Transplant and Stem Cell Immunobiology (TSI) Laboratory, Department of Surgery, University of California, San Francisco, San Francisco, CA, USA.
Immunogenetics and Transplantation Laboratory, Department of Surgery, University of California, San Francisco, San Francisco, CA, USA.
Nat Biotechnol. 2023 May;41(5):717-727. doi: 10.1038/s41587-022-01540-7. Epub 2023 Jan 2.
Allogeneic cell therapeutics for cancer therapy or regenerative medicine are susceptible to antibody-mediated killing, which diminishes their efficacy. Here we report a strategy to protect cells from antibody-mediated killing that relies on engineered overexpression of the IgG receptor CD64. We show that human and mouse iPSC-derived endothelial cells (iECs) overexpressing CD64 escape antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity from IgG antibodies in vitro and in ADCC-enabled mice. When CD64 expression was combined with hypoimmune genetic modifications known to protect against cellular immunity, B2MCIITA CD47/CD64-transgenic iECs were resistant to both IgG antibody-mediated and cellular immune killing in vitro and in humanized mice. Mechanistic studies demonstrated that CD64 or its intracellularly truncated analog CD64t effectively capture monomeric IgG and occupy their F, and the IgG bind and occupy their target antigens. In three applications of the approach, human CD64t-engineered thyroid epithelial cells, pancreatic beta cells and CAR T cells withstood clinically relevant levels of graft-directed antibodies and fully evaded antibody-mediated killing.
用于癌症治疗或再生医学的同种异体细胞治疗药物容易受到抗体介导的杀伤，从而降低其疗效。在这里，我们报告了一种保护细胞免受抗体介导的杀伤的策略，该策略依赖于 IgG 受体 CD64 的工程过表达。我们表明，过表达 CD64 的人 iPSC 衍生的内皮细胞 (iEC) 逃避了 IgG 抗体在体外和 ADCC 使能小鼠中的抗体依赖性细胞毒性 (ADCC) 和补体依赖性细胞毒性。当 CD64 表达与已知可抵抗细胞免疫的低免疫遗传修饰相结合时，B2MCIITA CD47/CD64 转基因 iEC 在体外和人源化小鼠中均对 IgG 抗体介导的和细胞免疫杀伤具有抗性。机制研究表明，CD64 或其细胞内截断类似物 CD64t 可有效捕获单体 IgG 并占据其 Fc，而 IgG 结合并占据其靶抗原。在该方法的三个应用中，人源 CD64t 工程甲状腺上皮细胞、胰腺β细胞和 CAR T 细胞能够抵抗临床相关水平的移植物靶向抗体，并完全逃避抗体介导的杀伤。
