CD4+ T cells do not contribute to GVL effects of DLI in freshly irradiated BMT recipients. Lethally irradiated B6 mice were reconstituted with a mixture of TCD B10.A and B6 bone marrow together with nondepleted DLI (□, n = 8; inoculum contained a total of 5.3 × 105 CD4+ plus 2.1 × 105 CD8+ T cells), CD4–CD8+ DLI (▴, n = 8; inoculum contained 2.0 × 105 CD8+ T cells), CD4+CD8– DLI (▿, n = 7; inoculum contained 5.4 × 105 CD4+ T cells), CD4–CD8– DLI (○, n = 8), or no DLI (*, n = 4) on day 0 followed by 1 × 103 EL4 cells on day 7. Additional groups received the same bone marrow inoculum and nondepleted DLI (▪, n = 8) or no DLI (♦, n = 4) but did not receive EL4 tumor. Graphs show (A) overall survival and (B) tumor-free survival in which nontumor deaths (as assessed at autopsy) were censored at the time of death.
