161533 TriKE is superior to 1633 BiKE to restore NK-cell function and proliferation in patients with MDS. (A) Cryopreserved PBMCs from MDS patients (n = 14) and HDs (n = 7) were rested overnight and stained, and NK cell frequencies were determined by flow cytometry. (B-C) Cryopreserved PBMCs from MDS patients (B) or HDs (C) were activated overnight with IL-15 (equal molar concentration to the IL-15 in TriKE [50 nM], BiKE [50 nM], or TriKE [50 nM]). Target cells were then added 6 hours prior to staining. NK cell degranulation (CD107a), IFN-γ production, and proliferation (Ki67) were evaluated. Data are shown as mean ± SEM, and statistical analyses were performed using paired Student t test.