DTH following adoptive T cell transfer. DbpA-immunized mice were treated with either Map19 or Ace40, as described above. On day 7, mice were sacrificed and spleens were harvested and enriched for T cells by nylon wool purification. Cells (5 × 10⁷) were injected intraperitoneally into syngeneic recipients. Twenty-four hours later, recipient mice were challenged with DbpA, and the DTH response was assessed as described above. T cells from DbpA-immunized Ace40-treated or T cells from DbpA-immunized (untreated) mice elicited a significant DTH response compared with unimmunized but challenged mice or to naive T cell–recipient mice (*P < 0.04; Student t test). T cells from DbpA-immunized, Map19-treated mice did not elicit a significant DTH response compared with positive control treatment groups (**P < 0.001; Student t test). Data are expressed as the mean ± SE of five mice.