Li Qiongshu, Liu Muyun, Wu Man, Zhou Xin, Wang Shaobin, Hu Yuan, Wang Youfu, He Yixin, Zeng Xiaoping, Chen Junhui, Liu Qubo, Xiao Dong, Hu Xiang, Liu Weibin
Shenzhen Beike Cell Engineering Research Institute, Shenzhen, Guangdong 518057, P.R. China.
Guangdong Provincial Key Laboratory of Cancer Immunotherapy Research and Guangzhou Key Laboratory of Tumor Immunology Research, Cancer Research Institute, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
Oncol Lett. 2018 Apr;15(4):5924-5932. doi: 10.3892/ol.2018.8075. Epub 2018 Feb 16.
Placenta-specific 1 (PLAC1), a novel cancer-testis antigen (CTA), is expressed in a number of different human malignancies. It is frequently produced in breast cancer, serving a function in tumorigenesis. Adoptive immunotherapy using T cell receptor (TCR)-engineered T cells against CTA mediates objective tumor regression; however, to the best of our knowledge, targeting PLAC1 using engineered T cells has not yet been attempted. In the present study, the cDNAs encoding TCRα- and β-chains specific for human leukocyte antigen (HLA)-A*0201-restricted PLAC1 were cloned from a cytotoxic T-lymphocyte, generated by by the stimulation of CD8+ T cells using autologous HLA-A2+ dendritic cells loaded with a PLAC1-specific peptide (p28-36, VLCSIDWFM). The TCRα/β-chains were linked by a 2A peptide linker (TCRα-Thosea asigna virus-TCRβ), and the constructs were cloned into the lentiviral vector, followed by transduction into human cytotoxic (CD8+) T cells. The efficiency of transduction was up to 25.16%, as detected by PLAC1 multimers. TCR-transduced CD8+ T cells, co-cultured with human non-metastatic breast cancer MCF-7 cells (PLAC1+, HLA-A2+) and triple-negative breast cancer MDAMB-231 cells (PLAC1+, HLA-A2+), produced interferon γ and tumor necrosis factor α, suggesting TCR activation. Furthermore, the PLAC1 TCR-transduced CD8+ T cells efficiently and specifically identified and annihilated the HLA-A2+/PLAC1+ breast cancer cell lines in a lactate dehydrogenase activity assay. Western blot analysis demonstrated that TCR transduction stimulated the production of mitogen-activated protein kinase signaling molecules, extracellular signal-regulated kinases 1/2 and nuclear factor-κB, through phosphoinositide 3-kinase γ-mediated phosphorylation of protein kinase B in CD8+ T cells. Xenograft mouse assays revealed that PLAC1 TCR-transduced CD8+T cells significantly delayed the tumor progression in mice-bearing breast cancer compared with normal saline or negative control-transduced groups. In conclusion, a novel HLA-A2-restricted and PLAC1-specific TCR was identified. The present study demonstrated PLAC1 to be a potential target for breast cancer treatment; and the usage of PLAC1-specific TCR-engineered T cells may be a novel strategy for PLAC1-positive breast cancer treatment.
胎盘特异性1（PLAC1）是一种新型的癌胚抗原（CTA），在多种不同的人类恶性肿瘤中表达。它在乳腺癌中经常产生，在肿瘤发生中发挥作用。使用针对CTA的工程化T细胞受体（TCR）的过继性免疫疗法可介导客观的肿瘤消退；然而，据我们所知，尚未尝试使用工程化T细胞靶向PLAC1。在本研究中，从细胞毒性T淋巴细胞中克隆了编码针对人类白细胞抗原（HLA）-A*0201限制性PLAC1的TCRα和β链的cDNA，该细胞毒性T淋巴细胞是通过使用负载有PLAC1特异性肽（p28-36，VLCSIDWFM）的自体HLA-A2+树突状细胞刺激CD8+T细胞产生的。TCRα/β链通过2A肽接头（TCRα-茶翅蛾病毒-TCRβ）连接，并将构建体克隆到慢病毒载体中，随后转导到人细胞毒性（CD8+）T细胞中。通过PLAC1多聚体检测，转导效率高达25.16%。将TCR转导的CD8+T细胞与人类非转移性乳腺癌MCF-7细胞（PLAC1+，HLA-A2+）和三阴性乳腺癌MDAMB-231细胞（PLAC1+，HLA-A2+）共培养，可产生干扰素γ和肿瘤坏死因子α，提示TCR激活。此外，在乳酸脱氢酶活性测定中，PLAC1 TCR转导的CD8+T细胞能有效且特异性地识别并消灭HLA-A2+/PLAC1+乳腺癌细胞系。蛋白质印迹分析表明，TCR转导通过磷酸肌醇3激酶γ介导的蛋白激酶B磷酸化刺激了丝裂原活化蛋白激酶信号分子、细胞外信号调节激酶1/2和核因子κB在CD8+T细胞中的产生。异种移植小鼠试验显示，与生理盐水或阴性对照转导组相比，PLAC1 TCR转导的CD8+T细胞显著延缓了荷乳腺癌小鼠的肿瘤进展。总之，鉴定出了一种新型的HLA-A2限制性且PLAC1特异性的TCR。本研究表明PLAC1是乳腺癌治疗的潜在靶点；使用PLAC1特异性TCR工程化T细胞可能是PLAC1阳性乳腺癌治疗的一种新策略。
