Figure 4.

Lysis of GBM cell lines by short-term γδ T cell lines. (A) Calcein-AM labeled A-172, T-98G, U-87MG and U-251MG target cells were co-cultured for 4 h at indicated E/T ratios with γδ T cells expanded from four to five healthy donors. Cytotoxicity assays were performed in the absence (black bars) or presence (gray bars) of BrHPP. (B) Involvement of NKG2D and TCR in γδ T cell-mediated killing. Calcein AM-labeled U-87MG cells were co-cultured for 4 h with γδ T cells from five different healthy donors at an E/T ratio of 20:1 with (right-hand panel, gray bars) or without BrHPP (left-hand panel, black bars). Prior to the co-culture, γδ T cells were pre-incubated for 1 h with 10 µg/mL anti-NKG2D and/or anti-Vγ9 TCR anti bodies or with IgG1 as an isotype control. Statistical significance is displayed as ** for p < 0.01 and * for p < 0.05.