Abstract
Abstract: :
Purpose:To determine whether fresh amniotic epithelial allografts display immune privilege on cornea and enhance survival of orthotopic corneal allografts. Methods:Full thickness central corneas of C57BL/6 mice were transplanted orthotopically into normal eyes of BALB/c mice. Some of corneal allografts were covered with fresh amniotic epithelial sheet of C57BL/6 mice by 11-0 nylon sutures. Corneal sutures were removed at 7 days. Graft fate was observed clinically and histologically. Cytokine gene expression in fresh amniotic epithelium was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and multiprobe RNase protection assay system. Results: Forty five percent of corneal allografts without coverage by fresh amniotic epithelial sheet survived more than 8 weeks. By contrast, all of corneal allografts which were covered by allogeneic fresh amniotic epithelial sheet were rejected swiftly. Histological study of corneal allografts which were covered by allogeneic fresh amniotic epithelial sheet revealed that center of corneal epithelium was distracted and resulted in the corneal epithelial defect in some grafts, and that stroma was neovascularized and infiltrated with leukocytes and the other lineage cells which look like amniotic epithelial cells. The fresh amniotic epithelium of C57BL/6 mice expressed mRNA of Interleukin (IL)-6, IL-18, IL-1 receptor antagonist, macrophage migration inhibitory factor (MIF), and fetal liver kinase(FLK)-1. Conclusion:Fresh amniotic epithelium of C57BL/6 mice expressed genes of both pro-inflammatory and anti-inflammatory factors. The fresh amniotic epithelial allografts did not display anti-inflammatory effect on orthotopically transplanted corneal allografts, but destroy corneal epithelium and enhanced corneal allo-rejection.
Keywords: 435 immunomodulation/immunoregulation • 607 transplantation • 380 cytokines/chemokines