Plasma cell differentiation. (A) Flow cytometry of CD138⁺B220^low plasma cells in the spleen and BM of SWAP-70^+/+ or SWAP-70^−/− mice at the indicated times after immunization with NP-KLH. Data represent the mean percentage of 4 independent experiments. (B) Immunoblot of lysates from splenocytes of wt and SWAP-70^−/− mice 14 days after NP-KLH immunization. Blots were probed with anti-BLIMP1. SMC1α is used as loading control. (C) Spleens stained for BLIMP1 (green) and B220 (red) at 14 days after immunization. (D) Spleens stained for BLIMP1 (green) and NP (red). All scale bars represent 200 μm. Data are representative of 3 independent experiments.