Figure 6. Treg-depletion reduces IL-7 production from ICAM1⁺ stroma.

(a–c) Graphs show IL-7 concentrations in the serum of Treg-depleted mice after syngeneic transplant (a), after allogeneic transplant (b), and in allogeneic transplanted BALB/c-rag2^−/−γc^−/− mice (c) that received or not host-Treg cells adoptive transfer (n=5 per group). Data are shown as means±s.d. *P<0.05, Student's t-test. (d) Donor B-cell percentage in PB of untreated or DT-treated FTR mice that received intraperitoneal administration of low-doses of IL-7. Statistical analysis of the differences between DT-treated FTR that received IL-7 and DT-treated FTR alone at different time points are shown. Representative data from one of three experiments is shown. Data are shown as means±s.d. ns=not significant, *P<0.05, **P<0.01, Student's t-test. (e). Representative results of immunostaining using Treg-depleted FTR mice 28 days after syngeneic transplantation (right panels). The images of transplanted untreated FTR mice are also shown as control (left panels). Note that the frequencies of B220⁺ cells (upper panels) and IL-7⁺ cells (upper and lower panels) are severely decreased in Treg-depleted FTR mice. (f). Representative plot data of non-haematopoietic cells in BM from WT mice. Total BM cells were flushed out and digested with collagenase. Bone related cells were also isolated from bone-derived digested cells. After gating for CD45⁻TER119⁻ cells (left panel), digested marrow cells were gated for ICAM1 and CD31 expression (middle) and bone related cells were gated for Sca1 and PDGFRα expression (right). (g–i). Quantitative RT-PCR data using non-haematopoietic cells from untreated or DT-treated FTR transplanted mice. il-7 mRNA (g), cxcl12 mRNA (h), and kitl mRNA (i) are shown (n=3 in each group). Data are shown as means±s.d. ns=not significant, *P<0.05, **P<0.01, ***P<0.001, Student's t-test.