Polymorphisms in the human leukocyte antigen (HLA) class I genes can cause the rejection of pluripotent stem cell (PSC)-derived products in allogeneic recipients. Disruption of the Beta-2 Microglobulin (B2M) gene eliminates surface expression of all class I molecules, but leaves the cells vulnerable to lysis by natural killer (NK) cells. Here we show that this 'missing-self' response can be prevented by forced expression of minimally polymorphic HLA-E molecules. We use adeno-associated virus (AAV)-mediated gene editing to knock in HLA-E genes at the B2M locus in human PSCs in a manner that confers inducible, regulated, surface expression of HLA-E single-chain dimers (fused to B2M) or trimers (fused to B2M and a peptide antigen), without surface expression of HLA-A, B or C. These HLA-engineered PSCs and their differentiated derivatives are not recognized as allogeneic by CD8⁺ T cells, do not bind anti-HLA antibodies and are resistant to NK-mediated lysis. Our approach provides a potential source of universal donor cells for applications where the differentiated derivatives lack HLA class II expression.

中文翻译：

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表达HLA-E的多能干细胞逃脱了同种异体反应并被NK细胞裂解

人类白细胞抗原（HLA）I类基因中的多态性可导致异源受体中多能干细胞（PSC）衍生产物的排斥。Beta-2微球蛋白（B2M）基因的破坏消除了所有I类分子的表面表达，但使细胞易于被自然杀伤（NK）细胞裂解。在这里，我们表明可以通过强制表达最小多态性HLA-E分子来防止这种“自我缺失”反应。我们使用腺相关病毒（AAV）介导的基因编辑来敲除B2M处的HLA-E基因以赋予HLA-E单链二聚体（与B2M融合）或三聚体（与B2M和一种肽抗原融合）的可诱导的，调控的表面表达的方式在人PSC中定位，而没有HLA-A，B或C.这些HLA改造的PSC及其分化的衍生物未被CD8 ⁺ T细胞识别为同种异体，不结合抗HLA抗体并且对NK介导的裂解具有抗性。我们的方法为分化的衍生物缺乏HLA II类表达的应用提供了通用供体细胞的潜在来源。