Kowash Ryan R, Sabnani Manoj, Gray Laura T, Deng Qing, Saleh Nusrat U A, Girard Luc, Naito Yujiro, Masahiro Kentaro, Minna John D, Gerber David E, Koyama Shohei, Liu Zhiqian Lucy, Baruah Hemanta, Akbay Esra A
Department of Pathology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA.
Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
J Immunother Cancer. 2025 Jan 6;13(1):e009867. doi: 10.1136/jitc-2024-009867.
Concurrent (STK11, KL) mutant non-small cell lung cancers (NSCLC) do not respond well to current immune checkpoint blockade therapies, however targeting major histocompatibility complex class I-related chain A or B (MICA/B), could pose an alternative therapeutic strategy through activation of natural killer (NK) cells.
Expression of NK cell activating ligands in NSCLC cell line and patient data were analyzed. Cell surface expression of MICA/B in NSCLC cell lines was determined through flow cytometry while ligand shedding in both patient blood and cell lines was determined through ELISA. We engineered an antibody-dependent cellular cytotoxicity (ADCC) enhanced MICA/B monoclonal antibody, AHA-1031, which prevents ligand shedding without interfering with binding to natural killer group 2D while targeting cancer cells via superior ADCC. We performed in vitro assays using ELISA and flow cytometry-based assays to confirm that our antibody potently binds to and stabilizes MICA/B expression across lung cancer and other solid tumor cell lines. Additionally, we used two KL mutant NSCLC cell lines and a KL mutant patient-derived xenograft (PDX) model to demonstrate in vivo antitumor efficacy and flow cytometry analysis for immune cell activation profiling.
NSCLC cell lines exhibit high MICA/B expression and secrete soluble MICA/B in vitro. Soluble MICA/B is also detected in patient blood samples. AHA-1031 binds to the α3 domain of MICA/B, preventing shedding and targeting tumor cells to ADCC. AHA-1031 exhibits high affinity and specificity to MICA/B, preventing MICA/B shedding in tumor lines and inducing ADCC in vitro. Our antibody also effectively binds and stabilizes MICA/B expression in additional tumor types and demonstrates broad specificity. We show that in two KL mutant NSCLC xenograft models and a KL mutant PDX model, treatment with AHA-1031 monotherapy significantly inhibits tumor growth compared with vehicle-treated animals with no observable toxicity. Tumor tissues from treated mice exhibit significantly increased immune cell infiltrates and activated NK cell populations.
Activating NK cells through MICA/B stabilization and inducing ADCC offers an alternative and potent therapy option in KL tumors. MICA/B are shed across different tumors making this therapeutic strategy universally applicable.
同时存在（STK11、KL）突变的非小细胞肺癌（NSCLC）对当前的免疫检查点阻断疗法反应不佳，然而靶向主要组织相容性复合体I类相关链A或B（MICA/B），可能通过激活自然杀伤（NK）细胞构成一种替代治疗策略。
分析NSCLC细胞系中NK细胞激活配体的表达及患者数据。通过流式细胞术测定NSCLC细胞系中MICA/B的细胞表面表达，同时通过酶联免疫吸附测定（ELISA）测定患者血液和细胞系中的配体脱落情况。我们构建了一种抗体依赖性细胞毒性（ADCC）增强的MICA/B单克隆抗体AHA-1031，它可防止配体脱落，在不干扰与自然杀伤细胞2D组（NKG2D）结合的情况下，通过卓越的ADCC靶向癌细胞。我们使用ELISA和基于流式细胞术的检测方法进行体外试验，以确认我们的抗体能有效结合并稳定肺癌及其他实体瘤细胞系中的MICA/B表达。此外，我们使用两个KL突变的NSCLC细胞系和一个KL突变的患者来源异种移植（PDX）模型来证明体内抗肿瘤疗效，并通过流式细胞术分析免疫细胞激活谱。
NSCLC细胞系在体外表现出高MICA/B表达并分泌可溶性MICA/B。在患者血液样本中也检测到可溶性MICA/B。AHA-1031与MICA/B的α3结构域结合，防止其脱落并将肿瘤细胞靶向至ADCC。AHA-1031对MICA/B表现出高亲和力和特异性，可防止肿瘤细胞系中的MICA/B脱落并在体外诱导ADCC。我们的抗体还能有效结合并稳定其他肿瘤类型中的MICA/B表达，并显示出广泛的特异性。我们表明，在两个KL突变的NSCLC异种移植模型和一个KL突变的PDX模型中，与未观察到毒性的载体处理动物相比，AHA-1031单药治疗显著抑制肿瘤生长。治疗小鼠的肿瘤组织显示免疫细胞浸润和活化NK细胞群体显著增加。
通过稳定MICA/B激活NK细胞并诱导ADCC为KL肿瘤提供了一种替代且有效的治疗选择。MICA/B在不同肿瘤中都会脱落，使得这种治疗策略具有普遍适用性。
