Limited response of Batf^ΔZ/ΔZ CD4⁺ T cells to T cell–dependent antigen. (A) CD4⁺ T cells from Batf^+/+ or Batf^ΔZ/ΔZ mice were injected into T cell–deficient mice, which were immunized with 5 × 10⁸ sRBC. After 8 d, Tfh cells in spleen and lymph nodes were quantified as in Fig. 4 A. Representative plots (n = 3) are shown. (B) Mean number of CXCR5⁺ cells from A per organ or per mouse lymph node (LN) is shown (n = 3). Error bars indicate SE. *, P < 0.05. (C) ELISA using sera isolated from mice in A to detect sRBC-specific IgM and IgG1. Mean and SE are shown (n = 3). *, P < 0.05.