TIM3 Dynamically Expressed on Peripheral Blood NK Cells in Acute Myeloid Leukemia Patients: The Expression Decreased When Untreated, and Restored While Disease Improved

Objective: Preliminary study the expression and clinical significance of TIM3 on peripheral blood NK cells in patients with acute myeloid leukemia (AML). Methods: We investigated the expression characteristics of TIM3 on the peripheral blood NK cells of newly diagnosed AML patients and its clinical significance. Peripheral blood was obtained from 50 patients with newly diagnosed AML before intervention, with peripheral blood from 30 cases of healthy volunteers collected as normal control. Expression levels of TIM3 on the peripheral blood NK cells and subsets were assayed with flow cytometry. Then the expression of gamma interferon in Tim3⁺CD56⁺NK cells and Tim3^-CD56⁺NK cells were analyzed by intracellular immunofluorescence labeling and flow cytometry. Results: Compared with the normal control, in the newly diagnosed AML patients, the NK cells percentage and the proportion of CD56^dimNK/CD56⁺NK reduced, while the proportion of CD56^brightNK/CD56⁺NK increased significantly, and the proportions of Tim3⁺CD56⁺NK/CD56⁺NK and Tim3⁺CD56^dimNK/CD56^dimNK decreased significantly. However, in AML patients with complete remission after chemotherapy, the proportion of peripheral blood NK cells and cell subsets recovered. Furthermore, compared with Tim3^-CD56⁺NK cells, IFN-γsecretion level of Tim3⁺CD56⁺NK cells in the newly diagnosed AML patients is increased significantly. Conclusion: The dynamic expression of TIM3 on NK cell and its cell subsets before and after chemotherapy in AML patients suggest that Tim3 and NK cells may play an important role in the occurrence and development of AML.