Cotinat, M. | Search bioRxiv

bioRxiv2026

Engineered muscle tissues with enhanced maturation enable the identification of clinically relevant rAAV capsids

Developing in vitro models that recapitulate both the structure and function of native human tissues is crucial for a better understanding of pathophysiology and for improving the reliability of preclinical studies. Here, we demonstrate that engineered muscle tissues derived from human pluripotent stem cells can serve as an in vitro platform for gene therapy. Recombinant vectors derived from the adeno-associated virus transduce engineered muscle tissues with high efficiency and in a dose-dependent manner, allowing long term assessment of transgene expression in a human cellular context. We next used this model to conduct a comparative analysis of 8 natural AAV capsids and showed that their relative efficiency depends on engineered muscle tissue maturation level. In more mature tissues subjected to uniaxial mechanical stretch, AAV9 performed better, which is reminiscent of its high clinical potential in patients with neuromuscular disorders. Finally, our model also confirmed the higher efficiency of artificial MyoAAV variants specifically developed to have an improved muscle transduction. Altogether, this work demonstrates the potential of human engineered muscle tissues in the preclinical testing of AAV vectors, paving the way for the development of personalized gene therapy platforms.

bioengineering↗

bioRxiv2024

In vitro models to mimic tumor endothelial cell-mediated immune cell reprogramming in lung adenocarcinoma

Tumor endothelial (TECs) cells play a critical role in regulating immune responses within the tumor microenvironment (TME). However, the mechanisms by which TECs modulate immune cell population remain unclear, particularly in non-small cell lung cancer (NSCLC). Here, we investigated how NSCLC cells tweak normal endothelial cells (NECs) into TECs and the subsequent effects on immune regulation. NECs were cocultured with various NSCLC cell lines, using 2D and 3D coculture models to evaluate TEC-mediated effects on immune cells. We show that direct coculture led to significant transcriptomic, proteomic and kinomic alterations in TECs, especially in pro-inflammatory pathways. We identified a downregulation of the co-stimulatory molecule OX40L in TECs compared to NECs, suggesting impaired T-cell proliferation support. While TECs showed a limited effect on CD8+ T-cell activation, TECs supported CD4 T-cells polarization into Treg and Th22 subsets. Moreover, TECs also promoted M2-like macrophages polarization, thereby potentially contributing to the TME immunosuppression. State-of-the-art single-cell RNA sequencing of 3D multicellular tumor spheroids (MCTS) revealed distinct TEC subpopulations, including an inflammatory subset with UPR signature. The latter was absent in 2D-cultured NECs but present in freshly isolated and 2D-cultured TECs from NSCLC patients. Importantly, we also identified within MCTS a perivascular M2-like macrophage subset, predicted to interact with TECs with MIF and Midkine signaling. In conclusion, TECs in NSCLC tumors play a pivotal role in remodeling the TME immune landscape by promoting immune suppression. This study highlights the complex immunoregulatory functions of TECs within our different in vitro models that mimic aspects of the TME. Our data may provide new insights into potential therapeutic strategies targeting TECs or regulatory signaling to improve the efficacy of immunotherapy in NSCLC.

cancer biology↗