摘要
Background Severe acute respiratory syndrome （SARS） is a disease with a mortality of 9.56%. Although SARS is etiologically linked to a new coronavirus （SARS-CoV） and functional cell receptor has been identified, the pathogenesis of the virus infection is largely unclear. Methods The clinical specimens were processed and analyzed using an indirect enzyme-linked immunosorbent assay （ELISA） in-house. Further investigations of target antigen included reviews of phage display technique, rapid amplification of cDNA ends （RACE） technique, protein expression and purification, Western blotting validation, serological and immunohistochemical staining in postmortem tissue. Results A type of medium or low titer anti-lung tissue antibodies were found in the sera of SARS patients at the early stage of the disease. Human long interspersed nuclear element 1 （LINE1） gene endonuclease （EN） domain protein was one of the target autoantigens and it was aberrantly expressed in the lung tissue of SARS patients. Anti-EN antibody was positive in the sera of 40.9% of SARS patients. Conclusions Human LINE1 endonuclease domain was identified as a putative target of SARS-associated autoantibodies, which were oresented in the serum of SARS oatients and may be involved in the pathogenesis of SARS.
Background Severe acute respiratory syndrome （SARS） is a disease with a mortality of 9.56%. Although SARS is etiologically linked to a new coronavirus （SARS-CoV） and functional cell receptor has been identified, the pathogenesis of the virus infection is largely unclear. Methods The clinical specimens were processed and analyzed using an indirect enzyme-linked immunosorbent assay （ELISA） in-house. Further investigations of target antigen included reviews of phage display technique, rapid amplification of cDNA ends （RACE） technique, protein expression and purification, Western blotting validation, serological and immunohistochemical staining in postmortem tissue. Results A type of medium or low titer anti-lung tissue antibodies were found in the sera of SARS patients at the early stage of the disease. Human long interspersed nuclear element 1 （LINE1） gene endonuclease （EN） domain protein was one of the target autoantigens and it was aberrantly expressed in the lung tissue of SARS patients. Anti-EN antibody was positive in the sera of 40.9% of SARS patients. Conclusions Human LINE1 endonuclease domain was identified as a putative target of SARS-associated autoantibodies, which were oresented in the serum of SARS oatients and may be involved in the pathogenesis of SARS.
基金
This study was supported by grants from the National Natural Science Foundation of China （No. 30340010） and the Natural Science Foundation of Beijing （No. 7034050）.
