CELL SUBSTRATE ADHESION DURING TRYPANOSOMA-CRUZI DIFFERENTIATION
CELL SUBSTRATE ADHESION DURING TRYPANOSOMA-CRUZI DIFFERENTIATION
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DOI：
10.1083/jcb.106.4.1349
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发表时间：
1988-04-01
影响因子：
7.8
通讯作者：
GOLDENBERG, S
中科院分区：
文献类型：
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作者：
BONALDO, MC;SOUTOPADRON, T;GOLDENBERG, S
在体外化学条件下，克氏锥虫向哺乳动物感染性亚循环锥虫的转化（亚循环发生）可以进行。在这些条件下，正在分化的副乳突体在转化为亚环锥乳突体之前会附着在一个表面上。黏附和非黏附寄生虫的扫描电镜和透射电镜显示，在第一种群中只发现附乳线虫和少数过渡形式，而细胞培养上清中只发现附乳线虫。对黏附和非黏附寄生虫的[35S]蛋氨酸代谢标记产物进行PAGE分析表明，虽然大多数多肽是保守的，但黏附寄生虫特异性表达4种45-50 kD范围内的多肽，等电点为4.8。这些蛋白可能参与黏附过程，并可被抗血清识别。该抗血清还能识别分化细胞中碘放射性标记表面蛋白中的一组45-50 kD，这为这些成分确实是表面抗原提供了直接证据。结果表明，在转化为亚循环锥马鞭毛虫之前，它们必须附着在一个底物上，然后在细胞形成过程完成时释放到培养基中。这可能与无脊椎动物宿主体内自然发生的过程相对应。
The transformation of Trypanosoma cruzi epimastigotes to the mammal infective metacyclic trypomastigotes (metacyclogenesis) can be performed in vitro under chemically defined conditions. Under these conditions, differentiating epimastigotes adhere to a surface before their transformation into metacyclic trypomastigotes. Scanning and transmission electron microscopy of adhered and non-adhered parasites during the metacyclogenesis process show that only epimastigotes and few transition forms are found in the first population, whereas metacyclic trypomastigotes are exclusively found in the cell culture supernatant. PAGE analysis of the [35S]methionine metabolic labeling products of adhered and non-adhered parasites shows that although most of the polypeptides are conserved, adhered parasites express specifically four polypeptides in the range of 45-50 kD with an isoelectric point fo 4.8. These proteins might be involved in the adhesion process and are recognized by an antiserum against total adhered parasite proteins. This antiserum also recognized a group of 45-50 kD in the iodine-radiolabeled surface proteins of differentiating cells, providing direct evidence that these components are indeed surface antigens. The results suggest that epimastigotes must adhere to a substrate before their transformation to metacyclic trypomastigotes, being released to the medium as the metacyclogenesis process is accomplished. This could correspond to the process naturally occurring within the triatomine invertebrate host.