Exploring the biological significance of EBNA1 variants and anti-EBNA1 antibodies in dogs.

• Main Authors: Chieh-Wen Huan, 黃玠文
• Other Authors: 邱繡河
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/46088648860234793209

碩士 === 國立中興大學 === 微生物暨公共衛生學研究所 === 104 === Epstein-Barr virus (EBV) is a gammaherpesvirus that causes widespread infection in the human population. It is associated with multiple human malignancies, such as nasopharyngeal carcinoma (NPC) and Burkitt’s lymphoma (BL). In addition, EBV is also correlated with the development of autoimmune diseases, in particular, systemic lupus erythematosus (SLE). EBV-encoded nuclear antigen 1 (EBNA1) is persistently expressed during EBV latent infection. Several studies have shown that antibodies against EBNA1 cross-react with the SLE-related autoantigen, Smith antigen (Sm) and Sjögren’s syndrome type A antigen (SSA). Previous studies by us and others have shown that EBV or EBV-like virus particles were detected in canine samples. Moreover, the anti-EBV antibodies were also detected in canine sera. Those results indicated that EBV or an EBV-like virus might be present in dogs. The purposes of this study are to investigate whether EBNA1 DNA sequence or EBNA1 variants could be present in dogs and to explore any potential linkage between anti-EBNA1 and SLE-related autoantibodies in dogs. By performing nested polymerase chain reaction (nested-PCR), we examined EBNA1 DNA sequence in canine peripheral blood mononuclear cells (PBMC), and identified two EBNA1 subtypes, prototype-alanine and prototype-threonine, from 15 dogs. On the other hand, we collected 88 sera from dogs with suspected autoimmune disorder and determined the presence of antinuclear antibodies (ANA) by indirect immunofluorescent assay (IFA). Furthermore, we expressed recombinant Sm (rSm), EBNA1 N-terminal (rEBNA1-N) and C-terminal (rEBNA1-C) proteins and detected anti-Sm and anti-EBNA1 antibodies in canine sera by Western blot analysis. Percentages of anti-rEBNA1-C antibody were higher in dog sera that were positive versus (vs.) those negative for ANA (36.6% vs. 8.5%) and anti-Sm (84.2% vs. 15.8%) antibodies. Our results indicate that the presence of anti-EBNA1-C antibody in dogs correlates with positive ANA (P < 0.01) and positive anti-Sm (P < 0.01), which are listed as a prerequisite and a marker autoantibody for SLE, respectively.