Impaired GC formation in CD23^crePP4^F/F mice immunized with TNP-Ficoll or infected with H1N1 virus.

<p>(<b>A</b>) IHC images of PNA (dark blue) vs B220 (brown) expression in spleen sections of WT and CD23^crePP4^F/F mice (n = 3–4/group) at day 14 post-injection of PBS or TNP-Ficoll. Data in the right panels are higher magnification images of the red rectangular areas in the center panels. Red arrows indicate GCs. (<b>B</b>) FACS profiles of B220 vs PNA expression in total splenocytes of the mice in (A). TNP-Ficoll-immunized WT and CD23^crePP4^F/F mice (n = 3–4/group) from those in (A) that were given a second injection of TNP-Ficoll at day 100 (Re-boost). (<b>C</b>) Quantitation of the percentage of PNA⁺B220⁺ GC B cells among total splenocytes of the mice in (B). Data are values for individual mice, and horizontal bars are geometric means. (<b>D</b>) FACS profiles of CD95 vs GL7 expression by B220⁺ splenic B cells isolated from WT and CD23^crePP4^F/F mice (n = 6/group) at day 15 post-injection of PBS or H1N1 virus. (<b>E</b>) Quantitation of the percentage of GL7⁺CD95⁺ GC B cells among total B cells from the data in (D). (<b>F</b>) FACS profiles of CXCR4 vs GL7 expression by B220⁺ splenic B cells from the mice in (D). (<b>G</b>) Quantitation of the percentage of GL7⁺CXCR4⁺ centroblasts among total B cells from the data in (F). For (A–G), results are representative of two independent experiments.