家禽傳染性支氣管炎病毒的血清檢測及疫苗開發

Abstract

本研究主要分成兩部分。其一為分析評估普遍使用之商業IBV抗體酵素連結免疫吸附 (ELISA) 套組，另一則是發展具有廣效保護台灣流行之IBVs潛力之重組腺病毒疫苗。 在台灣，IBVs主要分為兩大與其他國家不一樣之型別 [台灣一型 (TW-I) 和台灣二型 (TW-II)]。試驗主要使用商用抗體偵測酵素連結免疫吸附套組的可信度 (命名為 A、B和C) 檢測田野血清並予以與血球抑制凝集實驗比較評估。結果顯示三組 ELISA 的結果僅部分符合HI試驗。在種雞與蛋雞之結果，兩則相似。然而，在肉雞方面，部份ELISA 檢測為陰性的樣本在HI試驗上則為陽性。A、B和C ELISA套組之特異性分別為0.45、0.86和0.77。相對的，敏感性則分別為0.79、0.68和0.70。因此，我們總結利用國外進口之ELISA套組可能無法有效呈現出台灣現場家禽IBV之感染或免疫情形之全面觀。 另外，以血清學鑑別方式－病毒中和試驗 (Virus neutralization assay) 探討基因型與TWI型相似之分離株3575/08。我們發現3575/08之血清型與TW-I及TW-II相近 (R值分別為 14.20 % 和 10.24 %), 且與H120亦有一定的相近 (R = 5.64 %)。由於台灣是IBV流行區且地域性限制於TW-I和TW-II型，所以本土型疫苗的研發顯得必要以有效控制IBV。因此，我們選擇使用重組腺病毒表現系統快速發展可能具有交互保護作用的3577/08 S1次單位疫苗。

This study was divided into two parts. One was investigation and evaluation of common used commercial IBV antibody ELISA kits, and the other was about development of a recombinant adenoviral vaccine that potentially induced broadly immunity protection against IBV strains endemic in Taiwan. In Taiwan, IBVs are mainly restricted to two types (TW-I and TW-II) that distinct from other countries. To evaluate the reliable of commercial ELISA kits, imported commercial test kits (namely A, B and C) were used to test field samples. The results were further compared with hemagglutination inhibition (HI) test to figure out the consistency. Results showed that the 3 commercial ELISA kits had only partial consistency with HI results. In fact, testing result of breeders and layers bore resemblance to HI, whereas there were ELISAs negatively detecting results of broilers opposed in HI. The specificities of these ELISA kits were 0.45, 0.86 and 0.77 for ELISA kit A, B and C, respectively, and their sensitivities were 0.79, 0.68 and 0.70, respectively. In conclusion, using of commercial ELISA kits may not sustainably provide us the whole view of birds infected or vaccinated status. In addition, serological identification of a new isolate 3575/08 that genetically similar to TW-I strain by virus neutralization assay found that 3575/08 was serological related to TW-I as well as TW-II (R = 14.20 % and 10.24 %, respectively), and loosely related to H120 (R = 5.64 %). Since Taiwan is an IBV endemic country with geographically restricted to TW-I and TW-II strains, it is a necessary to develop a local vaccine effectively against these IBVs. Hence, we selected recombinant adenoviral expression system for rapid development of 3575/08 S1 subunit vaccine that may not only induce great cell-mediated and humoral protective immunity, but also elicit cross protection against other IBV genotypes.