近日，一篇发表于国际杂志EMBO molecular Medicine上的研究报告中，来自洛桑大学医院(Lausanne University Hospital)的研究人员通过研究设计了一种新型策略，其可以帮助确保成人表皮干细胞在应用于病人疗法之前是安全的;这种新型方法包括了一种克隆策略，其可以使得干细胞在进行检测以达到最高安全标准之前被大量收集并且进行培养，随后进行遗传化修饰以及单个细胞的分离。

研究者Yann Barrandon表示，截至目前为止并没有一种系统性的方法来确保成人表皮干细胞在进行疾病治疗前可以满足所必需的安全性要求，而本文研究中我们发明了一种单细胞技术，其可以在干细胞用于病人治疗之前利用细胞和分子分析来评估干细胞的安全性和活力，目前研究者已经在一系列临床疗法中对其开发的新技术进行了概念性的验证。

文章中研究人员对来自病人机体的表皮细胞进行培养并且将其用于皮肤再生，而研究者同时也进行了一系列实验来确定这种转导细胞是否可以满足干细胞多能性及安全性的必须要求;克隆分析结果显示，这种转导干细胞的能力可以发生改变来产生功能类型的VII胶原，当其最具活力时，修饰的干细胞就可以被选择移植进入免疫缺陷症的小鼠机体中帮助治疗疾病，而其安全性则需要通过确定病毒载体的整合位点来决定，其可以通过寻找基因重排来实现，就好比全基因组测序一样。

最后研究者表示，我们的研究结果显示，至少对于成人表皮干细胞而言我们可以采用一种克隆的方法来达到安全级别的运输，而这种克隆策略也可以同其它当前的靶向基因组编辑技术进行整合来提供更多的精确技术帮助提高干细胞的安全性检测，以使得干细胞可以更安全有效地应用于临床疾病的治疗中。

原文链接：A single epidermal stem cell strategy for safe ex vivo gene therapy

There is a widespread agreement from patient and professional organisations alike that the safety of stem cell therapeutics is of paramount importance, particularly forex vivo autologous gene therapy. Yet current technology makes it difficult to thoroughly evaluate the behaviour of genetically corrected stem cells before they are transplanted. To address this, we have developed a strategy that permits transplantation of a clonal population of genetically corrected autologous stem cells that meet stringent selection criteria and the principle of precaution. As a proof of concept, we have stably transduced epidermal stem cells (holoclones) obtained from a patient suffering from recessive dystrophic epidermolysis bullosa. Holoclones were infected with self‐inactivating retroviruses bearing a COL7A1 cDNA and cloned before the progeny of individual stem cells were characterised using a number of criteria. Clonal analysis revealed a great deal of heterogeneity among transduced stem cells in their capacity to produce functional type VII collagen (COLVII). Selected transduced stem cells transplanted onto immunodeficient mice regenerated a non‐blistering epidermis for months and produced a functional COLVII. Safety was assessed by determining the sites of proviral integration, rearrangements and hit genes and by whole‐genome sequencing. The progeny of the selected stem cells also had a diploid karyotype, was not tumorigenic and did not disseminate after long‐term transplantation onto immunodeficient mice. In conclusion, a clonal strategy is a powerful and efficient means of by‐passing the heterogeneity of a transduced stem cell population. It guarantees a safe and homogenous medicinal product, fulfilling the principle of precaution and the requirements of regulatory affairs. Furthermore, a clonal strategy makes it possible to envision exciting gene‐editing technologies like zinc finger nucleases, TALENs and homologous recombination for next‐generation gene therapy.

作者：Yann Barrandon 点击：次