236 research outputs found

    Assessment of red light running cameras in Fairfax County

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    A study was conducted to assess the Red Light Running (RLR

    Kidins220/ARMS binds to the B cell antigen receptor and regulates B cell development and activation

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    B cell antigen receptor (BCR) signaling is critical for B cell development and activation. Using mass spectrometry, we identified a protein kinase D\u2013interacting substrate of 220 kD (Kidins220)/ankyrin repeat\u2013rich membrane-spanning protein (ARMS) as a novel interaction partner of resting and stimulated BCR. Upon BCR stimulation, the interaction increases in a Src kinase\u2013independent manner. By knocking down Kidins220 in a B cell line and generating a conditional B cell\u2013specific Kidins220 knockout (B-KO) mouse strain, we show that Kidins220 couples the BCR to PLC\u3b32, Ca2+, and extracellular signal-regulated kinase (Erk) signaling. Consequently, BCR-mediated B cell activation was reduced in vitro and in vivo upon Kidins220 deletion. Furthermore, B cell development was impaired at stages where pre-BCR or BCR signaling is required. Most strikingly, \u3bb light chain\u2013positive B cells were reduced sixfold in the B-KO mice, genetically placing Kidins220 in the PLC\u3b32 pathway. Thus, our data indicate that Kidins220 positively regulates pre-BCR and BCR functionin

    B cell antigen receptor expression and phosphatidylinositol 3-kinase signaling regulate genesis and maintenance of mouse chronic lymphocytic leukemia

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    Chronic lymphocytic leukemia (CLL) is a frequent lymphoproliferative disorder of B cells. Although inhibitors targeting signal proteins involved in B cell antigen receptor (BCR) signaling constitute an important part of the current therapeutic protocols for CLL patients, the exact role of BCR signaling, as compared to genetic aberration, in the development and progression of CLL is controversial. To investigate whether BCR expression per se is pivotal for the development and maintenance of CLL B cells, we used the TCL1 mouse model. By ablating the BCR in CLL cells from TCL1 transgenic mice, we show that CLL cells cannot survive without BCR signaling and are lost within eight weeks in diseased mice. Furthermore, we tested whether mutations augmenting B cell signaling influence the course of CLL development and its severity. The Phosphatidylinositol-3-kinase (PI3K) signaling pathway is an integral part of the BCR signaling machinery and its activity is indispensable for B cell survival. It is negatively regulated by the lipid phosphatase PTEN, whose loss mimics PI3K pathway activation. Herein, we show that PTEN has a key regulatory function in the development of CLL, as deletion of the Pten gene resulted in greatly accelerated onset of the disease. By contrast, deletion of the gene TP53, which encodes the tumor suppressor p53 and is highly mutated in CLL, did not accelerate disease development, confirming that development of CLL was specifically triggered by augmented PI3K activity through loss of PTEN and suggesting that CLL driver consequences most likely affect BCR signaling. Moreover, we could show that in human CLL patient samples, 64% and 81% of CLL patients with a mutated and unmutated IgH VH, respectively, show downregulated PTEN protein expression in CLL B cells if compared to healthy donor B cells. Importantly, we found that B cells derived from CLL patients had higher expression levels of the miRNA-21 and miRNA-29, which suppresses PTEN translation, compared to healthy donors. The high levels of miRNA-29 might be induced by increased PAX5 expression of the B-CLL cells. We hypothesize that downregulation of PTEN by increased expression levels of miR-21, PAX5 and miR-29 could be a novel mechanism of CLL tumorigenesis that is not established yet. Together, our study demonstrates the pivotal role for BCR signaling in CLL development and deepens our understanding of the molecular mechanisms underlying the genesis of CLL and for the development of new treatment strategies

    The values and risks of an Intergovernmental Panel for One Health to strengthen pandemic prevention, preparedness, and response

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    The COVID-19 pandemic has shown the need for better global governance of pandemic prevention, preparedness, and response (PPR) and has emphasised the importance of organised knowledge production and uptake. In this Health Policy, we assess the potential values and risks of establishing an Intergovernmental Panel for One Health (IPOH). Similar to the Intergovernmental Panel on Climate Change, an IPOH would facilitate knowledge uptake in policy making via a multisectoral approach, and hence support the addressing of infectious disease emergence and re-emergence at the human-animal-environment interface. The potential benefits to pandemic PPR include a clear, unified, and authoritative voice from the scientific community, support to help donors and institutions to prioritise their investments, evidence-based policies for implementation, and guidance on defragmenting the global health system. Potential risks include a scope not encompassing all pandemic origins, unclear efficacy in fostering knowledge uptake by policy makers, potentially inadequate speed in facilitating response efforts, and coordination challenges among an already dense set of stakeholders. We recommend weighing these factors when designing institutional reforms for a more effective global health system

    Bacterial Killing Via A Type Iv Secretion System.

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    Type IV secretion systems (T4SSs) are multiprotein complexes that transport effector proteins and protein-DNA complexes through bacterial membranes to the extracellular milieu or directly into the cytoplasm of other cells. Many bacteria of the family Xanthomonadaceae, which occupy diverse environmental niches, carry a T4SS with unknown function but with several characteristics that distinguishes it from other T4SSs. Here we show that the Xanthomonas citri T4SS provides these cells the capacity to kill other Gram-negative bacterial species in a contact-dependent manner. The secretion of one type IV bacterial effector protein is shown to require a conserved C-terminal domain and its bacteriolytic activity is neutralized by a cognate immunity protein whose 3D structure is similar to peptidoglycan hydrolase inhibitors. This is the first demonstration of the involvement of a T4SS in bacterial killing and points to this special class of T4SS as a mediator of both antagonistic and cooperative interbacterial interactions.6645

    Influence of IFN-gamma and its receptors in human breast cancer

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    <p>Abstract</p> <p>Background</p> <p>Interferons are a group of proteins that trigger multiple responses including prevention of viral replication, inhibition of cell growth, and modulation of cell differentiation. In different mammary carcinoma cell lines IFNγ induces growth arrest at mid-G1. At the present there are no <it>in vivo </it>studies in human breast. The aim of this study was to investigate the expression patterns of IFNγ and its two receptors (IFNγ-Rα and IFNγ-Rβ) by Western blot and immunohistochemistry, in order to elucidate its role in the different types of human breast cancer (<it>in situ </it>and infiltrative).</p> <p>Methods</p> <p>Immunohistochemical and semiquantitative study of IFNγ, its receptors types (IFNγ-Rα and IFNγ-Rβ), cell proliferation (proliferating cell nuclear antigen, also named PCNA), and apoptosis (TUNEL method) was carried between the three breast groups (fibrocystic lesions, <it>in situ</it> tumors and infiltrating tumors).</p> <p>Results</p> <p>In the three groups of patients, IFNγ and IFNγ-Rα immunoreactions appeared in the cytoplasm while IFNγ-Rβ also was found in the nucleus. The optical density to IFNγ was higher in <it>in situ </it>carcinoma than in benign and infiltrating tumors. When we observed IFNγ-Rα, the optical density was lower in infiltrating carcinoma than in benign and <it>in situ </it>tumors (the higher density). To IFNγ-Rβ, the optical density was similar in the three group samples. In tumor samples PCNA and TUNEL index was significantly higher; than in benign diseases. PCNA index increased with the malignance. No significant differences were found between cancer types to TUNEL. IFNγ could be a potential therapeutic tool in breast cancer. However, tumor cells are able to escape from the control of this cytokine in the early tumor stages; this is probably due to a decreased expression of IFNγ, or also to an alteration of either its receptors or some transduction elements.</p> <p>Conclusion</p> <p>We conclude that the decrease in the % positive samples that expressed IFNγ and IFNγ-Rα together with the nuclear localization of IFNγ-Rβ, could be a tumoral cell response, although perhaps insufficient to inhibit the uncontrolled cell proliferation. Perhaps, IFNγ might be unable to activate p21 to stop the cell cycle, suggesting a possible participation in breast cancer development.</p

    NFATc1 supports imiquimod-induced skin inflammation by suppressing IL-10 synthesis in B cells

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    Epicutaneous application of Aldara cream containing the TLR7 agonist imiquimod (IMQ) to mice induces skin inflammation that exhibits many aspects of psoriasis, an inflammatory human skin disease. Here we show that mice depleted of B cells or bearing interleukin (IL)-10-deficient B cells show a fulminant inflammation upon IMQ exposure, whereas ablation of NFATc1 in B cells results in a suppression of Aldara-induced inflammation. In vitro, IMQ induces the proliferation and IL-10 expression by B cells that is blocked by BCR signals inducing NFATc1. By binding to HDAC1, a transcriptional repressor, and to an intronic site of the Il10 gene, NFATc1 suppresses IL-10 expression that dampens the production of tumour necrosis factor-α and IL-17 by T cells. These data indicate a close link between NFATc1 and IL-10 expression in B cells and suggest NFATc1 and, in particular, its inducible short isoform, NFATc1/αA, as a potential target to treat human psoriasis
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