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Updated: May 18, 2026
Murine Corneal Transplantation: A Model to Study the Most Common Form of Solid Organ Transplantation
Published on: November 17, 2014
Gamma-irradiation reduces the allogenicity of donor corneas
William Stevenson1, Sheng-Fu Cheng, Parisa Emami-Naeini
1Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA.
Purpose:
To evaluate the utility and allogenicity of gamma-irradiated corneal allografts.
Methods:
Corneal buttons were harvested from C57BL/6 mice and decellularized with gamma irradiation. Cell viability was assessed using TUNEL and viability/cytotoxicity assays. Orthotopic penetrating keratoplasty was performed using irradiated or nonirradiated (freshly excised) C57BL/6 donor grafts and BALB/c or C57BL/6 recipients. Graft opacity was assessed over an 8-week period and graft survival was evaluated using Kaplan-Meier survival curves. Mixed-lymphocyte reactions and delayed-type hypersensitivity assays were performed to evaluate T-cell alloreactivity. Real-time PCR was used to investigate the corneal expression of potentially pathogenic T-helper 1, 2, and 17 cell-associated cytokines.
Results:
Corneal cells were devitalized by gamma irradiation as evidenced by widespread cellular apoptosis and plasma membrane disruption. Nonirradiated allograft and isograft rates of survival were superior to irradiated allograft and isograft rates of survival (P < 0.001). Mixed lymphocyte reactions demonstrated that T-cells from irradiated allograft recipients did not exhibit a secondary alloimmune response (P < 0.001). Delayed-type hypersensitivity assays demonstrated that irradiated allografts did not elicit an alloreactive delayed-type hypersensitivity response in graft recipients (P ≤ 0.01). The corneal expression of T-helper 1, 2, and 17 cell-associated cytokines was significantly lower in failed irradiated allografts than rejected nonirradiated allografts (P ≤ 0.001).
Conclusions:
Gamma-irradiated corneas failed to remain optically clear following murine penetrating keratoplasty; however, gamma irradiation reduced the allogenicity of these corneas, potentially supporting their use in procedures such as anterior lamellar keratoplasty or keratoprosthesis implantation.
Insights
Gamma irradiation of corneal allografts reduced immune rejection but impaired graft clarity in mice. This suggests potential use in specific surgeries like keratoprosthesis implantation.
Area of Science:
- Ophthalmology
- Immunology
- Biomaterials Science
Background:
- Corneal transplantation is limited by immune rejection.
- Gamma irradiation is explored as a method to reduce graft immunogenicity.
Purpose of the Study:
- To assess the impact of gamma irradiation on corneal allograft utility and allogenicity in a murine model.
- To evaluate the optical clarity and immune response to irradiated corneal grafts.
Main Methods:
- Corneal buttons from C57BL/6 mice were gamma-irradiated.
- Orthotopic penetrating keratoplasty was performed using irradiated or non-irradiated grafts in BALB/c or C57BL/6 recipients.
- Graft survival, opacity, T-cell alloreactivity (mixed-lymphocyte reactions, delayed-type hypersensitivity), and cytokine expression were analyzed.
Main Results:
- Gamma irradiation devitalized corneal cells, leading to widespread apoptosis.
- Irradiated corneal allografts showed significantly lower survival rates and impaired optical clarity compared to non-irradiated grafts.
- Irradiated allografts demonstrated reduced T-cell alloreactivity and lower expression of pro-inflammatory cytokines.
Conclusions:
- While gamma irradiation decreases corneal allogenicity, it compromises graft optical clarity in penetrating keratoplasty.
- Irradiated corneas may be suitable for specific applications like anterior lamellar keratoplasty or keratoprosthesis implantation where optical clarity is less critical.
- Further research is needed to optimize irradiation protocols for improved graft survival and function.
