The ability to reproduce the developmental events of trypanosomes that occur in their mammalian host in vitro offers significant potential to assist in understanding of the underlying biology of the process. For example, the transition from bloodstream slender to bloodstream stumpy forms is a quorum-sensing response to the parasite-derived peptidase digestion products of environmental proteins. As an abundant physiological substrate in vivo , we studied the ability of a basement membrane matrix enriched gel (BME) in the culture medium to support differentiation of pleomorphic Trypanosoma brucei to stumpy forms . BME comprises extracellular matrix proteins, which are among the most abundant proteins found in connective tissues in mammals and known substrates of parasite-released peptidases. We previously showed that two of these released peptidases are involved in generating a signal that promotes slender-to-stumpy differentiation. Here, we tested the ability of basement membrane extract to enhance parasite differentiation through its provision of suitable substrates to generate the quorum sensing signal, namely oligopeptides. Our results show that when grown in the presence of BME, T. brucei pleomorphic cells arrest at the G0/1 phase of the cell cycle and express the differentiation marker PAD1, the response being restricted to differentiation-competent parasites. Further, the stumpy forms generated in BME medium are able to efficiently proceed onto the next life cycle stage in vitro , procyclic forms, when incubated with cis-aconitate, further validating the in vitro BME differentiation system. Hence, BME provides a suitable in vitro substrate able to accurately recapitulate physiological parasite differentiation without the use of experimental animals.

中文翻译：

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基底膜蛋白作为布鲁氏锥虫体外有效分化的底物

繁殖在哺乳动物宿主中发生的锥虫发育事件的能力提供了巨大的潜力，可帮助理解该过程的基础生物学。例如，从细长的血流到血块状的转变是对环境蛋白中寄生虫衍生的肽酶消化产物的群体感应反应。作为体内丰富的生理底物，我们研究了在培养基中富集基底膜基质凝胶（BME）的能力，以支持多形布鲁氏锥虫分化为块状形式。BME包含细胞外基质蛋白，它们是哺乳动物结缔组织中最丰富的蛋白之一，也是寄生虫释放的肽酶的已知底物。我们以前表明，这些释放的肽酶中有两个与产生促进纤细分化的信号有关。在这里，我们测试了基底膜提取物通过提供合适的底物以产生群体感应信号（即寡肽）来增强寄生虫分化的能力。我们的结果表明，当在BME存在下生长时，布鲁氏衣原体多形细胞在细胞周期的G0 / 1期停滞并表达分化标记PAD1，其响应仅限于能分化的寄生虫。此外，在BME培养基中产生的树桩形式在与顺式衣康酸酯一起孵育时能够有效地进入体外下一生命周期阶段，即顺环形式，从而进一步验证了体外BME分化系统。因此，