B- and T- cell acute lymphoblastic leukemia (B/T-ALL) may be refractory or recur after therapy by suppressing host anti-cancer immune surveillance mediated specifically by natural killer (NK) cells. We delineated the phenotypic and functional defects in NK cells of high-risk B/T-ALL patients using mass, flow, and in silico cytometry, with the goal of further elucidating the role of NK cells in sustaining ALL regression. We found that, compared to normal counterparts, NK cells in B/T-ALL patients are less cytotoxic, but exhibit an activated signature characterized by high CD56, high CD69, production of activated NK-origin cytokines, and calcium signaling. We demonstrated that defective maturation of NK cells into cytotoxic effectors prevents NK cells of ALL patients from lysing NK-sensitive targets as efficiently as normal NK cells. Additionally, we showed that NK cells in ALL are exhausted, which is likely caused by their chronic activation. We found that increased frequencies of activated cytokine-producing NK cells are associated with increased disease severity and independently predict poor clinical outcome in ALL patients. Our studies highlight the benefits of developing NK cell profiling as a diagnostic tool to predict clinical outcome in patients with ALL and underscore the clinical potential of allogeneic NK infusions to prevent ALL recurrence.
Caroline Duault, Anil Kumar, Adeleh Taghi Khani, Sung June Lee, Lu Yang, Min Huang, Christian Hurtz, Bryan Manning, Lucy Y Ghoda, Tinisha McDonald, Norman J Lacayo, Kathleen M Sakamoto, Martin P Carroll, Sarah K Tasian, Guido Marcucci, Jianhua Yu, Michael A Caligiuri, Holden T Maecker, Srividya Swaminathan