Immunogenicity of Induced Pluripotent Stem Cells

A new study shows the immunogenicity of inducedpluripotent stem cells by the direct transplantation of undifferentiated cells into syngenic mice. The reprogramming of somatic cells into pluripotent stem cells has been reported after introducing a combination of several defined factors, such as OCT3/4, SOX2, KLF4, and c-MYC, into the cells.1 These artificially established cells are termed induced pluripotent stem cells (iPSCs). The iPSCs show unlimited growth while maintaining their potential for differentiation into various cell types of all 3 germ layers. Their pluripotency has been clearly shown by their contribu-tion to chimeric animals and by the development of a full-term mouse during a tetraploid complementation exper-iment. These data also indicated that cells differentiated from iPSCs can at least partially replace the biological functions of various organs. Unlike embryonic stem cells (ESCs), iPSCs