A non-invasive tool for assessing pathogen prevalence in koala (Phascolarctos cinereus) populations: detection of Chlamydia pecorum and koala retrovirus (KoRV) DNA in genetic material sourced from scats
- Authors: Wedrowicz, Faye , Saxton, Tom , Mosse, Jennifer , Wright, Wendy , Hogan, Fiona
- Date: 2016
- Type: Text , Journal article
- Relation: Conservation Genetics Resources Vol. 8, no. 4 (2016), p. 511-521
- Full Text: false
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- Description: Pathogenic diseases may threaten the viability of wild animal populations, especially when already vulnerable. The mitigation of risks associated with pathogenic infections in populations is an important factor in conservation strategies. Koalas are of conservation concern across the north of their range and are affected by two main pathogens; Chlamydia pecorum and the koala retrovirus (KoRV). This study tested whether DNA from C. pecorum and KoRV could be detected in genetic material isolated from koala scats. Detection of C. pecorum in scat isolated DNA samples was compared with results obtained from urogenital swabs collected from the same individuals as part of an independent study. The ability to detect KoRV in scats from both northern and southern regions of the koala’s range was also assessed. There was a high level of concordance (5/6) between the detection of C. pecorum in DNA isolated from scats and urogenital swabs from the same individual. In positive samples, C. pecorumompA genotypes were identical between DNA from scats and urogenital swabs in two out of three cases. In samples from the south of the koala’s range, KoRV copy number was higher in DNA isolated from scats compared to DNA isolated from ear tissue, potentially indicating the detection of horizontally acquired infections. Our results demonstrate the ability to detect C. pecorum and KoRV in DNA isolated from koala scats. This method will be useful for studying the prevalence, transmission and impact of these pathogens in wild populations which may subsequently inform conservation management strategies. © 2016, Springer Science+Business Media Dordrecht.
Acquisition of laboratory skills by on-campus and distance education students
- Authors: Mosse, Jennifer , Wright, Wendy
- Date: 2010
- Type: Text , Book chapter
- Relation: Accessible Elements p. 109-129
- Full Text: false
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Antigenic drift of the pandemic 2009 A(H1N1) influenza virus in a ferret model
- Authors: Guarnaccia, Teagan , Carolan, Louise , Maurer-Stroh, Sebastian , Lee, Raphael , Job, Emma , Reading, Patrick , Petrie, Stephen , McCaw, James , McVernon, Jodie , Hurt, Aeron , Kelso, Anne , Mosse, Jennifer , Barr, Ian , Laurie, Karen
- Date: 2013
- Type: Text , Journal article
- Relation: PLoS Pathogens Vol. 9, no. 5 (2013), p. 1-18
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- Description: Surveillance data indicate that most circulating A(H1N1)pdm09 influenza viruses have remained antigenically similar since they emerged in humans in 2009. However, antigenic drift is likely to occur in the future in response to increasing population immunity induced by infection or vaccination. In this study, sequential passaging of A(H1N1)pdm09 virus by contact transmission through two independent series of suboptimally vaccinated ferrets resulted in selection of variant viruses with an amino acid substitution (N156K, H1 numbering without signal peptide; N159K, H3 numbering without signal peptide; N173K, H1 numbering from first methionine) in a known antigenic site of the viral HA. The N156K HA variant replicated and transmitted efficiently between naïve ferrets and outgrew wildtype virus in vivo in ferrets in the presence and absence of immune pressure. In vitro, in a range of cell culture systems, the N156K variant rapidly adapted, acquiring additional mutations in the viral HA that also potentially affected antigenic properties. The N156K escape mutant was antigenically distinct from wildtype virus as shown by binding of HA-specific antibodies. Glycan binding assays demonstrated the N156K escape mutant had altered receptor binding preferences compared to wildtype virus, which was supported by computational modeling predictions. The N156K substitution, and culture adaptations, have been detected in human A(H1N1)pdm09 viruses with N156K preferentially reported in sequences from original clinical samples rather than cultured isolates. This study demonstrates the ability of the A(H1N1)pdm09 virus to undergo rapid antigenic change to evade a low level vaccine response, while remaining fit in a ferret transmission model of immunization and infection. Furthermore, the potential changes in receptor binding properties that accompany antigenic changes highlight the importance of routine characterization of clinical samples in human A(H1N1)pdm09 influenza surveillance.
Assessing the viral fitness of oseltamivir-resistant influenza viruses in ferrets, using a competitive-mixtures model
- Authors: Hurt, Aeron , Nor'e, Sit , McCaw, James , Fryer, Helen , Mosse, Jennifer , McLean, Angela , Barr, Ian
- Date: 2010
- Type: Text , Journal article
- Relation: Journal Of Virology Vol. 84, no. 18 (2010 2010), p. 9427-9438
- Full Text: false
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- Description: To determine the relative fitness of oseltamivir-resistant strains compared to susceptible wild-type viruses, we combined mathematical modeling and statistical techniques with a novel in vivo “competitive-mixtures” experimental model. Ferrets were coinfected with either pure populations (100% susceptible wild-type or 100% oseltamivir-resistant mutant virus) or mixed populations of wild-type and oseltamivir-resistant influenza viruses (80%:20%, 50%:50%, and 20%:80%) at equivalent infectivity titers, and the changes in the relative proportions of those two viruses were monitored over the course of the infection during within-host and over host-to-host transmission events in a ferret contact model. Coinfection of ferrets with mixtures of an oseltamivir-resistant R292K mutant A(H3N2) virus and a R292 oseltamivir-susceptible wild-type virus demonstrated that the R292K mutant virus was rapidly outgrown by the R292 wild-type virus in artificially infected donor ferrets and did not transmit to any of the recipient ferrets. The competitive-mixtures model was also used to investigate the fitness of the seasonal A(H1N1) oseltamivir-resistant H274Y mutant and showed that within infected ferrets the H274Y mutant virus was marginally outgrown by the wild-type strain but demonstrated equivalent transmissibility between ferrets. This novel in vivo experimental method and accompanying mathematical analysis provide greater insight into the relative fitness, both within the host and between hosts, of two different influenza virus strains compared to more traditional methods that infect ferrets with only pure populations of viruses. Our statistical inferences are essential for the development of the next generation of mathematical models of the emergence and spread of oseltamivir-resistant influenza in human populations.
Characterization of the localized immune response in the respiratory tract of ferrets following infection with influenza A and B viruses
- Authors: Carolan, Louise , Rockman, Steve , Borg, Kathryn , Guarnaccia, Teagan , Reading, Patrick , Mosse, Jennifer , Kelso, Anne , Barr, Ian , Laurie, Karen
- Date: 2016
- Type: Text , Journal article
- Relation: Journal of Virology Vol. 90, no. 6 (2016), p. 2838-2848
- Full Text: false
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- Description: The burden of infection with seasonal influenza viruses is significant. Each year is typically characterized by the dominance of one (sub)type or lineage of influenza A or B virus, respectively. The incidence of disease varies annually, and while this may be attributed to a particular virus strain or subtype, the impacts of prior immunity, population differences, and variations in clinical assessment are also important. To improve our understanding of the impacts of seasonal influenza viruses, we directly compared clinical symptoms, virus shedding, and expression of cytokines, chemokines, and immune mediators in the upper respiratory tract (URT) of ferrets infected with contemporary A(H1N1)pdm09, A(H3N2), or influenza B virus. Gene expression in the lower respiratory tract (LRT) was also assessed. Clinical symptoms were minimal. Overall cytokine/chemokine profiles in the URT were consistent in pattern and magnitude between animals infected with influenza A and B viruses, and peak expression levels of interleukin-1α (IL-1α), IL-1β, IL-6, IL-12p40, alpha interferon (IFN-α), IFN-β, and tumor necrosis factor alpha (TNF-α) mRNAs correlated with peak levels of viral shedding. MCP1 and IFN-γ were expressed after the virus peak. Granzymes A and B and IL-10 reached peak expression as the virus was cleared and seroconversion was detected. Cytokine/chemokine gene expression in the LRT following A(H1N1)pdm09 virus infection reflected the observations seen for the URT but was delayed 2 or 3 days, as was virus replication. These data indicate that disease severities and localized immune responses following infection with seasonal influenza A and B viruses are similar, suggesting that other factors are likely to modulate the incidence and impact of seasonal influenza. © 2016, American Society for Microbiology.
Evaluation of a dry powder delivery system for laninamivir in a ferret model of influenza infection
- Authors: Panozzo, Jacqueline , Oh, Ding Yuan , Margo, Kenneth , Morton, David , Piedrafita, David , Mosse, Jennifer , Hurt, Aeron
- Date: 2015
- Type: Text , Journal article
- Relation: Antiviral Research Vol. 120, no. (2015), p. 66-71
- Full Text: false
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- Description: Laninamivir is a long-acting antiviral requiring only a single dose for the treatment of influenza infection, making it an attractive alternative to existing neuraminidase inhibitors that require multiple doses over many days. Like zanamivir, laninamivir is administered to patients by inhalation of dry powder. To date, studies investigating the effectiveness of laninamivir or zanamivir in a ferret model of influenza infection have administered the drug in a solubilised form. To better mimic the delivery action of laninamivir in humans, we assessed the applicability of a Dry Powder Insufflator™ (DPI) as a delivery method for laninamivir octanoate (LO) in ferrets to determine the effectiveness of this drug in reducing influenza A and B virus infections. In vitro characterisation of the DPI showed that both the small particle sized LO (0.7-6.0 μm diameter) and the large particle sized lactose carrier (20-100 μm diameter) were effectively discharged. However, LO delivered to ferrets via the DPI prior to infection with either A(H1N1)pdm09 or B viruses had a limited effect on nasal inflammation, clinical symptoms and viral shedding compared to placebo. Our preliminary findings indicate the feasibility of administering powder drugs into ferrets, but a better understanding of the pharmacokinetics and pharmacodynamics of LO in ferrets following delivery by the DPI is warranted prior to further studies. © 2015 Elsevier B.V.
Evaluation of a program designed to build science teaching capacity in rural Australia
- Authors: Sheehan, Grania , Mosse, Jennifer
- Date: 2013
- Type: Text , Journal article
- Relation: Australian Journal of Teacher Education Vol. 38, no. 1 (2013), p. 75-96
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- Description: This article reports on a qualitative evaluation of the Science in Schools program; a suite of science based activities delivered by staff of a regional university campus and designed to provide professional development for science teachers working in non-metropolitan schools in a socioeconomically disadvantaged region of Australia. The research identified a range of issues including: the influence of socioeconomic disadvantage and rurality on teachers' professional learning needs, and the importance of subject specific discourse communities and content knowledge for new and out-of-field teachers. Implications for the design and implementation of school-university partnerships are discussed.
Genes
- Authors: Mosse, Jennifer
- Date: 2010
- Type: Text , Book chapter
- Relation: Understanding Pathophysiology p. 77-80
- Full Text: false
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Genes, genetic diseases and the environment
- Authors: Mosse, Jennifer , Craft, Judy
- Date: 2010
- Type: Text , Book chapter
- Relation: Understanding Pathophysiology p. 1145-1169
- Full Text: false
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Genetic structure and diversity of the koala population in South Gippsland, Victoria : A remnant population of high conservation significance
- Authors: Wedrowicz, Faye , Mosse, Jennifer , Wright, Wendy , Hogan, Fiona
- Date: 2018
- Type: Text , Journal article
- Relation: Conservation Genetics Vol. 19, no. 3 (2018), p. 713-728
- Full Text: false
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- Description: In the Australian state of Victoria, the history of koalas and their management has resulted in the homogenisation and reduction of genetic diversity in many contemporary populations. Decreased genetic diversity may reduce a species’ ability to adapt to future environmental pressures such as climate change or disease. The South Gippsland koala population is considered to be unique in Victoria, as it is believed to be a remnant population, not originating from managed populations that have low genetic variation. This study investigated genetic structure and diversity of koalas in South Gippsland, with comparison to other populations in Victoria (French Island/Cape Otway, FI and Raymond Island, RI), New South Wales and south east Queensland. Population analyses were undertaken using both microsatellite genotype and mitochondrial DNA sequence data. Non-invasive sampling of koala scats was used to source koala DNA, allowing 222 South Gippsland koalas to be genotyped. Using nuclear data the South Gippsland koala population was found to be significantly differentiated (Djost 95% CI SG–RI = 0.03–0.06 and SG–FI = 0.08–012) and more diverse (AR 95% CI SG = 4.7–5.6, RI = 3.1–3.3, FI = 3.0–3.3; p = 0.001) than other Victorian koala populations, supporting the premise that koalas in the South Gippsland region are part of a remnant population, not derived from translocated island stock. These results were also supported by mitochondrial data where eight haplotypes (Pc4, Pc17, Pc26, Pc27, and Pc56–Pc59) were identified in South Gippsland while a single haplotype (Pc27) was found in all island koalas tested. Compared to other Victorian koala populations, greater genetic diversity found in South Gippsland koalas, may provide this population with a greater chance of survival in the face of future environmental pressures. The South Gippsland koala population is, therefore, of high conservation significance, warranting the implementation of strategies to conserve this population and its diversity into the future.
In vitro generation and characterisation of an influenza B variant with reduced sensitivity to neuraminidase inhibitors
- Authors: Cheam, Ai Lee , Barr, Ian , Hampson, Alan , Mosse, Jennifer , Hurt, Aeron
- Date: 2004
- Type: Text , Journal article
- Relation: Antiviral Research Vol. 63, no. 3 (2004), p. 177-181
- Full Text: false
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- Description: A contemporary influenza type B virus was passaged in vitro in the presence of increasing concentrations of the neuraminidase inhibitors, zanamivir and oseltamivir carboxylate (0.1-1000 μM over nine passages). After the fifth passage in the presence of zanamivir (10 μM), the virus acquired a Glu 119 Asp neuraminidase mutation (influenza A N2 subtype numbering) in the enzyme active site. After a further three passages, in which growth occurred in 100 μM of zanamivir, a Gln 218 Lys mutation (A (H3) numbering) in the HA1 domain of the haemagglutinin was found. In a fluorescence-based neuraminidase inhibition assay, viruses with the Glu 119 Asp NA mutation had a 32,000-fold reduction in sensitivity to the NA inhibitor zanamivir compared to the wild-type virus, while the mutation resulted in a 105-fold reduction in sensitivity to oseltamivir carboxylate. Viruses grown in the presence of 1000 μM oseltamivir carboxylate did not acquire any neuraminidase mutations but did have a His 103 Gln substitution (A (H3) numbering) in the HA1 region of the haemagglutinin which was demonstrated to significantly reduce receptor binding strength in vitro. Tissue culture assays demonstrated that the HA mutation caused a seven-fold reduction in sensitivity to oseltamivir carboxylate, and a 90-fold reduction in sensitivity to zanamivir.
Influenza viruses with B/Yamagata- and B/Victoria-like neuraminidases are differentially affected by mutations that alter antiviral susceptibility
- Authors: Farrukee, Rubaiyea , Leang, Sookkwan , Butler, Jeff , Lee, Raphael , Maurer-Stroh, Sebastian , Tilmanis, Danielle , Sullivan, Sheena , Mosse, Jennifer , Barr, Ian , Hurt, Aeron
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Antimicrobial Chemotherapy Vol. 70, no. 7 (2015), p. 2004-2012
- Full Text: false
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- Description: Objectives: The burden of disease due to influenza B is often underestimated. Clinical studies have shown that oseltamivir, a widely used neuraminidase inhibitor (NAI) antiviral drug, may have reduced effectiveness against influenza B viruses. Therefore, it is important to study the effect of neuraminidase mutations in influenza B viruses that may further reduce NAI susceptibility, and to determine whether these mutations have the same effect in the two lineages of influenza B viruses that are currently circulating (B/Yamagata-like and B/Victoria-like). Methods: We characterized the effect of 16 amino acid substitutions across five framework residues and four monomeric interface residues on the susceptibility to four different NAIs (oseltamivir, zanamivir, peramivir and laninamivir). Results: Framework residue mutations E117A and E117G conferred highly reduced inhibition to three of the four NAIs, but substantially reduced neuraminidase activity, whereas other framework mutations retained a greater level of NA activity. Mutations E105K, P139S and G140R of the monomeric interface were also found to cause highly reduced inhibition, but, interestingly, their effect was substantially greater in a B/Victoria-like neuraminidase than in a B/Yamagata-like neuraminidase, with some susceptibility values being up to 1000-fold different between lineages. Conclusions: The frequency and the effect of key neuraminidase mutations on neuraminidase activity and NAI susceptibility can differ substantially between the two influenza B lineages. Therefore, future surveillance, analysis and interpretation of influenza B virus NAI susceptibility should consider the B lineage of the neuraminidase in the same manner as already occurs for different influenza A neuraminidase subtypes.
Interval between infections and viral hierarchy are determinants of viral interference following influenza virus infection in a ferret model
- Authors: Laurie, Karen , Guarnaccia, Teagan , Carolan, Louise , Yan, Aada , Aban, Malet , Petrie, Stephen , Cao, Pengxing , Heffernan, Jane , McVernon, Jodie , Mosse, Jennifer , Kelso, Anne , McCaw, James , Barr, Ian
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Infectious Diseases Vol. 212, no. 10 (2015), p. 1701-1710
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- Description: Background. Epidemiological studies suggest that, following infection with influenza virus, there is a short period during which a host experiences a lower susceptibility to infection with other influenza viruses. This viral interference appears to be independent of any antigenic similarities between the viruses. We used the ferret model of human influenza to systematically investigate viral interference. Methods. Ferrets were first infected then challenged 1-14 days later with pairs of influenza A(H1N1)pdm09, influenza A(H3N2), and influenza B viruses circulating in 2009 and 2010. Results. Viral interference was observed when the interval between initiation of primary infection and subsequent challenge was <1 week. This effect was virus specific and occurred between antigenically related and unrelated viruses. Coinfections occurred when 1 or 3 days separated infections. Ongoing shedding from the primary virus infection was associated with viral interference after the secondary challenge. Conclusions. The interval between infections and the sequential combination of viruses were important determinants of viral interference. The influenza viruses in this study appear to have an ordered hierarchy according to their ability to block or delay infection, which may contribute to the dominance of different viruses often seen in an influenza season.
Is the evolution of biochemistry texts decreasing fitness? A case study of pedagogical error in bioenergetics
- Authors: Larkins, Jo-Ann , Mosse, Jennifer , Chapman, Brian
- Date: 2011
- Type: Text , Conference paper
- Relation: Australian Conference on Science and Mathematics Education (ACSME): Teaching for diversity -Challenges and strategies p. 187-192
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- Description: The initial impetus for this research was the discovery by the authors of a variety of common and consistent errors and misconceptions in pedagogical literature on the topic of thermodynamics in Biochemistry. A systematic survey was undertaken of material on thermodynamics in Biochemistry textbooks commonly used in Australian Universities over the period from the 1920s up to 2010. Four common areas of error and misconception were identified, and a number of factors associated with the initiation and propagation of troublesome pedagogical material through successive editions of Biochemistry textbooks were recognised. These factors included the introduction of multiple authors and also often the departure of the original author of a particular textbook. The very nature of Biochemistry as a rapidly expanding discipline leads to the constant introduction of new material in textbooks and the contraction of older material such as thermodynamics. Material is also often fragmented into a number of smaller sections in modern textbooks. Moreover, less development is likely to be applied to this older material, with considerable reuse of material from previous editions. The lessons learned from charting these particular errors in thermodynamics in Biochemistry textbooks may provide insight into how troublesome pedagogical material evolves in other disciplines.
Isolating DNA sourced non-invasively from koala scats: a comparison of four commercial DNA stool kits
- Authors: Wedrowicz, Faye , Mosse, Jennifer , Wright, Wendy , Hogan, Fiona
- Date: 2018
- Type: Text , Journal article
- Relation: Conservation Genetics Resources Vol. , no. (2018), p.
- Full Text: false
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- Description: Genetic sampling from faeces is a useful method for obtaining DNA samples non-invasively. The quantity and quality of DNA isolated from faecal samples is, however, an important factor affecting the success of downstream analyses. Commercial DNA isolation kits offer an efficient and convenient means for recovering DNA, but the kit methodology can influence the quantity and quality of DNA obtained. Comparisons of kit performance for the isolation of DNA from non-invasive sources for ecological studies based on genetic analysis are uncommon in the literature. This study compared the quantity and quality of DNA isolated from surface washings of fresh koala (Phascolarctos cinereus) faecal pellets (scats) using four commercial DNA isolation kits: Axygen® AxyPrep™ MAG Soil, Stool, and Water DNA Kit (AX), Bioline ISOLATE Fecal DNA Kit (BL), Qiagen QIAamp® Fast DNA Stool Mini Kit (QFS), and Qiagen QIAamp® DNA Stool Mini Kit (QS). DNA quantitation, standard PCR and electrophoresis, real time PCR and replicate genotyping using capillary electrophoresis were used to compare the performance of resultant DNA isolates. The performance of DNA isolated from koala scats varied substantially with the DNA kit utilised. All kits provided accurate genotypes but with differing amounts of missing data. Overall, kit AX performed best, providing DNA isolates of higher quantity and quality compared to kit QS, which has previously been thoroughly assessed for genotyping reliability using DNA from koala scats. Given the high variability noted, assessing kit performance is an important way to maximise data quality from non-invasively sourced DNA.
MDCK-SIAT1 cells show improved isolation rates for recent human influenza viruses compared to conventinal MDCK cells
- Authors: Oh, Ding , Barr, Ian , Mosse, Jennifer , Laurie, Karen
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of Clinical Microbiology Vol. 46, no. 7 (2008), p. 2189-2194
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- Description: The ability to isolate and propagate influenza virus is an essential tool for the yearly surveillance of circulating virus strains and to ensure accurate clinical diagnosis for appropriate treatment. The suitability of MDCK-SIAT1 cells, engineered to express increased levels of alpha-2,6-linked sialic acid receptors, as an alternative to conventional MDCK cells for isolation of circulating influenza virus was assessed. A greater number of influenza A (H1N1 and H3N2) and B viruses from stored human clinical specimens collected between 2005 and 2007 were isolated following inoculation in MDCK-SIAT1 cells than in MDCK cells. In addition, a higher titer of virus was recovered following culture in MDCK-SIAT1 cells. All A(H1N1) viruses recovered from MDCK-SIAT1 cells were able to agglutinate both turkey and guinea pig red blood cells (RBC), while half of the A(H3N2) viruses recovered after passage in MDCK-SIAT1 cells lost the ability to agglutinate turkey RBC. Importantly, the HA-1 domain of the hemagglutinin gene was genetically stable after passaging in MDCK-SIAT1 cells, a feature not always seen following MDCK cell or embryonated chicken egg passage of human influenza virus. These data indicate that the MDCK-SIAT1 cell line is superior to conventional MDCK cells for isolation of human influenza virus from clinical specimens and may be used routinely for the isolation and propagation of current human influenza viruses for surveillance, diagnostic, and research purposes.
Neuraminidase inhibitor drug susceptibility differs between influenza N1 and N2 neuraminidase following mutagenesis of two conserved residues
- Authors: Ho, Hui-Ting , Hurt, Aeron , Mosse, Jennifer , Barr, Ian
- Date: 2007
- Type: Text , Journal article
- Relation: Antiviral Research Vol. 76, no. 3 (2007), p. 263-266
- Full Text: false
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- Description: Neuraminidase (NA) inhibitors are a class of antivirals designed to target the conserved residues of the influenza NA active site. While there are many conserved residues in the NA active site that are involved in NA inhibitor binding, only a few have been demonstrated to confer resistance. As such, little is known regarding the potential of the other conserved residues in the NA active site to cause NA inhibitor resistance. Two conserved residues (E227 and E276) of an N1 NA that have not previously been associated with resistance to NA inhibitors were investigated. Site-directed mutagenesis was used to generate three alternative amino acids at each residue. Reverse genetics was used to generate recombinant mutant viruses which were characterized for growth, NA activity and NA inhibitor sensitivity. Of the six recombinant viruses expressing NA with mutations at either E227 or E276, only the E227D and E276D viruses were able to grow without supplementary NA activity, and all mutant viruses had a significant reduction in NA activity. The E227D virus demonstrated significantly reduced sensitivity to zanamivir while the E276D virus did not demonstrate any significant changes in NA inhibitor sensitivity. Interestingly, the resistance profiles of E227D and E276D in N1 NA were significantly different from these sites that have been reported for N2 NA. This study confirmed the essential role of NA active site residues in viral fitness, and identified clear differences in the role of residues E227 and E276 in NA inhibitor resistance with N1 and N2 neuraminidases.
Off-campus learning: what do students want?
- Authors: Mosse, Jennifer , Panther, Barbara , Wright, Wendy
- Date: 2011
- Type: Text , Conference paper
- Relation: Australian Conference on Science and Mathematics Education (ACSME) p. 205-210
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- Description: As universities attempt to increase enrolments of ‘time-poor’ students, effective teaching strategies that minimise attendance requirements are required. The increasing use of technology to record face-to-face lectures provides a useful alternative for students unable to attend. However, this study indicates that recorded lectures, alone, are inadequate for distant students, who make extensive use of a wide range of materials. Study guides remain the most highly valued and highly used items in the suite of materials available to off-campus students. The importance of contact between off-campus students, their lecturers and their peers is highlighted.
Potential control of human immunodeficiency virus type 1 asp expression by alternative splicing in the upstream untranslated region
- Authors: Barbagallo, Michael , Birch, Kate , Deacon, Nicholas , Mosse, Jennifer
- Date: 2012
- Type: Text , Journal article
- Relation: DNA and Cell Biology Vol. 31, no. 7 (2012), p. 1303-1313
- Full Text: false
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- Description: The negative-sense asp open reading frame (ORF) positioned opposite to the human immunodeficiency virus type 1 (HIV-1) env gene encodes the 189 amino acid, membrane-associated ASP protein. Negative-sense transcription, regulated by long terminal repeat sequences, has been observed early in HIV-1 infection in vitro. All subtypes of HIV-1 were scanned to detect the negative-sense asp ORF and to identify potential regulatory sequences. A series of highly conserved upstream short open reading frames (sORFs) was identified. This potential control region from HIV-1NL4-3, containing six sORFs, was cloned upstream of the reporter gene EGFP. Expression by transfection of HEK293 cells indicated that the introduction of this sORF region inhibits EGFP reporter expression; analysis of transcripts revealed no significant changes in levels of EGFP mRNA. Reverse transcriptase–polymerase chain reaction analysis (RT-PCR) further demonstrated that the upstream sORF region undergoes alternative splicing in vitro. The most abundant product is spliced to remove sORFs I to V, leaving only the in-frame sORF VI upstream of asp. Sequence analysis revealed the presence of typical splice donor- and acceptor-site motifs. Mutation of the highly conserved splice donor and acceptor sites modulates, but does not fully relieve, inhibition of EGFP production. The strong conservation of asp and its sORFs across all HIV-1 subtypes suggests that the asp gene product may have a role in the pathogenesis of HIV-1. Alternative splicing of the upstream sORF region provides a potential mechanism for controlling expression of the asp gene.
Potently immunosuppressive 5-fluorouracil-resistant mesenchymal stromal cells completely remit an experimental autoimmune disease
- Authors: Oh, Ding , Cui, Peng , Hosseini, Hamid , Mosse, Jennifer , Toh, Ban-Hock , Chan, Moh
- Date: 2012
- Type: Text , Journal article
- Relation: Journal Of Immunology Vol. 188, no. 5 (2012), p. 2207-2217
- Full Text: false
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- Description: We treated mice with 5-fluorouracil (5-FU) to isolate a quiescent and undifferentiated mesenchymal stromal cell (MSC) population from the bone marrow. We examined these 5-FU–resistant MSCs (5-FU–MSCs) free from hematopoietic components for CFU fibroblasts (CFU-Fs) and assessed their immunosuppressive potential in vitro and in vivo. We differentiated fibroblastic CFU-Fs (Fibro–CFU-Fs) from mixed CFU-Fs, based on the absence of in situ expression of CD11b and CD45 hematopoietic markers, as well as on their differentiation capacity. Fibro–CFU-Fs were associated with increased numbers of large-sized Fibro–CFU-Fs (≥9 mm2) that displayed enhanced capacity for differentiation into adipogenic and osteogenic mesenchymal lineages. Administration of these 5-FU–resistant CD11b−CD45− MSCs 6 d after myelin oligodendrocyte glycoprotein (MOG) immunization completely remitted MOG-induced experimental autoimmune encephalomyelitis after initial development of mild disease. The remission was accompanied by reduced CNS cellular infiltration and demyelination, as well as a significant reduction in anti-MOG Ab and splenocyte proliferation to MOG. MOG-stimulated splenocytes from these mice showed elevated levels of Th2 cytokines (IL-4, IL-5, and IL-6) and decreased IL-17. Compared with untreated MSCs, 5-FU–MSCs demonstrated potent immunosuppression of Con A-stimulated splenocytes in vitro, even at a 1:320 MSC/splenocyte ratio. Immunosuppression was accompanied by elevated IL-1ra, IL-10, and PGE2. Blocking IL-1ra, IL-10, and PGE2, but not IL-6, heme oxygenase-1, and NO, attenuated 5-FU–MSC–induced immunosuppression. Together, our findings suggested that immunosuppression by 5-FU-MSC is mediated by a combination of elevated IL-1ra, IL-10, and PGE2, anti-inflammatory Th2 cytokines, and decreased IL-17. Our findings suggested that 5-FU treatment identifies a population of potently immunosuppressive 5-FU–MSCs that have the potential to be exploited to remit autoimmune diseases.