Flow cytometric analysis
APC
All antibodies were purchased from BD Biosciences (Heidelberg, Germany) unless otherwise specified. For phenotypic analysis, cells were stained with anti-CD8 FITC (clone SK1), anti-CD25 PE (clone 2A3), anti-CD14 PerCP (clone MφP9), anti-CD56 APC (clone B159), anti-CD19 PE-Cy7 (clone SJ25C1), anti-CD4 APC-Cy7 (clone RPA-T4), anti-CD3 V450 (clone UCHT1), and anti-CD45 V500 (clone HI30). Gating included the exclusion of debris in a SSC vs. FSC plot. Leukocytes were gated in a CD45 vs SSC dot plot as CD45+ cells. The CD45high/SSClow population was termed lymphocytes and could be distinguished from monocytes and granulocytes. Within CD45high cells, subsets were characterized by expression of CD3 (T-cells), CD19 (B-cells), and CD56 (negative for CD3) NK-cells. Monocytes were gated as CD14+ SSC low cells.For analysis of CMV- and EBV-specific T-cells, 1x10