T-cell engraftment and Treg cell populations after BMT. To evaluate the effects of bortezomib on T cells, irradiated Balb/c mice were transplanted with bone marrow cells with or without spleen cells and treated with bortezomib (0.1 mg/kg) or vehicle control. Data were collected from 2 to 3 independent experiments with ≥8 mice per group. (A-B) Spleen cells were isolated at either day 11 or day 56 and analyzed for chimerism (Ly9.1⁺ stain for recipient-derived cells) by flow cytometry. (C-D) Thymus engraftment was analyzed by double-positive T cells (CD4⁺CD8⁺) at day 56 by flow cytometry. (E) Cellularity in secondary lymphoid organs at day 56. (F) Spleens were harvested and analyzed for Treg cell populations. (G) Total numbers of Treg cells. (H) Serum IL-6 levels were detected by cytometric bead array. All data were shown as mean ± SEM and analyzed by 1-way ANOVA with a Tukey post hoc test to compare between individual groups. *P < .05, **P < .01, and ***P < .001 were considered significant. Data were collected from 2 independent experiments with 8 mice per group.