Mechanical strategies to avoid interspecies competition in trypanosomes

像所有生物一样，寄生虫必须以最佳方式适应生态位。在寄生虫的情况下，这个生态位根据定义是敌对的，因为宿主已经形成了防御入侵者的策略。此外，寄主经常被一种以上的寄生虫感染，因此寄生虫之间可能会为同一感染生态位而竞争。因此，避免种间竞争是寄生进化成功的重要策略。我们假设对微环境物理的适应在这一过程中起着至关重要的作用。非洲锥虫是一种单细胞寄生虫，它们在宿主的细胞外定植体液。有趣的是，两个密切相关的物种，布氏绦虫和刚果绦虫，可以在同一寄主的完全不同的生态位，即组织间隙和周围毛细血管系统中定殖。这两种寄生虫只是在身体结构上略有不同，但在游泳行为和附着在宿主细胞上的能力上却有很大的不同。在这个项目中，我们想系统地研究这两种物种的物理特性和机械性能。我们将测量寄生虫对其环境施加的力量，并确定它们必须承受的力量。我们将在各种微环境中研究寄生虫，从血流、组织液和淋巴的微流体模型到精细的皮肤和脂肪组织模型。利用最先进的技术，从实时变形细胞术、点阵光片显微镜和全息术到单细胞RNA-Seq和中尺度模拟，我们的目标是以前所未有的精度测量寄生虫与其宿主生态位的物理串扰。在这样做的过程中，我们的目标是为我们对寄生物理学的理解做出重要贡献。

Like all living beings, parasites must adapt optimally to an ecological niche. In the case of parasites, this niche is by definition hostile, as the host has developed defence strategies against the invader. Furthermore, the host is often infested by more than one parasite species, so that competition between parasites for the same infection niche can occur. Accordingly, avoiding interspecific competition is an important strategy for the evolutionary success of parasitism. We postulate that adaptations to the physics of the microenvironment play a crucial role in this process. African trypanosomes are unicellular parasites that extracellularly colonise the body fluids of their hosts. Interestingly, two closely related species, T. brucei and T. congolense, can colonise quite different niches in the same host, namely tissue interstitial spaces and the peripheral capillary system. Both parasite species differ only slightly in their body architecture, but significantly in their swimming behaviour and their ability to attach to host cells. In this project, we want to systematically investigate the physical properties and mechanical capabilities of both species. We will measure both the forces the parasites can exert on their environment and determine the forces they have to endure. We will study the parasites in a variety of microenvironments, from microfluidic models of blood flow, tissue fluid and lymph to elaborate skin and adipose tissue models. Using state-of-the-art techniques ranging from real-time deformation cytometry, lattice light sheet microscopy and holography to single-cell RNA-Seq and mesoscale simulations, we aim to measure the physical cross-talk of the parasites with their host niche with unprecedented accuracy. In doing so, we aim to make an important contribution to our understanding of the Physics of Parasitism.