Polarization, the sub-cellular localization of cellular components such as receptors, signaling intermediates, vesicles and the cytoskeleton, is a fundamental element of cell regulation. It is particularly important in the activation of immune cells. T cells are the central regulatory cells of the adaptive immune response. NK cells are critical effectors of the innate immune response. Both activate by coupling to a second cell type, the antigen presenting or target cell, respectively. Both subsequently polarize towards the cellular interface as a central element of their function in a structure called the immunological synapse. In our laboratory, we have developed approaches to visualize lymphocyte polarization at the systems scale using 3D live cell video fluorescence microscopy. Systems-wide analysis is critical, as the subcellular localization of a single signaling intermediate becomes of interest when it can be related to those of multiple other components of lymphocyte polarization. Using a systems scale overview, we surprisingly found that the spatiotemporal organization of T cell activation is highly diverse. In a growing group of more than 40 elements of T cell activation, no two patterns were the same. The most likely interaction partners of a single signaling intermediate thus change continuously in time and space. Regulation of spatiotemporal patterning thus constitutes a powerful general mechanism to fine tune cell signaling. Current work focuses on how this is accomplished in molecular terms. As T and NK cells, despite substantial homologies in their signal transduction machineries, polarize to very different extents, investigating both in parallel is particularly informative.
Specifically, our efforts to understand how lymphocyte polarization regulates cellular activation contain three elements. First, we study the role of spatiotemporal patterning in the function of distinct groups of T and NK cell signaling intermediates. This includes Tec family tyrosine protein kinases and phosphatidylinositol lipid kinases in T cell activation and Rho GTPases in NK cell function. Second, we further develop methods to quantify spatiotemporal patterning in T cell signaling at the systems scale. This includes biochemical and computer-based image analysis approaches. The goal is to generate mathematical models of T cell signal transduction inside live T cells. In collaboration with Dr. Michael Rosen, we thus address the regulation of T cell actin dynamics. Third, the application of new insight from these studies to disease is often straightforward. In collaboration with Dr. Edward Wakeland, we analyze biochemical and cell biological features of T/B cell interactions in systemic lupus erythematosus.
RESEARCH INTERESTS
T cell polarization in T cell activation
NK cell polarization in NK cell-mediated cytolysis
The immunological synapse
Signal transduction in the regulation of lymphocyte polarization
RECENT PUBLICATIONS
Purtic, B., Pitcher, L. A., van Oers, N. S. C., and Wulfing, C., "T cell receptor (TCR) clustering in the immunological synpase integrates TCR and costimulatory signaling in selected T cells" Proc. Natl. Acad. Sci. USA, 102:1904-9, February 2005
I. Tskvitaria-Fuller, A. Seth, N. Mistry, H. Gu, M.K. Rosen, and C. Wulfing, "Specific Patterns of Cdc42 Activity Are Related to Distinct Elements of T cell Polarization" J. Immunol., 177:1708, August 2006
Singelton, K., Parvaze, N., Dama, K. R., Chen, K. S., Jennings, P., Purtic, B., Sjaastad, M. D., Gilpin, C., Davis, M. M., and Wulfing, C., "A large T cell invagination with CD2 enrichment resets receptor engagement in the immunological synpase" J. Immunol., 177:4402-13, October 2006
Tskvitaria-Fuller, I., Mistry, N., Sun, S., and Wulfing, C., "Protein transduction as a means of effective manipulation of Cdc42 activity in primary T cells" J. immunol. Methods, 319:64-78, January 2007
Singleton, K. L., Roybal, K. T., Sun, Y., Fu, G., Gascoigne, N. R. J., van Oers, N. S. C., and Wulfing, C., "Spatiotemporal patterning during T cell activation is highly diverse" Sci. Signal., 2:ra15, April 2009
SIGNIFICANT PUBLICATIONS
Wulfing, C., Klem, J., Purtic, B., and Schatzle, J. D., "Stepwise cytoskeletal polarization as a series of checkpoints in innate but not adaptive cytolytic killing." Proc. Natl. Acad. Sci. USA, 100:7767, June 2003
Purtic, B., Pitcher, L. A., van Oers, N. S. C., and Wulfing, C., "T cell receptor (TCR) clustering in the immunological synapse integrates TCR and costimulatory signaling in selected T cells" Proc. Natl. Acad. Sci. USA, 102:2904-9, 2005
I. Tskvitaria-Fuller, A. Seth, N. Mistry, H. Gu, M.K. Rosen, and C. Wulfing, "Specific Patterns of Cdc42 Activity Are Related to Distinct Elements of T cell Polarization" J. Immunol., 177:1708-20, August 2006
Singelton, K., Parvaze, N., Dama, K. R., Chen, K. S., Jennings, P., Purtic, B., Sjaastad, M. D., Gilpin, C., Davis, M. M., and Wulfing, C., "A large T cell invagination with CD2 enrichment resets receptor engagement in the immunological synapse" J. Immunol., 177:4402-13, October 2006
Singleton, K. L., Roybal, K. T., Sun, Y., Fu, G., Gascoigne, N. R. J., van Oers, N. S. C., and Wulfing, C., "Spatiotemporal patterning during T cell activation is highly diverse" Sci. Signal., 2:ra15, April 2009
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