Department of Biological Sciences, National University of Singapore, Singapore.
Cell Transplant. 2020 Jan-Dec;29:963689720965529. doi: 10.1177/0963689720965529.
Mesenchymal stromal cells (MSCs) are viewed as immune-privileged cells and have been broadly applied in allogeneic adoptive cell transfer for regenerative medicine or immune-suppressing purpose. However, the surface expression of human leukocyte antigen (HLA) class I molecules on MSCs could still possibly induce the rejection of allogeneic MSCs from the recipients. Here, we disrupted the β2 microglobulin () gene in human peripheral blood mononuclear cell-derived induced pluripotent stem cells (iPSCs) with two clustered regulatory interspaced short palindromic repeat (CRISPR)-associated Cas9 endonuclease-based methods. The B2M knockout iPSCs did not express HLA class I molecules but maintained their pluripotency and genome stability. Subsequently, MSCs were derived from the HLA-negative iPSCs (iMSCs). We demonstrated that B2M knockout did not affect iMSC phenotype, multipotency, and immune suppressive characteristics and, most importantly, reduced iMSC immunogenicity to allogeneic peripheral blood mononuclear cells. Thus, B2M knockout iPSCs could serve as unlimited off-the-shelf cell resources in adoptive cell transfer, while the derived iMSCs hold great potential as universal grafts in allogeneic MSC transplantation.
间充质基质细胞（MSCs）被视为免疫特权细胞，并已广泛应用于同种异体过继细胞转移的再生医学或免疫抑制目的。然而，MSCs 表面 HLA Ⅰ类分子的表达仍可能导致受体排斥同种异体 MSCs。在这里，我们使用两种基于成簇规律间隔短回文重复（CRISPR）相关的 Cas9 内切酶的方法破坏了人外周血单个核细胞来源的诱导多能干细胞（iPSCs）中的β2 微球蛋白（β2M）基因。B2M 敲除 iPSCs 不表达 HLA Ⅰ类分子，但保持其多能性和基因组稳定性。随后，我们从 HLA 阴性 iPSCs（iMSCs）中衍生出 MSC。我们证明 B2M 敲除并不影响 iMSC 的表型、多能性和免疫抑制特性，最重要的是，降低了 iMSC 对同种异体外周血单个核细胞的免疫原性。因此，B2M 敲除 iPSCs 可作为过继细胞转移的无限制现成细胞资源，而衍生的 iMSCs 作为同种异体 MSC 移植中的通用移植物具有巨大潜力。
