Transplantation of Allograft Transforming Growth Factor–β1 Transfected CD103+ Lamina Propria Dendritic Cells Could Effectively Induce Antigen-Specific Regulatory T Cells In Vivo

Organ transplantation is the best treatment of some end-stage diseases such as renal failure. Unfortunately, not every transplant is successful due to rejection or dysfunction of the transplanted organ. Induction of allograft tolerance is the most important goal of clinical transplantation. Regulatory T cells (Tregs) have opened up exciting opportunities for this enterprise. Because Tregs can be induced from naïve CD4 T cells (induced Tregs [iTregs]) by lamina propria dendritic cells (LpDCs) via transforming growth factor–β (TGF-β) and retinoic acid (RA) iTregs show in vitro and in vivo functions similar to those of natural Tregs (nTregs), we sought to convert naive CD4 T cells to iTregs using mTGF-β1-modified allograft LpDCs in vivo. Adoptive transfer of mTGF-β1–modified LpDCs of BALB/c mice into C57BL/6 mice induced higher levels of mTGF-β1 and mIL-10 in sera as well as a greater proportion of antigen-specific Tregs. These data support the role of mTGF-β1–modified allograft LpDCs to induce high levels of antigen-specific Tregs in vivo.