Laboratoire Colloïdes et Matériaux Divisés, CNRS UMR 8231, Chemistry Biology & Innovation, ESPCI Paris, PSL Research University, 10 rue Vauquelin, F-75005 Paris, France.
Lab Chip. 2017 Nov 7;17(22):3851-3861. doi: 10.1039/c7lc00649g.
In many cell types, migration can be oriented towards a chemical stimulus. In mammals, for example, embryonic cells migrate to follow developmental cues, immune cells migrate toward sites of inflammation, and cancer cells migrate away from the primary tumour and toward blood vessels during metastasis. Understanding how cells migrate in 3D environments in response to chemical cues is thus crucial to understanding directed migration in normal and disease states. To date, chemotaxis in mammalian cells has been primarily studied using 2D migration models. However, it is becoming increasingly clear that the mechanisms by which cells migrate in 2D and 3D environments dramatically differ, and cells in their native environments are confronted with a complex chemical milieu. To address these issues, we developed a microfluidic device to monitor the behaviour of cells embedded in a 3D collagen matrix in the presence of complex concentration fields of chemoattractants. This tuneable microsystem enables the generation of (1) homogeneous, stationary gradients set by a purely diffusive mechanism, or (2) spatially evolving, stationary gradients, set by a convection-diffusion mechanism. The device allows for stable gradients over several days and is large enough to study the behaviour of large cell aggregates. We observe that primary mature dendritic cells respond uniformly to homogeneous diffusion gradients, while cell behaviour is highly position-dependent in spatially variable convection-diffusion gradients. In addition, we demonstrate a directed response of cancer cells migrating away from tumour-like aggregates in the presence of soluble chemokine gradients. Together, this microfluidic device is a powerful system to observe the response of different cells and aggregates to tuneable chemical gradients.
在许多细胞类型中，迁移可以朝向化学刺激定向。例如，在哺乳动物中，胚胎细胞迁移以遵循发育线索，免疫细胞向炎症部位迁移，癌细胞在转移过程中从原发性肿瘤迁移并朝向血管迁移。因此，了解细胞如何在 3D 环境中响应化学线索迁移对于理解正常和疾病状态下的定向迁移至关重要。迄今为止，哺乳动物细胞中的趋化性主要使用 2D 迁移模型进行研究。然而，越来越明显的是，细胞在 2D 和 3D 环境中迁移的机制有很大的不同，并且细胞在其自然环境中面临着复杂的化学环境。为了解决这些问题，我们开发了一种微流控设备来监测嵌入在 3D 胶原基质中的细胞在复杂浓度场趋化剂存在下的行为。这种可调谐微系统能够产生（1）由纯扩散机制设定的均匀、稳定的梯度，或（2）由对流扩散机制设定的空间演化、稳定的梯度。该设备允许在几天内保持稳定的梯度，并且足够大，可以研究大细胞聚集体的行为。我们观察到，原代成熟树突状细胞对均匀的扩散梯度均匀响应，而在空间变化的对流扩散梯度中，细胞行为高度依赖于位置。此外，我们证明了在可溶性趋化因子梯度存在下，癌细胞从肿瘤样聚集体迁移的定向反应。总之，这种微流控设备是一种强大的系统，可以观察不同细胞和聚集体对可调谐化学梯度的反应。
