Figure 1.

BEN+TBI compared to CY+TBI conditioning results in host DCs less stimulatory of alloreactive T-cells and improves GvHD. (A) BALB/c recipient mice received 40 mg/kg BEN i.v. or 200 mg/kg CY i.p. on day −2, 400 cGy TBI on day −1 and 10⁷ T-cell depleted bone marrow (TCD-BM) with 3 × 10⁶ purified T-cells (tT) on day 0. Created with Biorender.com. (B) Pooled survival data from 3 experiments are shown, n = 15 mice/group. A log-rank Mantel-Cox test was used to determine significance. ****P < 0.0001. (C) The weekly average of the mean clinical GvHD score per group is shown with SEM. (D) The weekly mean percent weight change from the starting weight with SEM is shown. Pooled data from 3 experiments are shown, n = 15 mice/group. Multiple t-tests were used to determine significance. *P < 0.05, **P < 0.01, ***P < 0.001. (E) BALB/c recipient mice received 40 mg/kg BEN i.v. or 200 mg/kg CY i.p. on day −2 and 400 cGy TBI on day −1. Splenic DCs from naïve or BEN or CY treated mice with or without TBI were isolated by MACS negative selection on day 0 and used as stimulators of allogeneic T-cells. MLRs were plated at a stimulator to responder ratio of 1:10. T-cell proliferation was assessed by tritiated-thymidine uptake after 4 days of co-culture and shown as percent proliferation (relative to Naïve DCs) with SEM. Pooled data from 4 experiments are shown, n = 3–4 mice/group. Mann-Whitney unpaired t-tests were used to determine significance (BEN vs. CY P = 0.34; BEN+TBI vs. CY+TBI P = 0.40).