Reduction of MZ B cells and relative increase of GCs in the spleen of B/WcKO mice. (A) Splenic sections of WT, B/WcKO, and WKO mice were stained for B220 (blue), MOMA (green), and CD1d (red). MZ B cells (in purple) surround MOMA⁺ metallophilic macrophages in the spleen of WT mice but are severely depleted in B/WcKO and WKO mice. Scale bars, 150 μm. Eight mice per group were examined in 2 different experiments. Representative images are shown. (B) GC formation was assessed by staining for B220 (blue), PNA (red), and MOMA (green). Scale bars, 150 μm. Eight mice per group were examined in 2 different experiments. Representative images are shown. (C) The mean area occupied by follicles (FO; left panel) and by GCs (middle panel) is shown and was quantitated on immunohistologic slides as described in “Immunofluoresecence.” In addition, the GC/FO ratio of the respective areas is reported in the right panel. Values from individual spleen sections are shown. Significance was measured with 1-way ANOVA and Bonferroni posttest analysis. *P < .05.