Figure 6.

Galectin-9 produced by acute myeloid leukemia (AML) cells induces pro-apoptotic processes in VISTA-expressing T cells but not in VISTA non-expressing NK cells. THP-1 human AML cells were pre-treated for 24 h with 100 nM phorbol 12-myristate 13-acetate (PMA). Then they were co-cultured for 16 h with Jurkat T cells (these cells were also pre-treated with 100 nM PMA for 24 h before co-culturing with THP-1) at a ratio of 1:1or with primary human NK cells at a ratio of 1 THP-1: 2 NK. Caspase-3 activity and PARP cleavage were then measured in Jurkat T and NK cells as outlined in Materials and Methods. Images are from one experiment representative of four which gave similar results. Data are shown as mean values ± SEM for four independent experiments; *p < 0.05 vs control.