| Summary: | 碩士 === 國立臺灣大學 === 微生物學研究所 === 86 === Epstein-Barr ( EB ) 病毒的感染被認為與鼻咽癌的生成有密切的關係。EB 病毒在
被其感染之細胞中進行複製時，EB 病毒特異性的DNA 聚合 DNA polymerase; DP ) 為D
NA複製時之一重要酵素。關於其是否可在鼻咽癌病人的血清中引發特異性抗體，過去的研
究中顯示，EB 病毒 DNA 聚合的活性中和抗體遍存於鼻咽癌病人血清中，並認為該抗體
有助於鼻咽癌之早期診斷及預後追蹤。為建立一個可運用於大規模檢測鼻咽癌之血清學篩
檢試劑，故本實驗擬分析重組之全長 DP ( DPf ) 與其短截蛋白 ( DP1~DP8 ) 應用於酵
素連結免疫吸附分析法 ( ELISA ) 的可行性。 為了分析鼻咽癌病人血清中抗 EB 病
毒 DP 的抗體，本實驗以 ELISA 檢測了 827 個血清 [ 包括了 316 個鼻咽癌病人 ( NPC
)， 264 個正常人 ( Community control; C.C. ) 及 247 個鼻咽部其他病變患者 ( Ho
spital control; H.C. ) 的血清 ]，結果得到檢測鼻咽癌病人的靈敏度及精確度分別為
44.6 % 與 81.04 %，且鼻咽癌病人的陽性率高於正常人與其他病人。我們也更進一步利
用不同的 DP 短截蛋白以分析 DP 引發抗體產生的主要抗原決定位，結果發現利用 ELISA
檢測時，DP1 ( a.a 1~206 ) 及 DP4 ( a.a. 600~798 ) 與鼻咽癌病人血清有較強的抗
原-抗體反應情形，若同樣也應用 DP4 的 ELISA 檢測了上述 827 個血清，得到檢測鼻咽
癌病人的靈敏度及精確度則分別為21% 與88.8 %。 為了比較 DP 的 ELISA 檢測與活
性中和試驗此二方法的相關性，我們也利用 Akata 細胞中的 EB 病毒 DNA 聚合性，
檢測了相同的鼻咽癌病人血清，結果顯示利用聚合活性中和試驗檢測出鼻咽癌病人的陽
性率為 87.9 %，並發現 ELISA 反應陽性者多半於活性中和試驗亦呈陽性，且含有較高量
的活性中和抗體。
Epstein-Barr virus ( EBV ) infection is associated with nasopharyngeal carci
noma. One critical enzyme responsible for EBV DNA replication in productively
infected cells is EBV-specified DNA polymerase ( DP ). It has been demonstrate
d high frequency and high titer of DP activity neutralizing-antibody in NPC se
ra and suggested the benefit of utilizing this antibody for early diagnosis or
prognosis of NPC. In an attempt to develop a diagnostic kit for serological s
creening NPC in a large scale, the potential of using the recombinant full-len
gth DP ( DPf ) or truncated proteins ( DP1~DP8 ) in ELISA was investigated.
To detect the presence of antibodies to the EBV DP, DPf / ELISA was carried o
ut by using 827 sera, including 316 sera from NPC patients, 264 sera from norm
al people in community as control ( C.C. ) and 247 sera from patients with oth
er nasopharyngeal diseases as hospital control ( H.C. ). The diagnosis sensiti
vity and specificity for NPC were 44.6% and 81.04%, and the
positivity rate of N
PC was relatively higher than those for C.C. and H.C.. We further used differe
nt truncated DP proteins to analyze the major antigenic epitopes of DP in deta
il. We found that DP1 ( a.a 1~206 ) and DP4 ( a.a. 600~798 ) had stronger reac
tions to NPC sera and the major epitopes of DP localized in the region of DP1
and DP4 were suspected. Therefore, we further analyzed the presence of antibod
ies to the DP4 by ELISA using the above 827 sera, and the sensitivity and spec
ificity for detecting NPC patients were 29.7% and 88.8 %. In order to correlat
e the DPf / ELISA and DP neutralization test, we also analyzed the DP activity
neutralizing-antibody in the NPC sera with the EBV DNA polymerase extracted f
rom activated Akata cells. 87.9 % of NPC patients can be detected using DP neu
tralization test and we found these two detection methods were partially corre
lated since most ELISA positive individuals were positive for DP neutralizatio
n test and contained higher levels of the neutralizing antibody.
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