Immunological studies on the cellular phenotype involved in corneal allograft rejection.

OBJECTIVE

To investigate the cellular phenotype involved in corneal allograft rejection using wholemounts analysis.

METHODS

Corneal transplantation was performed between Sprague Dawley (SD) and Wistar rats. Corneal wholemounts were prepared from control rats and those after corneal transplantation on day 7 and 12. Immunohistochemical stain was performed on these wholemounts using monoclonal antibodies to transforming growth factor beta 1(TGF-beta 1), CD3, CD4, CD8, B lymphocytes, macrophages, dendritic cells and major histocompatibility complex (MHC) class II antigen.

RESULTS

Corneal allograft rejection started on day 7 and reached its maximum from 10 to 14 days after corneal transplantation. Presence of TGF-beta 1-, CD3-, CD4-, CD8-, MHC class II-positive cells, macrophages and dendritic cells were noted at the limbus of both SD rats and Wistar rats. No positive cell was present in the central cornea of normal rats. All positive cells but B lymphocyte were noted in large numbers in the cornea after corneal allograft transplantation. Marked staining for TGF-beta 1 was noted during graft rejection.

CONCLUSION

The corneal wholemounts technique provides a good visualization for the cellular phenotype involved in corneal allograft rejection. A variety of cells including TGF-beta 1, CD3, CD4, CD8, MHC class II antigen positive cells, macrophages and dendritic cells are involved in corneal allograft rejection. TGF-beta 1-positive cell might be an important immunosuppressive factor after corneal transplantation and also involved in the induction of fibrosis.