Abstract
Abstract: :
Purpose: Experimental coronavirus retinopathy is an animal model of a progressive retinal degenerative disease that is triggered by a virus. The disease is characterized by the presence of anti–retinal/anti–RPE autoantibodies in genetically susceptible mice (BALB/c). This study proposes to identify retinal autoantigens in mice susceptible to the retinal degenerative disease. Methods: BALB/c mice were intravitreally infected with mouse hepatitis virus, strain JHM (MHV JHM). Twenty days after infection, sera from MHV–infected mice were collected and evaluated for the presence of anti–retinal/anti–RPE antibodies by immunohistochemistry on rat ocular tissue. Positive samples were pooled and examined by Western blot analyses on rat, mouse and bovine retina and RPE preparations to determine the number and sizes of possible antigen(s). A rat retina cDNA expression library was screened with the sera. Reactive phage clones were purified and the insert cDNA sequenced. The sequence obtained was compared to sequences in GenBank to determine the identity of the protein(s). Results: Sera from virus infected mice tested by immunohistochemistry revealed reactivity to RPE, ganglion cells and other areas of the neuroretina. Western blot analyses of rat RPE proteins with sera from MHV–infected mice showed reactivity to three protein species, 21 kDa, 26 kDA and 80 kDa proteins. Western blot analyses of bovine RPE proteins with sera from MHV–infected mice showed reactivity to two protein species, 65 kDa and >188 kDa. Western blot analyses of mouse and bovine retina proteins with sera from MHV–infected mice showed reactivity to proteins between 33–40 kDa and >188 kDa. Using sera from MHV–infected BALB/c mice, a rat retina cDNA expression library was screened and a positive clone was identified. The clone is a protein serine/threonine kinase. Conclusions: These studies identify the presence of multiple retinal and RPE autoantigens in ECOR. One of these proteins was identified as a serine/threonine kinase. Studies are now underway to determine the role of these autoantigens in ECOR and other retinal degenerative disorders.
Keywords: retinal degenerations: cell biology • autoimmune disease • retinitis