Fig. 4.

Cognate iNKT-cell help preferentially expands innate B-cell populations. Splenocytes from C57BL/6 mice immunized with vehicle [PBS/0.1% (wt/vol) BSA], 100 μg NP-KLH plus 0.5 μg αGalCer (αGC), or 0.5 μg NPαGalCer (NPαGC) were assessed by FACS analysis for numbers of follicular (FO) B220⁺NP⁺CD21⁻CD23⁺ B cells, B220⁺NP⁺Fas⁺GL7⁺ NP-specific germinal center (GC Fas⁺GL7⁺) B cells, and MZ B220⁺NP⁺CD23^loCD21⁺ B cells at days (A) 4 and (B) 8 postimmunization. Pie charts show B-cell subsets as percentages of total B cells in the spleen (A) 4 and (B) 8 d after immunization with NPαGC or NP-KLH plus αGC (representative of two experiments; n = 8–10 mice per group). *P ≤ 0.05 to vehicle control; ^#P ≤ 0.05 to NP-KLHαGC.