Th1/Th2分化调节在人芽囊原虫感染小鼠模型中的机制研究

人芽囊原虫是一种导致人类腹泻的重要机会致病原虫，其免疫及致病机制尚未完全阐明。本课题组在前期研究发现：广西南部沿海地区居民人芽囊原虫感染率高达26.35%，高于其他地区，而感染人群的临床表现从无症状到间歇性腹泻至经常性腹泻，在小鼠动物模型中我们发现：人芽囊原虫可引起肠黏膜不同程度的炎性改变，相关免疫细胞和细胞因子检测结果提示原虫感染早期主要发生Th1应答，之后向Th2应答漂移。由此我们推测：Th1/Th2分化失调可能是该虫致病的主要原因。本项目拟开展以下研究：①体内实验探索强化或削弱Th1/Th2应答强度后，能否直接导致感染的恶化或改善？②Th1/Th2失调是虫体抗原通过肠Payer's patches诱导免疫系统产生不适当应答的关键。项目的开展可望进一步阐明人芽囊原虫的免疫应答机制，并为人芽囊原虫的药物研发和防治提供新的线索。

Blastocystis hominis is a kind of important opportunistic protozoa which can result in diarrhea and its immunity and disease-causing mechanisms have not been fully clarified.Our seminar in earlier research find that the rate of infected people in the southern coastal areas of Guang xi reaches up to 26.35% and is higher than other places. The clinical manifestation of infected people often can be seen from symptomless to intermittent then recurrent diarrhea. At the same time, in mice model, we find that Blastocystis hominis can affect inflammatory changes of intestinal mucosa in different levels and testing results related to immune cells and cytokines. It points out that Blastocystis hominis in earlier period can cause Th1 response and then drift to Th2 response.Therefore, we can conjecture: the differentiation disorder of Th1 and Th2 is the main reason the Blastocystis hominis can be pathogenic.This project will carry out several following researches: 1. can strengthening vivo research and weakening the Th1 and Th2 response result in deterioration or improve of infection; 2.the disorder of Th1 and Th2 is the key the worm antigens cause inappropriate responses by intestinal Payer's patches-induced immune system. This project will be expected to give a further clarification to the immune response regulation of Blacocystis hominis and a new clue for medicine researching and controlling of Blacocystis hominis.