Publications by authors named "Pippa Hawes"

African swine fever virus is a cytolytic virus that leads to the apoptosis of both cultured cells and primary macrophages. Cell culture supernatants of virus-infected cells are routinely used for virological and immunological studies, despite differences in the biological behavior between such preparations and highly purified virus. In addition, more recent data suggests that exosomes containing viral proteins may be secreted from infected cells.

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The intracellular actions of interferon (IFN)-regulated proteins, including IFN-induced proteins with tetratricopeptide repeats (IFITs), attribute a major component of the protective antiviral host defense. Here we applied genomics approaches to annotate the chicken IFIT locus and currently identified a single IFIT (chIFIT5) gene. The profound transcriptional level of this effector of innate immunity was mapped within its unique cis-acting elements.

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Background: Hendra virus (HeV) is a pleomorphic virus belonging to the Paramyxovirus family. Our long-term aim is to understand the process of assembly of HeV virions. As a first step, we sought to determine the most appropriate cell culture system with which to study this process, and then to use this model to define the morphology of the virus and identify the site of assembly by imaging key virus encoded proteins in infected cells.

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When exiting the cell vaccinia virus induces actin polymerization and formation of a characteristic actin tail on the cytosolic face of the plasma membrane, directly beneath the extracellular particle. The actin tail acts to propel the virus away from the cell surface to enhance its cell-to-cell spread. We now demonstrate that African swine fever virus (ASFV), a member of the Asfarviridae family, also stimulates the polymerization of actin at the cell surface.

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Marek's disease virus (MDV) is an oncogenic herpesvirus that induces fatal T cell lymphomas in chickens. With more than 20 billion doses of vaccine used annually, vaccination constitutes the cornerstone of Marek's disease control. Despite the success of vaccination, evolution of virulence among MDV strains continues to threaten the effectiveness of the current Marek's disease vaccines.

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Intimin facilitates intestinal colonization by enterohemorrhagic Escherichia coli O157:H7; however, the importance of intimin binding to its translocated receptor (Tir) as opposed to cellular coreceptors is unknown. The intimin-Tir interaction is needed for optimal actin assembly under adherent bacteria in vitro, a process which requires the Tir-cytoskeleton coupling protein (TccP/EspF(U)) in E. coli O157:H7.

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A specific interaction between the F and H proteins is required to enable fusion of the virus and host cell membranes and in some cases these proteins are not interchangeable between related viruses of the family Paramyxoviridae. For example, the F and H proteins of two ruminant morbilliviruses, rinderpest virus (RPV) and Peste-des-petits-ruminants virus (PPRV), are not interchangeable since viable virus could not be rescued from cDNA constructs where an individual glycoprotein gene of RPV was replaced with that from PPRV. To investigate which domain of the H protein, extracellular or cytoplasmic/transmembrane, was most important for preventing this interaction, two chimeric H gene constructs were made where the normal H gene of RPV was substituted with variant H genes where the transmembrane/cytoplasmic tail region (pRPV2C-PPRTm) or the whole ectodomain (pRPV2C-PPRExt) were derived from PPRV.

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Burkholderia pseudomallei is a Gram-negative facultative intracellular pathogen that enters and escapes from eukaryotic cells using the power of actin polymerization. We have identified a bacterial protein (BimA) that is required for the ability of B. pseudomallei to induce the formation of actin tails.

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The role of the neuroendocrine environment in the pathogenesis of enteric bacterial infections is increasingly being recognized. Here we report that norepinephrine augments Escherichia coli O157:H7-induced intestinal inflammatory and secretory responses as well as bacterial adherence to intestinal mucosa in a bovine ligated ileal loop model of infection. Norepinephrine modulation of enteritis and adherence was dependent on the ability of E.

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Burkholderia pseudomallei is the causative agent of melioidosis, a serious infectious disease of humans and animals that is endemic in subtropical areas. B. pseudomallei is a facultative intracellular pathogen that may invade and survive within eukaryotic cells for prolonged periods.

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