Dissous C, Grzych J M, Capron A
Nature. 1986;323(6087):443-5. doi: 10.1038/323443a0.
The expression of similar antigenic determinants by trematode parasites and their intermediate (invertebrate) or definitive (vertebrate) hosts has been previously reported. Studies of experimental and human infection by the parasite Schistosoma mansoni have revealed the strong immunogenicity of a surface antigen with a relative molecular mass (Mr) 38,000 (38K). Here we provide evidence that the important protective epitope of the 38K molecule is expressed by the uninfected intermediate host of S. mansoni, Biomphalaria glabrata and is synthesized both by the mollusc and by the parasite throughout its life cycle, thus confirming our original hypothesis. Deglycosylation experiments indicate that the protective epitope is an oligosaccharide and in B. glabrata, is associated with a 90K component. Analysis of soluble extracts from different freshwater mollusc species shows that the same protective epitope is found in schistosome as well as in non-schistosome hosts. Moreover, it was also found on the haemocyanin of the keyhole limpet (Megathura crenulata), a carrier protein widely used in immunological studies.
此前已有报道称，吸虫寄生虫与其中间宿主（无脊椎动物）或终宿主（脊椎动物）表达相似的抗原决定簇。对曼氏血吸虫寄生虫的实验性感染和人类感染的研究表明，一种相对分子质量（Mr）为38,000（38K）的表面抗原具有很强的免疫原性。在此，我们提供证据表明，38K分子的重要保护性表位由曼氏血吸虫未感染的中间宿主光滑双脐螺表达，并且在整个生命周期中由软体动物和寄生虫共同合成，从而证实了我们最初的假设。去糖基化实验表明，保护性表位是一种寡糖，在光滑双脐螺中，它与一种90K成分相关。对不同淡水软体动物物种的可溶性提取物的分析表明，在血吸虫宿主以及非血吸虫宿主中都发现了相同的保护性表位。此外，在免疫研究中广泛使用的载体蛋白——钥孔戚血蓝蛋白上也发现了该表位。
