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71.
McNeela EA Burke A Neill DR Baxter C Fernandes VE Ferreira D Smeaton S El-Rachkidy R McLoughlin RM Mori A Moran B Fitzgerald KA Tschopp J Pétrilli V Andrew PW Kadioglu A Lavelle EC 《PLoS pathogens》2010,6(11):e1001191
Pneumolysin (PLY) is a key Streptococcus pneumoniae virulence factor and potential candidate for inclusion in pneumococcal subunit vaccines. Dendritic cells (DC) play a key role in the initiation and instruction of adaptive immunity, but the effects of PLY on DC have not been widely investigated. Endotoxin-free PLY enhanced costimulatory molecule expression on DC but did not induce cytokine secretion. These effects have functional significance as adoptive transfer of DC exposed to PLY and antigen resulted in stronger antigen-specific T cell proliferation than transfer of DC exposed to antigen alone. PLY synergized with TLR agonists to enhance secretion of the proinflammatory cytokines IL-12, IL-23, IL-6, IL-1β, IL-1α and TNF-α by DC and enhanced cytokines including IL-17A and IFN-γ by splenocytes. PLY-induced DC maturation and cytokine secretion by DC and splenocytes was TLR4-independent. Both IL-17A and IFN-γ are required for protective immunity to pneumococcal infection and intranasal infection of mice with PLY-deficient pneumococci induced significantly less IFN-γ and IL-17A in the lungs compared to infection with wild-type bacteria. IL-1β plays a key role in promoting IL-17A and was previously shown to mediate protection against pneumococcal infection. The enhancement of IL-1β secretion by whole live S. pneumoniae and by PLY in DC required NLRP3, identifying PLY as a novel NLRP3 inflammasome activator. Furthermore, NLRP3 was required for protective immunity against respiratory infection with S. pneumoniae. These results add significantly to our understanding of the interactions between PLY and the immune system. 相似文献
72.
When cells are exposed to radiation serious lesions are introduced into the DNA including double strand breaks (DSBs), single strand breaks (SSBs), base modifications and clustered damage sites (a specific feature of ionizing radiation induced DNA damage). Radiation induced DNA damage has the potential to initiate events that can lead ultimately to mutations and the onset of cancer and therefore understanding the cellular responses to DNA lesions is of particular importance. Using γH2AX as a marker for DSB formation and RAD51 as a marker of homologous recombination (HR) which is recruited in the processing of frank DSBs or DSBs arising from stalled replication forks, we have investigated the contribution of SSBs and non-DSB DNA damage to the induction of DSBs in mammalian cells by ionizing radiation during the cell cycle. V79-4 cells and human HF19 fibroblast cells have been either irradiated with 0–20 Gy of γ radiation or, for comparison, treated with a low concentration of hydrogen peroxide, which is known to induce SSBs but not DSBs. Inhibition of the repair of oxidative DNA lesions by poly(ADP ribose) polymerase (PARP) inhibitor leads to an increase in radiation induced γH2AX and RAD51 foci which we propose is due to these lesions colliding with replication forks forming replication induced DSBs. It was confirmed that DSBs are not induced in G1 phase cells by treatment with hydrogen peroxide but treatment does lead to DSB induction, specifically in S phase cells. We therefore suggest that radiation induced SSBs and non-DSB DNA damage contribute to the formation of replication induced DSBs, detected as RAD51 foci. 相似文献
73.
Damian P. O’Neill Sandra E. Davidson Victoria C. Clarke Yukika Yamauchi Shinjiro Yamaguchi Yuji Kamiya James B. Reid John J. Ross 《Planta》2010,232(5):1141-1149
The synthesis and deactivation of bioactive gibberellins (GA) are regulated by auxin and by GA signalling. The effect of GA
on its own pathway is mediated by DELLA proteins. Like auxin, the DELLAs promote GA synthesis and inhibit its deactivation.
Here, we investigate the relationships between auxin and DELLA regulation of the GA pathway in stems, using a pea double mutant
that is deficient in DELLA proteins. In general terms our results demonstrate that auxin and DELLAs independently regulate
the GA pathway, contrary to some previous suggestions. The extent to which DELLA regulation was able to counteract the effects
of auxin regulation varied from gene to gene. For Mendel’s LE gene (PsGA3ox1) no counteraction was observed. However, for another synthesis gene, a GA 20-oxidase, the effect of auxin was weak and in
WT plants appeared to be completely over-ridden by DELLA regulation. For a key GA deactivation (2-oxidase) gene, PsGA2ox1, the up-regulation induced by auxin deficiency was reduced to some extent by DELLA regulation. A second pea 2-oxidase gene,
PsGA2ox2, was up-regulated by auxin, in a DELLA-independent manner. In Arabidopsis also, one 2-oxidase gene was down-regulated by auxin while another was up-regulated. Monitoring the metabolism pattern of
GA20 showed that in Arabidopsis, as in pea, auxin can promote the accumulation of bioactive GA. 相似文献
74.
75.
Although commonly associated with infection in cattle, bovine viral diarrhea viruses (BVDV) also replicate in many domestic and wildlife species, including cervids. Bovine viral diarrhea viruses have been isolated from a number of cervids, including mule deer (Odocoileus hemionus), European roe deer (Capreolus capreolus), red deer (Cervus elaphus), white-tailed deer (Odocoileus virginianus), and mouse deer (Tragulus javanicus), but little information is available regarding clinical presentation and progression of infection in these species. In preliminary studies of experimental infection of deer with BVDV, researchers noted seroconversion but no clinical signs. In this study, we infected white-tailed deer fawns that were negative for BVDV and for antibodies against BVDV, with either a type 1 or a type 2 BVDV that had been isolated from white-tailed deer. Fawns were monitored for changes in basal temperature, circulating lymphocytes, and platelets. The clinical progression following inoculation in these fawns was similar to that seen with BVDV infections in cattle and included fever and depletion of circulating lymphocytes. Because free-ranging cervid populations are frequently in contact with domestic cattle in the United States, possible transfer of BVDV between cattle and cervids has significant implications for proposed BVDV control programs. 相似文献
76.
Identification of a novel risk locus for progressive supranuclear palsy by a pooled genomewide scan of 500,288 single-nucleotide polymorphisms
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Melquist S Craig DW Huentelman MJ Crook R Pearson JV Baker M Zismann VL Gass J Adamson J Szelinger S Corneveaux J Cannon A Coon KD Lincoln S Adler C Tuite P Calne DB Bigio EH Uitti RJ Wszolek ZK Golbe LI Caselli RJ Graff-Radford N Litvan I Farrer MJ Dickson DW Hutton M Stephan DA 《American journal of human genetics》2007,80(4):769-778
To date, only the H1 MAPT haplotype has been consistently associated with risk of developing the neurodegenerative disease progressive supranuclear palsy (PSP). We hypothesized that additional genetic loci may be involved in conferring risk of PSP that could be identified through a pooling-based genomewide association study of >500,000 SNPs. Candidate SNPs with large differences in allelic frequency were identified by ranking all SNPs by their probe-intensity difference between cohorts. The MAPT H1 haplotype was strongly detected by this methodology, as was a second major locus on chromosome 11p12-p11 that showed evidence of association at allelic (P<.001), genotypic (P<.001), and haplotypic (P<.001) levels and was narrowed to a single haplotype block containing the DNA damage-binding protein 2 (DDB2) and lysosomal acid phosphatase 2 (ACP2) genes. Since DNA damage and lysosomal dysfunction have been implicated in aging and neurodegenerative processes, both genes are viable candidates for conferring risk of disease. 相似文献
77.
Since the discovery of the green alga Caulerpa taxifolia in Lake Macquarie (New South Wales, Australia) in 2001, the New South Wales Department of Primary Industries (Fisheries)
has attempted various control methods, including covering the alga with granulated sea salt to induce osmotic shock and cell
lysis. In Lake Macquarie, C. taxifolia often occurs in patches within beds of the native seagrass Zostera capricorni. Although the effects of the salt treatment on blades of Z. capricorni and infauna have been shown to be minimal, there have been no tests of any effects on other native biota, including seagrass
epifauna. In this study, we tested the general hypothesis that the abundance and diversity of epifauna would be reduced by
salting. We used a ‘Beyond BACI’ experimental design whereby epifaunal invertebrates were sampled 3 months, 6 weeks and 6
days before and then again after salting. Epifaunal abundances at the putatively impacted (salted) location were compared
to those at 4 control locations (where no salt was applied). Abundances of most organisms varied significantly among times
and locations with no evidence of the consistent effect of salting on diversity or abundance of epifauna. The study represents
an example of the use of large-scale managerial action as a scientific experiment.
Electronic supplementary material Supplementary material is available for this article at <> and accessible for authorised users 相似文献
78.
There is increasing evidence that hydrogen peroxide (H2O2) may act as a neuromodulator in the brain, as well as contributing to neurodegeneration in diseased states, such as Parkinson's disease. The ability to monitor changes in endogenous H2O2 in vivo with high temporal resolution is essential in order to further elucidate the roles of H2O2 in the central nervous system. Here, we describe the in vitro characterization of an implantable catalase-based H2O2 biosensor. The biosensor comprises two amperometric electrodes, one with catalase immobilized on the surface and one without enzyme (blank). The analytical signal is then the difference between the two electrodes. The H2O2 sensitivity of various designs was compared, and ranged from 0 to 56 ± 4 mA cm−2 M−1. The most successful design incorporated a Nafion® layer followed by a poly-o-phenylenediamine (PPD) polymer layer. Catalase was adsorbed onto the PPD layer and then cross-linked with glutaraldehyde. The ability of the biosensors to exclude interference from ascorbic acid, and other interference species found in vivo, was also tested. A variety of the catalase-based biosensor designs described here show promise for in vivo monitoring of endogenous H2O2 in the brain. 相似文献
79.
Dawn B. Neill 《Human nature (Hawthorne, N.Y.)》2007,18(3):209-224
Health research has shown that overweight and obesity in children and adults are becoming significant public health problems
in the developing world. Evidence suggests that this phenomenon is more marked in urban than rural areas and may be associated
with modernization. However, the underlying reasons for this nutrition transition remain unclear. Dietary shifts, often in
conjunction with income and time constraints in urban environments, may entail a greater reliance on more convenient sugar
and fat-dense food. Also, the necessity of labor-intensive agricultural work to meet rural subsistence needs is supplanted
in urban environments by sedentary work. This paper extends the application of human behavioral ecology theory into the realm
of international development and policy by applying Kaplan’s embodied capital theory to explore differences in food habits
and nutritional status of Indo-Fijian children within the context of urbanization. Urban high-embodied-capital women demonstrate
higher rates of wage-earning employment than urban low-embodied-capital or rural women. Findings indicate that urban high-embodied-capital
households spend significantly more on food purchases, purchase a greater proportion of processed foods, and have children
with higher body mass indexes (BMI) than do urban low-embodied-capital or rural households. This suggests that urban high-embodied-capital
mothers, who tend to be employed, may be making trade-offs between income and food choices.
相似文献
Dawn B. NeillEmail: |
80.
Multi‐gene phylogenetic analyses of New Zealand coralline algae: Corallinapetra Novaezelandiae gen. et sp. nov. and recognition of the Hapalidiales ord. nov.
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Wendy A. Nelson Judith E. Sutherland Tracy J. Farr Darren R. Hart Kate F. Neill Hee Jeong Kim Hwan Su Yoon 《Journal of phycology》2015,51(3):454-468
Coralline red algae from the New Zealand region were investigated in a study focused on documenting regional diversity. We present a multi‐gene analysis using sequence data obtained for four genes (nSSU, psaA, psbA, rbcL) from 68 samples. The study revealed cryptic diversity at both genus and species levels, confirming and providing further evidence of problems with current taxonomic concepts in the Corallinophycidae. In addition, a new genus Corallinapetra novaezelandiae gen. et sp. nov. is erected for material from northern New Zealand. Corallinapetra is excluded from all currently recognized families and orders within the Corallinophycidae and thus represents a previously unrecognized lineage within this subclass. We discuss rank in the Corallinophycidae and propose the order Hapalidiales. 相似文献