Deletion of Cdc42 impairs BCR and BAFF-R signaling. Splenic B cells were purified from WT and Cdc42−/− (KO) mice using CD43 microbeads. (A) Freshly isolated cells were stimulated with or without 33 μg/mL anti-IgM F(ab′)2 antibody for 60 minutes and then subjected to Western blot (left). Vertical lines have been inserted to indicate the gel lanes being switched in position from the original blots. Western blotting for BCR was carried out in parallel (right) or (B) purified B cells were either stained immediately with BAFF-R antibody or cultured overnight in the presence or absence of 2 μg/mL anti-IgM F(ab′)2 antibody before the antibody labeling. Stained cells were analyzed by flow cytometry (left). Purified cells were also examined for BAFF-R mRNA expression by quantitative reverse transcription–PCR analysis (right; **P < .01). Data are means ± SD. (C) Purified B cells were stimulated with or without 100 ng/mL BAFF for 60 minutes and then subjected to Western blotting.
