Floor plan - 2013 Annual Meeting - American Association for Hand ...

Supportive Therapy with Donor Bone Marrow Transplantation and Role of Regulatory T-cell
for Allograft Survival in Facial Allograft Model
Institution where the work was prepared: Cleveland Clinic, Cleveland, OH, USA
Aleksandra Klimczak, PhD; Mehmet Bekir Unal; Yavuz Demir; Maria Siemionow; Cleveland Clinic
PURPOSE:
We have formerly achieved functional tolerance in fully MHC mismatched rat hemifacial allotransplantation model under Cyclosporine-
A (CsA) monotheraphy. In this study we have evaluated the effect of supportive therapy with donor bone marrow transplantation (DBMT)
under short-term ·‚-TCRmAb and CsA 7-day protocol, on chimerism induction in hemifacial allograft model across MHC barrier.
METHODS:
Thirty six hemiface allotransplantation were performed between LBN(RT1l+n) donors and LEW(RT1l) recipients in 6 groups of 6 rats
each. Controls: Group 1 isograft and Group 2 allograft recipients without treatment, Group 3 received intraosseous DBMT only. Groups
4, 5 and 6 received ·‚-TCRmAb/CsA 7-day therapy. Additionally Groups 5 and 6 were augmented with intraosseous DBMT of 35x106,
and 100x106 bone marrow cells (BMC) respectively. Before transplantation BMC were stained with PKH dye to evaluate migratory
process of donor BMC. Flow cytometry assessed immunodepletion of T–lymphocytes, donor-specific chimerism for MHC class I-RT1n
antigens and presence of regulatory T-cells (Treg) CD4/CD25. Histological grading of graft rejection was assessed by H+E staining.
RESULTS:
Isograft controls survived indefinitely, whereas controls without immunosuppression rejected transplanted allograft within 5 to 8 days.
Group 3 treated with only DBMT accepted transplant up to 13 days. Median survival time (MST) of facial allograft (Group 4) under ·‚-
TCRmAb/CsA therapy was 35 days. In both Groups 5 and 6 augmented with donor BMC MST was 48 days. However, the longest survival
time in Groups receiving 35x106 or 100x106 BMC was 465 and 498 days respectively. In long-term survaivals split tolerance was
assessed because these animals lose the hair but skin was pliable. PKH-positive cells of donor origin were present within lymphoid
organs and skin of recipients. In rejected allografts T-cell chimerism declined