Generation of a homozygous CIITA knockout iPS cell line using the CRISPR-Cas9 system

Human induced pluripotent stem cells (iPSCs) have great promise in regenerative medicine. However, several limitations, including immune-incompatibility, have raised concerns regarding their clinical application. Recent studies have shown that human iPSCs and their derivatives lose their immunogenicity when major histocompatibility complex (MHC) class I and II genes are inactivated and CD47 is over-expressed. In this study, we used CRISPR-Cas9 technology to generate an isogenic iPSC line with a homozygous frameshift mutation in the MHC II transactivator (CIITA) gene. The CIITA(-/-) iPSCs exhibit typical morphology of pluripotent cells, normal karyotype, expression of pluripotency markers and differentiation capacity in the three germ layers.