Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, OH, USA
The Center of Lymphoma and Multiple Myeloma, ChangZheng Hospital, The Second Military Medical University, Shanghai, P. R. China
Haematologica. 2021 Mar 1;106(3):838-846. doi: 10.3324/haematol.2019.236836.
Dickkopf-1 (DKK1), broadly expressed by tumor cells from human multiple myeloma (MM) and other cancers but absent from most normal tissues, may be an ideal target for immunotherapy. Our previous studies have shown that DKK1 (peptide)-specific cytotoxic T lymphocytes can effectively lyse primary MM cells in vitro. To develop DKK1-based vaccines that can be easily and inexpensively made and used by all patients, we identified a DKK1 long peptide (LP), DKK13-76-LP, that contains 74 amino acids and epitopes that can potentially bind to all major MHC class I and II molecules. Using HLA-A0201- and HLA-DR4-transgenic mouse models, we found that DKK1-specific CD4+ and CD8+ T-cell responses, detected by DKK1 short peptide (P20 and P66v)-HLA-A*0201 tetramer staining and cytotoxic assay for CD8+ T cells or by carboxyfluorescein diacetate succinimidyl ester (CSFE) dilution and IFN-g secretion for CD4+ T cells, respectively, can be induced in vivo by immunizing mice with the DKK13-76-LP. In addition, DKK13-76-LP also induced anti-DKK1 humoral immunity in the transgenic mice and the DKK1 antibodies were functional. Finally, DKK13-76-LP stimulated human blood T cells ex vivo to generate DKK1-specific CD4+ and CD8+ T-cell responses from 8 out of 10 MM patients with different MHC backgrounds. The generated DKK1-specific CD8+ cells efficiently lysed autologous MM cells from these patients. Thus, these results confirm the immunogenicity of the DKK13-76-LP in eliciting DKK1-specific CD4+ and CD8+ T-cell responses in vitro and in vivo, and suggest that the DKK13-76-LP can be used for immunotherapy of MM and other cancers.
Dickkopf-1（DKK1）广泛表达于人类多发性骨髓瘤（MM）和其他癌症的肿瘤细胞中，但在大多数正常组织中不存在，可能是免疫治疗的理想靶点。我们之前的研究表明，DKK1（肽）特异性细胞毒性 T 淋巴细胞可以有效地体外溶解原发性 MM 细胞。为了开发基于 DKK1 的疫苗，使其易于制造且所有患者都可以负担得起和使用，我们鉴定了一个 DKK1 长肽（LP），DKK13-76-LP，它包含 74 个氨基酸和表位，可能与所有主要的 MHC Ⅰ类和Ⅱ类分子结合。使用 HLA-A0201-和 HLA-DR4-转基因小鼠模型，我们发现 DKK1 特异性 CD4+和 CD8+T 细胞反应，可以通过 DKK1 短肽（P20 和 P66v）-HLA-A*0201 四聚体染色和 CD8+T 细胞的细胞毒性测定或通过羧基荧光素二乙酸琥珀酰亚胺酯（CSFE）稀释和 IFN-γ分泌来检测，分别可以通过用 DKK13-76-LP 免疫小鼠在体内诱导。此外，DKK13-76-LP 还在转基因小鼠中诱导了抗 DKK1 体液免疫，并且 DKK1 抗体具有功能。最后，DKK13-76-LP 刺激人外周血 T 细胞在体外从 10 名具有不同 MHC 背景的 MM 患者中的 8 名产生 DKK1 特异性 CD4+和 CD8+T 细胞反应。产生的 DKK1 特异性 CD8+细胞有效地从这些患者的自体 MM 细胞中溶解。因此，这些结果证实了 DKK13-76-LP 在体外和体内诱导 DKK1 特异性 CD4+和 CD8+T 细胞反应的免疫原性，并表明 DKK13-76-LP 可用于 MM 和其他癌症的免疫治疗。
