Different proportions of antigen-specific CD8⁺ T cells in the BM. (A) Examples of flow cytometric dual expression profiles showing tetramer-positive CD8⁺ T cells in paired blood and BM sample. The proportion of EBV lytic antigen–specific CD8⁺ T cells were analyzed by staining with HLA-B*0801 tetramer for RAKFKQLL peptide from BZLF-1 lytic protein. EBV-latent antigen-specific CD8⁺ T cells were stained by a HLA-B*0801 tetramer for FLRGRAYGL peptide of EBNA3A latent protein. The proportion of CMV-specific CD8⁺ T cells were analyzed by staining with a HLA-B*0702 tetramer for TPRVTGGGAM peptide of pp65 protein. The proportion of influenza-specific CD8⁺ T cells were analyzed by staining with a HLA-A*0201 tetramer for GILGFVFTL of matrix protein. Percentages represent proportion of each subset within CD8⁺ T-cell population. (B) The frequency of antigen-specific CD8⁺ T cells in paired blood and BM samples. Graphs show the proportion of CD8⁺ T cells specific for CMV, EBV lytic antigen, EBV latent antigen, and influenza. P values were obtained using a Wilcoxon signed rank test as described in “Statistical analysis.” *P ≤ .05.