APS Practice 2013: Difference between revisions
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We present a quantitative assay of the pericellular coat, a tethered polymer matrix that decorates the surface of numerous cell types. In these assays, we look at how passivated microspheres of varying diameter penetrate the cell coat. Distinct spatial distributions correspond to different particle sizes. These measurements confirm that the cell coat (on the chondrocyte RCJ-P cell line) has a spatially varying mesh size, in agreement with our independent assays performed with optical force probe microscopy. The data indicate that particles with diameters of 500 nm or greater do not penetrate the inner layer of the matrix, while particles smaller than 500 nm reach different regions, with the smallest reaching the cell surface. In an ongoing effort, we are developing a model for the observed statistical distribution of the beads. These experiments show that accessibility of the cell surface is strongly mediated by the presence of the cell coat, and they have important implications regarding the transport of molecules to the cell surface, protection from bacterial infection, drug delivery, as well as the way the cell interacts and adheres to the surrounding extracellular matrix. | We present a quantitative assay of the pericellular coat, a tethered polymer matrix that decorates the surface of numerous cell types. In these assays, we look at how passivated microspheres of varying diameter penetrate the cell coat. Distinct spatial distributions correspond to different particle sizes. These measurements confirm that the cell coat (on the chondrocyte RCJ-P cell line) has a spatially varying mesh size, in agreement with our independent assays performed with optical force probe microscopy. The data indicate that particles with diameters of 500 nm or greater do not penetrate the inner layer of the matrix, while particles smaller than 500 nm reach different regions, with the smallest reaching the cell surface. In an ongoing effort, we are developing a model for the observed statistical distribution of the beads. These experiments show that accessibility of the cell surface is strongly mediated by the presence of the cell coat, and they have important implications regarding the transport of molecules to the cell surface, protection from bacterial infection, drug delivery, as well as the way the cell interacts and adheres to the surrounding extracellular matrix. | ||
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===Daniel Kovari (Curtis Lab) [http://meetings.aps.org/Meeting/MAR13/Event/186419 APS Abstract: M45.00002]=== | |||
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Session M45: Focus Session: Physics of the Cytoskeleton I | |||
8:12 AM–8:24 AM, Wednesday, March 20, 2013 | |||
Hilton Baltimore Room: Holiday Ballroom 4 | |||
Measuring actin dynamics during phagocytosis using photo-switchable fluorescence | |||
Phagocytosis has traditionally been investigated in terms of the relevant biochemical signaling pathways. However, a growing number of studies investigating the physical aspects of phagocytosis have demonstrated that several distinct forces are exerted throughout particle ingestion. We use variations on FRAP (Fluorescence Recovery After Photobleaching) in combination with photo-switchable fluorescent protein to investigate actin dynamics as a phagocyte attempts to engulf its prey. The goal of our actin studies are to determine the recruitment and polymerization rate of actin in the forming phagosome and whether an organized \textit{contractile actin ring} is present and responsible for phagosome closure, as proposed in the literature. These experiments are ongoing and contribute to our long term effort of developing a physics based model of phagocytosis. | |||
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Revision as of 21:43, 24 January 2013
We will be rehearsing talks for the 2013 APS "March Meeting" on March 14th, 2013. Following the APS format, presentation will be 10 minutes with 5 minutes of questions. The list of presenters and their abstracts can be found in the table below.
APS 2013 Practice Schedule
| Time | Speaker |
|---|---|
| 12:00 | Patrick Chang (Curtis Lab) |
| 12:15 | - |
| 12:30 | - |
| 12:45 | - |
| 1:00 | - |
| 1:15 | - |
Abstracts
Patrick Chang (Curtis Lab) APS Abstract: N45.00006
Session N45: Focus Session: Cell Mechanics I 12:39 PM – 12:51 PM, Wednesday, March 20, 2013 Quantitative particle exclusion assays of the pericellular coat reveal changing mesh size We present a quantitative assay of the pericellular coat, a tethered polymer matrix that decorates the surface of numerous cell types. In these assays, we look at how passivated microspheres of varying diameter penetrate the cell coat. Distinct spatial distributions correspond to different particle sizes. These measurements confirm that the cell coat (on the chondrocyte RCJ-P cell line) has a spatially varying mesh size, in agreement with our independent assays performed with optical force probe microscopy. The data indicate that particles with diameters of 500 nm or greater do not penetrate the inner layer of the matrix, while particles smaller than 500 nm reach different regions, with the smallest reaching the cell surface. In an ongoing effort, we are developing a model for the observed statistical distribution of the beads. These experiments show that accessibility of the cell surface is strongly mediated by the presence of the cell coat, and they have important implications regarding the transport of molecules to the cell surface, protection from bacterial infection, drug delivery, as well as the way the cell interacts and adheres to the surrounding extracellular matrix.
Daniel Kovari (Curtis Lab) APS Abstract: M45.00002
Session M45: Focus Session: Physics of the Cytoskeleton I
8:12 AM–8:24 AM, Wednesday, March 20, 2013
Hilton Baltimore Room: Holiday Ballroom 4
Measuring actin dynamics during phagocytosis using photo-switchable fluorescence
Phagocytosis has traditionally been investigated in terms of the relevant biochemical signaling pathways. However, a growing number of studies investigating the physical aspects of phagocytosis have demonstrated that several distinct forces are exerted throughout particle ingestion. We use variations on FRAP (Fluorescence Recovery After Photobleaching) in combination with photo-switchable fluorescent protein to investigate actin dynamics as a phagocyte attempts to engulf its prey. The goal of our actin studies are to determine the recruitment and polymerization rate of actin in the forming phagosome and whether an organized \textit{contractile actin ring} is present and responsible for phagosome closure, as proposed in the literature. These experiments are ongoing and contribute to our long term effort of developing a physics based model of phagocytosis.
