Figure 5. Host-Treg cells adoptive transfer promotes B-cell reconstitution.

Immune-deficient BALB/c-rag2^−/−γc^−/− (H-2^d) mice were transplanted with 1 × 10⁶ TCD BM from allogeneic B6 (H-2^b) mice and were treated with host-Treg cells at day 0 of transplantation. (a) Donor H-2k^b+CD19⁺ B cells in PB of transplanted BALB/c-rag2^−/−γc^−/− mice in the absence (left) or presence (right) of host-Treg cells treatment. (b,c) PB donor chimerism of total CD45⁺ cells (b) and donor B-cell percentage (c) over time after transplantation of Treg cells-treated and untreated BALB/c-rag2^−/−γc^−/− mice. Data are shown as means±s.d. ns=not significant, *P<0.05, **P<0.01, Student's t-test. (d,e) Frequencies of total donor cells, donor CD4⁺ T cells, donor CD8⁺ T cells and donor B cells in the BM (d) and in the spleen (e) of transplanted mice at day 28 after transplantation (n=5 in each group). Data are shown as means±s.d. ns=not significant, **P<0.01, Student's t-test. (f) Frequencies of CD44, CD62L, CD69, CD103, ICOS, KLRG1, LAG3 and PD1 expressions on donor CD8⁺ T cells in the BM of transplanted mice at day 8 after transplantation (n=5 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. (g–j). Serum concentrations of different cytokines in transplanted BALB/c-rag2^−/−γc^−/− mice that received or not host-Treg cells adoptive transfer. Data are shown as means±s.d. ns=not significant, *P<0.05, Student's t-test.