Valarie A. Barr, Ph.D.
Dr. Barr is head of the LCMB Microscopy Core, which is a light microscopy facility for confocal and super resolution microscopy, open to scientists at the National Cancer Institute. The Core instruments include a Leica SP8 laser scanning confocal microscope, a Nikon total internal reflection fluorescence (TIRF) microscope, and a spinning disk confocal microscope that can perform rapid live cell imaging. The Core provides access to cutting-edge technology and training on the Core's instruments as well as expert assistance with experimental design. In addition, Dr. Barr also carries out independent research on signal transduction in T cells.
1) localization microscopy, 2) TIRF microscopy, 3) confocal microscopy, 4) live cell imaging, 5) immunofluorescence, 6) stimulated emission depletion (STED) imaging
The Microscopy Core facility provides state-of-the-art equipment, advice and training to researchers with particular expertise in live cell imaging. Most of the research done in the Core facility focuses on the movement of proteins involved in signal transduction pathways. In collaboration with Dr. Samelson, we study the movements of proteins initially found in signaling complexes that form at activated T cell receptors. These studies use a model system where chimeric proteins tagged with variants of green fluorescent protein (GFP) are visualized in Jurkat T cells. These cells are activated either by contact with antibody-coated coverslips or by contact with superantigen-pulsed Raji B cells. Using this system, we have studied the formation of signaling complexes, the movement of proteins involved in reorganization of the actin cytoskeleton, and the trafficking of SLP-76, an important adaptor protein involved in T cell activation.
In addition to Core operations, Dr. Barr does research on the visualization of signaling complexes. Much of this work centers on the immediate responses to T cell receptor activation in T cells using a combination of localization microscopy, live cell imaging, and immunofluorescence.
Selected Recent Publications
- Immunol Cell Biol. 92: 721-8, 2014. [ Journal Article ]
Cutting edge: cell surface linker for activation of T cells is recruited to microclusters and is active in signaling.J Immunol. 190: 3849-53, 2013. [ Journal Article ]
Multipoint binding of the SLP-76 SH2 domain to ADAP is critical for oligomerization of SLP-76 signaling complexes in stimulated T cells.Mol Cell Biol. 33: 4140-51, 2013. [ Journal Article ]
- Methods. 59: 261-9, 2013. [ Journal Article ]
- Immunol Rev. 251: 21-35, 2013. [ Journal Article ]
Dr. Barr obtained her Bachelor and Master of Science degrees from the University of Illinois. She completed her graduate work at The Johns Hopkins University, Department of Cell Biology and Anatomy and obtained a Ph.D in cell biology in 1994. After a postdoctoral fellowship in the laboratory of Dr. Simean Taylor at the Diabetes Branch in the National Institute of Diabetes, Digestive and Kidney Diseases, Dr. Barr joined the Laboratory of Cellular and Molecular Biology in the National Cancer Institute in 2001.
|Itoro O. Akpan M.S.||Research Biologist|