Establishment of a new EAU animal model by endotoxin injection following immunization with IRBP emulsified in complete Freund adjuvant / 中华实验眼科杂志

ABSTRACT

Background The pathogenesis and management of human autoimmunity uveoretinitis is a focus in ophthalmology.For decades,a traditional experimental autoimmunity uveoretinitis (EAU) induced by pertussis toxin (PTX) was used for the basic investigation,which was thought to have a large deviation from the natural course of human autoimmunity uveoretinitis.Objective This study was to establish a new mice model of autoimmunity uveoretinitis which mimics the human autoimmunity uveoretinitis pathogenesis and offer a basis for the investigation and treatment of uveoretinitis.Methods Twenty 6-8 weeks old specific pathogen-free female C57BL/6 (H-2b) mice were randomized into normal control group,only endotoxin (lipopolysaccharide,LPS) induced uveitis group (endotoxin induced uveitis [EIU] group),interphotoreceptor retinoid-binding protein (IRBP1-20) +complete Freund adjuvant (CFA) induced uveoretinitis group (EAU group) and IRBP+CFA+LPS induced uveoretinitis group (LPS-EAU group).The mice of the EAU were only immunized with IRBP emulsified in CFA,and LPS-EAU group firstly were immunized with IRBP emulsified in CFA and then LPS was injected in the footpad of the mice on 7 days following immunization.The ocular pathological examination,histopathological scoring,delayed-type hypersensitivity and specific lymphocyte proliferating response were evaluated and compared with the EIU models,traditional EAU models without PTX and LPS-EAU models.The use and care of experimental animals complied with Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results No inflammatory response was found in the iris,cilliary body and retina of mice in the normal control group.However,mild blood vessels dilation and fibrin exudation were seen in the iris and cilliary body of mice in the EIU group.In the EAU group,mild vasculitis and swelling of nerve fiber layer were exhibited in the retinas; while in the LPS-EAU group,severe disorder of retinal structure,infiltration of inflammatory cells and damage of photoreceptor were found under the optical microscope.The pathological score was 0 in the models of the normal control group and EIU group,0.5 score in the EAU group and 3.0 scores in the LPS-EAU group,with a significant difference in the pathological scores between the EAU group and the LPS-EAU group (U=16.246,P =0.001).The earthickness of the mice was (35.60±0.55) μm in the LPS-EAU group,and this value was significantly higher than (12.60±0.55) μm of the EIU group (q =23.003,P＜0.01),but closed to (34.80±0.84) μm of the EAU group (t =0.820,P＞0.05).The obvious cloning were seen and theradiation count per minute was (8 540.00 ±54.77)/min in the model mice of the LPS-EAU group,and that in the EAU group was (8 484.00±47.75)/min,without significant difference between them (q =56.634,P =0.069).Compared with the β particle number (2 050.00±50.00)/min in the EIU group,that of the LPS-EAU group was significantly elevated (q =195.683,P =0.000).Conclusions LPS injection can induce EAU in mice,and this model can better imitate the pathogenesis of human autoimmunity uveoretinitis.