Kawanaka M, Carter C E
Department of Parasitology, National Institute of Health, Tokyo, Japan.
Exp Parasitol. 1992 Mar;74(2):143-50. doi: 10.1016/0014-4894(92)90041-8.
The release pattern of excretory-secretory (E-S) products of Schistosoma japonicum eggs was investigated using eggs cultured in a chemically defined medium (MEMSE-J) for 16 days. The amount of protein released in culture supernatants was greater in 0- to 4-day and 12- to 16-day cultures than in 4- to 12-day cultures. The protein composition of E-S products and soluble extracts of newly laid eggs (N-SEA) and in vitro matured eggs (M-SEA) was analyzed by SDS-PAGE. Silver staining patterns of N-SEA and M-SEA were found to be similar except for the band at approximately 66 kDa, which appeared in highest concentrations in N-SEA. Western blot analysis with human infected sera showed antibody recognition of a 140- to 160-kDa antigen present in E-S products from mature eggs, while E-S products from immature eggs were unreactive. When either [35S]methionine or [3H]glucosamine was added to the culture medium, newly synthesized proteins or glycoproteins of the SEA and E-S products were labeled. Incorporation of both isotopes into SEA appears to correlate with developmental activity of the eggs. In contrast, release of E-S proteins and glycoproteins is more apparent as the miracidium matures. These results suggested that the source of E-S products from immature eggs is likely to be the collapsing vitelline cells and that of E-S products from mature eggs to be mainly miracidial secretions.
利用在化学成分明确的培养基（MEMSE-J）中培养16天的日本血吸虫卵，研究了其排泄-分泌（E-S）产物的释放模式。培养上清液中释放的蛋白量在0至4天和12至16天的培养物中比在4至12天的培养物中更多。通过SDS-PAGE分析了新产卵（N-SEA）和体外成熟卵（M-SEA）的E-S产物及可溶性提取物的蛋白质组成。发现N-SEA和M-SEA的银染模式相似，除了约66 kDa处的条带，该条带在N-SEA中的浓度最高。用人感染血清进行的蛋白质印迹分析显示，成熟卵的E-S产物中存在的140至160 kDa抗原可被抗体识别，而未成熟卵的E-S产物无反应。当向培养基中添加[35S]甲硫氨酸或[3H]葡糖胺时，SEA和E-S产物的新合成蛋白质或糖蛋白被标记。两种同位素掺入SEA似乎与卵的发育活性相关。相反，随着毛蚴成熟，E-S蛋白和糖蛋白的释放更为明显。这些结果表明，未成熟卵的E-S产物来源可能是正在解体的卵黄细胞，而成熟卵的E-S产物来源主要是毛蚴分泌物。
