Lipid Rafts

A major project in our laboratory concerns spatiotemporal aspect of cell signaling in CD4+ helper T lymphocytes with the focus on cholesterol-rich membrane nanodomains, also known as lipid rafts. Lipid rafts show high representation of sphingolipids, glycosyl-phosphatidylinsitol (GPI)-anchored proteins (e.g., Ly-6 proteins) and a number of lipid modified signaling molecules. These membrane nanodomains are compositionally heterogeneous, dynamic and exist as 10-100 nanometer size structures in a variety of cell types. The nanodomains coalesce during cellular interactions to form larger raft platforms. A significant research interest in my laboratory is to examine their role in orchestrating signals on the plasma membrane of naive CD4+ T cells after it interacts with antigen-presenting cells (APC) (e.g., dendritic cell), presenting a foreign antigen