METHODS AND KIT FOR ASSAYING LYTIC POTENTIAL OF IMMUNE EFFECTOR CELLS

To overcome the difficulty in achieving a quantitative assessment of CTL function in clinical settings, the inventors aimed at developing a new method inspired by their knowledge of the CTL/tumor target biology and based on flow cytometry. In particular, to directly detect the earliest steps of tumor cell resistance to CTL attack at the lytic synapse the inventors developed a method to monitor CTL/tumor cells interaction in the presence of FM1-43, a fluorescent lipophilic dye that rapidly intercalates into lipid bilayer during the membrane turnover that accompanies plasma membrane reparation. This assay allows the inventors to measure reparative membrane turnover of tumor cells under CTL attack by FACS analysis at the whole tumor cell population level. They initially applied this approach to compare the response of melanoma cell (D10 cells) to CTL attack as compared to conventional target cells that are sensitive to CTL mediated cytotoxicity (EB V -transformed B cells, JY cells). The methodology allows to rapidly assessing the synaptic resistance of tumor target cells to CTL attack and the intrinsic capacity of CD8+CTL to efficiently kill their target cells. Thus, the present invention relates to methods and kit for assaying lytic potential of immune effector cells and uses thereof in diagnostic assays.