CIN85 does not affect BCR internalization. (A) BJAB cells (control and stable transformants expressing either WT or SH3-deleted CIN85) and (B) BJAB cells (control and CIN85-knockdown) were incubated at 4°C with F(ab′)2 goat anti–human IgM for 30 minutes. The cells were washed, warmed to 37°C for the indicated time intervals, stained at 4°C for 30 minutes with a FITC-labeled anti–goat IgG pAb, and analyzed by flow cytometry. The results are expressed as the percentage of surface BCRs remaining. The data are presented as the average and SEM of 3 independent experiments. (C) Control BJAB cells, stable transformants expressing either WT or SH3-deleted CIN85, and CIN85-knockdown BJAB cells were incubated at 4°C with 20 μg/mL F(ab′)2 goat anti–human IgM for 30 minutes. The cells were washed and warmed to 37°C for the indicated time periods. The cells were fixed, permeabilized, stained with a FITC-labeled anti–goat IgG pAb, and analyzed by fluorescence microscopy. The images shown are representative of 3 independent experiments.
