Shp2 is required for FcεRΙ-evoked degranulation and synthesis of cytokine mRNAs in RBL cells.

<p>(A–B) FcεRΙ-evoked degranulation is defective in Shp2 knockdown RBL cells. Three populations of RBL cells sensitized by anti-DNP-IgE were starved and stimulated with 10 or 100 ng/ml DNP (A) or PMA plus ionomycin (B). The levels of degranulation were determined by measuring the release of β-hexosaminidase. Results are reported as the percentage of total net release. Representative data expressed as mean ± SEM from one of at least 3 experiments are shown. **, <i>P</i><0.01; *, <i>P</i><0.05. ns, not significant as determined by Student <i>t</i> test compared to controls. (C-E) FcεRΙ-induced generation of cytokine mRNAs is significantly inhibited in Shp2 knockdown RBL cells. Three populations of RBL cells were sensitized, starved, and stimulated with 10 ng/ml DNP for 1 h, or left unstimulated. Total RNA was isolated and synthesis of IL-1β (C), IL-10 (D), and MCP-1 (E) transcripts was detected by real-time RT-PCR. Values were normalized to GAPDH expression and presented as mean ± SEM. Representative results from one of a minimum of 4 experiments are shown. **, <i>P</i><0.01, Student <i>t</i> test.