Normal follicular, but impaired MZ B-cell responses in B/WcKO mice. (A) WT, B/WcKO, or WKO mice were immunized intraperitoneally with 100 μg of TNP-KLH and challenged with 25 μg of TNP-KLH 14 days later. Seven days after TNP-challenge, TNP-specific IgG responses (total TNP-specific IgG response, left panel; high-affinity TNP-specific IgG response, right panel) were measured by ELISA. Preimmune serum from WT mice was used as a control. Results are reported as mean ± SEM of 5 mice per group. The differences were not significant with 2-way ANOVA and Bonferroni posttest analysis, P > .05. (B) WT, B/WcKO, and WKO mice were immunized subcutaneously with noncapsulated PnWCV twice 2 weeks apart. PnWCV-specific IgG responses were measured by ELISA in sera collected 1 week after the second immunization. Preimmune serum from WT mice was used as a control. Mean ± SEM values of 5 mice per group are shown. The differences were not significant with 2-way ANOVA and Bonferroni posttest analysis. P > .05. (C) WT, WKO, and B/WcKO mice were immunized intravenously with 1 μg of Pneumovax23 vaccine. At the indicated times, serum was tested by ELISA for pneumococcal capsular polysaccharide-specific IgM (left) and IgG (right) Abs. Mean ± SEM values of 5 mice per group are shown. Significance was assessed by 2-way ANOVA and Bonferroni posttest analysis. ****P < .0001. (D) WT, WKO, and B/WcKO mice were infected with 2 × 108 PFU UV-inactivated VSV. At the indicated times, serum was tested in a VSV neutralization assay for total neutralizing Ig. Mean ± SEM values of 5 mice per group are shown. Significances were assessed by 2-way ANOVA and Bonferroni posttest analysis. **P < .01.
