活體外第二型豬的環狀病毒和豬瘟疫苗毒對單核球來源樹突細胞的影響

Abstract

兔化豬瘟疫苗(Lapinized Philippines Coronel, LPC)為豬瘟病毒(Classical Swine Fever Virus, CSFV)的減毒株，目前已有研究指出第二型豬環狀病毒 (Porcine Circovirus type 2, PCV2)的感染會減少LPC疫苗的保護效力，為了探討PCV2影響LPC疫苗的可能機制，本研究使用單核球來源之樹突細胞(Monocyte-derived dendritic cells, MoDCs)進行活體外的相關分析，以探討PCV2和豬瘟疫苗毒株(LPC Virus, LPCV)之間的交互作用。結果顯示，當PCV2和LPCV共同感染時，在早期可檢測到IL-1、IL-6、IL-8、IL-10、IFN-α和TNF-α有較高的mRNA表現量，在蛋白質層次也檢測到IL-8、IL-12p40和INF-γ有較高的表現量，另外也發現PCV2的感染會使MoDCs的存活率減低，凋亡率和壞死率升高。從本研究的實驗結果推論PCV2所誘導的免疫反應，特別是高表現的量的INF-γ以及誘導MoDCs的凋亡或許可以解釋PCV2影響LPC疫苗效價的部分原因。

The Lapinized Philippines Coronel (LPC) vaccine, an attenuated strain of classical swine fever virus (CSFV), it has been noted that porcine circovirus type 2 (PCV2) infection adversely affects the protective efficacy of LPC vaccine. In order to investigate the possible mechanisms of the PCV2-derived interference, an in vitro model was established to study the interaction of LPC virus (LPCV) and PCV2 in Monocyte-derived dendritic cells (MoDCs). The results showed that IL-1, IL-6, IL-8, IL-10, IFN-α and TNF-α mRNA expression can be detected in early stage of PCV2 and LPCV co-infection in MoDCs. In addition, higher protein level of IL-8, IL-12p40 and INF-γ was also compatible present. Finally, apoptosis and low surviral rate can be induced by PCV2 and PCV2/LPCV in the late stage culture of MoDCs. The results of the present study may partially explain how PCV2 infection interferes with the efficacy of LPC vaccine.