Combined pretreatment with KGF and androgen blockade before BMT significantly improves CD8 T-cell responses against L monocytogenes after allogeneic BMT. Lethally irradiated C57BL/6 Ly5.2⁺ recipients of congenic (C57BL/6 Ly5.1⁺) bone marrow were left untreated (BMT Control) or pretreated with KGF, leuprolide acetate, or KGF + leuprolide acetate and immunized at day 42 after BMT alongside unmanipulated age/sex-matched B6 control animals (non-BMT Control). For primary immunization, 10⁶ CFU of an attenuated strain of L monocytogenes that express recombinant full-length chicken ovalbumin (ΔactA-Lm-OVA) was intravenously injected. (A) Absolute numbers of donor-derived Ly5.1⁺CD44⁺CD8⁺ K^b-OVA_257-64–specific T cells were quantified in peripheral blood of infected animals by FACS 7 days after primary infection. (B) Immunized mice were then rechallenged with 10⁵ CFU of the virulent parent strain, Lm-OVA, 42 days after primary infection. After 3 days, isolated splenocytes of infected animals were restimulated ex vivo for 5 h with OVA_257-64, and donor-derived CD8 T cells were analyzed by FACS for IFNγ production. *P < .05 compared with untreated BMT control mice; #P < .05 compared with KGF- and leuprolide acetate–treated BMT recipients.