The Role of Membrane Micro-domains on Target Cells in Control on NK Cell Activity (89.29)

Abstract

Abstract Natural killer (NK) cells are large granular lymphocytes that comprise 5–15% of peripheral blood mononuclear cells and function through cytokine production or cytotoxicity. The response of NK cells to contact with other cells is regulated through many different receptor-ligand interactions. Lipid rafts are membrane micro-domains, enriched in glycosphingolipids, sphingomyelins, and cholesterol, which influence receptor signaling in lymphocytes. It is not clear yet to what extent distribution of ligands in micro-domains of target cells controls NK cell responses. To investigate the role of membrane micro-domains on target cells, and to avoid the use of inhibitors such as cyclodextrin, cholesterol-auxotroph insect cells were grown in serum-free conditions to eliminate cholesterol-enriched domains. Insect cells transfected with the GPI-linked CD48 and ULBP1 molecules, ligands for 2B4 and NGK2D respectively, are currently being tested for their ability to activate NK cells.