Department of Pathology, Immunology and Laboratory Medicine, Newark, NJ, United States.
School of Graduate Studies, Rutgers Biomedical and Health Sciences, Newark, NJ, United States.
Front Immunol. 2021 Jul 23;12:652223. doi: 10.3389/fimmu.2021.652223. eCollection 2021.
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is highly contagious and presents a significant public health issue. Current therapies used to treat coronavirus disease 2019 (COVID-19) include monoclonal antibody cocktail, convalescent plasma, antivirals, immunomodulators, and anticoagulants. The vaccines from Pfizer and Moderna have recently been authorized for emergency use, which are invaluable for the prevention of SARS-CoV-2 infection. However, their long-term side effects are not yet documented, and populations with immunocompromised conditions (e.g., organ-transplantation and immunodeficient patients) may not be able to mount an effective immune response. In addition, there are concerns that wide-scale immunity to SARS-CoV-2 may introduce immune pressure that could select for escape mutants to the existing vaccines and monoclonal antibody therapies. Emerging evidence has shown that chimeric antigen receptor (CAR)- natural killer (NK) immunotherapy has potent antitumor response in hematologic cancers with minimal adverse effects in recent studies, however, the potentials of CAR-NK cells in treating COVID-19 has not yet been fully exploited. Here, we improve upon a novel approach for the generation of CAR-NK cells for targeting SARS-CoV-2 and its various mutants. CAR-NK cells were generated using the scFv domain of S309 (henceforward, S309-CAR-NK), a SARS-CoV and SARS-CoV-2 neutralizing antibody (NAbs) that targets the highly conserved region of SARS-CoV-2 spike (S) glycoprotein and is therefore more likely to recognize different variants of SARS-CoV-2 isolates. S309-CAR-NK cells can specifically bind to pseudotyped SARS-CoV-2 virus and its D614G, N501Y, and E484K mutants. Furthermore, S309-CAR-NK cells can specifically kill target cells expressing SARS-CoV-2 S protein and show superior killing activity and cytokine production, compared to that of the recently reported CR3022-CAR-NK cells. Thus, these results pave the way for generating 'off-the-shelf' S309-CAR-NK cells for treatment in high-risk individuals as well as provide an alternative strategy for patients unresponsive to current vaccines.
严重急性呼吸系统综合症冠状病毒 2 型（SARS-CoV-2）具有高度传染性，是一个重大的公共卫生问题。目前用于治疗 2019 年冠状病毒病（COVID-19）的疗法包括单克隆抗体鸡尾酒疗法、恢复期血浆、抗病毒药物、免疫调节剂和抗凝剂。辉瑞（Pfizer）和莫德纳（Moderna）的疫苗最近已被授权紧急使用，这对于预防 SARS-CoV-2 感染非常有价值。然而，它们的长期副作用尚未记录在案，免疫功能低下的人群（例如器官移植和免疫缺陷患者）可能无法产生有效的免疫反应。此外，人们担心对 SARS-CoV-2 的广泛免疫可能会产生免疫压力，从而选择逃避现有疫苗和单克隆抗体疗法的突变体。新出现的证据表明，嵌合抗原受体（CAR）-自然杀伤（NK）免疫疗法在血液系统癌症中具有强大的抗肿瘤反应，且在最近的研究中副作用极小，然而，CAR-NK 细胞在治疗 COVID-19 方面的潜力尚未得到充分利用。在这里，我们改进了一种针对 SARS-CoV-2 及其各种突变体的新型 CAR-NK 细胞生成方法。使用针对 SARS-CoV 和 SARS-CoV-2 的中和抗体（NAbs）S309 的 scFv 结构域（以下简称 S309-CAR-NK）生成 CAR-NK 细胞，该抗体针对 SARS-CoV-2 刺突（S）糖蛋白的高度保守区域，因此更有可能识别不同的 SARS-CoV-2 分离株变体。S309-CAR-NK 细胞可以特异性结合假型 SARS-CoV-2 病毒及其 D614G、N501Y 和 E484K 突变体。此外，S309-CAR-NK 细胞可以特异性杀伤表达 SARS-CoV-2 S 蛋白的靶细胞，并表现出优于最近报道的 CR3022-CAR-NK 细胞的杀伤活性和细胞因子产生。因此，这些结果为高危人群生成“现成”的 S309-CAR-NK 细胞用于治疗铺平了道路，并为对当前疫苗无反应的患者提供了另一种策略。
