1,331 research outputs found
Autosomal Dominant Gain-of-function STAT1 Mutation is a Novel Genetic Etiology of Penicillium Marneffei Infection
Symposium / Free Paper 4: ImmunologyConference Theme: Inflammatory Basis of Perinatal and Childhood DiseasesBackground: Penicillium marneffei infection is indigenous to Southeast Asia.
Majority of cases occur in patients with AIDS and secondary immunodeficiencies.
We previously reported 4 HIV-negative children with chronic mucocutaneous
candidiasis (CMC) and severe penicilliosis. Hyper-IgE syndrome was diagnosed
in one of them, but extensive genetic studies on IL12-IFNγ axis, CARD9 and AIRE
were unrevealing for the rest. Recently, STAT1 hyperphosphorylation causing
defective Th1 and Th17 immunity is recognized as a cause of CMC.
Objective: To investigate the genetic and functional defects of STAT1 signaling in
children affected by penicilliosis.
Methods: Targeted sequencing of STAT1 gene or total exome sequencing was
performed in 3 patients with CMC and penicilliosis. PBMCs were isolated from
patients and normal controls. Intracellular STAT1 phosphorylation (pSTAT1)
towards interferon-α and interferon-γ stimulation was evaluated by flow
cytometry. Cytokine production in PBMCs towards PMA and ionomycin stimulation
was assessed. PBMCs were co-cultured with live Candida albicans and
P. marneffei to evaluate interferon-γ response.
Results: Heterozygous STAT1 missense mutations were identified in all 3 patients.
Two mutations were located in the coiled-coil domain (P1 and P2) and one in
the DNA-binding domain (P3). All 3 patients recovered from penicilliosis, but P1
eventually died of fulminant aspergillosis. The percentage of pSTAT1-positive
PBMCs induced by interferon-α and interferon-γ was significantly higher in all
3 patients than normal controls, indicating that they had gain-of-function mutations. PBMCs from all patients displayed defective interferon-γ and
interleukin-17 production towards PMA and PMA plus ionomycin, respectively.
Interferon-γ production induced by C. albicans and P. marneffei in P2 was
significantly lower than normal controls.
Conclusions: For the first time, we demonstrated STAT1 gain-of-function
mutation as an important and novel genetic etiology of invasive mycosis including
penicilliosis and aspergillosis. Penicilliosis should be regarded as an indicator
disease for primary immunodeficiencies in children without HIV infection unless
proven otherwise.published_or_final_versio
Penicillium marneffei infection and impaired IFN-γ immunity in humans with autosomal-dominant gain-of-phosphorylation STAT1 mutations
postprin
Pressure-Induced Amorphization of Small Pore Zeolites-the Role of Cation-H2O Topology and Anti-glass Formation
Systematic studies of pressure-induced amorphization of natrolites (PIA) containing monovalent extra-framework cations (EFC) Li+, Na+, K+, Rb+, Cs+ allow us to assess the role of two different EFC-H2O configurations within the pores of a zeolite: one arrangement has H2O molecules (NATI) and the other the EFC (NAT(II)) in closer proximity to the aluminosilicate framework. We show that NAT(I) materials have a lower onset pressure of PIA than the NAT(II) materials containing Rb and Cs as EFC. The onset pressure of amorphization (P-A) of NAT(II) materials increases linearly with the size of the EFC, whereas their initial bulk moduli (P-1 phase) decrease linearly. Only Cs- and Rb-NAT reveal a phase separation into a dense form (P-2 phase) under pressure. High-Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF-STEM) imaging shows that after recovery from pressures near 25 and 20 GPa long-range ordered Rb-Rb and Cs-Cs correlations continue to be present over length scales up to 100 nm while short-range ordering of the aluminosilicate framework is significantly reduced-this opens a new way to form anti-glass structuresopen
Robust Automated Tumour Segmentation on Histological and Immunohistochemical Tissue Images
Tissue microarray (TMA) is a high throughput analysis tool to identify new diagnostic and prognostic markers in human cancers. However, standard automated method in tumour detection on both routine histochemical and immunohistochemistry (IHC) images is under developed. This paper presents a robust automated tumour cell segmentation model which can be applied to both routine histochemical tissue slides and IHC slides and deal with finer pixel-based segmentation in comparison with blob or area based segmentation by existing approaches. The presented technique greatly improves the process of TMA construction and plays an important role in automated IHC quantification in biomarker analysis where excluding stroma areas is critical. With the finest pixel-based evaluation (instead of area-based or object-based), the experimental results show that the proposed method is able to achieve 80% accuracy and 78% accuracy in two different types of pathological virtual slides, i.e., routine histochemical H&E and IHC images, respectively. The presented technique greatly reduces labor-intensive workloads for pathologists and highly speeds up the process of TMA construction and provides a possibility for fully automated IHC quantification
Wnt signaling in breast cancer: have we come full circle?
Since the original identification of Wnt1 as a mammary oncogene in mouse mammary tumor virus infected mice, questions have been asked about its relevance to human breast cancer. Wnt1 is now known to be one of a large family of Wnt genes encoding structurally similar secreted signaling proteins, several of which are functionally redundant. The principal intracellular signaling pathway activated by these proteins has been elucidated in recent years. Components of this pathway include proto-oncogene products, such as β-catenin, and tumor suppressor proteins such as APC. Although WNT1 itself has not been implicated in human breast neoplasms, it has been reported that other WNT genes are sometimes overexpressed in human breast cancer and there is growing evidence that downstream components of the Wnt signaling pathway are activated in a significant proportion of breast tumors
Effect of root age on the biomechanics of seminal and nodal roots of barley (<i>Hordeum vulgare L.</i>) in contrasting soil environments
Acknowledgments The James Hutton Institute receives funding from the Scottish Government. The authors would also like to thank Jim McNicol from Biomathematics and Statistics Scotland for his advice on statistical analysis.Peer reviewedPostprin
Effects of root dehydration on biomechanical properties of woody roots of <i>Ulex europaeus</i>
A Novel Fibronectin Binding Motif in MSCRAMMs Targets F3 Modules
BBK32 is a surface expressed lipoprotein and fibronectin (Fn)-binding microbial surface component recognizing adhesive matrix molecule (MSCRAMM) of Borrelia burgdorferi, the causative agent of Lyme disease. Previous studies from our group showed that BBK32 is a virulence factor in experimental Lyme disease and located the Fn-binding region to residues 21-205 of the lipoprotein.Studies aimed at identifying interacting sites between BBK32 and Fn revealed an interaction between the MSCRAMM and the Fn F3 modules. Further analysis of this interaction showed that BBK32 can cause the aggregation of human plasma Fn in a similar concentration-dependent manner to that of anastellin, the superfibronectin (sFn) inducing agent. The resulting Fn aggregates are conformationally distinct from plasma Fn as indicated by a change in available thermolysin cleavage sites. Recombinant BBK32 and anastellin affect the structure of Fn matrices formed by cultured fibroblasts and inhibit endothelial cell proliferation similarly. Within BBK32, we have located the sFn-forming activity to a region between residues 160 and 175 which contains two sequence motifs that are also found in anastellin. Synthetic peptides mimicking these motifs induce Fn aggregation, whereas a peptide with a scrambled sequence motif was inactive, suggesting that these motifs represent the sFn-inducing sequence.We conclude that BBK32 induces the formation of Fn aggregates that are indistinguishable from those formed by anastellin. The results of this study provide evidence for how bacteria can target host proteins to manipulate host cell activities
Small-scale modelling of plant root systems using 3D printing, with applications to investigate the role of vegetation on earthquake-induced landslides
The genomes of two key bumblebee species with primitive eusocial organization
Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation
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