Department of Hematology, Second Affiliated Hospital, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China.
J Immunother. 2021 May 1;44(4):141-150. doi: 10.1097/CJI.0000000000000350.
Our previous research has shown that monocytic leukemia-associated antigen-34 (MLAA-34) was a novel antiapoptotic molecule with unique expression in acute monocytic leukemia (M5), making it an ideal target for T-cell-based immunotherapy. Here, we sought to identify HLA-A0201-restricted cytotoxic T-lymphocyte (CTL) epitope of MLAA-34 by reverse immunology. In all, 10 HLA-A0201 restricted epitopes of MLAA-34 were predicted by bioinformatics. MLAA-34324-332, MLAA-34293-301, and MLAA-34236-244 showed the strongest HLA-A0201-binding affinity. The percentages of HLA-A0201-MLAA-34236-244 tetramer+ CD8+ T cells in MLAA-34236-244-induced CTLs were raised apparently. Enzyme-linked immunospot showed that MLAA-34236-244 and MLAA-34324-332-specific CTLs produced a higher amount of interferon-γ. MLAA-34236-244-induced CTLs presented a stronger cytotoxic effect on THP-1 cells (HLA-A0201+MLAA-34+) at various effector to target ratios. MLAA-34236-244 peptide vaccine could inhibit the tumor growth and improve mean survival time of leukemia-bearing human peripheral blood lymphocyte reconstituting severe combined immunodeficient mice. Mice immunized with MLAA-34236-244 vaccine had increased percentages of MLAA-34236-244 tetramer+ CD8+ T cells in the spleen after each round of immunization. High-purity CD8+ and CD4+ T cells were sorted by Dynabeads as effector cells. The killing activity of CD8+ T cells was higher than that of CD4+ T cells. CTLs derived from the MLAA-34 peptide vaccine group were significantly higher than other therapeutic groups and showed specific cytotoxicity to THP-1 cells. Increased interferon-γ and interleukin (IL)-2 and decreased IL-10 and IL-4 were seen in the MLAA-34236-244 peptide vaccine group. MLAA-34236-244 peptide (ILDRHNFAI) is an effective HLA-A0201-restricted CTL epitope and that it may serve as a promising strategy in designing antigen-specific immunotherapy against MLAA-34-positive acute monocytic leukemia.
我们之前的研究表明，单核细胞白血病相关抗原-34（MLAA-34）是一种新型抗凋亡分子，在急性单核细胞白血病（M5）中具有独特的表达，使其成为基于 T 细胞的免疫治疗的理想靶点。在这里，我们试图通过反向免疫学来鉴定 MLAA-34 的 HLA-A0201 限制性细胞毒性 T 淋巴细胞（CTL）表位。通过生物信息学共预测了 10 个 MLAA-34 的 HLA-A0201 限制性表位。MLAA-34324-332、MLAA-34293-301 和 MLAA-34236-244 显示出最强的 HLA-A0201 结合亲和力。在 MLAA-34236-244 诱导的 CTL 中，HLA-A0201-MLAA-34236-244 四聚体+ CD8+T 细胞的百分比明显升高。酶联免疫斑点法显示，MLAA-34236-244 和 MLAA-34324-332 特异性 CTL 产生了更高量的干扰素-γ。在各种效应物与靶物比值下，MLAA-34236-244 诱导的 CTL 对 THP-1 细胞（HLA-A0201+MLAA-34+）表现出更强的细胞毒性作用。MLAA-34236-244 肽疫苗可抑制肿瘤生长并提高白血病荷用人外周血淋巴细胞重建严重联合免疫缺陷小鼠的平均生存时间。用 MLAA-34236-244 疫苗免疫的小鼠在每轮免疫后脾脏中 MLAA-34236-244 四聚体+ CD8+T 细胞的百分比增加。通过 Dynabeads 分离出高纯度的 CD8+和 CD4+T 细胞作为效应细胞。CD8+T 细胞的杀伤活性高于 CD4+T 细胞。来自 MLAA-34 肽疫苗组的 CTL 明显高于其他治疗组，并对 THP-1 细胞表现出特异性细胞毒性。在 MLAA-34236-244 肽疫苗组中观察到干扰素-γ和白细胞介素（IL）-2 增加，IL-10 和 IL-4 减少。MLAA-34236-244 肽（ILDRHNFAI）是一种有效的 HLA-A0201 限制性 CTL 表位，可能是针对 MLAA-34 阳性急性单核细胞白血病设计抗原特异性免疫治疗的有前途的策略。
