In vitro pulsed B cells induce anergy in memory CD4+ T cells ex vivo. Enriched B220+ B cells (A) or CD11c+ enriched DCs (B) from spleens of five normal BALB/c mice were pulsed with the indicated doses of cOVA323–339 peptide for 3 h, incubated with memory CD4+ T cells for 48 h, and tested for anergy as described in the legend of Fig. 2 using [3H]thymidine incorporation. Data shown represent one of four independent experiments. Bars represent mean ± SD of triplicate cultures. For A, *, p < 0.001, 0.15, or 1.5 nM vs 0.0015 or 15,000 nM peptide (Student’s t test).