T_M from LCMV-immune and H60-vaccinated donors mediate GVL and provide protection from LCMV infection. See supplemental Figure 3 for experimental design. B6.H60 mice were irradiated and reconstituted with C3H.SW BM, B6.H60 mBC-CML cells, with no T cells, or with: 5 × 10⁴ CD8⁺ T_M from DEC-H60-vaccinated or unmanipulated C3H.SW mice; 2.5 × 10⁵ CD8⁺ T_M from LCMV-immune C3H.SW mice; 3 × 10⁵ CD8⁺ T_M from LCMV-immune and DEC-H60-vaccinated mice; or a combination of 5 × 10⁴ CD8⁺ T_MH60 and 2.5 × 10⁵ CD8⁺ T_M from LCMV-immune donors. An additional group of mice was transplanted with 2.5 × 10⁵ T_M from LCMV-immune mice without mBC-CML cells. All recipients of T_M from LCMV immune donors received ∼ 6 × 10³ Tet^H60+ cells. Cohorts of surviving mice were challenged with LCMV clone 13 on day 18 after transplantation. Cohorts were killed 7 days later to assess the anti-LCMV T-cell response. (A) Survival. P < .0001 comparing T_MH60, T_MH60-_LCMV or T_MH60 + T_MLCMV recipients with BM alone controls, T_M recipients, or T_MLCMV recipients. P > .09 comparing T_MH60 recipients with T_MH60-LCMV or T_MH60 + T_MLCMV groups. (B) Numbers of NGFR⁺EGFP⁺ cells in peripheral blood at day +15. P ≤ .0007 comparing T_MH60, T_MH60-LCMV or T_MH60 + T_MLCMV recipients with BM alone controls; P > .07 comparing T_M recipients or T_MLCMV-cell recipients with BM alone controls. P = .3510 comparing T_MH60 recipients with T_MH60+LCMV recipients. (C) Expansion of Tet^H60+ cells in peripheral blood at day +9. Representative flow cytometry (gated on CD8⁺ cells; left panel) and total numbers of Tet^H60+ cells (right panel). (D) Representative flow cytometry of NP396, GP276, and GP33 tetramer⁺ cells in spleen at day +7 after LCMV challenge (gated on CD8 cells). (E) Total numbers of tetramer⁺ cells. P > .39 comparing T_MLCMV recipients with T_{MH60 + LCMV} or T_MH60 + T_MLCMV recipients for all epitopes. (F) Serum LCMV titers at day 7 after challenge. Data are from 1 of 2 experiments with similar results.