Blocking expression of inhibitory receptor NKG2A overcomes tumor resistance to NK cells. Blocking expression of inhibitory receptor NKG2A overcomes tumor resistance to NK cells

A key mechanism of tumor resistance to immune cells is mediated by expression of peptide-loaded HLA-E in tumor cells, which suppresses natural killer (NK) cell activity via ligation of the NK inhibitory receptor CD94/NKG2A. To bypass HLA-E inhibition, we developed a way to generate highly functional NK cells lacking NKG2A. Constructs containing a single-chain variable fragment derived from an anti-NKG2A antibody were linked to endoplasmic reticulum-retention domains. After retroviral transduction in human peripheral blood NK cells, these NKG2A Protein Expression Blockers (PEBLs) abrogated NKG2A expression. The resulting NKG2Anull NK cells had higher cytotoxicity against HLA-E-expressing tumor cells. Overall design: We examined the expression of NK cell receptor in NKG2A-prified NK cells after transduction with PEBL or green fluorescent protein by using RNA-seq.

肿瘤对免疫细胞产生耐药性的关键机制之一，由肿瘤细胞表面表达的装载肽的人类白细胞抗原E（HLA-E）所介导：该分子可通过结合NK细胞抑制性受体CD94/NKG2A，抑制自然杀伤（NK）细胞的活性。为绕过HLA-E介导的免疫抑制，我们开发了一种制备缺失NKG2A的高功能NK细胞的方法。将源自抗NKG2A抗体的单链可变片段与内质网滞留结构域相连，构建得到重组载体。将该载体通过逆转录病毒转导至人外周血NK细胞后，这类NKG2A蛋白表达阻断剂（PEBLs）可有效消除细胞表面NKG2A的表达。所获得的NKG2A缺失型NK细胞，对表达HLA-E的肿瘤细胞展现出更强的细胞毒性。实验整体设计：我们通过RNA测序技术，分析了经PEBL或绿色荧光蛋白转导后的NK细胞中NK细胞受体的表达情况。