Nanoscale Membrane Organization and Receptor Signaling in T- Lymphocytes

The presence of microdomains (i.e., lipid rafts) in the plasma membrane and their proposed role(s) in the signal transduction by cell surface receptors, particularly in immune cells, has elicited broad interest yet much debate. Here, we aim to review some observations made by our and other groups over past years on the structural and functional properties of membrane microdomains, focusing mainly on T cells and more particularly on activation of signaling cascades triggered by T-cell receptor (TCR) and Fas/CD95, respectively. We will focus on the progress made at both the experimental and conceptual levels. We will then discuss our recent studies on the identification and characterization of nano-sized membrane domains in the plasma membrane of living cells using an original fluorescent correlation spectroscopy (FCS) approach.