[Cloning and prokaryotic expression of recombinant Jo-1 antigen and identification of its antigen specificity].
OBJECTIVE
To obtain highly purified Jo-1 autoantigens.


METHODS
The full length of DNA sequence coding for Jo-1 (histidyl-tRNA synthetase) was obtained from human placenta by RT-PCR and then it was inserted into pTYB11 or pMAL-c to construct the expression vectors pTYB11-Jo-1 and pMAL-c-Jo-1. The recombinant plasmids were transformed into ER2566 and BL21 of E.coli, respectively.


RESULTS
The fusion Jo-1 antigens were expressed, Western blot analysis demonstrated they responded specifically to anti-Jo-1 antibody from the patients with autoimmune disease polymyositis and dermatomyositis, but did not respond to normal sera and 188 sera containing anti-RNP, Sm, Ro/La or RNP/Ro antibodies from rheumatosis patients.


CONCLUSIONS
The expressed protein of pMAL-c-Jo-1 is soluble, which accounts for more then 50% of total proteins of cells and can be purified by affinity chromatography. The purified proteins can be used as reagents for determining the anti Jo-1 antibody in the serum of patients.
Zhao
Xiao-Yu
XY
College of Life Science, Hebei University, Reseach Center for Bioengineering Technology of Hebei Province, Baoding 071002, China.
Bi
Zhi-Li
ZL
Wu
Yi-Hong
YH
Xin
Hai-Tao
HT
D000937:Antigen-Antibody Reactions / Q000276:immunology*; D003882:Dermatomyositis / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005822:Genetic Vectors; D006643:Histidine-tRNA Ligase / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D006801:Humans; D010920:Placenta / Q000378:metabolism; D017285:Polymyositis / Q000276:immunology; D011247:Pregnancy; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D011994:Recombinant Proteins; D006643:Histidine-tRNA Ligase