degree of covariance amongst the IBV strains providing phylogenetic evidence that this structure exists and is potentially involved in replication, supporting previous observations that a BCoV stem-loop homologue was essential for replication of BCoV defective interfering RNAs.
Thomas D D, Donnelly C A, Wood R J, Alphey L S (2000)

Insect population control using a dominant, repressible, lethal genetic system

Science 287 (5462), 2474-2476

Abstract

A major modification to the sterile insect technique is described, in which transgenic insects homozygous for a dominant, repressible, female-specific lethal gene system are used. We demonstrate two methods that give the required genetic characteristics in an otherwise wild-type genetic background. The first system uses a sex-specific promoter or enhancer to drive the expression of a repressible transcription factor, which in turn controls the expression of a toxic gene product. The second system uses non-sex-specific expression of the repressible transcription factor to regulate a selectively Lethal gene product. Both methods work efficiently in Drosophila melanogaster, and we expect these principles to be widely applicable to more economically important organisms.

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