[Attenuation of hyperacute rejection from xenograft by reseeding of endothelial cell]

The potential solution to palliate the critical shortage of suitable donor organs for transplantation may be xenogenic transplantation. However, hyperacute rejection (HAR) after xenotransplantation is the main problem in this process. Since the vascular endothelial cell of donor organ is the primary target cell in rejection, the replacement of endothelium in donor organs with endothelial cell from recipients themselves may be beneficial to the prevention of HAR. Discordant xenotransplantation model (guinea pig-to-rat) was adopted in this study. Firstly, endothelial cell from rat abdominal aorta was separated and cultured. Secondly, the guinea pig abdominal aorta of which the endothelium had been removed was cultured with the suspension containing rat endothelial cells (4 x 10(6)/ml). The viability of cultured vessel was assessed using light microscopy and transmission electron microscopy. The guinea pig vessel reseeded with rat endothelial cell was then examined by immuno-fluorescence staining assay to find out whether IgM and C3 in rat serum were bound to it after preincubation with rat serum. It was found that rat endothelial cells grew into the monolayer endothelium on the inner surface of guinea pig vessel with previous endothelial loss. IgM and C3 in rat serum did not deposit along the new endothelium of guinea pig vessel in the treated group as shown by immuno-fluorescence microscopy, whereas possive results were observed in the untreated normal guinea pig aorta. These findings indicate that donor vessel reseeded with endothelial cell from recipients undergoes less severe rejection and this technique may be very useful for the attenuation of HAR.