Figure 3

Prevent graft rejection by using CD40 and CD80 siRNA expression vector. (A) Allograft survival curve. Recipient BALB/c mice were injected with 50μg of CD40 and CD80 siRNA vectors by hydrodynamic injection through the tail vein at 3 days before transplantation. A low dose (2Gy) of whole body irradiation was administered to the recipient mice before heart transplantation. MHC fully mismatched allogeneic cardiac transplantation was performed from C57BL/6 mice to BALB/c mice. At 7 and 14, 21 days after transplantation, mice were treated with 50 μg CD40 and CD80 siRNA vectors. The groups of mice that were treated with PBS treated or scrambled siRNA vectors were used as controls (*p < 0.05 vs control groups). (B) Histopathology of cardiac allograft from recipient mice. Mice were used and treated as described in (A). Cardiac allografts were collected at the time of rejection or 100 days post transplantation. Tissues were sectioned and stained with H&E. Sections from rejected mice (a) and CD40 and CD80 siRNA vector treated tolerant mice (b) are compared (magnification x200).