龐飛2006-07-262018-07-092006-07-262018-07-092005http://ntur.lib.ntu.edu.tw//handle/246246/28736離乳豬多系統消耗性症候群 (Postweaning multisystemic wasting syndrome, PMWS) 是由第二型豬環狀病毒(Porcine circovirus type 2, PCV2)引起，由於PCV2 患豬 常伴有繼發性病原感染，且PCV2 與豬生殖與 呼吸綜合症病毒(Porcine reproductive and respiratory syndrome virus, PRRSV)在豬場的 混合感染情形極為普遍，加上PCV2 及PRRSV 感染的標的細胞皆為單核球及巨噬細胞，因此 釐清PCV2 之致病機制及混合PRRSV 感染對 免疫細胞的影響，在對本病之控制及減輕其危 害上將有所助益。第一年度的研究已針對 PCV2 與PRRSV 單獨或不同順序混合感染豬 肺臟巨噬細胞(AMs)之病毒感染率、細胞死亡 及凋亡率、細胞對念珠菌的吞噬力及殺菌能 力、氧自由基及細胞激素IL-1β、IFN-α、IL-8 及TNF-α產生能力進行探討，同時亦證實 PCV2 感染AMs 可誘導產生IFN-α而抑制同時 或後續的PRRSV 感染。本年度則進一步發現 PCV2 感染AMs 能促進其表現多種細胞驅化 激素，含alveolar macrophage-derived neutrophil chemotactic factors II (AMCF-II)、granulocyte colony-stimulating factor (G-CSF)、monocyte chemotactic protein-1 (MCP-1)及IL-8，亦發現 PCV2 單獨感染能增加AMs 表現與肺臟急性 炎症及上皮細胞凋亡相關之Fas ligand (FasL)，但Fas 的表現則不受影響。以上結果 推測這些因PCV2 感染AMs 所誘導增加的炎 症中介物與PMWS 感染豬所呈現的間質性肺 炎之致病機制具重要的相關性。此外，本實驗 亦證實相對於PCV2 或PRRSV 之單獨感染， PCV2 與PRRSV 在共同感染情形下，可偵測 到同時有TNF-α、IL-8 及IFN-α之表現增加， 且FasL 表現更有顯著增加之情形，這些現象 可用以部分解釋臨床觀察所見之PMWS 豬隻 在PRRSV 共同感染所導致加重病情之致病機 制。Porcine circovirus 2 (PCV2) is currently considered the primary causative agent of postweaning multisystemic wasting syndrome (PMWS); however, porcine reproductive and respiratory syndrome virus (PRRSV) has been suggested as a co-factor needed for the full development of PMWS. Both viruses attack monocyte/macrophage lineage cells and are suggested immunocompromised. In our previous study, we have demonstrated the effects of the infection of both viruses, singular or combined, on the infectious rate, viability, apoptosis, phagocytosis and microbial killing function of swine alveolar macrophages (AMs). We also have proved the high level of interferon-α induced by PCV2-infected AMs may cause a reduction in PRRSV replication and PRRSV-related AM dysfunction. In present study, we revealed that the levels of tumor necrosis alpha (TNF-α), interleukin 8 (IL-8), alveolar macrophage-derived neutrophil chemotactic factors II (AMCF-II), granulocyte colony-stimulating factor (G-CSF), monocyte chemotactic protein-1 (MCP-1), and a commonly known apoptotic inducer and also an inflammatory mediator, Fas ligand (FasL), were strongly up-regulated in PCV2-infected AMs. The enhanced expression levels of various inflammatory cytokines, chemokines and FasL in PCV2-infected AMs may contribute to the pathogenesis of interstitial pneumonia in pigs with PMWS. Moreover, a significant increase in the expression of FasL and a concurrent appearance of TNF-α, IL-8, and IFN-α were observed in PCV2 and PRRSV dually infected groups as compared with PCV2- or PRRSV- infected AMs. The result may contribute, at least partially, to the enhancement of PMWS in PRRSV co-infected cases and the pathogenesis of the full development of PMWS clinically.application/pdf118815 bytesapplication/pdfzh-TW國立臺灣大學獸醫學系暨研究所離乳豬多系統消耗性症候群第二型豬環狀病毒豬生殖與呼吸綜合症病毒豬肺臟巨噬細胞細胞激素細胞驅化激素Porcine circovirus 2 (PCV2)postweaning multisystemic wasting syndrome (PMWS)porcine reproductive and respiratory syndrome virus (PRRSV)swine alveolar macrophages (AMs)cytokinechemokinereporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/28736/1/932313B002043.pdf