School of Biochemistry, Biomedical Sciences Building, University Walk, University of Bristol, Bristol BS8 1TD, UK.
School of Cellular and Molecular Medicine, Biomedical Sciences Building, University Walk, University of Bristol, Bristol BS8 1TD, UK.
J Cell Sci. 2024 Aug 15;137(16). doi: 10.1242/jcs.262202. Epub 2024 Aug 29.
After tissue injury, inflammatory cells are rapidly recruited to the wound where they clear microbes and other debris, and coordinate the behaviour of other cell lineages at the repair site in both positive and negative ways. In this study, we take advantage of the translucency and genetic tractability of zebrafish to evaluate the feasibility of reprogramming innate immune cells in vivo with cargo-loaded protocells and investigate how this alters the inflammatory response in the context of skin and skeletal repair. Using live imaging, we show that protocells loaded with R848 cargo (which targets TLR7 and TLR8 signalling), are engulfed by macrophages resulting in their switching to a pro-inflammatory phenotype and altering their regulation of angiogenesis, collagen deposition and re-epithelialization during skin wound healing, as well as dampening osteoblast and osteoclast recruitment and bone mineralization during fracture repair. For infected skin wounds, R848-reprogrammed macrophages exhibited enhanced bactericidal activities leading to improved healing. We replicated our zebrafish studies in cultured human macrophages, and showed that R848-loaded protocells similarly reprogramme human cells, indicating how this strategy might be used to modulate wound inflammation in the clinic.
组织损伤后，炎症细胞迅速募集到伤口部位，在那里它们清除微生物和其他碎片，并以积极和消极的方式协调修复部位其他细胞谱系的行为。在这项研究中，我们利用斑马鱼的透明性和遗传可操作性，评估用负载货物的原细胞在体内重新编程先天免疫细胞的可行性，并研究这如何改变皮肤和骨骼修复背景下的炎症反应。通过活体成像，我们表明负载 R848 货物（靶向 TLR7 和 TLR8 信号）的原细胞被巨噬细胞吞噬，导致它们转变为促炎表型，并改变它们在皮肤伤口愈合过程中的血管生成、胶原蛋白沉积和再上皮化的调节，以及在骨折修复过程中抑制成骨细胞和破骨细胞的募集和骨矿化。对于感染的皮肤伤口，R848 重编程的巨噬细胞表现出增强的杀菌活性，从而改善愈合。我们在培养的人巨噬细胞中复制了我们的斑马鱼研究，并表明负载 R848 的原细胞同样可以重编程人细胞，这表明这种策略如何在临床上用于调节伤口炎症。
