Background/Aims: Skin transplantation aims to cover skin defects but often fails due to immune rejection of the transplantated tissue. Immature dendritic cells (imDCs) induce immune tolerance but have a low migration rate. After stimulation, imDCs transform into mature DCs, which activate immune rejection. Thus, inducing imDC to obtain a high migration counteracts development of immune tolerance. Methods & Results: We transfected imDCs with a recombinant adenovirus carrying the CCR7 gene (Ad-CCR7) and a small interfering RNA targeting RelB (RelB-siRNA) to concurrently overexpress CCR7 and downregulate RelB expression. Functionally, such cells showed a significantly enhanced migration rate in the chemotactic assay and decreased T-cell proliferation after lipopolysaccharide stimulation in mixed lymphocyte reactions. Cotransfected cells showed an increased ability to induce immune tolerance by upregulating T regulatory (Treg) cells and shifting the Th1/Th2 ratio. Cotransfection of Ad-CCR7 and RelB-siRNA endowed imDCs with resistance to apoptosis and cell death. CCR7 overexpression and RelB knockdown (KD) in imDCs improve skin-graft survival in a murine skin-transplantation model. Conclusion: Transfection with Ad-CCR7 and RelB KD in imDCs may be an effective approach inducing immune tolerance, thus being potentially valuable for inhibiting allograft rejection.
Concurrent CCR7 Overexpression and RelB Knockdown in Immature Dendritic Cells Induces Immune Tolerance and Improves Skin-Graft Survival in a Murine Model