篩選並分析感染 C 型肝炎病毒併發蕭格式症候群病人的類風濕性因
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The Isolation and Characterization of Rheumatoid Factors from a
Hepatitis C Virus Infected Patient with Sjö;gren’s Syndrome
中文摘要 我們先前已經從類風濕性關節炎併發 ITP 的病人中使用噬菌體展現系統篩選出 一些類風濕性因子。為了了解 IgG 的類風濕性因子在其他自體免疫疾病上所扮演 的角色，我們從 C 型肝炎病毒感染併發蕭格式症候群 Sjögren＇s syndrome (SS) 的病人上做了一個噬菌體展現抗體基因庫。蕭格式症候群的特徵是會侵害外分泌 腺的淋巴細胞導致乾眼症 (xerostomia) 和淋巴性唾腺炎 (heratoconjunctivitis sicca)。經過針對人類 IgG 分子所做的重組基因庫篩選之後，我們利用西方墨點 分析法在 14 個隨機挑選的噬菌體菌株，觀察是否有 Fab 分子 50 kd 蛋白的表現。 我們找到了其中的 13 個是含有 lambda 輕鏈基因，而找到的類風濕性因子都會對 人類 Fc 片段分子呈現特異性的結合，相對於牛血清白蛋白 (bovine serum albumin) 則不會有結合的反應。我們也使用酵素連接免疫吸附分析法 (ELISA) 去分析這 些篩選出來的類風濕性因子對於人類 Fc 片段的特異性和先前從 ITP 病人上篩選 的 GG3 和 GG48 兩個類風濕性因子有何不同。從 DNA 的序列分析上發現了這些 類風濕性因子菌株分成 3 個族群，分別呈現的代表號碼為 hcvrf1、hcvrf2 和 hcvrf11。有趣的是，我們發現 hcvrf11 的重鏈 V 基因和 hcvrf2 是相同的，而輕鏈 V 基因則是和 hcvrf1 相同。然而 hcvrf11 的類風濕性因子結合力卻不會受到這些 改變影響。綜合這些實驗結果顯示在蕭格式症候群的病人身上會產生 IgG 類風濕 性因子，並且這些類風濕性因子可能在這些自體免疫的病人病因上扮演重大的角 色。 英文摘要We have previously isolated several IgG rheumatoid factors (RFs) from both patients with rheumatoid arthritis (RA) and idiopathic thrombocytopenia purpura (ITP) using phage display system. To study IgG RFs in patients with other autoimmune disease, we have constructed phage display antibody libraries from a hepatitis C virus infected patient with Sjögren’s syndrome (SS) which is characterized by lymphocytic invasion of exocrine glands resulting in xerostomia and heratoconjunctivitis sicca. After panning against human IgG molecules, the expression of Fab fragments from 14 randomly selected phage clones was identified as a band of 50 kd in a western blotting analysis. Of which, 13 clones contain lambda light chain gene. All
albumin (BSA). ELISA data also revealed that their Fc binding activity is comparable to that of GG3 and GG48 clones previously isolated from ITP patient. Sequence determination suggested that these RFs consisted of 3 groups of clones, represented by hcvrf1, hcvrf2 and hcvrf11. Interestingly, the heavy chain V gene of hcvrf11 is identical to that of hcvrf2 and its light chain V gene is the same as that of hcvrf1. However, the RF activity of hcvrf11 is retained regardless of this promiscuity. Taken together, these results suggested that IgG RFs may be generated in patients with Sjögren’s syndrome and may play an important role in the pathogenesis of this autoimmune disease.
