Murine Corneal Transplantation: A Model to Study the Most Common Form of Solid Organ Transplantation

Summary

Mice have been used as a model for studying many forms of transplantation, including corneal transplantation. We describe in this report a murine model for both acute and late-term corneal transplantation.

Abstract

Corneal transplantation is the most common form of organ transplantation in the United States with between 45,000 and 55,000 procedures performed each year. While several animal models exist for this procedure and mice are the species that is most commonly used. The reasons for using mice are the relative cost of using this species, the existence of many genetically defined strains that allow for the study of immune responses, and the existence of an extensive array of reagents that can be used to further define responses in this species. This model has been used to define factors in the cornea that are responsible for the relative immune privilege status of this tissue that enables corneal allografts to survive acute rejection in the absence of immunosuppressive therapy. It has also been used to define those factors that are most important in rejection of such allografts. Consequently, much of what we know concerning mechanisms of both corneal allograft acceptance and rejection are due to studies using a murine model of corneal transplantation. In addition to describing a model for acute corneal allograft rejection, we also present for the first time a model of late-term corneal allograft rejection.

Introduction

Corneal transplantation is one of the most successful and common types of transplantation performed in humans. The reasons why this surgery is performed are a result of injury, infectious disease¹, or other forms of non-infectious corneal disease². Figures from the Eye Bank Association of America indicate that over 46,000 were performed in 2011 (see web site at: restoresight.org/eye_banks/eye_banks.html). An indication of its success is that one year failure rates for allogeneic corneal grafts range from 10 to 15% and at 5 years the success is in excess of 70%^3-8. As many studies have shown, the success of corneal allografts is directl....

Protocol

NOTE: All animals used in this procedure are treated in accordance with the Association for Research in Vision and Ophthalmology statement for the Use of Animals in Ophthalmic and Vision Research as well as the guidelines set down by the animal oversight committee at Saint Louis University.
NOTE: All surgical instruments and solutions are sterilized prior to surgery to limit microbial infection of the eye. It should be noted that while the animals do experience some pain from this procedure, we do not employ analgesics.  The reason for this is because all analgesics are anti-inflammatory and since corneal transplantation responses involve inflammation,....

Results

The murine model of corneal transplantation has been used for over 20 years to successfully characterize mechanisms of both corneal allograft rejection^19-23 and corneal allograft acceptance^{13,15,16,18, 24-27}. This model was used to establish the importance of FasL expression in corneal allograft acceptance, in that animals that lack FasL were not able to accept corneal allografts¹⁵. It has also been used to demonstrate that vascular endothelial growth factor receptor.......

Discussion

The murine model of corneal transplantation described here enables the investigator to study human corneal allograft rejection in a model that is predictive of what factors are best associated with both rejection^{15,17,18,20, 26-30} and acceptance^21-25 of corneal allografts. Unlike human corneal transplantation, in which patients are given either topical or systemic steroid treatment to either treat or prevent rejection³¹, this model is typically used to determine those factors that are rel.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Zeiss Surgical Microscope	Zeiss	Rebuilt
1 ml Syringe	BD	305122
3 ml Syringe	BD	309657
10 ml Syringe	BD	309602
Vannus Scissors	Stortz	E-3387
11-0 Sutures	Alcon	717939M
Trephine 2.0 mm	Katena	K 2-7520
Trephine 1.5 mm	Katena	K 2-7510
Tricaine Hydrochloride 0.5%	Alcon	NDC 0065-0741-12
Healon	Abbott	Healon OVD
Forceps	FST	11251-20
7-0 Sutures	Alcon	8065
2.5% Phenylephrine HCl	Alcon	NDC 61314-342-02
1% Tropicamide	Bausch & Lomb	NDC-24208-585-59
Hamilton Syringe	Hamilton	7654-01
33 gauge needle	Hamilton	90033
Cell Strainer (100 μm nylon)	BD Falcon	352360
Hemocytometer	Cardinal Health	B3175
Trypan Blue	Sigma	T8154