Current immunotherapy has limited efficacy on metastatic castrate-resistant prostate cancer (mCRPC). We therefore sought to improve the antitumor ability of mCRPC patient-derived CD8⁺ T-cells by the endowment of specificity to prostate-specific membrane antigen (PSMA) and insensitivity to immunosuppressant molecule transforming growth factor-β (TGF-ß) under the control of herpes simplex virus-1 thymidine kinase. CD8⁺ T-cells were collected by leukapheresis and cultured in a Food and Drug Administration-approved Cell Processing Work Station. We developed a chimeric antigen receptor retroviral construct using an anti-PSMA chimeric immunoglobulin-T-cell receptor(ζ) gene (PZ1) and dominant negative TGF-ß type II receptor (TßRIIDN), that could induce CD8⁺ T-cells to be PSMA reactive and insensitive to TGF-ß. Cr⁵¹ release assay was performed on PC-3 and PC-3-PSMA. The further antitumor functions of PSMA-specific, TGF-ß insensitive CD8⁺ T-cells was evaluated using an immunodeficient RAG-1^–/– mouse model. We found PSMA-specific, TGF-ß insensitive CD8⁺ T-cells from mCRPC were expanded with strong expression of PZ1 and thymidine kinase genes, and their growth was not suppressed by TGF-ß. The survival of these cells decreased sharply after treatment with ganciclovir. Treatment of PSMA-specific TGF-ß, insensitive CD8⁺ T-cells was associated with 61.58% specific lysis on PC-3-PSMA, and significantly suppressed PC3-PSMA tumor compared with the PC3 tumor. A large amount of tumor apoptosis and CD8⁺ T-cell infiltration were found only in the PC3-PSMA tumor. This study verified that PSMA-specific, TGF-ß insensitive CD8⁺ T-cells derived from mCRPC patients could be successfully expanded and used to overcome the immunosuppressive effects of the tumor microenvironment to control PSMA-expressing PC in vitro and in vivo. This may provide a promising approach for men with mCRPC who fail androgen deprivation therapy.

Patient summary

We investigated the role of a novel chimeric antigen receptor T-immunotherapy based on autologous metastatic castrate-resistant prostate cancer patient-derived prostate-specific membrane antigen (PSMA)-specific, transforming growth factor-ß insensitive CD8⁺ T-cells on PSMA-positive prostate cancer. We found that this chimeric antigen receptor T-cells could kill PSMA-positive prostate cancer specifically. The results suggest that this novel immunotherapy treatment is a potential new approach for men with metastatic castrate-resistant prostate cancer.

中文翻译：

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前列腺特异的膜抗原特异的，转化性生长因子-β不敏感的遗传靶向CD8 ⁺ T细胞从人类转移性去势抵抗性疾病患者那里获得的抗人前列腺癌的功效

当前的免疫疗法对转移性去势抵抗性前列腺癌（mCRPC）的疗效有限。因此，我们试图通过赋予对前列腺特异性膜抗原（PSMA）的特异性和对免疫抑制剂分子转化生长因子-β（TGF-ß）的不敏感性来改善mCRPC患者来源的CD8 ⁺ T细胞的抗肿瘤能力单纯疱疹病毒1胸苷激酶 通过白细胞分离术收集CD8 ⁺ T细胞，并在食品和药物管理局批准的细胞加工工作站中进行培养。我们使用抗PSMA嵌合免疫球蛋白T细胞受体（ζ）基因（PZ1）和显性的负性TGF-βII型受体（TßRIIDN），该受体可能诱导CD8 ⁺ T细胞对PSMA具有反应性，并且对TGF-ß不敏感。在PC-3和PC-3-PSMA上进行了Cr ⁵¹释放测定。使用免疫缺陷型RAG-1 ^{– / –}小鼠模型评估了PSMA特异性，TGF-β不敏感的CD8 ⁺ T细胞的其他抗肿瘤功能。我们发现来自mCRPC的PSMA特异性TGF-β不敏感CD8 ⁺ T细胞随着PZ1和胸苷激酶基因的强表达而扩增，并且它们的生长不受TGF-β抑制。用更昔洛韦处理后，这些细胞的存活率急剧下降。治疗PSMA特异性TGF-ß，不敏感的CD8⁺ T细胞与PC-3-PSMA上的61.58％特异性裂解相关，与PC3肿瘤相比，可显着抑制PC3-PSMA肿瘤。仅在PC3-PSMA肿瘤中发现大量的肿瘤细胞凋亡和CD8 ⁺ T细胞浸润。这项研究证实，可以成功地扩增源自mCRPC患者的PSMA特异性，TGF-β不敏感的CD8 ⁺ T细胞，并用于克服肿瘤微环境的免疫抑制作用，以在体外和体内控制表达PSMA的PC。这可能为雄激素剥夺治疗失败的mCRPC男性提供一种有前途的方法。

病人总结

我们研究了基于自体转移去势抵抗性前列腺癌患者衍生的前列腺特异性膜抗原（PSMA）特异性，转化生长因子-β不敏感的CD8 ⁺ T细胞对自体转移性去势抵抗性前列腺癌患者的新型嵌合抗原受体T免疫疗法的作用。前列腺癌阳性。我们发现，这种嵌合抗原受体T细胞可以特异性杀死PSMA阳性的前列腺癌。结果表明，这种新颖的免疫疗法对于转移性去势抵抗性前列腺癌的男性是一种潜在的新方法。