Event

Bioengineering Seminar Series: Arpita Upadhyaya

Friday, April 22, 2011
11:00 a.m.
Room 1200, Jeong H. Kim Engineering Building
Professor Sameer Shah
sameer@umd.edu

Spreading Itself Thin: Biophysics of Cell Junctions in the Immune System

Arpita Upadhyaya
Assistant Professor
Department of Physics
University of Maryland, College Park

Spreading of cells over substrates is a dramatic process which involves large scale physical rearrangements of the actin cytoskeleton and the cell membrane. The spreading of T and B-lymphocytes on antibody coated substrates mimics the formation of the immune synapse, a multi-protein signaling machine. As signaling events are initiated within a minute of contact, early spreading leading to rapid increases in contact area and accumulation of receptors is a critical step of the immune response. We have quantitatively characterized the spreading kinetics of cells and studied actin dynamics during the spreading process. We found that the contact area growth in time can be well described by a common physico-chemical mechanism. Under certain conditions, we observe dramatic fluctuations of the edge velocity and the formation of membrane waves driven by actin polymerization at the cell substrate interface. Membrane deformations induced by such wavelike organization of the cytoskeleton may be a general phenomenon that underlies cell movement and cell-substrate interactions. Finally, we studied cell spreading on elastic substrates to investigate the possible role of the mechanical environment on T cell spreading and activation.

Audience: Graduate  Faculty  Post-Docs