Product Development Division, LucasBio Co., Ltd., Seoul, South Korea.
Division of Respiratory, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
Front Immunol. 2021 Dec 23;12:751869. doi: 10.3389/fimmu.2021.751869. eCollection 2021.
Immunological characteristics of COVID-19 show pathological hyperinflammation associated with lymphopenia and dysfunctional T cell responses. These features provide a rationale for restoring functional T cell immunity in COVID-19 patients by adoptive transfer of SARS-CoV-2 specific T cells.
To generate SARS-CoV-2 specific T cells, we isolated peripheral blood mononuclear cells from 7 COVID-19 recovered and 13 unexposed donors. Consequently, we stimulated cells with SARS-CoV-2 peptide mixtures covering spike, membrane and nucleocapsid proteins. Then, we culture expanded cells with IL-2 for 21 days. We assessed immunophenotypes, cytokine profiles, antigen specificity of the final cell products.
Our results show that SARS-CoV-2 specific T cells could be expanded in both COVID-19 recovered and unexposed groups. Immunophenotypes were similar in both groups showing CD4+ T cell dominance, but CD8+ and CD3+CD56+ T cells were also present. Antigen specificity was determined by ELISPOT, intracellular cytokine assay, and cytotoxicity assays. One out of 14 individuals who were previously unexposed to SARS-CoV-2 failed to show antigen specificity. Moreover, ex-vivo expanded SARS-CoV-2 specific T cells mainly consisted of central and effector memory subsets with reduced alloreactivity against HLA-unmatched cells suggesting the possibility for the development of third-party partial HLA-matching products.
In conclusion, our findings show that SARS-CoV-2 specific T cell can be readily expanded from both COVID-19 and unexposed individuals and can therefore be manufactured as a biopharmaceutical product to treat severe COVID-19 patients.
Ex-vivo expanded SARS-CoV-2 antigen specific T cells developed as third-party partial HLA-matching products may be a promising approach for treating severe COVID-19 patients that do not respond to previous treatment options.
COVID-19 的免疫学特征表现为与淋巴细胞减少和 T 细胞功能障碍相关的病理性过度炎症。这些特征为通过过继转移 SARS-CoV-2 特异性 T 细胞来恢复 COVID-19 患者的功能性 T 细胞免疫提供了依据。
为了产生 SARS-CoV-2 特异性 T 细胞，我们从 7 名 COVID-19 康复者和 13 名未接触者的外周血单核细胞中分离出来。随后，我们用涵盖刺突、膜和核衣壳蛋白的 SARS-CoV-2 肽混合物刺激细胞。然后，我们用 IL-2 将细胞培养扩增 21 天。我们评估了最终细胞产物的免疫表型、细胞因子谱和抗原特异性。
我们的结果表明，SARS-CoV-2 特异性 T 细胞可以在 COVID-19 康复者和未接触者两组中扩增。两组的免疫表型相似，均表现为 CD4+ T 细胞优势，但也存在 CD8+和 CD3+CD56+ T 细胞。抗原特异性通过 ELISPOT、细胞内细胞因子测定和细胞毒性测定来确定。在之前未接触过 SARS-CoV-2 的 14 个人中，有 1 个人未能显示抗原特异性。此外，体外扩增的 SARS-CoV-2 特异性 T 细胞主要由中央和效应记忆亚群组成，对 HLA 不匹配的细胞的同种异体反应性降低，这表明有可能开发出第三方部分 HLA 匹配产品。
总之，我们的发现表明，SARS-CoV-2 特异性 T 细胞可以从 COVID-19 康复者和未接触者中轻易扩增，因此可以作为生物制药产品来治疗对先前治疗方案无反应的严重 COVID-19 患者。
作为第三方部分 HLA 匹配产品开发的体外扩增 SARS-CoV-2 抗原特异性 T 细胞可能是治疗对先前治疗方案无反应的严重 COVID-19 患者的一种很有前途的方法。
