Influence of vaccination on the engraftment efficacy of human PBMC. (A) Schema of 9-wk engraftment protocol in which vaccination was performed using 1 × 106 mDC given on day 42 and day 49. Spleens were isolated on day 63. (B) Schema of 4-wk engraftment protocol using injection of 1 × 106 mDC on day 14 and day 21. Spleens were isolated on day 28. (C) Representative examples for CD3 vs. SSC, CD4 vs. CD62L and CD8 vs. CD62L (from left to right) of flow cytometry analysis comparing engraftment efficacy of 9-wk (left of each block) and 4-wk (right of each block) schemes. (D) Statistical analysis of engraftment efficacy comparing 9-wk and 4-wk protocols and mice vaccinated using 7-day 4C-matured DC (circles), 3-day 4C-matured (squares) or 3-day 5C+R848-matured (triangles) DC; means are given in brackets. Statistical analyses were performed using a two-tailed Mann-Whitney test and p < 0.05 were considered significant. Engraftment experiments were performed at least 3 times with similar results. (E) Amounts of human IFN-γ in sera of vaccinated mice engrafted with the 9-wk or 4-wk protocol, respectively, were assessed using a standard ELISA. Depicted are means and SEM of 8 mice generated in two individual experiments. The open square and open circle represent levels in individual non-vaccinated mice.