482 research outputs found

    Anti-infective and cytotoxic properties of Bupleurum marginatum

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    Bupleurum marginatum Wall. ex DC (Apiaceae) is a perennial herb widely used in traditional Chinese and Kampo medicine for the treatment of various infectious diseases. The biological activities of B. marginatum have not been fully investigated. This study aims to investigate the antitrypanosomal, antimicrobial and antiviral activities of methanol (ME) and dichloromethane (DCM) extracts of B. marginatum aerial parts and the ability of both extracts to inhibit the growth of different cancer cell lines. Methods Phytochemical characterization of the extracts was performed by LC-MS profiling. The antitrypanosomal activity was evaluated using the resazurin method. The antimicrobial activity was assessed using agar diffusion and microdilution methods, and the minimum inhibitory concentration (MIC) values were determined. The antiviral activity was determined for 6.25, 12.5, and 50 μg/mL doses using a plaque reduction assay. Cytotoxicity was investigated in eight cancer cell lines (Caco-2, CCL-81, CCRF-CEM, COS-7, HL-60, MIA PaCa-2, MCF-7, and PANC-1) using the MTT assay and the caspase 3/7 activity was determined over the range of 62.5–1000 μg/mL. Results Phytochemical analyses resulted in the characterization of 15 components, mainly flavonoids and lignans. The DCM extract showed significant antitrypanosomal activity (IC50: 36.21 μg/mL) and moderate activity against Streptococcus pyogenes (MIC value: 0.25 mg/mL). At a dose of 12.5 μg/mL, the DCM extract inhibited 73.6% of the plaque production by hepatitis A virus. CCRF-CEM cells were the most sensitive to both extracts (IC50: 12.5–22.7 μg/mL). The cytotoxicity was mediated by induction of apoptosis (19-fold increase in the cellular caspase 3/7 level after treatment with the DCM extract at 1 mg/mL). Conclusions ME and DCM extract of B. marginatum showed anti-infective and antiproliferative effects

    The 193-Kd Vault Protein, Vparp, Is a Novel Poly(Adp-Ribose) Polymerase

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    Mammalian vaults are ribonucleoprotein (RNP) complexes, composed of a small ribonucleic acid and three proteins of 100, 193, and 240 kD in size. The 100-kD major vault protein (MVP) accounts for >70% of the particle mass. We have identified the 193-kD vault protein by its interaction with the MVP in a yeast two-hybrid screen and confirmed its identity by peptide sequence analysis. Analysis of the protein sequence revealed a region of ∼350 amino acids that shares 28% identity with the catalytic domain of poly(ADP-ribose) polymerase (PARP). PARP is a nuclear protein that catalyzes the formation of ADP-ribose polymers in response to DNA damage. The catalytic domain of p193 was expressed and purified from bacterial extracts. Like PARP, this domain is capable of catalyzing a poly(ADP-ribosyl)ation reaction; thus, the 193-kD protein is a new PARP. Purified vaults also contain the poly(ADP-ribosyl)ation activity, indicating that the assembled particle retains enzymatic activity. Furthermore, we show that one substrate for this vault-associated PARP activity is the MVP. Immunofluorescence and biochemical data reveal that p193 protein is not entirely associated with the vault particle, suggesting that it may interact with other protein(s). A portion of p193 is nuclear and localizes to the mitotic spindle

    The ASDEX Upgrade divertor IIb—a closed divertor for strongly shaped plasmas

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    A new divertor configuration (DIV-IIb) has been implemented in ASDEX Upgrade. In order to accommodate a large variety of plasma shapes with bottom triangularities (δbot) up to 0.48, the outer strikepoint region was modified and the roof baffle was lowered and diminished at its outer part in comparison with the previous divertor (DIV-II). The inner part of the divertor strikepoint module remains unchanged, but a smooth transition to the central column is provided at the divertor entrance to minimize local hydrogen recycling. An increase in power density is observed due to geometrical reasons at the outer target, whereas the divertor radiation for similar configurations and discharge conditions is unchanged. The pumping characteristics for D and He are almost retained, suggesting a large influence of the inner divertor leg, the configuration of which remains as before. Detachment in L-mode discharges fits well into a scaling deduced from JET data and earlier ASDEX Upgrade data. A significant reduction (20%) of the L–H threshold is observed compared with DIV-II. Its density dependence is weaker than in the previous DIV-II configuration and there are hints for an influence of triangularity on power threshold. Finally, clear evidence for a parasitic plasma below the divertor roof baffle is found

    HLA-DRB3/4/5 Matching Improves Outcome of Unrelated Hematopoietic Stem Cell Transplantation

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    The HLA-DRB3/4/5 loci are closely linked to the HLA-DRB1 gene. Mismatches in these loci occur with a frequency of about 8%–12% in otherwise 10/10 HLA-matched transplant pairs. There is preliminary evidence that these disparities may associate with increased acute graft-versus-host disease (GvHD) rates. The aim of this study was to analyze a large cohort of German patients and their donors for HLA-DRB3/4/5 compatibility and to correlate the HLA-DRB3/4/5 matching status with the outcome of unrelated hematopoietic stem cell transplantation (uHSCT). To this end, 3,410 patients and their respective donors were HLA-DRB3/4/5 and HLA-DPB1 typed by amplicon-based nextgeneration sequencing (NGS). All patients included received their first allogeneic transplant for malignant hematologic diseases between 2000 and 2014. Mismatches in the antigen recognition domain (ARD) of HLA-DRB3/4/5 genes were correlated with clinical outcome. HLA-DRB3/4/5 incompatibility was seen in 12.5% (n = 296) and 17.8% (n = 185) of the 10/10 and 9/10 HLA-matched cases, respectively. HLA-DRB3/4/5 mismatches in the ARD associated with a worse overall survival (OS), as shown in univariate (5-year OS: 46.1% vs. 39.8%, log-rank p = 0.038) and multivariate analyses [hazard ratio (HR) 1.25, 95% CI 1.02–1.54, p = 0.034] in the otherwise 10/10 HLAmatched subgroup. The worse outcome was mainly driven by a significantly higher nonrelapse mortality (HR 1.35, 95% CI 1.05–1.73, p = 0.017). In the 9/10 HLA-matched cases, the effect was not statistically significant. Our study results suggest that mismatches within the ARD of HLA-DRB3/4/5 genes significantly impact the outcome of otherwise fully matched uHSCT and support their consideration upon donor selection in the future

    DC-SIGN Induction in Alveolar Macrophages Defines Privileged Target Host Cells for Mycobacteria in Patients with Tuberculosis

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    BACKGROUND: Interplays between Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB) in human and host professional phagocytes, namely macrophages (Mφs) and dendritic cells (DCs), are central to immune protection against TB and to TB pathogenesis. We and others have recently shown that the C-type lectin dendritic cell–specific intercellular adhesion molecule-3 grabbing nonintegrin (DC-SIGN; CD209) mediates important interactions between mycobacteria and human monocyte-derived DCs (MoDCs) in vitro. METHODS AND FINDINGS: In order to explore the possible role of DC-SIGN in M. tuberculosis infection in vivo, we have analysed DC-SIGN expression in broncho-alveolar lavage (BAL) cells from patients with TB (n = 40) or with other non-mycobacterial lung pathologies, namely asthma (n = 14) and sarcoidosis (n = 11), as well as from control individuals (n = 9). We show that in patients with TB, up to 70% of alveolar Mφs express DC-SIGN. By contrast, the lectin is barely detected in alveolar Mφs from all other individuals. Flow cytometry, RT-PCR, and enzyme-linked immunosorbent assay analyses of BAL-derived fluids and cells indicated that M. tuberculosis infection induces DC-SIGN expression in alveolar Mφs by a mechanism that is independent of Toll-like receptor-4, interleukin (IL)-4, and IL-13. This mechanism most likely relies on the secretion of soluble host and/or mycobacterial factors that have yet to be identified, as both infected and uninfected bystander Mφs were found to express DC-SIGN in the presence of M. tuberculosis. Immunohistochemical examination of lung biopsy samples from patients with TB showed that the bacilli concentrate in pulmonary regions enriched in DC-SIGN-expressing alveolar Mφs in vivo. Ex vivo binding and inhibition of binding experiments further revealed that DC-SIGN–expressing alveolar Mφs constitute preferential target cells for M. tuberculosis, as compared to their DC-SIGN(−) counterparts. In contrast with what has been reported previously in MoDCs in vitro, ex vivo DC-SIGN ligation by mycobacterial products failed to induce IL-10 secretion by alveolar Mφs, and IL-10 was not detected in BALs from patients with TB. CONCLUSION: Altogether, our results provide further evidence for an important role of DC-SIGN during TB in humans. DC-SIGN induction in alveolar Mφs may have important consequences on lung colonization by the tubercle bacillus, and on pulmonary inflammatory and immune responses in the infected host

    MyD88 signalling in myeloid cells is sufficient to prevent chronic mycobacterial infection

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    Tuberculosis is a chronic infectious disease caused by Mycobacterium tuberculosis that is responsible for almost 1.5 million deaths per year. Sensing of mycobacteria by the host's immune system relies on different families of receptors present on innate immune cells. Amongst them, several members of the TLR family are involved in the activation of immune cells by mycobacteria, yet the in vivo contribution of individual TLRs to the protective immune response remains controversial. On the contrary, MyD88, the adaptor molecule for most TLRs, plays a non-redundant role in the protection against tuberculosis and mice with a complete germline deletion of MyD88 succumb very early to infection. MyD88 is expressed in both immune and non-immune cells, but it is not clear whether control of mycobacteria requires ubiquitous or cell-type specific MyD88 expression. Therefore, using novel conditional switch-on mouse models, we aimed to investigate the importance of MyD88 signalling in DCs and macrophages for the induction of protective effector mechanisms against mycobacterial infection. We conclude that specific reactivation of MyD88 signalling in CD11c- or lysozyme M-expressing myeloid cells during Mycobacterium bovis Bacille Calmette-Guerin infection is sufficient to restore systemic and local inflammatory cytokine production and to control pathogen burden.Fil: Berod, Luciana. Helmholtz Centre for Infection Research; Alemania. Medical School Hanover; AlemaniaFil: Stüve, Philipp. Medical School Hanover; Alemania. Helmholtz Centre for Infection Research; AlemaniaFil: Swallow, Maxine. Medical School Hanover; Alemania. Helmholtz Centre for Infection Research; AlemaniaFil: Arnold Schrauf, Catharina. Medical School Hanover; Alemania. Helmholtz Centre for Infection Research; AlemaniaFil: Kruse, Friederike. Medical School Hanover; Alemania. Helmholtz Centre for Infection Research; AlemaniaFil: Gentilini, Maria Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Helmholtz Centre for Infection Research; Alemania. Medical School Hanover; AlemaniaFil: Freitag, Jenny. Medical School Hanover; Alemania. Helmholtz Centre for Infection Research; AlemaniaFil: Holzmann, Bernhard. Universitat Technical Zu Munich; Alemania. Helmholtz Centre for Infection Research; AlemaniaFil: Sparwasser, Tim. Medical School Hanover; Alemania. Helmholtz Centre for Infection Research; Alemani

    T Helper 1 (Th1) and Th2 Characteristics Start to Develop During T Cell Priming and Are Associated with an Immediate Ability to Induce Immunoglobulin Class Switching

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    The respective production of specific immunoglobulin (Ig)G2a or IgG1 within 5 d of primary immunization with Swiss type mouse mammary tumor virus [MMTV(SW)] or haptenated protein provides a model for the development of T helper 1 (Th1) and Th2 responses. The antibody-producing cells arise from cognate T cell B cell interaction, revealed by the respective induction of Cγ2a and Cγ1 switch transcript production, on the third day after immunization. T cell proliferation and upregulation of mRNA for interferon γ in response to MMTV(SW) and interleukin 4 in response to haptenated protein also starts during this day. It follows that there is minimal delay in these responses between T cell priming and the onset of cognate interaction between T and B cells leading to class switching and exponential growth. The Th1 or Th2 profile is at least partially established at the time of the first cognate T cell interaction with B cells in the T zone
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