Impaired GC formation in CD23^crePP4^F/F mice immunized with TNP-KLH.

<p>(<b>A</b>) Immunohistochemical (IHC) images of PNA (dark blue) vs B220 (brown) expression in spleen sections of WT and CD23^crePP4^F/F mice (n = 3–6/group) at day 7 post-injection of PBS (control) or TNP-KLH. Data in the right panels are higher magnification images of the red rectangular areas in the center panels. (<b>B</b>) FACS profiles of B220 vs PNA expression by splenocytes from the mice in (A) at day 7 post-injection of PBS or TNP-KLH. (<b>C</b>) FACS profiles of CD95 vs GL7 expression by B220⁺-gated splenocytes from the mice in (A) at day 7 post-injection of PBS or TNP-KLH. (<b>D</b>) Quantitation of the percentage of GL7⁺CD95⁺ GC B cells among total B cells from the data in (C). Data are values for individual mice, and horizontal bars are geometric means. For (A–C), results are representative of two independent experiments.