Chaudhuri P P, Das D, Sarkar S, Munoz M L, Das P
Department of Parasitology, National Institute of Cholera and Enteric Diseases, Calcutta, India.
Parasitol Res. 1997;83(6):604-10. doi: 10.1007/s004360050304.
The crude soluble antigens (CSA) of Giardia lamblia trophozoites and their analytically purified fractions were characterized biochemically and immunologically to determine the most immunogenic fraction and its localization on the parasite. Both Sephacryl S-300 column chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed the highly complex and heterogeneous nature of CSA. Gel filtration of CSA showed four fractions (FI-FIV) with molecular masses of 250, 150, 110, and 10 kDa for fractions I-IV, respectively. Protein profiles of CSA demonstrated 28 Coomassie-blue bands in the range of 200-14 kDa. Similar banding patterns with fewer polypeptides were observed in the FI fraction. However, fractions II and III showed polypeptide bands in the region of 97-14 kDa. The glycoprotein nature of CSA and its-fractions were demonstrated in physicochemical analysis. In antigenic activity analysis the high-molecular-weight FI antigen was found to be 8 times more immunogenic than CSA as well as the other fractions. Major differences in the immunoreactivity of CSA and FI antigens were noted at 220, 30, and 22 kDa for the FI antigen and at 205, 84, 55, 43, and 20 kDa for CSA. Some of these FI polypeptides were found to be surface-associated as revealed by immunofluorescence and immunoblot assay. These results suggest the future use of the FI antigen in the serodiagnosis of and immunoprophylaxis against giardiasis.
对蓝氏贾第鞭毛虫滋养体的粗可溶性抗原（CSA）及其经分析纯化的组分进行了生化和免疫学特性分析，以确定最具免疫原性的组分及其在寄生虫上的定位。Sephacryl S - 300柱层析和十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳（SDS - PAGE）均显示CSA具有高度复杂和异质性。CSA的凝胶过滤显示有四个组分（FI - FIV），组分I - IV的分子量分别为250、150、110和10 kDa。CSA的蛋白质谱显示在200 - 14 kDa范围内有28条考马斯亮蓝带。在FI组分中观察到类似的条带模式，但多肽较少。然而，组分II和III在97 - 14 kDa区域显示有多肽带。在理化分析中证实了CSA及其组分的糖蛋白性质。在抗原活性分析中，发现高分子量的FI抗原的免疫原性比CSA以及其他组分高8倍。FI抗原和CSA抗原的免疫反应性在220、30和22 kDa（FI抗原）以及205、84、55、43和20 kDa（CSA）处存在主要差异。免疫荧光和免疫印迹分析显示，其中一些FI多肽与表面相关。这些结果表明FI抗原在贾第虫病血清诊断和免疫预防中的未来应用。
