The Experts below are selected from a list of 126 Experts worldwide ranked by ideXlab platform
Axel T Brunger - One of the best experts on this subject based on the ideXlab platform.
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quantitative imaging of Lymphocyte Membrane protein reorganization and signaling
Biophysical Journal, 2005Co-Authors: Peter M Kasson, Johannes B Huppa, Michelle Krogsgaard, Mark M Davis, Axel T BrungerAbstract:Changes in Membrane protein localization are critical to establishing cell polarity and regulating cell signaling. Fluorescence microscopy of labeled proteins allows visualization of these changes, but quantitative analysis is needed to study this aspect of cell signaling in full mechanistic detail. We have developed a novel approach for quantitative assessment of Membrane protein redistribution based on four-dimensional video microscopy of fluorescently labeled proteins. Our analytic system provides robust automated methods for cell surface reconstruction, cell shape tracking, cell-surface distance measurement, and cluster formation analysis. These methods permit statistical analyses and testing of mechanistic hypotheses regarding cell signaling. We have used this approach to measure antigen-dependent clustering of signaling molecules in CD4+ T Lymphocytes, obtaining clustering velocities consistent with single-particle tracking data. Our system captures quantitative differences in clustering between signaling proteins with distinct biological functions. Our methods can be generalized to a range of cell-signaling phenomena and enable novel applications not feasible with single-particle studies, such as analysis of subcellular protein localization in live organ culture.
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Quantitative analysis of Lymphocyte Membrane protein redistribution from fluorescence microscopy
2004 International Conference on Image Processing 2004. ICIP '04., 2004Co-Authors: Peter M Kasson, Johannes B Huppa, Mark M Davis, Axel T BrungerAbstract:The relocalization of plasma Membrane proteins is critical for establishing cellular polarity and regulating cell signaling. Three-dimensional fluorescence video microscopy allows the dynamic visualization of proteins in living cells. We have developed a robust and automated method to employ fluorescence data acquired in this manner for quantitative analysis of Membrane protein movements across the cell surface. Our method utilizes level-set-based surface reconstruction followed by a maximum likelihood surface registration algorithm for rigid-body alignment of noisy images. A surface-walking technique yields distance maps for the cell surface, which are then used to measure changes in protein surface distribution over time. Applying this method to signaling in T Lymphocytes, we have used it to monitor receptor movements and have validated these results against previously reported single-particle tracking data.
L.s. De Clerck - One of the best experts on this subject based on the ideXlab platform.
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Influence of hyposensitization on soluble interleukin‐2 receptor, eosinophil cationic protein, in vitro Lymphocyte proliferation, in vitro Lymphocyte adhesion, and Lymphocyte Membrane markers in childhood asthma
Allergy, 1994Co-Authors: M. M. Moens, H. P. Van Bever, W. J. Stevens, A. V. Mertens, Chris H. Bridts, L.s. De ClerckAbstract:Soluble interleukin-2 receptor (sIL-2R), eosinophil cationic protein (ECP), the lymphoproliferative response to house-dust mite (HDM), adhesion to human umbilical vein endothelial cells (HUVEC), and Lymphocyte Membrane markers were studied in three groups of children: healthy children, asthmatic children without hyposensitization (HS), and asthmatic children with HS. HS was associated with significantly lower numbers of peripheral blood eosinophils (PBE) and lower sIL-2R serum levels and with a tendency to lower ECP serum levels and lymphoproliferative response to HDM. There were no changes in the T-Lymphocyte phenotypic markers CD4 and CDS among the three groups. The interleukin-2 receptor (IL-2R, CD25) on HDM-stimulated T Lymphocytes increased over unstimulated T Lymphocytes in the three groups. The CD25 expression was higher on HDM-stimulated Lymphocytes in both asthmatic groups than in healthy children. Adhesion of Lymphocytes on HUVEC increased significantly after HDM stimulation in asthmatic children without HS, whereas no change was observed in the two other groups. However, there was no change in the expression of adhesion molecules CD29 and CD1 la on Lymphocytes in either of the groups. This study provides further evidence that HS can modify Lymphocyte and eosinophil functions.
Xu Shi-wen - One of the best experts on this subject based on the ideXlab platform.
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Influence of cadmium on chicken spleen Lymphocyte Membrane antioxidant function
Chinese journal of veterinary science, 2012Co-Authors: Xu Shi-wenAbstract:To research the influence of cadmium on chicken spleen Lymphocyte Membrane antioxidant function,spleen Lymphocyte was contaminated with 10 μmol/L CdCl2.After cultured 12,24,36,48 and 72 h,contaminated cells were collected separately.By comparing the colors of kits,GSH-Px of Membrane,activity of SOD,content of MDA in Membrane were determined to observe Membrane antioxidant function when spleen lymplocyte the was damaged by cadmium.The results showed that the cadmium exposure induced,the decreased Lymphocyte Membrane GSH-Px,SOD activity,and the increased MAD.There are obvious distinctions between tested groups and control groups(P0.05 or P0.01).Cadmium can inhibited spleen Lymphocyte Membrane antioxidant function,destroyed Membrane oxidant integrity.
Bart W. Hoogenboom - One of the best experts on this subject based on the ideXlab platform.
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Lipid specificity of the immune effector perforin
2020Co-Authors: Adrian Hodel, Ilia Voskoboinik, Joseph A Trapani, Jesse A. Rudd-schmidt, Bart W. HoogenboomAbstract:Perforin is a pore forming protein used by cytotoxic T Lymphocytes to remove cancerous or virus-infected cells during immune response. During the response, the Lymphocyte Membrane becomes refractory to perforin function by accumulating densely ordered lipid rafts and externalizing negatively charged lipid species. The dense Membrane packing lowers the capacity of perforin to bind, and negatively charged lipids scavenge any residual protein before pore formation. Using atomic force microscopy on model Membrane systems, we here provide insight into the molecular basis of perforin lipid specificity.
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Lipid specificity of the immune effector perforin
Faraday Discussions, 2020Co-Authors: Adrian W Hodel, Ilia Voskoboinik, Joseph A Trapani, Jesse A. Rudd-schmidt, Bart W. HoogenboomAbstract:Perforin is a pore forming protein used by cytotoxic T Lymphocytes to remove cancerous or virus-infected cells during immune response. During the response, the Lymphocyte Membrane becomes refractory to perforin...
Stephen Shaw - One of the best experts on this subject based on the ideXlab platform.
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phospholipase c mediated hydrolysis of pip2 releases erm proteins from Lymphocyte Membrane
Journal of Cell Biology, 2009Co-Authors: Jianjiang Hao, Yin Liu, Michael J Kruhlak, Karen Debell, Barbara L Rellahan, Stephen ShawAbstract:Mechanisms controlling the disassembly of ezrin/radixin/moesin (ERM) proteins, which link the cytoskeleton to the plasma Membrane, are incompletely understood. In Lymphocytes, chemokine (e.g., SDF-1) stimulation inactivates ERM proteins, causing their release from the plasma Membrane and dephosphorylation. SDF-1–mediated inactivation of ERM proteins is blocked by phospholipase C (PLC) inhibitors. Conversely, reduction of phosphatidylinositol 4,5-bisphosphate (PIP2) levels by activation of PLC, expression of active PLC mutants, or acute targeting of phosphoinositide 5-phosphatase to the plasma Membrane promotes release and dephosphorylation of moesin and ezrin. Although expression of phosphomimetic moesin (T558D) or ezrin (T567D) mutants enhances Membrane association, activation of PLC still relocalizes them to the cytosol. Similarly, in vitro binding of ERM proteins to the cytoplasmic tail of CD44 is also dependent on PIP2. These results demonstrate a new role of PLCs in rapid cytoskeletal remodeling and an additional key role of PIP2 in ERM protein biology, namely hydrolysis-mediated ERM inactivation.
