Bortezomib treatment promotes bone marrow PC reduction in the skin graft of sensitized rhesus macaque. (A) Skin sensitization. Recipient animals were transplanted with abdominal skin from recipient (left panel) and donor (right panel) with no treatment. Syngeneic skin grafts (left panel) were fully accepted, whereas allogeneic skin grafts (right panel) were rejected with a mean survival time of <2 weeks. (B) Dosing strategy for desensitization. Rhesus macaques after skin grafting were treated with desensitization regimens for 4 weeks after their DSA levels stabilized. (C) Absolute white blood cells (WBCs), lymphocytes, and T and B cell counts before and after bortezomib treatment. There was no significant difference in absolute counts of WBCs, lymphocytes, and CD3 and CD20 cells between pre- and postbortezomib treatment. (D) Representative flow plot showing IgD−CD20− cells in bone marrow aspirates by flow cytometry. The frequency of the gated population (CD19+CD38+) is shown as a bar graph. *P<0.05. (E) Representative total IgG-specific ELISPOT assays from pre- and postbortezomib treatment. The frequency of IgG-producing cells in pre- and postbortezomib treatment in bone marrow was evaluated. Lower frequency of ASCs was seen after bortezomib treatment. Data are expressed as the mean±SEM of four independent experiments. BM, bone marrow; BTZ, bortezomib; IV, intravenous; MFI, mean fluorescence intensity; POD, post-transplant day.