Expression of lupus-associated autoantigens and detection of antiphospholipid antibodies in dogs

• Main Authors: Yu-Jean Chen, 陳榆蓁
• Other Authors: 邱繡河
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/34304426797006873594

碩士 === 國立中興大學 === 獸醫微生物學研究所 === 92 === Abstract The goals of this study are to express the systemic lupus erythematosus (SLE) associated autoantigens Sm, SSA, and SSB, and to detect antiphospholipid antibodies (aPL) in SLE dogs. Autoantibodies to Sm, SSA, and SSB are often found in SLE or other autoimmune diseases. These antibodies are therefore served as markers for the autoimmune diseases. In this study, we cloned cDNAs of human Sm, SSA, and SSB from HEp-2 cells. Prokaryotic expression plasmids, designated as pEThuSm, pEThuSSA and pEThuSSB, were introduced respectively into Escherichia coli to express recombinant protein of Sm, SSA, and SSB. Results from Western blot analysis showed that bacteria carrying pEThuSm and pEThuSSA produced recombinant fusion proteins with the expected molecular weights of Sm (43 kDa) and SSA (70 kDa). In addition, recombinant Sm and SSA proteins were recognized specifically by their respective reference sera, and not by negative control sera. Both reagents may be employed to assist in the immunological diagnosis of SLE and other autoimmune diseases. On the other hand, as an important marker for human SLE and other autoimmune diseases, aPL is correlated to clinical symptoms including thrombocytopenia, thrombosis, hemolytic anemia and fetal loss. These symptoms are common in canine SLE. Nonetheless, aPL has not been reported in dogs yet. To investigate whether SLE dogs possess aPL, we collected serum samples from 8 SLE dogs, including 4 SLE dogs manifesting with thrombocytopenia, and from 38 healthy dogs. Enzyme-linked immunosorbent assay (ELISA) was carried out to detect aPL in dog sera. Positive threshold for aPL was set as the mean OD reading of the healthy control group plus 2 time of its standard diviation (+ 2 SD). Among 8 SLE dogs, 5 were diagnosed as aPL positive and 3 were negative. Serum aPL levels among SLE dogs with thrombocytopenia were significantly higher than that among the control group (p < 0.01). Our findings indicated that aPL did exist in SLE dogs having thrombocytopenia. Therefore, it is imperative in the future to further investigate whether to include aPL as one immunological marker for canine SLE diagnosis.