Keratin 8 is a novel autoantigen of rheumatoid arthritis.
OBJECTIVE
This research aims to verify Keratin 8 (K8) as a specific autoantigen in rheumatoid arthritis (RA).


METHODS
First, total RNA was extracted from HaCaT cell to obtain cDNA by inverse transcription. Then, PCR was performed to amplify corresponding gene by K8 primers. Next, cloning, expression, and purification technology were used to obtain the recombinant human K8 (rhK8). At last, the purified rhK8, after identified by mass spectrometer, was used to perform further disease-related Western blotting and ELISA test with real clinical samples.


RESULTS
Purified rhK8 was successfully obtained and then Western blotting confirmed antigenicity of K8 in rheumatoid arthritis. The reactivity of serum IgG against rhK8 was further detected in 34 of 50 RA patients (68%). The reactivity of RA serum IgG antibodies against K8 was significantly higher than healthy controls and systemic lupus erythematosus (SLE) patients.


CONCLUSIONS
This research confirmed Keratin 8 as a novel autoantigen of RA.
112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Xiaoxu
X
Wang
112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Peng
P
Chen
112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Jiawen
J
Cui
112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Chunhe
C
Yang
112 Lab, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, China. Electronic address: hwdu93@126.com.
Hongwu
H
Du
D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000235:genetics / Q000276:immunology*; D015153:Blotting, Western; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000235:genetics; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D053533:Keratin-8 / Q000235:genetics / Q000276:immunology*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D055815:Young Adult
D001323:Autoantibodies; D001324:Autoantigens; D000939:Epitopes; D007074:Immunoglobulin G; C426203:KRT8 protein, human; D053533:Keratin-8; D011994:Recombinant Proteins
Autoantigen; Keratin 8; Rheumatoid arthritis