Center for iPS cell Research and Application, Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto, Japan.
PLoS One. 2009 Dec 2;4(12):e8067. doi: 10.1371/journal.pone.0008067.
For therapeutic usage of induced Pluripotent Stem (iPS) cells, to accomplish xeno-free culture is critical. Previous reports have shown that human embryonic stem (ES) cells can be maintained in feeder-free condition. However, absence of feeder cells can be a hostile environment for pluripotent cells and often results in karyotype abnormalities. Instead of animal feeders, human fibroblasts can be used as feeder cells of human ES cells. However, one still has to be concerned about the existence of unidentified pathogens, such as viruses and prions in these non-autologous feeders.
METHODOLOGY/PRINCIPAL FINDINGS: This report demonstrates that human induced Pluripotent Stem (iPS) cells can be established and maintained on isogenic parental feeder cells. We tested four independent human skin fibroblasts for the potential to maintain self-renewal of iPS cells. All the fibroblasts tested, as well as their conditioned medium, were capable of maintaining the undifferentiated state and normal karyotypes of iPS cells. Furthermore, human iPS cells can be generated on isogenic parental fibroblasts as feeders. These iPS cells carried on proliferation over 19 passages with undifferentiated morphologies. They expressed undifferentiated pluripotent cell markers, and could differentiate into all three germ layers via embryoid body and teratoma formation.
CONCLUSIONS/SIGNIFICANCE: These results suggest that autologous fibroblasts can be not only a source for iPS cells but also be feeder layers. Our results provide a possibility to solve the dilemma by using isogenic fibroblasts as feeder layers of iPS cells. This is an important step toward the establishment of clinical grade iPS cells.
对于诱导多能干细胞（iPS）的治疗用途，实现无动物源培养至关重要。先前的报告表明，人类胚胎干细胞（ES）可以在无饲养细胞的条件下维持。然而，缺少饲养细胞可能对多能细胞构成恶劣环境，并且常常导致染色体异常。与人 ES 细胞的饲养细胞相反，可以用人成纤维细胞作为饲养细胞。然而，人们仍然不得不关注这些非自体饲养细胞中存在的未鉴定病原体，如病毒和朊病毒。
方法/主要发现：本报告证明，人诱导多能干细胞（iPS）可以在同源亲本饲养细胞上建立和维持。我们测试了 4 种独立的人皮肤成纤维细胞，以确定它们维持 iPS 细胞自我更新的能力。所有测试的成纤维细胞及其条件培养基都能够维持 iPS 细胞的未分化状态和正常核型。此外，iPS 细胞可以在同源亲本成纤维细胞作为饲养细胞的情况下生成。这些 iPS 细胞在增殖超过 19 代后仍保持未分化的形态。它们表达未分化的多能细胞标记物，并可通过胚状体和畸胎瘤形成分化为三个胚层。
结论/意义：这些结果表明，自体成纤维细胞不仅可以作为 iPS 细胞的来源，也可以作为饲养层。我们的结果提供了一种可能性，通过使用同源成纤维细胞作为 iPS 细胞的饲养层来解决这一困境。这是向建立临床级 iPS 细胞迈出的重要一步。
