Is an intermediate state populated on the folding pathway of ubiquitin?

AbstractIn the last couple of years, there has been increasing debate as to the presence and role of intermediate states on the folding pathways of several small proteins, including the 76-residue protein ubiquitin. Here, we present detailed kinetic studies to establish whether an intermediate state is ever populated during the folding of this protein. We show that the differences observed in previous studies are attributable to the transient aggregation of the protein during folding. Using a highly soluble construct of ubiquitin, which does not aggregate during folding, we establish the conditions in which an intermediate state is sufficiently stable to be observed by kinetic measurements

Seasonality of Social Behaviour Among Immature Belugas (Delphinapterus leucas) in Managed Care

Belugas ( Delphinapterus leucas ) in managed care have been reported to show seasonal variation in socio-sexual behaviour, hormone levels and respiration rates; however, little is known about the social interactions of wild belugas when they are not in summer, near-shore congregations. To better understand if belugas show seasonal variation in social interactions, this study recorded the behaviour of 10 belugas (five females, five males, ranging from birth to 10 years of age) housed in managed care. Social interactions typically peaked in the summer months but persisted at very low levels during the rest of the year. Sea - sonal variation was most dramatic for socio-sexual behaviour but was generally mirrored in pattern by agonistic and affiliative interactions. Subjects closer to maturity displayed more seasonal variation than younger subjects, and males displayed more seasonal variation compared to females. The peak in social interactions found in this study aligns rather closely with wild belugas’ sum - mer, near-shore congregations, where belugas have increased opportunities for socializing. Although belugas in managed care do not experience a seasonal change in habitat, they do show seasonal changes in social behaviour, which are likely driven by seasonal fluctuations in hormone levels. It is therefore expected that wild beluga populations would show similar behavioural pat - terns if they were observed throughout the remainder of the year. This research has applications for belugas in managed care and may provide a framework for understanding the social behaviour of wild belugas

Plant microbiome-dependent immune enhancing action of Echinacea purpurea is enhanced by soil organic matter content

© 2019 The Authors Anthemis austriaca Jacq. flowers are traditionally used to alleviate abdominal pain, hemorrhoids, ovary diseases and pneumonia. This study aimed to investigate the effects of A. austriaca flowers, which are frequently used in gynecological disorders, on the rat endometriosis model. The rat endometriosis model was used to evaluate the potential activity of the plant in endometriosis. The dried plant material was extracted with n-hexane, ethyl acetate (EtOAc), and methanol (MeOH), successively. The obtained extracts from A. austriaca flowers were applied to the rats. The adhesion scores, endometrial foci areas, and cytokine levels of the peritoneal fluids were measured on surgical induction of endometriosis in rats. The adhesion scores, endometriotic volume, and cytokine levels of the peritoneal fluids were reduced in the EtOAc, MeOH, and buserelin acetate-treated (reference) groups. The MeOH extract reduced the adhesion scores and endometrial foci areas from 3.1 to 1.1 (p \u3c 0.01) and from 86.4 to 40.5 (p \u3c 0.01), respectively and also the MeOH extract reduced tumor necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), and interleukin (IL)-6 levels of the peritoneal fluids from 13.7 to 3.8 (p \u3c 0.01), from 28.4 to 16.3 (p \u3c 0.05) and from 50.2 to 24.3 (p \u3c 0.01), respectively. Therefore, isolation studies were conducted on the EtOAc and MeOH extracts. After the MeOH extract was fractionated using RP-18 column, the obtained subfractions were evaluated again on the endometriosis rat model. Subfractions A and C of the MeOH extract displayed statistically significant activity on the endometriosis rat model. Phytochemical investigation resulted in the isolation of 4-β-D-glucopyranosyloxy-6-methyl-2H-pyran-2-one (1) from Fr. A and quercetin (2), apigenin-7-O-(3″-O-acetyl)-β-D-glucopyranoside (3), apigenin-7-O-(6″-O-acetyl)-β-D-glucopyranoside (4), apigenin-7-O-β-D-glucopyranoside (5), quercetin-7-O-β-D-glucopyranoside (6) from Fr. C. Moreover, β-sitosterol-3-O-β-D-glucopyranoside (7) was isolated from the EtOAc extract. As a conclusion, the MeOH extract obtained from A. austriaca flowers contributed to the regression of endometriosis. In addition, flavonoids and sterols of the plant were detected as the possible compounds responsible for the activity

A novel HLA-B18 restricted CD8+ T cell epitope is efficiently cross-presented by dendritic cells from soluble tumor antigen

NY-ESO-1 has been a major target of many immunotherapy trials because it is expressed by various cancers and is highly immunogenic. In this study, we have identified a novel HLA-B*1801-restricted CD8<sup>+</sup>T cell epitope, NY-ESO-1<sub>88–96</sub> (LEFYLAMPF) and compared its direct- and cross-presentation to that of the reported NY-ESO-1<sub>157–165</sub> epitope restricted to HLA-A*0201. Although both epitopes were readily cross-presented by DCs exposed to various forms of full-length NY-ESO-1 antigen, remarkably NY-ESO-1<sub>88–96</sub> is much more efficiently cross-presented from the soluble form, than NY-ESO-1<sub>157–165</sub>. On the other hand, NY-ESO-1<sub>157–165</sub> is efficiently presented by NY-ESO-1-expressing tumor cells and its presentation was not enhanced by IFN-γ treatment, which induced immunoproteasome as demonstrated by Western blots and functionally a decreased presentation of Melan A<sub>26–35</sub>; whereas NY-ESO-1<sub>88–96</sub> was very inefficiently presented by the same tumor cell lines, except for one that expressed high level of immunoproteasome. It was only presented when the tumor cells were first IFN-γ treated, followed by infection with recombinant vaccinia virus encoding NY-ESO-1, which dramatically increased NY-ESO-1 expression. These data indicate that the presentation of NY-ESO-1<sub>88–96</sub> is immunoproteasome dependent. Furthermore, a survey was conducted on multiple samples collected from HLA-B18+ melanoma patients. Surprisingly, all the detectable responses to NY-ESO-1<sub>88–96</sub> from patients, including those who received NY-ESO-1 ISCOMATRIX™ vaccine were induced spontaneously. Taken together, these results imply that some epitopes can be inefficiently presented by tumor cells although the corresponding CD8<sup>+</sup>T cell responses are efficiently primed in vivo by DCs cross-presenting these epitopes. The potential implications for cancer vaccine strategies are further discussed

Genetic Diversity of PCR-Positive, Culture-Negative and Culture-Positive Mycobacterium ulcerans Isolated from Buruli Ulcer Patients in Ghana.

Culture of Mycobacterium ulcerans from Buruli ulcer patients has very low sensitivity. Thus confirmation of M. ulcerans infection is primarily based on PCR directed against IS2404. In this study we compare the genotypes obtained by variable number of tandem repeat analysis of DNA from IS2404-PCR positive cultures with that obtained from IS2404 positive, culture-negative tissue. A significantly greater genetic heterogeneity was found among culture-negative samples compared with that found in cultured strains but a single genotype is over-represented in both sample sets. This study provides evidence that both the focal location of bacteria in a lesion as well as differences in the ability to culture a particular genotype may underlie the low sensitivity of culture. Though preliminary, data from this work also suggests that mycobacteria previously associated with fish disease (M. pseudoshottsii) may be pathogenic for humans

DNA copy number, including telomeres and mitochondria, assayed using next-generation sequencing

<p>Abstract</p> <p>Background</p> <p>DNA copy number variations occur within populations and aberrations can cause disease. We sought to develop an improved lab-automatable, cost-efficient, accurate platform to profile DNA copy number.</p> <p>Results</p> <p>We developed a sequencing-based assay of nuclear, mitochondrial, and telomeric DNA copy number that draws on the unbiased nature of next-generation sequencing and incorporates techniques developed for RNA expression profiling. To demonstrate this platform, we assayed UMC-11 cells using 5 million 33 nt reads and found tremendous copy number variation, including regions of single and homogeneous deletions and amplifications to 29 copies; 5 times more mitochondria and 4 times less telomeric sequence than a pool of non-diseased, blood-derived DNA; and that UMC-11 was derived from a male individual.</p> <p>Conclusion</p> <p>The described assay outputs absolute copy number, outputs an error estimate (p-value), and is more accurate than array-based platforms at high copy number. The platform enables profiling of mitochondrial levels and telomeric length. The assay is lab-automatable and has a genomic resolution and cost that are tunable based on the number of sequence reads.</p

Infrared Eclipses of the Strongly Irradiated Planet WASP-33b, and Oscillations of its Host Star

We observe two secondary eclipses of the strongly irradiated transiting planet WASP-33b in the Ks band, and one secondary eclipse each at 3.6- and 4.5 microns using Warm Spitzer. This planet orbits an A5V delta-Scuti star that is known to exhibit low amplitude non-radial p-mode oscillations at about 0.1-percent semi-amplitude. We detect stellar oscillations in all of our infrared eclipse data, and also in one night of observations at J-band out of eclipse. The oscillation amplitude, in all infrared bands except Ks, is about the same as in the optical. However, the stellar oscillations in Ks band have about twice the amplitude as seen in the optical, possibly because the Brackett-gamma line falls in this bandpass. We use our best-fit values for the eclipse depth, as well as the 0.9 micron eclipse observed by Smith et al., to explore possible states of the exoplanetary atmosphere, based on the method of Madhusudhan and Seager. On this basis we find two possible states for the atmospheric structure of WASP-33b. One possibility is a non-inverted temperature structure in spite of the strong irradiance, but this model requires an enhanced carbon abundance (C/O>1). The alternative model has solar composition, but an inverted temperature structure. Spectroscopy of the planet at secondary eclipse, using a spectral resolution that can resolve the water vapor band structure, should be able to break the degeneracy between these very different possible states of the exoplanetary atmosphere. However, both of those model atmospheres absorb nearly all of the stellar irradiance with minimal longitudinal re-distribution of energy, strengthening the hypothesis of Cowan et al. that the most strongly irradiated planets circulate energy poorly. Our measurement of the central phase of the eclipse yields e*cos(omega)=0.0003 +/-0.00013, which we regard as being consistent with a circular orbit.Comment: 23 pages, 9 figures, 3 tables, accepted for the Astrophysical Journa

Personal values, social capital, and higher education student career decidedness: a new 'protean'-informed model

This study investigates the role of personal values as motivational antecedents for understanding HE student career decidedness among university business school (UBS) students. We propose a new ‘protean’ informed HE student career decidedness model for theorizing how both personal values and social capital mediators (student social capital; personal, social and enterprise skills; access to resources) help in the student-centric and self-directed processes of career decision-making. A mixed methods study combines a (stage 1) survey of 308 UBS students from five (UK) university business schools, with results from (stage 2) four student focus groups, and (stage 3) two staff-student interactive seminars. From an employability perspective, arguably, the ultimate responsibility for becoming a ‘protean graduate’ rests with each UBS student, whilst the obligation of HE staff is to effectively facilitate and nurture all possible personal growth and skills development opportunities

An agonistic anti-CD137 antibody disrupts lymphoid follicle structure and T-cell-dependent antibody responses

CD137 is a costimulatory receptor expressed on natural killer cells, T cells, and subsets of dendritic cells. An agonistic monoclonal antibody (mAb) against CD137 has been used to reduce tumor burden or reverse autoimmunity in animal models and clinical trials. Here, we show that mice treated with an agonistic anti-CD137 mAb have reduced numbers of germinal center (GC) B cells and follicular dendritic cells (FDCs) in lymphoid tissues, which impair antibody responses to multiple T-cell-dependent antigens, including infectious virus, viral proteins, and conjugated haptens. These effects are not due to enhanced apoptosis or impaired proliferation of B cells but instead correlate with changes in lymphoid follicle structure and GC B cell dispersal and are mediated by CD137 signaling in CD