Wang Fangming, Xing Nianzeng, Li Jianxing
Department of Urology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China.
Department of Urology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Front Immunol. 2025 May 21;16:1572676. doi: 10.3389/fimmu.2025.1572676. eCollection 2025.
Castration-resistant prostate cancer (CRPC) has a poor prognosis and requires novel therapeutic approaches. Previously, we discovered that a high dose of human peripheral blood-derived natural killer (PB-NK) cells can have antitumor effects against CRPC. However, whether antibodies against prostate-specific membrane antigen (PSMA) can direct adoptive NK cells to the tumor site and therefore decrease NK cell dosage through antibody-dependent cellular cytotoxicity remains unknown.
NK cells were obtained from the blood samples of healthy donors. To engineer an anti-PSMA antibody (Ab), a llama was immunized with human PSMA protein, and the anti-PSMA variable domains of camelid heavy-chain antibody (VHH) clones were isolated using phage display. The VHH was recombinantly fused with the human Fc region to produce an anti-PSMA Ab. , NK cell cytotoxicity was evaluated using cell counting kit-8. Levels of cytokines and prostate-specific antigen (PSA) were determined using ELISA. The expression of CD107a and CD16 (the Ab Fc-receptor) in NK cells and the Ab affinity were detected using flow cytometry. Antitumor effects were evaluated in patient-derived organoid (PDO) models and in 22RV1 tumor-bearing mice .
We constructed an anti-PSMA Ab and validated its high affinity toward the PSMA antigen. CD16 is abundantly expressed in PB-NK cells. The anti-PSMA Ab significantly enhanced the cytotoxicity of NK cells against CRPC cells , evidenced by increased killing rate, upregulation of the degranulation marker CD107a, increased secretion of interferon-γ, and decreased PSA levels. Furthermore, our combined treatment showed powerful antitumor effects in PDO and CRPC xenograft mouse models.
Combined treatment with anti-PSMA Ab and human PB-NK cells improves antitumor efficacy against CRPC and is a promising approach to treating CRPC in clinical settings.
去势抵抗性前列腺癌（CRPC）预后较差，需要新的治疗方法。此前，我们发现高剂量的人外周血来源的自然杀伤（PB-NK）细胞对CRPC具有抗肿瘤作用。然而，抗前列腺特异性膜抗原（PSMA）抗体是否能将过继性NK细胞导向肿瘤部位，从而通过抗体依赖性细胞毒性降低NK细胞剂量仍不清楚。
从健康供体的血液样本中获取NK细胞。为构建抗PSMA抗体（Ab），用人类PSMA蛋白免疫一只美洲驼，并用噬菌体展示法分离骆驼科动物重链抗体（VHH）克隆的抗PSMA可变区。将VHH与人Fc区重组融合以产生抗PSMA抗体。使用细胞计数试剂盒-8评估NK细胞的细胞毒性。使用酶联免疫吸附测定法测定细胞因子和前列腺特异性抗原（PSA）水平。使用流式细胞术检测NK细胞中CD107a和CD16（抗体Fc受体）的表达以及抗体亲和力。在患者来源的类器官（PDO）模型和22RV1荷瘤小鼠中评估抗肿瘤作用。
我们构建了一种抗PSMA抗体，并验证了其对PSMA抗原的高亲和力。CD16在PB-NK细胞中大量表达。抗PSMA抗体显著增强了NK细胞对CRPC细胞的细胞毒性，表现为杀伤率增加、脱颗粒标志物CD107a上调、干扰素-γ分泌增加以及PSA水平降低。此外，我们的联合治疗在PDO和CRPC异种移植小鼠模型中显示出强大的抗肿瘤作用。
抗PSMA抗体与人PB-NK细胞联合治疗可提高对CRPC的抗肿瘤疗效，是临床治疗CRPC的一种有前景的方法。
