為了瞭解JC 病毒抗原與抗體之間的關係。以便提供臨床檢測JC 病毒之訊息，我們利用血球凝集抑制反應及immunoblot 的方法進行分析。結果發現人體抗JC 病毒的抗血清只能與native的JC 病毒顆粒反應因而在血球凝
集抑制及dot bolt呈陽性反應。但無法與denatured JC 病毒VP1反應，所以 Western blot 呈陰性反應。藉由以上的訊息我們利用血球凝集抑制反應進行偵測健康人( 221人 )，孕婦( 100人 )，自體免疫疾病病人( 81人)的血清。以前的研究顯示這三個族群的尿液排放JC 病毒率各為13.3％，26.0％及37.5％。在我們的偵測結果發現這三個族群皆有約76％為JC病毒抗體陽性反應。另外我們也偵測713名兒童血清，0-11歲，結果發現年齡越高者JC 病毒抗體陽性率愈高。但總平均值為46.5％，遠低於成人的76％。此結果意味著JC 病毒感染起自兒童時期。為了更進一步探討病毒顆粒表面抗原決定部位，我們將JC 病毒主要殼體蛋白 VP1片段分別於E.coli 表達並純化以進行免疫反應，結果發現BC loop（ 氨基酸57-90）為主要參與抗體反應的區域。此外，為了瞭解與JC 病毒結合的紅血球表面分子，我們將紅血球以neuraminidase 處理後發現紅血球無法與JC病毒結合而失去血球凝集反應。相反地，當以neuraminidase 處理的紅血球插入含有 sialic acid 的ganglioside 後，該紅血球又能與JC 病毒結
合而產生血球凝集反應 。此結果證實紅血球表面 的 sialic acid為直接參與和JC 病毒結合之分子。然而一些JC 病毒的permissive cells ，如人類腦細胞及腎臟細胞的接受體( receptor )是否也含有sialic acid分子須更進一步探討。
order to understand the antigenecity of human JC virus,hemagglutination inhibition ( HAI ) and immunoblot were
performed. The results showed that human anti-JCV serum could only react with native JCV capsid rather than denatured VP1 protein as demonstrated by HAI, dot blot and Western blot.Based on the results mentioned above, HAI was employed to screen human sera collected from 221 healthy individuals 100 pregnant women and 81 autoimmune disease patients. These three group were previously demonstrated to shed JCV in the urine sample at 13.3%, 26% and 37.5% respectively. The HAI results showed that about 76% of the examined serum sample from these group were JCV
positive. In addition, 713 children sera were also examined by HAI . It is found that the positive rate was increased with age.
It may indicate that JCV infection occurs during childhood.To!
investigate antigenic epitope of JCV, the fragments of the major capsid protein VP1 were expressed in E.coli and purified for immunological examination. The results showed that BC loop, amino acid 36 to 90, was involved in immunoreactivity.
Furthermore, the interacting molecular on red blood cell ( RBC )to JCV was also investigated RBC treated with neuraminidase were not able to interact with JCV and abolished hemagglutination activity. When ganglioside was added to the neuraminidase treated RBC, the hemagglutination activity was restored. These results indicates that sialic acid on RBC may involved in the interaction between RBC and JCV.
