Figure 5.

Increased numbers of NP⁺ B cells in spleens of Cd19^Cre/+mice immunized with NP-Ficoll. Mice were immunized as described in the legend to Figure 3. Cells in spleens (SPL) on D14 after immunization were stained with 7-AAD, NP-FITC plus antibodies against B220/CD19/CD5 and CD138 (A–C) or cultured on NP₂₅-BSA-coated PVDF membranes for ELISPOT analysis (D,E). (A) Bar graphs showing the percentages (upper panel) and numbers (lower panel) of NP⁺ cells within gated B2 (CD19⁺B220^high), B220^low (CD19⁺B220^low), B1a (CD19⁺B220^lowCD5⁺), and CD5⁻(CD19⁺B220^lowCD5⁻) B cells in WT vs. Cd19^Cre/+ mice. Gates for CD19⁺B220^low/CD19⁺B220^lowCD5⁻ cells were the same as those for B1/B1b in Figure 2A, respectively. (B) Representative FACS plots showing the gating strategies for CD19⁺CD138^low (CD138⁺), CD19^lowCD138^high (CD138⁺⁺) or the percentages of NP⁺ within gated CD138^+/CD138⁺⁺ cells in WT vs. Cd19^Cre/+ mice. A sample stained with all the antibodies but without NP-FITC (NO-NP, 2nd row) served as the negative control. (C) Bar graphs showing the percentages (upper panel) and numbers (lower panel) of CD138^+/CD138⁺⁺ cells or NP⁺ cells within gated CD138^+/CD138⁺⁺ populations in the two groups of mice. (D,E) Representative pictures (D) or bar graphs (E) showing the numbers of NP-specific spots in spleens of naive (NA) and immunized (IM) WT vs. Cd19^Cre/+ mice. Each symbol represents one single male mouse of the indicated genotype, and results are expressed as mean ± SEM (A,C,E). * p < 0.05; ** p < 0.01.