人類微小病毒B19是微小病毒科中可以感染人類並且致病的病毒。過去研究證據顯示肝臟疾病患者之血液或是肝臟組織中有B19病毒蹤影,許多文獻也指出感染B19病毒與肝臟發炎損傷有關。近幾年研究發現B19-VP1u的磷脂酶A2區域(phospholipase A2 motif)與B19病毒感染細胞及引起發炎反應有密切關係,但是詳細機轉仍不清楚。本篇研究利用轉染技術將VP1u蛋白表現在COS-7 細胞,經由皮下注射方式打入Balb/c小鼠並利用IVIS非侵入式活體影像系統進行觀察,探討B19-VP1u對Balb/c小鼠之影響和發炎反應分子機制。結果發現B19-VP1u會促進Balb/c小鼠肝臟基質金屬蛋白酶(MMP9)活性及蛋白表現並活化磷酸化蛋白p38和ERK及IKK-α、IκB與NF-κB訊號傳遞分子。此外,發炎相關蛋白C-Reactive Protein (CRP)、IL-1β及IL-6蛋白表現也明顯增加並透過磷酸化蛋白STAT-1訊號傳遞引起肝臟發炎損傷。由實驗結果結果顯示B19-VP1u可引發肝臟損傷的免疫致病機轉。
Human Parvovirus B19 is a significant human pathogen in Parvoviridae. It has been re-ported that B19 can be detected in blood or liver specimens in patient with liver diseases. Indeed, various studies have postulated a connection between B19 infection and liver injury. Recently, studies suggested that the PLA2 motif of B19-VP1u play an important role in closely associated with B19-infected and inflammatory. However, the precise mechanism is still obscure. In the present study, we aimed to investigate the influence of B19-VP1u in Balb/c mice by injected subcutaneously with COS-7 cells expressing VP1u and observed using a non-invasive IVIS bio-luminescent imaging system. Our experimental results revealed that enhanced MMP-9 activity and increased phosphorylation of p38, ERK, IKK-α, IκB and NF-κB(p65) proteins in liver from Balb/c mice receiving B19-VP1u. Additionally, significantly increased inflammatory associated proteins, including CRP, IL-1β and IL-6 were observed in liver from Balb/c mice receiving B19-VP1u. Notably, phosphorylated STAT1 proteins were involved in the induction of inflammatory cytokines in liver from Balb/c mice receiving B19-VP1u. Our findings revealed the effects of B19-VP1u on liver injury and provide a clue in understanding the role of immuno-pathogenesis of B19-VP1u.