錦鯉疱疹病毒在錦鯉吞噬細胞中複製之可能性之探討

Abstract

錦鯉疱疹病毒koi herpesvirus (KHV)，為鯉魚疱疹病毒第三型 (Cyprinid herpes virus-3，CyHV-3) 對錦鯉及鯉魚造成嚴重的感染。KHV是在1998年由Hedrick等從以色列及美國的發病鯉魚與錦鯉分離出來。以後各國陸續有疫情的爆發，2002涂等證實台灣有KHV的發生。 本實驗室以原位雜交 (in situ hybridization) 方法定位病毒的胸腺嘧啶激酶 (thymidine kinase) 基因核酸發現發病魚組織中的病毒核酸訊號不強，但多數訊號是存在吞噬細胞中。故本研究的目的是要了解KHV會在錦鯉的吞噬細胞中複製或只是被錦鯉的吞噬細胞所吞噬後，而被機械性的攜帶或被殺死分解掉。所以本實驗分別自帶病毒錦鯉魚和健康錦鯉魚分離出吞噬細胞，攻毒KHV後在23 ℃恆溫下培養，再利用real time PCR來偵測吞噬細胞內病毒量是否增加。結果顯示，KHV的DNA在帶源魚及健康魚體外攻毒KHV的吞噬細胞中確實有增加，故可知KHV可在吞噬細胞中增殖。

Koi herpes virus (KHV), also called Cyprinid herpes virus-3 (CyHV-3), can cause serious disease in koi (Cyprinus carpio koi) and common carp (Cyprinus carpio carpio). It was confirmed for the first time in the carps in Israel and the United States during the outbreak in 1998. The disease has soon spread all over the world, including Taiwan in 2002. Our previous data showed KHV DNA located by thymidine kinase gene were observed in macrophages of diseased koi using in situ hybridization morphologically. The aim of this study is to verify whether the KHV detected in macrophage is able to replicate or just carried mechanically within macrophage. Phagocytes isolated from KHV infected koi and KHV had been inoculated to phagocytes which were isolated from normal koi were cultured in 23 ℃. Then the KHV copy numbers in the phagocytes were quantified periodically by real time PCR. Since KHV genome copies of tested phagocytes was increased, it indicates that KHV propagated in phagocytes.