The CpG-ODN–induced expansion of CD4 and CD8 T cells is not dependent on the presence of B cells.

C57BL/6 mice and μMT^−/− (B-cell deficient) mice underwent 9 daily injections of CpG-ODN or Neg-ODN. One day after the last ODN injection, the draining axillary lymph nodes (A) and spleens (B) were harvested. Cell numbers for each subset were estimated by flow cytometry as described in the legend of Figure 8.