(A) Flow cytometry of B220+ splenic cells from Pten+/+Baff+/+Cd19Cre, PtenL/LBaff+/+Cd19Cre, Pten+/+Baff−/−Cd19Cre, and PtenL/LBaff−/−Cd19Cre mice. Data are representative of n>8 mice per group. (B) Absolute numbers of splenocytes and splenic B220+ B cells (top panel), and splenic B cell subsets (bottom panel). Shown is n=7 mice per group from n=5 experiments; small horizontal lines indicate mean. (C) Expression of CD21/35 on B220+-gated IgMloIgDhi splenic B cells from Pten+/+Baff+/+Cd19Cre, PtenL/LBaff+/+Cd19Cre, Pten+/+Baff−/−Cd19Cre, and PtenL/LBaff−/−Cd19Cre mice. MFI=mean fluorescence intensity. (D) ELISA of nitrophenol-specific IgM (top) or IgG (bottom) in the sera of Pten+/+Baff+/+Cd19Cre, PtenL/LBaff+/+Cd19Cre, Pten+/+Baff−/−Cd19Cre, and PtenL/LBaff−/−Cd19Cre mice prior to immunization (day 0), and 7 or 14 days post-immunization with 100 μg NP-KLH in alum. (E) Flow cytometric analysis of splenic GC B cells (B220+ gated) from immunized mice (top). Graph summarizes the percent of B220+GL7+Fas+ B cells 14 days post-immunization (bottom).