Deoxyribonuclease inhibitory antibodies in systemic lupus erythematosus

• Main Authors: Hung-Chuan, Chang, 常宏傳
• Other Authors: 葉才明
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/75304687699058398315

碩士 === 國立成功大學 === 微生物暨免疫學研究所 === 86 === 英文摘要 Systemic lupus erythematosus (SLE) is a prototypic systemic autoimmune disease characterized by the production of autoantibodies against nuclear components . Dexoxyribonuclease I (DNase I), an endonuclease capable of hydrolyzing of DNA, is normally present in human serum and urine. In our study, antibodies binding to bovine DNase I were investigated by ELISA in SLE patients and anti-nuclear antibody (ANA) negative normal sera. About 62.4% of SLE patients (63/101) were positive for anti-DNase antibodies while only 8% of normal controls (8/98) were positive. A positive correlation was found between the concentrations of anti-DNase and anti-DNA antibodies in SLE patients. Affinity-purified anti-DNase IgG from pooled SLE patients serum and BALB/c mice immunized with bovine DNase bound to DNase as well as DNA coated ELISA plates. A synthetic peptide which cross-response to the catalytic site of DNase was able to completely inhibit anti-DNase IgG bound to DNase but not DNA coated plate. Indirect immunofluorescence of anti-DNase IgG displayed speckled and nucleolar patterns of Hep-2 cells but no reaction to the kinetoplast DNA in Crithidia luciliae. In addition to bovine DNase, anti-DNase IgG also bound to DNase in streptococcal supernatants and human urine and inhibited their enzymatic activities . It was also noticed that BALB/c and NZB/NZW mice immunized with bovine DNase I produced more anti-DNase and anti-DNA antibodies than na鴳e mice. Besides, immunized BALB/c mice showed fibroblast cells in renal tubule walls under histological examination showed.Based on the data above, we conclude that it is possible that the inhibition of DNase I activity by the anti-DNase antibodies may cause a defect in DNA degradation and stimulate or enhance anti-DNA antibodies production.