Expansion of donor-derived CMV-specific T cells after donor lymphocyte infusion. (A) Conversion to donor chimerism was associated with massive expansion of donor-derived CMV-specific T cells in the weeks after DLI. (B) Serial chimerism analyses demonstrating the shift to donor chimerism within the different T-cell compartments. Taken together, the results demonstrate effective priming and expansion of a primary immune response from the virus-naive donor.