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Updated: Aug 9, 2026
Murine Corneal Transplantation: A Model to Study the Most Common Form of Solid Organ Transplantation
Published on: November 17, 2014
Differences in leukocyte phenotype and interferon-gamma expression in stroma and endothelium during corneal graft
Susan M Nicholls1, Sanjiv Banerjee, Francisco C Figueiredo
1Unit of Ophthalmology, Department of Clinical Science at South Bristol, School of Medical Sciences, University Walk, Bristol, BS8 1TD, UK. s.m.nicholls@bris.ac.uk
Insights
Preventing corneal endothelial rejection is vital for transplant success. This study reveals distinct immune cell infiltration patterns in corneal layers, with unique profiles on the endothelium and in the epithelial rejection line.
Area of Science:
- Ophthalmology
- Immunology
- Transplantation Biology
Background:
- Corneal transplant success hinges on preventing endothelial rejection.
- Understanding the cellular infiltrate in corneal rejection is limited.
Purpose of the Study:
- To characterize the immune cell infiltrate in different layers of rejecting rat corneal allografts.
- To compare endothelial infiltrate with stromal and epithelial infiltrates.
Main Methods:
- Rat corneal transplantation (LEW to PVG recipients).
- Monitoring clinical rejection via slit lamp.
- Flat-mount preparation of corneal layers for cellular analysis at various time points.
- Flow cytometry to identify immune cell subsets and cytokine production (TNF-alpha, IFN-gamma).
Main Results:
- Clinical rejection occurred between days 10-15, marked by epithelial and endothelial infiltration.
- Allografts showed significantly more stromal leukocyte infiltration than isografts.
- Endothelium showed no infiltration on day 10, but on day 15, macrophages, MHC class II(+), and CD8(+) cells predominated.
- T cells and NK cells were prominent in the epithelial rejection line.
- No IFN-gamma-producing cells were found on the endothelium, despite their presence in stroma and epithelium.
Conclusions:
- Corneal rejection involves distinct immune cell infiltration patterns across different tissue layers.
- The endothelium exhibits a unique, restricted immune cell profile, notably lacking IFN-gamma.
- The anterior chamber environment may modulate the anti-endothelial immune response.
Abstract:
Critical to the success of human corneal transplants is prevention of corneal endothelial rejection, yet little is known about the endothelial infiltrate. To examine the endothelium, a method for removal and processing this layer as a flat sheet was used and the infiltrate was compared with stroma and epithelium. LEW or PVG strain rat corneas were transplanted to PVG strain recipients. Clinical changes after transplantation were monitored by slit lamp and animals sacrificed at a range of time points during rejection. Clinically defined rejection, accompanied by an epithelial rejection line and endothelial cell infiltration, occurred between days 10 and 15. There was some infiltration of leukocytes in the stroma of isografts at these time points, but significantly more in allografts (p<0.003 for all subsets). There was no infiltration of isograft endothelium at any time and no infiltration of allograft endothelium on day 10. On day 15, there were similar numbers of all major subsets except B cells in the stroma, while on the endothelium macrophages, MHC class II(+) cells and CD8(+) cells predominated (p<0.001 CD4(+) vs CD8(+) cells). T cells and NK cells predominated in the epithelial rejection line. While TNF-alpha and IFN-gamma-producing cells were numerous in stroma and epithelium, no IFN-gamma-producing cells were found on endothelium. Distinct differences in infiltrative profile within layers of the cornea suggest that the mechanisms of rejection may also differ. The restricted endothelial cell profile and lack of IFN-gamma suggests that the anti-endothelial response may be modulated by the anterior chamber environment.
