Fig. 4.
Ability of Gaμ-ab and Gaδ-ab to activate the signal transducing pathway in CD38-positive B-CLL cells.
(A) B-CLL cells (patient G) were stimulated with NGI, Gaμ-ab, or Gaδ-ab at the optimal concentration (10 μg/mL) for the indicated time. Cell lysates (20 μg/lane) were separated on 10% reducing SDS-PAGE gels and analyzed by immunoblotting with the antiphosphotyrosine mAb, 4G10. Molecular weight in kilodalton is indicated on the right. (B) B-CLL cells (patient H) were stimulated for 3 or 5 minutes with the indicated stimuli. Cell lysates were immunoprecipitated with antiphosphotyrosine mAb (4 G10). The immunoprecipitates were separated on 10% reducing SDS-PAGE gels and probed with an anti-syk mAb (top) or anti-PLCγ1 mAb (bottom). (C) Fura2/AM loaded B-CLL cells were stimulated with Gaμ-ab or Gaδ-ab and studied for [Ca++]i mobilization. Means ± SD of the experiments on the 10 different patients with B-CLL (patients A-L) examined. Panels on the right show the typical profiles of [Ca++]i response to the indicated stimuli (patient A).