FIGURE 6.

Different roles of LAT and NTAL in mast cell chemotaxis and cross-talk with CD9. A, BMMCs derived from Lat^−/−, Ntal^−/−, 2KO, and corresponding littermate (Lat^+/+, Ntal^+/+) control mice were sensitized overnight with TNP-specific IgE and their migration toward Ag (250 ng/ml of TNP-BSA) was tested in the Transwell system. B, the same IgE-sensitized BMMCs as in A were activated with Ag (250 ng/ml TNP-BSA) for 30 min and β-glucuronidase released into the supernatant was determined as described under “Experimental Procedures.” C, BMMCs from Ntal^+/+ and Ntal^−/− mice were sensitized with IgE and treated with the indicated concentrations of anti-CD9 mAb 2H9. Chemotaxis toward Ag was determined as in A. Numbers of cells migrating toward Ag were normalized to controls, 2H9 nontreated cells. Mean ± S.D. were calculated from 3 to 5 independent experiments performed in duplicates. **, p < 0.01; ***, p < 0.001.