Detection of candidate antigen of Acanthamoeba castellanii practicable for immunological examination of Amoebic Keratitis

我们研究了棘阿米巴T2、T4和T7基因对人角膜上皮细胞(HCE-T)的细胞病变作用。细胞病变效应不仅见于T4型，也见于18SrRNA基因分型判定为非致病的T2型。这些结果提示棘阿米巴的18sRNA分型与实际致病力之间存在差异。此外，我们还发现，蛋白水解酶抑制剂不能抑制棘阿米巴对HCE-T细胞的细胞病变作用，并且棘阿米巴作用于兔肾13细胞后，可通过干扰素敏感反应元件诱导干扰素的产生。提示棘阿米巴角膜炎存在新的发病机制。为了探索可用于诊断阿米巴角膜炎的抗原，我们构建了卡氏不动杆菌的cDNA文库，并用兔抗卡氏阿米巴可溶性抗原的多克隆抗体进行了免疫学筛选。然而，尽管我们期待着，我们还是无法获得阳性克隆。

We investigated cytopathic effect of Acanthamoeba T2, T4 and T7 genotypes on human corneal epithelial cell (HCE-T). Cytopathic effects were observed not only in T4 genotype but also in T2 genotypes that classified as nonpathogenic species by 18SrRNA genotyping. These results suggested the discrepancy between 18sRNA typing and actual pathogenicity of Acanthamoeba species. In addition, we found that protease inhibitor did not inhibit cytopathic effect of Acanthameoba on HCE-T cell, and after challenging Acanthamoeba to rabbit kidney 13 cell induced interferon via interferon-sensitive response element. These results suggested the existence of novel mechanism of Acanthamoeba keratitis. To investigate antigen which might be useful for diagnosis of amoebic keratitis, we constructed cDNA library of A. castellanii and screened immunologically using polyclonal rabbit antibody against A. castellanii soluble antigen. However, in spite of our expectation, we could not obtain positive clones.