Department of Hematology, Oncology and Tumor Immunology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
Institute of Immunology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
Cytotherapy. 2022 Aug;24(8):818-826. doi: 10.1016/j.jcyt.2022.03.005. Epub 2022 May 4.
Epstein-Barr virus (EBV) is associated with solid and hematopoietic malignancies. After allogeneic stem cell transplantation, EBV infection or reactivation represents a potentially life-threatening condition with no specific treatment available in clinical routine. In vitro expansion of naturally occurring EBV-specific T cells for adoptive transfer is time-consuming and influenced by the donor's T-cell receptor (TCR) repertoire and requires a specific memory compartment that is non-existent in seronegative individuals. The authors present highly efficient identification of EBV-specific TCRs that can be expressed on human T cells and recognize EBV-infected cells.
Mononuclear cells from six stem cell grafts were expanded in vitro with three HLA-B35:01- or four HLA-A02:01-presented peptides derived from six EBV proteins expressed during latent and lytic infection. Epitope-specific T cells expanded on average 42-fold and were single-cell-sorted and TCRαβ-sequenced. To confirm specificity, 11 HLA-B35:01- and six HLA-A02:01-restricted dominant TCRs were expressed on reporter cell lines, and 16 of 17 TCRs recognized their presumed target peptides. To confirm recognition of virus-infected cells and assess their value for adoptive therapy, three selected HLA-B35:01- and four HLA-A02:01-restricted TCRs were expressed on human peripheral blood lymphocytes. All TCR-transduced cells recognized EBV-infected lymphoblastoid cell lines.
The authors' approach provides sets of EBV epitope-specific TCRs in two different HLA contexts. Resulting cellular products do not require EBV-seropositive donors, can be adjusted to cell subsets of choice with exactly defined proportions of target-specific T cells, can be tracked in vivo and will help to overcome unmet clinical needs in the treatment and prophylaxis of EBV reactivation and associated malignancies.
EB 病毒（EBV）与实体瘤和血液系统恶性肿瘤有关。异基因造血干细胞移植后，EBV 感染或再激活是一种潜在的危及生命的疾病，临床常规治疗方法尚无特效药物。体外扩增天然存在的 EBV 特异性 T 细胞进行过继转移耗时较长，并且受到供体 T 细胞受体（TCR）库的影响，需要一个不存在于 EBV 血清阴性个体中的特定记忆区室。作者提出了一种高效的 EBV 特异性 TCR 鉴定方法，该方法可以在人 T 细胞上表达并识别 EBV 感染的细胞。
从 6 例干细胞移植供者的单个核细胞中体外扩增，用 3 种 HLA-B35:01-或 4 种 HLA-A02:01 呈递的肽段，这些肽段来源于潜伏和裂解感染期间表达的 6 种 EBV 蛋白。平均扩增 42 倍的抗原特异性 T 细胞进行单细胞分选和 TCRαβ 测序。为了确认特异性，将 11 种 HLA-B35:01-和 6 种 HLA-A02:01 限制性优势 TCR 在报告细胞系上表达，17 个 TCR 中有 16 个识别其假定的靶肽。为了确认对病毒感染细胞的识别，并评估其用于过继治疗的价值，将 3 种选定的 HLA-B35:01-和 4 种 HLA-A02:01 限制性 TCR 在人外周血淋巴细胞上表达。所有 TCR 转导的细胞均识别 EBV 感染的淋巴母细胞系。
作者的方法提供了两种不同 HLA 背景下的 EBV 表位特异性 TCR 组。由此产生的细胞产物不需要 EBV 血清阳性供者，可以根据选择的细胞亚群进行调整，具有确切定义比例的靶特异性 T 细胞，可在体内进行跟踪，并将有助于满足 EBV 再激活及相关恶性肿瘤治疗和预防方面的未满足的临床需求。
