Equine recurrent uveitis–a spontaneous horse model of uveitis.

This research study focuses on equine recurrent uveitis (ERU), a common autoimmune disease in horses, to find insights into its human counterpart. The researchers have identified new autoantigens by comparing the protein patterns in the retinas of healthy horses and those with ERU.

Understanding Equine recurrent uveitis (ERU)

• ERU is an autoimmune disease happening commonly in horses, with a prevalence of 10%. An autoimmune disease is a condition where the body’s immune system mistakenly attacks its own healthy cells.
• This disease is repeatedly inflaming the uvea, the middle layer of the eye, affecting the horse’s vision, and potentially can lead to blindness if untreated.
• ERU can serve as an effective model for studying human autoimmune uveitis due to its spontaneous occurrence and similarity to the human condition.

Identification and Analysis of Autoantigens

• In this study, the researchers analysed the autoantibody-binding pattern of horses affected by ERU in comparison to that of the healthily retinal proteome. In other words, they identified the protein molecules which the malfunctioning immune system of horses produces to attack its own body cells.
• The researchers successfully identified novel autoantigens, such as malate dehydrogenase, recoverin, and CRALBP (Cellular Retinaldehyde-binding Protein). These are proteins that stimulate the immune system to produce antibodies, leading to an autoimmune response.
• Especially, the CRALBP protein seems to be a significant antigen also for human autoimmune uveitis, implicating that the study’s finding might contribute to developing treatments for the human disease.

Analysis of Differentially Regulated Proteins

• The study includes proteomic screening, a method used to detect and measure the levels of different proteins, of vitreous and retinal samples from ERU affected cases compared to healthy controls.
• This comparative analysis has led to the identification of a set of differentially regulated proteins essential to the immune system and the maintenance of the blood-retinal barrier, a part of the eye’s defense system that regulates the movement of ions, molecules, and cells between the bloodstream and the eye.
• Knowing the proteins’ role in ERU could provide a biochemical insight, helping to design future therapeutic interventions.