Immune Checkpoint Receptors in AML-Leukemic Initiating Cells

Leukemic Initiating Cells (LIC) were shown to play a key role in AML relapses, and are characterized by resistance to treatment and a high capacity to escape to immune system. Immune checkpoints (ICP) maintain self-tolerance and physiological amplitude of the immune response. We decided to focus our work on ICP receptors and ligand that could be expressed by AML LIC and lymphocytes subsets. The tumor cells are able to express these ligands to exploit the ICP to overcome the anti-cancer immune response. Few studies are published in AML in the field of ICP, some studied limited cohort and others analyzed the expression of these ligands in total leukemic population, with a limited interest since the LIC fraction represents a small subset but mainly contributes to relapse. These cells are rare and their profile of expression could be highly different but not detectable in these studies because of technical limits. We aim at analyzing ICP ligands and receptors expression at diagnosis and relapse, the phenotype of BM cells will be analyzed by flow cytometry according to different panels of monoclonal antibodies using standard immunostaining protocols.