IL-21 promotes optimal GC B cell development in a vaccine dose-dependent manner.

<p>Draining lymph node cells from IL-21R−/− or wild-type C57BL/6 mice immunized in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002129#pntd-0002129-g004" target="_blank">Figure 4</a> were analyzed for the presence of B cells displaying a GC phenotype (B220⁺GL7^hiCD95/Fas^hi). A, Representative gating strategy from IL-21R−/− or C57BL/6 mice immunized with rRABV or PBS to identify B220⁺ B cells from total live lymph node cells. B, Representative gating strategy from IL-21R−/− or wild-type mice immunized with rRABV or PBS to identify GC B cells. C and D, Number of GC B cells per 100,000 draining lymph node cells was determined in IL-21R−/− or wild-type mice immunized with 10³ (C) or 10⁵ (D) ffu/mouse 7 or 14 days post-immunization with rRABV or PBS alone. Statistical difference in GC B cell data between two groups of data was determined using an unpaired, two-tailed t test and data is presented at the mean ± SEM. *p<0.05, **p = 0.01–0.001, ***p≤0.001; (N = 5 mice per group); (ffu = focus forming units).