The effects of siRNA on protein expression and degranulation in HuMCs. HuMCs were incubated with (A-E) the indicated siRNAs or appropriate controls for a total of 72 hours; then the cells were either processed for (A-C) immunoblot analysis or (D-E) degranulation experiments. Immunoblot analyses for the indicated proteins and β-hex release assays were then conducted as described in Figure 1. The blots are representative of 3 to 4 similar experiments in which NTAL-siRNA induced an average 70% knockdown of NTAL expression, and LAT-siRNA induced an average 61% knockdown of LAT expression. The release data are means ± SEM of 4 to 6 separate experiments conducted in duplicate. • indicates cells alone, no siRNA; ○, GFP-siRNA; ▴, NTAL-siRNA; ▾, LAT-siRNA; and ⋄, NTAL + LAT siRNA. (E) The horizontal dashed line represents the antigen response in the absence of siRNA and SCF.