GvL against Bcr-Abl–induced B-lymphoblastic leukemia. (A) Flow cytometric analysis of chimerism (top row) and B-lymphoblastic leukemia (bottom row) in serial peripheral blood samples from a representative mouse with mixed chimerism and Bcr-Abl–induced B-ALL. Circulating leukemic cells were detected with antibody against the B-cell differentiation antigen BP-1/6C3.²⁶  Blood sampling and analysis were performed on days 13, 16, 19, and 24 after BMT, and DLI was administered on days 14, 17, and 20 with a total of 1.1 × 10⁸ allogeneic splenocytes. Note the disappearance of GFP⁺ cells by day 24, accompanied by conversion to full allogeneic chimerism. (B) Wright-Giemsa stain of day-16 peripheral blood from panel A, demonstrating circulating immature mononuclear blasts (magnification, 500 ×). (C-D) Cumulative leukemic mortality (C) and overall survival (D) for recipients of TCD p210 BCR-ABL–transduced BM from non–5-FU-treated Balb/c donors and TCD B6 BM, either without DLI treatment (blue, n = 4), with administration of allogeneic splenocytes at the time of BMT (green, n = 4), or with early DLI treatment of established mixed chimeras with B-ALL (yellow, n = 20). The frequency of fatal B-ALL in the DLI-treated group was significantly lower than in untreated chimeras (P = .007, Fisher exact test). Two mice in the cohort that received splenocytes at BMT died because of engraftment failure on day 7 and 8 after transplantation (see the second paragraph on this page). (E) Genomic DNA from the indicated tissues (PE indicates pleural effusion) was analyzed by Southern blot as in Figure 2G. Lanes 4 to 7 are DNAs from leukemic chimeric mice with B-ALL that did not receive DLI; note near single-copy levels of BCR-ABL provirus in lanes 5 and 6. Lanes 8 and 9 are the spleen DNAs from 2 different mice that received splenocytes at the time of BMT. No GFP⁺ clones or BCR-ABL provirus are detectable, and the spleen is composed mostly of cells of B6 origin. Lanes 10 to 24 represent DNAs from chimeric mice with B-ALL treated with DLI. Lanes 10 to 11 and 25 to 26 are from 2 mice that failed DLI because of poor or absent chimerism. Brackets indicate samples from the same individual mice.