745 research outputs found
DNA Vaccines Encoding Antigen Targeted to MHC Class II Induce Influenza-Specific CD8+ T Cell Responses, Enabling Faster Resolution of Influenza Disease
Current influenza vaccines are effective but imperfect, failing to cover against emerging strains of virus and requiring seasonal administration to protect against new strains. A key step to improving influenza vaccines is to improve our understanding of vaccine induced protection. Whilst it is clear that antibodies play a protective role, vaccine induced CD8+ T cells can improve protection. To further explore the role of CD8+ T cells we used a DNA vaccine that encodes antigen dimerised to an immune cell targeting module. Immunising CB6F1 mice with the DNA vaccine in a heterologous prime boost regime with the seasonal protein vaccine improved the resolution of influenza disease compared to protein alone. This improved disease resolution was dependent on CD8+ T cells. However, DNA vaccine regimes that induced CD8+ T cells alone were not protective and did not boost the protection provided by protein. The MHC targeting module used was an anti-I-Ed single chain antibody specific to the BALB/c strain of mice. To test the role of MHC targeting we compared the response between BALB/c, C57BL/6 mice and an F1 cross of the two strains (CB6F1). BALB/c mice were protected, C57BL/6 were not and the F1 had an intermediate phenotype; showing that the targeting of antigen is important in the response. Based on these findings, and in agreement with other studies using different vaccines, we conclude that in addition to antibody, inducing a protective CD8 response is important in future influenza vaccines
TP53 mutations in myelodysplastic syndromes with deletion of 5q
The myelodysplastic syndromes (MDS) constitute a heterogeneous group of malignant bone marrow disorders characterized by peripheral cytopenia(s) and increased risk of progression to acute myeloid leukemia (AML). International Prognostic Scoring system (IPSS) Low- or Intermediate (INT)-1 risk MDS with a deletion of 5q (del5q) were considered to have an indolent course and a low risk for progression to AML as compared to other MDS subtypes. However, more recent studies have shown that overall survival (OS) and risk for AML progression vary greatly in del(5q) MDS patients indicating that factors beyond established risk scoring systems impact patient outcome. Molecular abnormalities have emerged as putative prognostic markers.
We performed molecular studies in a patient with classical 5q-syndrome who unexpectedly evolved to high-risk MDS with complex karyotype (Paper I). Immunohistochemistry (IHC) of pre-treatment marrow biopsies revealed a small fraction of progenitors with strong p53 expression and sequencing confirmed a TP53 mutation. TP53 mutated subclones had not been described in MDS with isolated del(5q) and indicated a previously unknown heterogeneity.
In a subsequent study of 55 patients with lower-risk del(5q) MDS, 18% of the patients were found to have TP53 mutated subclones at diagnosis which rendered them at higher risk for progression (Paper II). Interestingly, the association with outcome was even stronger for p53 IHC indicating a high sensitivity of this method for early identification of patients with adverse outcome.
As a next step, we assessed p53 protein expression in a cohort of 85 lower-risk del(5q) MDS patients treated with lenalidomide within a clinical trial (Paper IV). P53 IHC positive patients showed significantly shorter overall survival, higher risk for leukemic transformation, and lower cytogenetic response rate to lenalidomide, hence validating the results from Paper II. Importantly, pyrosequencing analysis of microdissected IHC stained cells confirmed that cells with strong staining carried TP53 mutations, while moderate staining reflected wild-type TP53.
Due to the apparently exquisite sensitivity of the del(5q) clone to len, we hypothesized that higher doses of lenalidomide may induce cytogenetic and clinical responses also in patients with high-risk MDS/AML with chromosome 5 abnormalities who were refractory or ineligible for standard treatment (Paper III). In this study, we demonstrated that treatment was able to inhibit the del(5q)tumor clone in a cohort of patients with extremely advanced disease, which suggests that the selective inhibitory effect of len in vitro may be translated into a therapeutic response in vivo. Importantly, TP53 mutations were common (62%) in this cohort, and uniformly associated with treatment failure.
Altogether, our findings suggest an important role of the p53 pathway in both low- and high-risk del(5q) MDS, and in relation to treatment with lenalidomide. These findings will have major implications for risk stratification and the choice of therapy
Transplanting the leafy liverwort Herbertus hutchinsiae : A suitable conservation tool to maintain oceanic-montane liverwort-rich heath?
Thanks to the relevant landowners and managers for permission to carry out the experiments, Chris Preston for helping to obtain the liverwort distribution records and the distribution map, Gordon Rothero and Dave Horsfield for advice on choosing experimental sites and Alex Douglas for statistical advice. Juliane Geyer’s help with fieldwork was greatly appreciated. This study was made possible by a NERC PhD studentship and financial support from the Royal Botanic Garden Edinburgh and Scottish Natural Heritage.Peer reviewedPostprin
Surface-initiated growth of copper using isonicotinic acid-functionalized aluminum oxide surfaces
Isonicotinate self-assembled monolayers (SAM) were prepared on alumina surfaces (A) using isonicotinic acid (iNA). These functionalized layers (iNA-A) were used for the seeded growth of copper films (Cu-iNA-A) by hydrazine hydrate-initiated electroless deposition. The films were characterized by scanning electron microscopy (SEM), electron-dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and advancing contact angle measurements. The films are Cu0 but with surface oxidation, and show a faceted morphology, which is more textured (Rq = 460 ± 90 nm) compared to the SAM (Rq = 2.8 ± 0.5 nm). In contrast, growth of copper films by SnCl2/PdCl2 catalyzed electroless deposition, using formaldehyde (CH2O) as the reducing agent, shows a nodular morphology on top of a relatively smooth surface. No copper films are observed in the absence of the isonicotinate SAM. The binding of Cu2+ to the iNA is proposed to facilitate reduction to Cu0 and create the seed for subsequent growth. The films show good adhesion to the functionalized surface
Long-term and realistic global change manipulations had low impact on diversity of soil biota in temperate heathland
In a dry heathland ecosystem we manipulated temperature (warming), precipitation (drought) and atmospheric concentration of CO(2) in a full-factorial experiment in order to investigate changes in below-ground biodiversity as a result of future climate change. We investigated the responses in community diversity of nematodes, enchytraeids, collembolans and oribatid mites at two and eight years of manipulations. We used a structural equation modelling (SEM) approach analyzing the three manipulations, soil moisture and temperature, and seven soil biological and chemical variables. The analysis revealed a persistent and positive effect of elevated CO(2) on litter C:N ratio. After two years of treatment, the fungi to bacteria ratio was increased by warming, and the diversities within oribatid mites, collembolans and nematode groups were all affected by elevated CO(2) mediated through increased litter C:N ratio. After eight years of treatment, however, the CO(2)-increased litter C:N ratio did not influence the diversity in any of the four fauna groups. The number of significant correlations between treatments, food source quality, and soil biota diversities was reduced from six to three after two and eight years, respectively. These results suggest a remarkable resilience within the soil biota against global climate change treatments in the long term
Wild-type and mutant SOD1 share an aberrant conformation and a common pathogenic pathway in ALS.
Many mutations confer one or more toxic function(s) on copper/zinc superoxide dismutase 1 (SOD1) that impair motor neuron viability and cause familial amyotrophic lateral sclerosis (FALS). Using a conformation-specific antibody that detects misfolded SOD1 (C4F6), we found that oxidized wild-type SOD1 and mutant SOD1 share a conformational epitope that is not present in normal wild-type SOD1. In a subset of human sporadic ALS (SALS) cases, motor neurons in the lumbosacral spinal cord were markedly C4F6 immunoreactive, indicating that an aberrant wild-type SOD1 species was present. Recombinant, oxidized wild-type SOD1 and wild-type SOD1 immunopurified from SALS tissues inhibited kinesin-based fast axonal transport in a manner similar to that of FALS-linked mutant SOD1. Our findings suggest that wild-type SOD1 can be pathogenic in SALS and identify an SOD1-dependent pathogenic mechanism common to FALS and SALS
CD47 plays a critical role in T-cell recruitment by regulation of LFA-1 and VLA-4 integrin adhesive functions
CD47 plays an important but incompletely understood role in the innate and adaptive immune responses. CD47, also called integrin-associated protein, has been demonstrated to associate in cis with β1 and β3 integrins. Here we test the hypothesis that CD47 regulates adhesive functions of T-cell α4β1 (VLA-4) and αLβ2 (LFA-1) in in vivo and in vitro models of inflammation. Intravital microscopy studies reveal that CD47(−/−) Th1 cells exhibit reduced interactions with wild-type (WT) inflamed cremaster muscle microvessels. Similarly, murine CD47(−/−) Th1 cells, as compared with WT, showed defects in adhesion and transmigration across tumor necrosis factor-α (TNF-α)–activated murine endothelium and in adhesion to immobilized intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion protein 1 (VCAM-1) under flow conditions. Human Jurkat T-cells lacking CD47 also showed reduced adhesion to TNF-α–activated endothelium and ICAM-1 and VCAM-1. In cis interactions between Jurkat T-cell β2 integrins and CD47 were detected by fluorescence lifetime imaging microscopy. Unexpectedly, Jurkat CD47 null cells exhibited a striking defect in β1 and β2 integrin activation in response to Mn(2+) or Mg(2+)/ethylene glycol tetraacetic acid treatment. Our results demonstrate that CD47 associates with β2 integrins and is necessary to induce high-affinity conformations of LFA-1 and VLA-4 that recognize their endothelial cell ligands and support leukocyte adhesion and transendothelial migration
Countries with Higher Levels of Gender Equality Show Larger National Sex Differences in Mathematics Anxiety and Relatively Lower Parental Mathematics Valuation for Girls.
Despite international advancements in gender equality across a variety of societal domains, the underrepresentation of girls and women in Science, Technology, Engineering, and Mathematics (STEM) related fields persists. In this study, we explored the possibility that the sex difference in mathematics anxiety contributes to this disparity. More specifically, we tested a number of predictions from the prominent gender stratification model, which is the leading psychological theory of cross-national patterns of sex differences in mathematics anxiety and performance. To this end, we analyzed data from 761,655 15-year old students across 68 nations who participated in the Programme for International Student Assessment (PISA). Most importantly and contra predictions, we showed that economically developed and more gender equal countries have a lower overall level of mathematics anxiety, and yet a larger national sex difference in mathematics anxiety relative to less developed countries. Further, although relatively more mothers work in STEM fields in more developed countries, these parents valued, on average, mathematical competence more in their sons than their daughters. The proportion of mothers working in STEM was unrelated to sex differences in mathematics anxiety or performance. We propose that the gender stratification model fails to account for these national patterns and that an alternative model is needed. In the discussion, we suggest how an interaction between socio-cultural values and sex-specific psychological traits can better explain these patterns. We also discuss implications for policies aiming to increase girls' STEM participation
Quasi-free (p,pN) scattering of light neutron-rich nuclei around N = 14
Background: For many years, quasifree scattering reactions in direct kinematics have been extensively used to study the structure of stable nuclei, demonstrating the potential of this approach. The RB3 collaboration has performed a pilot experiment to study quasifree scattering reactions in inverse kinematics for a stable C12 beam. The results from that experiment constitute the first quasifree scattering results in inverse and complete kinematics. This technique has lately been extended to exotic beams to investigate the evolution of shell structure, which has attracted much interest due to changes in shell structure if the number of protons or neutrons is varied. Purpose: In this work we investigate for the first time the quasifree scattering reactions (p,pn) and (p,2p) simultaneously for the same projectile in inverse and complete kinematics for radioactive beams with the aim to study the evolution of single-particle properties from N=14 to N=15. Method: The structure of the projectiles O23, O22, and N21 has been studied simultaneously via (p,pn) and (p,2p) quasifree knockout reactions in complete inverse kinematics, allowing the investigation of proton and neutron structure at the same time. The experimental data were collected at the R3B-LAND setup at GSI at beam energies of around 400 MeV/u. Two key observables have been studied to shed light on the structure of those nuclei: the inclusive cross sections and the corresponding momentum distributions. Conclusions: The knockout reactions (p,pn) and (p,2p) with radioactive beams in inverse kinematics have provided important and complementary information for the study of shell evolution and structure. For the (p,pn) channels, indications of a change in the structure of these nuclei moving from N=14 to N=15 have been observed, i.e., from the 0d5/2 shell to the 1s1/2. This supports previous observations of a subshell closure at N=14 for neutron-rich oxygen isotopes and its weakening for the nitrogen isotopes
Sexual (Dis)satisfaction and Its Contributors Among People Living with HIV Infection in Sweden
Earlier research reports lower sexual satisfaction among people living with HIV (PLHIV) compared to HIV-negative persons. A number of psychosocial factors directly associated with sexual dissatisfaction have been identified. Little is known about sexual satisfaction and their contributors among PLHIV in Sweden. The aim of this study was to examine direct and indirect effects of variables within sociodemographic, clinical HIV-related, psychological, and sexual domains on sexual(dis)satisfaction among PLHIV in Sweden. Data for this study was derived from a national representative, anonymous survey among PLHIV conducted in 2014 (n=1096). Statistical analysis included four steps: descriptive analyses, identification of variables associated with sexual (dis)satisfaction, identification of variables associated with those contributors of sexual (dis)satisfaction, and a path model integrating all these analyses. A total of 49% of participants reported being sexually dissatisfied and no significant differences were observed when non-heterosexual men, heterosexual men and women were compared. Among women, a negative change in sex life after HIV diagnosis and distress with orgasmic difficulties were directly associated with sexual dissatisfaction. For men, hopelessness, high HIV stigma, sexual inactivity in the last 6 months, and a negative change in sex life after HIV diagnosis were directly associated with sexual dissatisfaction. Path analyses showed in both men and women significant indirect association between not being involved in an intimate relationship, lower self-reported CD4 cell counts, and perceiving obligation to disclose HIV status to sexual partners as a barrier to look for a long-term partner and sexual dissatisfaction. Our results show that despite good treatment outcomes, the HIV diagnosis has a negative bearing on sexual satisfaction. The need for gender-tailored interventions and clinical implications of these findings are discussed
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