AMD3100 Enhances Engraftment Figure 2. Post transplant administration of AMD3100 selectively enhances reconstitution of all donor-derived hematological lineages of cells. KTLS cells from C57BL/Ka CD45.1 Thy1.1 mice were injected via tail vein into lethally irradiated C57BL/6 CD45.2 Thy1.2 mice (250 KTLS cells per mouse). Beginning 2 days after transplant (day +2), the mice were injected subcutaneously with PBS control or AMD3100 at 5 mg/kg body weight every Monday, Wednesday, and Friday until day +56. Hematological recovery and cell subset analyses were determined at the time points indicated, as described in Methods. The graphs are representative of 3 separate sets of experiments with 10 mice in each group in each experiment. A: Blood nucleated cell counts (/ml) (normal range of mouse white cell counts: 1.8–10.76103/ml). B: Donor-derived CD45.1+ cell counts (/ml). C: Blood recipient origin CD45.2+ cell counts (/ml). D: Blood CD3+ T cell counts (/ml). E: Blood B220+ B cell counts (/ml). F: Hemoglobin concentration (g/dl) (normal range of mouse hemoglobin level: 11– 15.1 g/dl). G: Blood platelet counts (6106/ml) (normal range of mouse platelet count: 592–29726106/ml). *: p,0.05. doi:10.1371/journal.pone.0011316.g002 between AMD3100 injected mice and mock control mice (Fig. 2C). These data demonstrate that AMD3100 selectively augments donor derived cell reconstitution. We next performed multi-color cell subset analyses on the blood samples. We found that AMD3100 injection augmented the reconstitution of not only neutrophils, but also B cells and T cells (Fig. 2D and 2E). Again, the difference was predominantly attributed to enhanced recovery of donor derived cells (data not shown). In a separate set of experiment, we measured the hemoglobin concentration and platelet count at the indicated time-points. As shown in Fig. 2F, AMD3100 administration significantly enhanced red blood cell recovery. Although the platelet count was higher in AMD3100-treated mice at day +43 post transplantation, the difference was not statistically significant (Fig. 2G). This may be because the platelet count had reached normal levels in both groups at the time the platelet counts were measured. Nevertheless, these data suggest that AMD3100 administration enhances reconstitution of all hematological lineages. 3. Post transplant administration of AMD3100 reduces pro-inflammatory cytokine production It is noteworthy that there is a temporal difference between animal survival benefit and the blood hematological recovery seen in AMD3100-treated mice. The reduced mortality seen in AMD3100- PLoS ONE | www.plosone.org 3 June 2010 | Volume 5 | Issue 6 | e11316