| Summary: | 碩士 === 國立中興大學 === 獸醫微生物學研究所 === 92 === Human and canine SLE share similar diagnostic criteria, varying only in few specific autoantibodies in the immunological disorder. Among these autoantibodies, anti-heterogeneous nuclear ribonucleoprotein G (hnRNP G) antibody that has been listed as one important immunological marker for canine SLE remains unexplored in human SLE. In this study, a recombinant protein encompassing the major immunodominant region of the hnRNP G was served as an detecting antigen and the presence of anti-hnRNP G antibody in human SLE was investigated by Western blot analysis. Of 40 serum samples from SLE patients, 12 (number 14, 24, 25, 28, 29, 30, 31, 33, 35, 36, 38, 39) possessed autoantibody to the recombinant hnRNP G protein, but not to the fusion protein translated from the expression vector. Using nuclear antigen for Western blot analysis, we confirmed that these 12 serum samples recognized hnRNP G (43 kDa) from HeLa cells. Furthermore, we extracted nuclear antigen from HeLa cell to carry on a competition reaction. After incubating patients’ sera with increased amounts of HeLa nuclear antigen, we observed reduced signals of antibody that specifically recognized hnRNP G recombinant protein. These results indicate that anti-hnRNP G autoantibody does exist in
SLE patients.
SLE is a disease involving multiple factors. In addition to genetic factor, infectious factor may have a role during its pathogenesis. Recent studies suggest a correlation between Epstein-Barr virus (EBV) infection and the development of human SLE. Because canine SLE is extremely similar to human SLE, it is imperative to investigate whether EBV or other gamma herpesvirus may exist in dogs. In this study, antibodies recognizing EBV antigens were identified in sera of one SLE dog (E58), one ANA positive dog (A195) and one healthy dog (A187) by employing Western blot analysis. Antibodies of the SLE dog specifically recognized four EBV recombinant proteins, including EBV DNA polymerase (EDP), DNA binding protein (DBP), thymidine kinase (TK) and EBV nuclear antigen-1 (EBNA-1). We performed polymerase chain reaction (PCR) to detect EBV-related sequences in leukocytes DNA of 7 dogs (32h, 33h, 34h, 63h, E58, A187, A195). The results showed that, within the 241 bp amplified region, 3 dogs (32h , 33h, A187) had identical DNA sequence with BamHI W fragment of EBV. In addition, an 289 bp DNA sequence amplified from 1 dog (A187) was identical with EDP gene region of EBV. On the other hand, an 264 bp DNA sequence homologous with
EBNA-1 gene region of EBV was detected in 3 dogs (32h, 33h, 34h).
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