Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleSharrock J, Estacio Gomez A, Jacobson J, et al., 2019,
fs(1)h controls metabolic and immune function and enhances survival via AKT and FOXO in Drosophila
, Disease Models & Mechanisms, Vol: 12, ISSN: 1754-8403The Drosophila fat body is the primary organ of energy storage as well as being responsible for the humoral response to infection. Its physiological function is of critical importance to the survival of the organism; however, many molecular regulators of its function remain ill-defined. Here, we show that the Drosophila melanogaster bromodomain-containing protein FS(1)H is required in the fat body for normal lifespan as well as metabolic and immune homeostasis. Flies lacking fat body fs(1)h exhibit short lifespan, increased expression of immune target genes, an inability to metabolize triglyceride, and low basal AKT activity, mostly resulting from systemic defects in insulin signalling. Removal of a single copy of the AKT-responsive transcription factor foxo normalises lifespan, metabolic function, uninduced immune gene expression and AKT activity. We suggest that the promotion of systemic insulin signalling activity is a key in vivo function of fat body fs(1)h.
-
Journal articleHopkins E, Roumeliotis TI, Mullineaux-Sanders C, et al., 2019,
Intestinal epithelial cells and the microbiome undergo swift reprogramming at the inception of colonic Citrobacter rodentium infection
, mBio, Vol: 10, ISSN: 2150-7511We used the mouse attaching and effacing (A/E) pathogen Citrobacter rodentium, which models the human A/E pathogens enteropathogenic Escherichia coli and enterohemorrhagic E. coli (EPEC and EHEC), to temporally resolve intestinal epithelial cell (IEC) responses and changes to the microbiome during in vivo infection. We found the host to be unresponsive during the first 3 days postinfection (DPI), when C. rodentium resides in the caecum. In contrast, at 4 DPI, the day of colonic colonization, despite only sporadic adhesion to the apex of the crypt, we observed robust upregulation of cell cycle and DNA repair processes, which were associated with expansion of the crypt Ki67-positive replicative zone, and downregulation of multiple metabolic processes (including the tricarboxylic acid [TCA] cycle and oxidative phosphorylation). Moreover, we observed dramatic depletion of goblet and deep crypt secretory cells and an atypical regulation of cholesterol homeostasis in IECs during early infection, with simultaneous upregulation of cholesterol biogenesis (e.g., 3-hydroxy-3-methylglutaryl–coenzyme A reductase [Hmgcr]), import (e.g., low-density lipoprotein receptor [Ldlr]), and efflux (e.g., AbcA1). We also detected interleukin 22 (IL-22) responses in IECs (e.g., Reg3γ) on the day of colonic colonization, which occurred concomitantly with a bloom of commensal Enterobacteriaceae on the mucosal surface. These results unravel a new paradigm in host-pathogen-microbiome interactions, showing for the first time that sensing a small number of pathogenic bacteria triggers swift intrinsic changes to the IEC composition and function, in tandem with significant changes to the mucosa-associated microbiome, which parallel innate immune responses.
-
Journal articleMaurice JB, Garvey L, Tsochatzis EA, et al., 2019,
Monocyte-macrophage activation is associated with nonalcoholic fatty liver disease and liver fibrosis in HIV monoinfection independently of the gut microbiome and bacterial translocation.
, AIDS, Vol: 33, Pages: 805-814, ISSN: 0269-9370BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is common among people living with HIV. There are limited data available on the pathophysiology of NAFLD and the development of fibrosis in this population. OBJECTIVES: The aim of this study was to investigate the association of bacterial translocation, adipose tissue dysfunction, monocyte activation and gut dysbiosis in patients with HIV monoinfection and NAFLD. METHODS: Cases with biopsy-proven NAFLD and HIV monoinfection were age and sex-matched to HIV-positive and HIV-negative controls. Markers of bacterial translocation [lipopolysaccharide-binding protein (LBP), bacterial DNA and lipopolysaccharide (LPS)], adipose tissue dysfunction (leptin, adiponectin) and monocyte activation (sCD14 and sCD163) were measured by ELISA. Hepatic patterns of macrophage activation were explored with immunohistochemistry. 16 s rRNA sequencing was performed with stool. RESULTS: Thirty-three cases were included (≥F2 fibrosis n = 16), matched to HIV-positive (n = 29) and HIV-negative (n = 17) controls. Cases with NAFLD were more obese (BMI 31.0 ± 4.4 vs. 24.1 ± 2.8 kg/m, P < 0.001) and had significantly increased levels of sCD14, sCD163 and higher leptin to adiponectin ratio vs. HIV-positive controls. Cases with ≥F2 verses < F2 fibrosis had increased sCD14 (1.4 ± 0.4 vs. 1.1 ± 0.3 μg/ml, P = 0.023) and sCD163 (1.0 ± 0.3 vs. 0.8 ± 0.3 μg/ml, P = 0.060), which correlated with waist circumference (sCD14 P = 0.022, sCD163 P = 0.011). Immunohistochemistry showed increased hepatic portal macrophage clusters in patients with fibrosis. No markers of bacterial translocation or changes to the microbiome were associated with NAFLD or fibrosis. CONCLUSION: NAFLD fibrosis stage in HIV monoinfected patients is associated with monocyte activation in the context of obesity, which may be independent of bacterial translocation and gut microbiome.
-
Journal articleZhang P, Wang Z, Zhao S, et al., 2019,
<SUP>1</SUP>H, <SUP>13</SUP>C and <SUP>15</SUP>N NMR assignments of Bacillus subtilis bacteriophage SPO1 protein Gp46
, BIOMOLECULAR NMR ASSIGNMENTS, Vol: 13, Pages: 245-247, ISSN: 1874-2718- Author Web Link
- Cite
- Citations: 3
-
Journal articleWarris A, Bercusson A, Armstrong-James D, 2019,
<i>Aspergillus</i> colonization and antifungal immunity in cystic fibrosis patients
, MEDICAL MYCOLOGY, Vol: 57, Pages: S118-S126, ISSN: 1369-3786- Author Web Link
- Cite
- Citations: 23
-
Journal articleMiliara X, Tatsuta T, Berry J-L, et al., 2019,
Structural determinants of lipid specificity within Ups/PRELI lipid transfer proteins
, Nature Communications, Vol: 10, Pages: 1-15, ISSN: 2041-1723Conserved lipid transfer proteins of the Ups/PRELI family regulate lipid accumulation in mitochondria by shuttling phospholipids in a lipid-specific manner across the intermembrane space. Here, we combine structural analysis, unbiased genetic approaches in yeast and molecular dynamics simulations to unravel determinants of lipid specificity within the conserved Ups/PRELI family. We present structures of human PRELID1–TRIAP1 and PRELID3b–TRIAP1 complexes, which exert lipid transfer activity for phosphatidic acid and phosphatidylserine, respectively. Reverse yeast genetic screens identify critical amino acid exchanges that broaden and swap their lipid specificities. We find that amino acids involved in head group recognition and the hydrophobicity of flexible loops regulate lipid entry into the binding cavity. Molecular dynamics simulations reveal different membrane orientations of PRELID1 and PRELID3b during the stepwise release of lipids. Our experiments thus define the structural determinants of lipid specificity and the dynamics of lipid interactions by Ups/PRELI proteins.
-
Journal articleFilloux A, Davies JC, 2019,
Chronic infection by controlling inflammation
, NATURE MICROBIOLOGY, Vol: 4, Pages: 378-379, ISSN: 2058-5276 -
Journal articleYu L-S, Rodriguez-Manzano J, Malpartida-Cardenas K, et al., 2019,
Rapid and sensitive detection of azole-resistant Aspergillus fumigatus by tandem-repeat loop-mediated isothermal amplification
, Journal of Molecular Diagnostics, Vol: 21, Pages: 286-295, ISSN: 1525-1578Invasive human fungal infections caused by multi-azole resistant Aspergillus fumigatus are associated with increasing rates of mortality in susceptible patients. Current methods of diagnosing infections caused by multi-azole resistant A. fumigatus are, however, not well suited for use in clinical point-of-care testing or in the field. Loop-mediated isothermal amplification (LAMP) is a widely used method of nucleic acid amplification with rapid and easy-to-use features, making it suitable for use in different resource settings. Here, we developed a LAMP assay to detect a 34 bp tandem repeat, named TR34-LAMP. TR34 is a high-prevalence allele that, in conjunction with the L98H single nucleotide polymorphism, is associated with the occurrence of multi-azole resistance in A. fumigatus in the environment and in patients. This process was validated with both synthetic double stranded DNA and genomic DNA prepared from azole-resistant isolates of A. fumigatus. Use of our assay resulted in rapid and specific identification of the TR34 allele with high sensitivity, detecting down to 10 genomic copies per reaction within 25 minutes. Fluorescent and colorimetric detections were used for the analysis of 11 clinical isolates as cross validation. These results show that the TR34-LAMP assay has the potential to accelerate the screening of clinical and environmental A. fumigatus to provide a rapid and accurate diagnosis of azole resistance, which current methods struggle to achieve.
-
Journal articleLorenz A, Preusse M, Bruchmann S, et al., 2019,
Importance of flagella in acute and chronic Pseudomonas aeruginosa infections
, Environmental Microbiology, Vol: 21, Pages: 883-897, ISSN: 1462-2912Pseudomonas aeruginosa is an environmental microorganism and a causative agent of diverse acute and chronic, biofilm‐associated infections. Advancing research‐based knowledge on its adaptation to conditions within the human host is bound to reveal novel strategies and targets for therapeutic intervention. Here, we investigated the traits that P. aeruginosa PA14 as well as a virulence attenuated ΔlasR mutant need to survive in selected murine infection models. Experimentally, the genetic programs that the bacteria use to adapt to biofilm‐associated versus acute infections were dissected by passaging transposon mutant libraries through mouse lungs (acute) or mouse tumours (biofilm‐infection). Adaptive metabolic changes of P. aeruginosa were generally required during both infection processes. Counter‐selection against flagella expression was observed during acute lung infections. Obviously, avoidance of flagella‐mediated activation of host immunity is advantageous for the wildtype bacteria. For the ΔlasR mutant, loss of flagella did not confer a selective advantage. Apparently, other pathogenesis mechanisms are active in this virulence attenuated strain. In contrast, the infective process of P. aeruginosa in the chronic biofilm model apparently required expression of flagellin. Together, our findings imply that the host immune reactions against the infectious agent are very decisive for acuteness and duration of the infectious disease. They direct disease outcome.
-
Conference paperOvadia C, Perdones-Montero A, Mullish B, et al., 2019,
Ursodeoxycholic acid treatment of cholestatic pregnancy can alter the gut microbiota to enhance bile acid modification and production of metabolically-active secondary bile acids - an explanation for 'responders' and 'non-responders'?
, Publisher: WILEY, Pages: 17-17, ISSN: 1470-0328
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.
Where we are
CBRB
Imperial College London
Flowers Building
Exhibition Road
London SW7 2AZ