Identification of Hnrph3 as an autoantigen for acute anterior uveitis.

Acute anterior uveitis (AAU) is the most common form of autoimmune uveitis in the eye with few known autoantigens. Identification of autoantigens will improve our understanding of the molecular mechanisms and capability for disease diagnosis. Phage display is a powerful technology for autoantigen identification. However, because of uncontrollable reading frames, phage display with conventional cDNA libraries identifies high percentage of non-open reading frames (non-ORFs) with minimal implications for autoantigen identification. We recently developed ORF phage display technology with minimal reading frame problem. Herein we used ORF phage display to identify 18 patient-specific clones, including 16 ORFs encoding endogenous proteins as candidate autoantigens for AAU. One of the identified antigens was heterogeneous nuclear ribonucleoprotein H3 (Hnrph3) that was further characterized for AAU relevance and independently verified by Western blot. These results demonstrate that ORF phage display is a valuable approach for identification of unknown autoantigens.