Figure 1.

Defective NK cell degranulation in patients with homozygous STX11 c.173T > C mutations. (A–D) PBMC were isolated from three patients with homozygous STX11 c.173T > C, p.L58P mutations, relatives (n = 10, all six parents in addition to four siblings) as well as transport (n = 3) and local controls (n = 5). PBMC (A) freshly isolated or (C) stimulated with IL-2 overnight were mixed with ⁵¹Cr labeled K562 target cells. After 4 h, ⁵¹Cr-release was quantified in supernatants and specific lysis was calculated. Symbols indicate individual values for patients or mean values for relatives and controls. Error bars indicate SD. PBMC (B) freshly isolated or (D) stimulated with IL-2 overnight were mixed with target cells and antibodies, as indicated. The cells were stained with antibodies to lineage markers and CD107a. The frequency of cells expressing surface CD107a was determined by flow cytometry. Symbols indicate values for patients and bars mean for relatives and controls. Error bars indicate SD.