Figure 6.

Inhibition of the actin response in combination with anti-HLA-G blocking antibody substantially improves NK cell-mediated killing of CLL cells. (A) Conjugation frequency of primary CLL cells as quantified by imaging flow cytometry in the absence or presence of HLA-G blocking antibody. Target cells were incubated with 10 µg/mL control IgG or blocking antibody against HLA-G, and were used either untreated (IgG, HLA-G), DMSO treated, or after incubation with 50 µM ZCL278 for 1 h before conjugation. Effector and target cells were co-cultured at a 3:1 E:T ratio for 45 min at 37°C and fixed with 2 v/v% PFA. Target cells in conjugation are shown as % of total target cells. (B) Quantitative analysis of primary CLL-NK cell conjugates with an actin response in the presence of control IgG or anti-HLA-G blocking antibody by imaging flow cytometry. Target cell were either untreated (IgG, HLA-G) or conjugated after treatment with vehicle (DMSO) or 50 µM ZCL278. For each patient, a minimum of 100 conjugates were analyzed. (C) Average percentage of Live-or-Dye NucFix™ Red positive primary CLL cells in conjugation with NK-92MI cells in the presence of control IgG or anti-HLA-G blocking antibody. Target cells are either untreated, treated with vehicle control or 50 µM ZCL278.