McGowan Timothy J, Lewerenz Nicolas, Maino Eleonora, Thürkauf Marco, Jörin Lena, Rüegg Markus A
Biozentrum, University of Basel, Spitalstrasse 41, 4056 Basel, Switzerland.
Mol Ther Methods Clin Dev. 2025 Mar 14;33(2):101451. doi: 10.1016/j.omtm.2025.101451. eCollection 2025 Jun 12.
Adeno-associated viruses (AAVs) of different serotypes are commonly used in gene therapies and gene interrogation studies to deliver transgenes to skeletal muscle in humans and mice. While efficient muscle fiber transduction is possible, little is known of their capacity to transduce muscle-residing mononuclear cells. Here, we addressed this question for AAV8 and the two myotropic AAVs, AAVMYO and AAVMYO2, by engineering them to express the tdTomato gene. AAVs were then injected intramuscularly or intravenously at two different doses into adult mice followed by flow-cytometry-based isolation of endothelial cells, immune cells, muscle stem cells, and fibro-adipogenic progenitor cells from the muscle. Overall, we noted varying rates of tdTomato expression across all cell types. Transduction efficiency fluctuated in AAV serotype-dependent, titer-dependent, administration-dependent, and cell-dependent manners. By visualizing AAV DNA , we confirmed that AAV8, AAVMYO, and AAVMYO2 deliver transgenes to muscle-residing mononuclear cells. We show that mononuclear cells are also successfully transduced in the / mouse model of LAMA2-related muscular dystrophy. Altogether, we demonstrate that muscle-residing mononuclear cells are transduced by AAVs and provide an insightful guidance for researchers aiming to target muscle-resident mononuclear cells in their studies.
不同血清型的腺相关病毒（AAV）常用于基因治疗和基因研究，以便将转基因传递到人类和小鼠的骨骼肌中。虽然高效的肌纤维转导是可行的，但对于它们转导驻留在肌肉中的单核细胞的能力却知之甚少。在这里，我们通过改造使其表达tdTomato基因，来研究AAV8以及两种亲肌性AAV（AAVMYO和AAVMYO2）的这一问题。然后，将AAV以两种不同剂量分别通过肌肉注射或静脉注射到成年小鼠体内，随后基于流式细胞术从肌肉中分离出内皮细胞、免疫细胞、肌肉干细胞和成纤维脂肪生成祖细胞。总体而言，我们注意到所有细胞类型中tdTomato的表达率各不相同。转导效率以依赖于AAV血清型、滴度、给药方式和细胞类型的方式波动。通过可视化AAV DNA，我们证实AAV8、AAVMYO和AAVMYO2能将转基因传递到驻留在肌肉中的单核细胞。我们表明，在与LAMA2相关的肌肉营养不良的/小鼠模型中，单核细胞也能成功被转导。总之，我们证明驻留在肌肉中的单核细胞可被AAV转导，并为旨在在研究中靶向驻留在肌肉中的单核细胞的研究人员提供了有见地的指导。
