登革病毒(DV)是廣泛流行在熱帶及副熱帶區域的重大傳染性致病原，登革病毒感染病人依照症狀嚴重程度可以分三大類:登革熱(DF)、登革出血熱(DHF)及登革出血休克症候群(DSS)。DHF/DSS病人常發生在二次感染不同血清型登革病毒狀況下，而這些病人最大的病理特徵是血管通透性(vascular permeability)增加所導致的血漿滲出(plasma leakage)/出血(hemorrhage)以及血小板減少(thrombocytopenia)。在這些DHF/DSS病人中，免疫系統已經被發現參與登革熱的致病機制:免疫致病機轉(immunopathogenesis)理論提出病人體內產生的自體抗體(autoantibody)在疾病發展過程中，扮演了相當重要的角色，因為分子模擬性(molecular mimicry)與交叉反應性(cross-reactivity)，這些抗體可以與自體抗原(autoantigen)結合，並藉由免疫系統的作用，導致自體細胞的破壞。我們利用抗前趨膜/抗外套膜單株抗體(anti-prM/anti-E mAbs)可以跟大鼠的肝、腎組織的血管內皮細胞產生交叉結合反應(cross-reaction)，探討這些有交叉反應抗登革病毒抗體的病理角色。將這些抗體以靜脈注射方式處理大鼠，我們觀察到抗體可以結合到血管內皮細胞上，並且會滲透到組織中。這暗示當抗體結合到內皮細胞後，可能會增加內皮細胞的通透性。此外，施打會與大鼠血小板結合的抗體後，我們觀察到血小板有減少的現象。由這些結果，我們推論在活體動物內，抗登革病毒且具交叉反應的自體抗體與自體抗原的結合，會導致細胞功能的失常或破壞。

Dengue virus is an important pathogen that causes endemic disease in tropic and sub-tropic area in the world. According to the symptom, dengue disease can range from mild dengue fever (DF) to severe dengue hemorrhage fever (DHF) and dengue shock syndrome (DSS). DHF/DSS patients are often found in secondary infection with different serotypes of dengue virus. The major characteristics of DHF/DSS are plasma leakage and thrombocytopenia. Immunopathogenesis has been proposed to be involved in the pathogenesis of dengue disease and autoantibodies play important roles in the DHF/DSS. Due to the molecular mimicry and cross-reactivity, these anti-dengue antibodies can cross-react to autoantigen and cause target cells damage by immune system. In our study, we found that some anti-DV monoclonal antibodies can cross-react with endothelial cell in rat liver and kidney tissue sections. These antibodies bind to endothelial cells and leak into interstitial tissue after intravenous administration into rat. The antibodies bound to endothelial cells may induce vascular permeability change. Using the antibody cross-reactive to platelets, the circulating platelet counts were decreased after infusion into the rat. We conclude that the anti-dengue antibodies that cross-react to autoantigen will cause target cell to damage or function loss.

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