Effect of host-type CD8α⁺ DC immunization on donor T-cell expansion and cytokines after allo-BMT. B6 animals were irradiated and transplanted after immunization of the donors as in “Vaccination protocol.” Splenocytes and serum were harvested from the recipients on day 7 and 14 after BMT. (A) Donor (CD45.2 or H2k^d) CD4⁺ and CD8⁺ T-cell expansion was determined by FACS analysis. Data represent the mean ± SE. *P < .05 between allorecipients of host-type CD8α⁺ DC–vaccinated donors and diluent control or host-type CD8α⁻ DC–vaccinated donors. (B-D) Serum cytokines were measured (n = 4/group) on days 7 and 14 after BMT. Serum levels of (B) IFN-γ, (C) TNF-α, and (D) IL-10. N.D indicates not detected. *P < .05 between allorecipients of host-type CD8α⁺ DC-vaccinated donors versus the diluent control. Data are from one of 2 similar experiments. (E-G) Representative figure of IL-10 production from donor T cells (n = 3 or 4/group) on day 14 after BMT (E). Gated on donor-specific (H-2k^d) cells for the double-positive population of CD3 and IL-10. The percentage IL-10⁺ donor T cells (F) and the absolute cell numbers (G). P < .05.