Despite advances in antibody treatments and vaccines, COVID-19 caused by SARS-CoV-2 infection remains a major health problem resulting in excessive morbidity and mortality and the emergence of new variants has reduced the effectiveness of current vaccines. Here, as a proof-of-concept we engineered primary CD8 T cells to express SARS-CoV-2 Spike protein-specific CARs, using extracellular region of ACE2, and demonstrated their highly specific and potent cytotoxicity towards Spike-expressing target cells. To improve on this concept as a potential therapeutic, we developed a bispecific T cell engager combining ACE2 with an anti-CD3 scFv (ACE2-Bite) to target infected cells and the virus. Similar to CAR-T cell approach, ACE2-Bite endowed cytotoxic cells to selectively kill Spike-expressing targets. Furthermore, ACE2-Bite neutralized the pseudoviruses of SARS-CoV, SARS-CoV-2 wild-type and variants including Delta and Omicron, as a decoy protein. Remarkably, ACE2-Bite molecule showed a higher binding and neutralization affinity to Delta and Omicron variants compared to SARS-CoV-2 wild-type Spike proteins, suggesting the potential of this approach as a variant-proof, therapeutic strategy for future SARS-CoV-2 variants, employing both humoral and cellular arms of the adaptive immune response.

中文翻译：

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通过结合 ACE2 的 CAR-T 类双特异性 T 细胞接合剂靶向 SARS-CoV-2 感染

尽管抗体治疗和疫苗取得了进展，但由 SARS-CoV-2 感染引起的 COVID-19 仍然是一个主要的健康问题，导致发病率和死亡率过高，并且新变种的出现降低了当前疫苗的有效性。在这里，作为概念验证，我们使用 ACE2 的细胞外区域设计了原代 CD8 T 细胞以表达 SARS-CoV-2 Spike 蛋白特异性 CAR，并证明了它们对表达 Spike 的靶细胞具有高度特异性和强大的细胞毒性。为了改进这一概念作为一种潜在的治疗方法，我们开发了一种双特异性 T 细胞接合剂，将 ACE2 与抗 CD3 scFv (ACE2-Bite) 结合起来，以靶向感染细胞和病毒。与 CAR-T 细胞方法类似，ACE2-Bite 赋予细胞毒性细胞选择性地杀死表达 Spike 的靶标。此外，ACE2-Bite 作为诱饵蛋白中和了 SARS-CoV、SARS-CoV-2 野生型和变体（包括 Delta 和 Omicron）的假病毒。值得注意的是，与 SARS-CoV-2 野生型 Spike 蛋白相比，ACE2-Bite 分子对 Delta 和 Omicron 变体显示出更高的结合和中和亲和力，这表明这种方法有可能成为未来 SARS-CoV 的变体证明和治疗策略-2 变体，采用适应性免疫反应的体液和细胞臂。