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血吸蟲症(schistosomiasis)目前在世界上有兩億人受到感染，世界衛生組織將此病列為第二重大熱帶疾病。為了解台灣株日本血吸蟲在被感染宿主體內之免疫反應和Th1及Th2細胞間的相互關係，本研究以反轉錄聚合連月每免疫吸附分析法分析宿主感染日本血吸蟲後，脾臟helper T細胞所產生之細胞激素的種類、活性及其動力學反應。本研究以六種細胞激素IFN-y，IL-2，IL-4，IL-5，IL-1O以及TNF-α為評估的對象。C57BL/6J小鼠每隻感染50隻台灣株日本血吸蟲之尾動幼蟲，感染後3-12週，每隔一週將小鼠犧牲。實驗結果顯示，IFN-y mnRNA在感染後第3週明顯增加，第5週開始減少。IL-2 mRNA亦在感染後第3週明顯增加。IL-4及IT-10 mRNA則在第7-9週開始上升且達到高峰，在第12週，有下降的趨勢。TNF-αmRNA及蛋白質皆於第9週達到高峰。從本研究得知蟲體產卵之前IFN-y及IL-2為主要的免疫反應，但開始產卵後，lL-4，IL-5，以及IL-1O則為主要的免疫反應，而且此時IFN-y之產量會被壓抑。以上結果顯示，Th1細胞和感染早期(3-5週)之免疫反應有關；Th2的免疫反應及TNF-α的生成則為急性感染期(7-12週)之主要現象。
Schistosomiasis is considered the second most important tropical disease by the World Health Organization and more than 200 million people are estimated to be infected. The purpose of this study was to elucidate the immune response against Schistosoma japonicum in infected hosts, and the relationships between Th1 and Th2 cells. Mice were infected with a Taiwanese strain of S. Japonicum. We used the reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) to analyze the type, activity and the kinetics of splenic Th1 and Th2 cytokine responses. Six cytokines were evaluated, i.e. IFN-γ, IL- 2, IL-4, IL-5, IL-1O, and TNF-α. C57BL/6J mice were percutaneously infected with 50 cercariae, and four mice were sacrificed at 3, 5, 7, 9, and 12 wk postinfection. The results showed that IFN-γ mRNA level increased significantly at 3 wk postinfection, and started to decrease at 5 wk. The IL-2 mRNA expression also increased markedly at 3 wk. The IL-4 and IL- 1O mRNA levels, however, began to rise and reached maxinum at 7-9 wk, then decrease at 12 wk. TNF-α and its mRNA both reached the peak at 9 wk. The assay showed that IFN-γ and IL-2 played a major role in immune response before the egg laying, while IL-4, IL-5, and IL-1O were the major players after the egg laying, at which time the production of IFN-γ was suppressed. In the early stage (3 - 5 wk) of S. Japonicum infection, The cells played a conspicuous role, while during the acute stage (7 - 9 wk) Th2 cells and TNF-α were more important.
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