Identification of hnRNP C1/C2 as an Autoantigen in Patients with Behcet's Disease.

BACKGROUND: Ribonucleoproteins particles that form the spliceosomes are among the most frequently targeted molecules of the autoimmune response. In the last few years, autoantibodies against all A/B hnRNP proteins have been found in the sera of patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD), and serve as diagnostic markers for several rheumatic diseases. However, the functional role of hnRNP C1/C2 in autoimmune diseases is still not clearly understood.

OBJECTIVE: To identify hnRNP C1/C2 as an autoantigen in patients with Behcet's Disease (BD).

METHODS: First, HaCaT and EA.hy926 cells were cultured and RNA was extracted. Second, amplification of the corresponding gene by RT-PCR, cloning, and purification techniques was applied to acquire the recombinant protein hnRNP C1/C2. Third, the target protein band was excised from gel electrophoresis, digested with trypsin, and analyzed by (MALDI-TOF/). Finally, Western blotting and ELISA were performed to verify the immunoreactivity of BD serum with recombinant hnRNPC1/C2.

RESULTS: Results demonstrated that the reactivity of BD serum against recombinant hnRNP C1/C2 protein was significantly higher as compared to healthy control (P<0.001).

CONCLUSION: hnRNP C1/C2 can be considered as a self antigen which might be involved in BD pathology in Hans Chinese population.