Related Experiment Videos
Cell subpopulations in failed human corneal grafts
L Kuffová1, V Holán, L Lumsden
1Department of Ophthalmology, Charles University, Prague, Czech Republic.
The British Journal of Ophthalmology
|November 27, 1999
Summary
Corneal allografts show high levels of macrophages and dendritic cells (DC) upon rejection, regardless of inflammation. These findings suggest DC play a key role in T cell activation and graft rejection.
Area of Science:
- Immunology
- Ophthalmology
- Transplantation Science
Background:
- Healthy corneas lack inflammatory cells and antigen-presenting cells (APC) in their central region.
- Corneal allograft rejection involves complex immune responses.
- Understanding the cellular infiltrate in rejected grafts is crucial for improving outcomes.
Purpose of the Study:
- To investigate and phenotype inflammatory cell populations in rejected corneal allografts.
- To specifically examine T cell subpopulations and macrophages.
- To localize dendritic cells (DC) and MHC class II positive cells in non-inflamed rejected, inflamed rejected, and control dystrophic corneas.
Main Methods:
- Analysis of 30 corneal buttons from keratoplasty: 15 non-inflamed rejected, 5 inflamed rejected, and 10 control dystrophic explants.
- Immunohistochemical staining using monoclonal antibodies against CD3, CD4, CD8, CD14, CD25, CD68, HLA-DP, and HLA-DR.
- Detection of dendritic cells (DC) via dual immunostaining (CD1a+, MHC class II+, CD19-).
- Quantification of cell densities on a scale of 0 to +4.
Main Results:
- Control dystrophic corneas showed no significant immunostaining.
- Rejected corneas (inflamed and non-inflamed) exhibited moderate to high densities of CD8+, CD14+, and CD68+ cells (macrophages).
- Strong expression of HLA-DP and HLA-DR molecules was observed in the epithelium, stroma, and endothelium of rejected grafts.
- Dendritic cells (DC) were present in the epithelium and stroma of 50% of rejected grafts.
- Weak CD4 and CD25 positivity was noted in a subset of rejected corneas.
Conclusions:
- High macrophage frequency and the presence of dendritic cells (DC) characterize rejected corneal allografts, irrespective of inflammation.
- Strong expression of HLA-DP and HLA-DR on resident cells indicates an active immune environment.
- The presence of DC in the stroma suggests their primary role in T cell activation and subsequent corneal allograft rejection due to their potent APC capabilities.