Department of Cancer Therapy and Research, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka, 812-8582, Japan.
Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
J Cancer Res Clin Oncol. 2023 Nov;149(16):14619-14630. doi: 10.1007/s00432-023-05250-8. Epub 2023 Aug 16.
In a previous study, protein tyrosine phosphatase non-receptor type (PTPN) 3 was identified as an immune checkpoint molecule in lymphocytes, and its potential as a novel target for cancer immunotherapy was anticipated. However, evaluation of dendritic cell (DC) function as antigen-presenting cells is critical for the development of immunotherapy. In this study, we aimed to analyze the biological effect of PTPN3 on DCs induced from human peripheral blood monocytes obtained from healthy individuals.
We used short-interfering RNA to knock down PTP3 in DCs. For DC maturation, we added cancer cell lysate and tumor necrosis factor-α/interferon-α to immature DCs. In the cytotoxic assay, the target cancer cells were SBC5, unmatched with DCs from healthy human leukocyte antigen (HLA)-A24, or Sq-1, matched with DCs. Enzyme-linked immunosorbent assay was used to determine the amount of cytokines. To examine the intracellular signaling system, intracellular staining was used.
PTPN3 knockdown significantly increased the number of DCs, expression of CD80 and chemokine receptor (CCR)7, and production of interleukin-12p40/p70 in mature DCs. In the HLA-A24-restricted DC and human lung squamous cell carcinoma cell cytotoxic assay, inhibition of PTPN3 expression in mature DCs induced cytotoxic T lymphocytes with increased production of INF-γ and granzyme B, and enhanced toxicity against cancer cells and migration to cancer. Furthermore, inhibition of PTPN3 expression activated the mitogen-activated protein kinase pathway in DCs.
Based on our findings, inhibition of PTPN3 expression could contribute to the development of novel cancer immunotherapies that activate not only lymphocytes but also DCs.
在之前的一项研究中，鉴定出蛋白酪氨酸磷酸酶非受体型（PTPN）3 是淋巴细胞中的一种免疫检查点分子，预计其可作为癌症免疫治疗的新靶点。然而，作为抗原呈递细胞的树突状细胞（DC）功能的评估对于免疫疗法的发展至关重要。在这项研究中，我们旨在分析 PTPN3 对来自健康个体外周血单核细胞诱导的 DC 的生物学影响。
我们使用短发夹 RNA 敲低 DC 中的 PTPN3。为了使 DC 成熟，我们将癌细胞裂解物和肿瘤坏死因子-α/干扰素-α添加到未成熟的 DC 中。在细胞毒性测定中，靶癌细胞为 SBC5，与健康人白细胞抗原（HLA）-A24 不匹配的 DC 或与 DC 匹配的 Sq-1。酶联免疫吸附测定用于确定细胞因子的量。为了检查细胞内信号转导系统，使用细胞内染色。
PTPN3 敲低显著增加了 DC 的数量、CD80 和趋化因子受体（CCR）7 的表达以及成熟 DC 中白细胞介素-12p40/p70 的产生。在 HLA-A24 限制性 DC 和人肺鳞状细胞癌细胞细胞毒性测定中，成熟 DC 中 PTPN3 表达的抑制诱导产生 IFN-γ和颗粒酶 B 的增加的细胞毒性 T 淋巴细胞，并增强对癌细胞的毒性和向癌细胞的迁移。此外，PTPN3 表达的抑制激活了 DC 中的丝裂原激活蛋白激酶途径。
根据我们的发现，抑制 PTPN3 的表达可能有助于开发不仅能激活淋巴细胞，而且能激活 DC 的新型癌症免疫疗法。
