The Functional and Prognostic Impact of TIGIT Expression on Bone Marrow NK Cells in Core Binding Factor-Acute Myeloid Leukemia Patients at Diagnosis.

: The effect of the expression of the newly identified immune checkpoint, T cell immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain (TIGIT) on NK cells in core binding factor-acute myeloid leukemia (CBF-AML) remains to be investigated. : Fresh bone marrow samples from a total of 39 newly diagnosed CBF-AML patients and 25 healthy donors (HDs) were collected for testing the phenotype and function state of total NK, CD56, and CD56 NK cell subsets after in vitro stimulation. : The frequencies of TIGIT cells in total NK, CD56, and CD56 NK cell subsets had no significant difference between patients and HDs. TNF-α and INF-γ levels were uniformly lower in TIGIT cells than the corresponding TIGIT cells in all HDs, whereas those for TIGIT to TIGIT cells in patients were highly heterogenous; TIGIT expression was not related to PFP and GZMB expression in HDs, whereas it was related to higher intracellular PFP and GZMB levels in patients. Patients' TIGIT NK cells displayed lower K562 cell-killing activity than their TIGIT NK cells. In addition, high frequencies of TIGIT cells in total NK and CD56 NK cells were associated with poor RFS. : TIGIT expression affected the diagnostic bone marrow-sited NK cell function and had prognostic significance in CBF-AML patients.