PD-1 blockade restores impaired function of ex vivo expanded CD8(+) T cells and enhances apoptosis in mismatch repair deficient EpCAM(+)PD-L1(+) cancer cells.
PD-1 blockade restores impaired function of ex vivo expanded CD8(+) T cells and enhances apoptosis in mismatch repair deficient EpCAM(+)PD-L1(+) cancer cells.
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PD-1阻断可恢复离体扩增的CD8 T细胞受损的功能，并增强错配修复缺陷的EpCACAM PD-L1癌细胞的凋亡
DOI：
10.2147/ott.s130131
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发表时间：
2017
影响因子：
4
通讯作者：
Xiu J
中科院分区：
文献类型：
--
作者：
Kumar R;Yu F;Zhen YH;Li B;Wang J;Yang Y;Ge HX;Hu PS;Xiu J
近年来，过继T细胞治疗已被证明是一种很有前途的治疗癌症的方式。然而，抑制受体的表达增加可以负向调节转移T细胞的功能和持久性，介导T细胞的能量、衰竭和肿瘤消退。在这项研究中，我们研究了阻断PD-1后有效免疫治疗后细胞毒性活性的增加。PD-1阻断后，扩增的CD8+ ctl的细胞毒功能和与肿瘤细胞的相互作用被研究。体外扩增的CD8+ ctl与错配修复（MMR）稳定或缺陷（高微卫星不稳定性[MSI-H]）的EpCAM+肿瘤细胞共培养。采用酶联免疫吸附斑点法检测IFN-γ和GrB水平。流式细胞术和共聚焦显微镜用于评估CD107a的动员、胞质摄取和细胞迁移。在体外扩增过程中，观察到CD8+ ctl表面PD-1表达急剧增加。CD8+ ctl与单克隆抗体孵养后，PD-1水平下调约40%，增强IFN-γ、GrB和CD107a的分泌。此外，PD-1阻断增强了CD8+ ctl与MMR缺陷（MSI-H） EpCAM+PD-L1+肿瘤细胞之间的细胞迁移和胞质交换。阻断PD-1可增强CD8+ ctl对MMR缺陷肿瘤细胞的细胞毒作用。总之，我们提出在CD8+ ctl扩增过程中阻断PD-1可能会提高基于细胞的过继免疫治疗的临床疗效。
Adoptive T cell therapy has been proven to be a promising modality for the treatment of cancer patients in recent years. However, the increased expression of inhibitory receptors could negatively regulate the function and persistence of transferred T cells which mediates T cell anergy, exhaustion, and tumor regression. In this study, we investigated increased cytotoxic activity after the blockade of PD-1 for effective immunotherapy. The cytotoxic function of expanded CD8+ CTLs and interactions with tumor cells investigated after blocking of PD-1. Ex vivo expanded CD8+ CTLs were co-cultured with mismatch repair (MMR) stable or deficient (high microsatellite instability [MSI-H]) EpCAM+ tumor cells. The levels of IFN-γ and GrB were detected by enzyme-linked immunosorbent spot assay. Flow cytometry and confocal microscopy were used to assess CD107a mobilization, cytosolic uptake, and cell migration. A dramatic increase in PD-1 expression on the surface of CD8+ CTLs during ex vivo expansion was observed. PD-1 level was downregulated by approximately 40% after incubation of the CD8+ CTLs with monoclonal antibody which enhanced the secretion of IFN-γ, GrB, and CD107a. Additionally, PD-1 blockade enhanced cell migration and cytosolic exchange between CD8+ CTLs and MMR deficient (MSI-H) EpCAM+PD-L1+ tumor cells. The blockade of PD-1 enhanced the cytotoxic efficacy of CD8+ CTLs toward MMR deficient tumor cells. In conclusion, we propose that blocking of PD-1 during the expansion of CD8+ CTLs may improve the clinical efficacy of cell-based adoptive immunotherapy.