开发一种抗 PD-L1 的叙利亚仓鼠单克隆抗体，使在免疫功能正常、病毒复制允许的环境中进行溶瘤腺病毒免疫治疗建模成为可能。
Development of a Syrian hamster anti-PD-L1 monoclonal antibody enables oncolytic adenoviral immunotherapy modelling in an immunocompetent virus replication permissive setting.
机构信息
Cancer Gene Therapy Group, Translational Immunology Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
R&D Department, TILT Biotherapeutics Ltd, Helsinki, Finland.
出版信息
Front Immunol. 2023 Feb 3;14:1060540. doi: 10.3389/fimmu.2023.1060540. eCollection 2023.
INTRODUCTION
Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer, but preclinical testing of hypotheses such as combination therapies has been complicated, in part due to species incompatibility issues. For example, one of few known permissive animal models for oncolytic adenoviruses is the Syrian hamster, for which an ICI, mainly an anti-PD-L1 monoclonal antibody (mAb) was not previously available. In this study, we developed an anti-Syrian hamster PD-L1 mAb to enable the evaluation of safety and efficacy, when combining anti-PD-L1 with an oncolytic adenovirus encoding tumour necrosis factor alpha (TNFα) and interleukin-2 (IL-2) (Ad5/3-E2F-D24-hTNFα-IRES-hIL-2 or TILT-123).
METHODS
Recombinant Syrian hamster PD-L1 was expressed and mice immunized for mAb formation using hybridoma technology. Clonal selection through binding and functional studies in vitro, in silico and in vivo identified anti-PD-L1 clone 11B12-1 as the primary mAb candidate for immunotherapy modelling. The oncolytic virus (OV) and ICI combination approach was then evaluated using 11B12-1 and TILT-123 in a Syrian hamster model of pancreatic ductal adenocarcinoma (PDAC).
RESULTS
Supernatants from hybridoma parent subclone 11B12B4 provided the highest positive PD-L1 signal, on Syrian hamster PBMCs and three cancer cell lines (HT100, HapT1 and HCPC1). In vitro co-cultures revealed superior immune modulated profiles of cell line matched HT100 tumour infiltrating lymphocytes when using subclones of 7G2, 11B12 and 12F1. Epitope binning and epitope prediction using AlphaFold2 and ColabFold revealed two distinct functional epitopes for clone 11B12-1 and 12F1-1. Treatment of Syrian hamsters bearing HapT1 tumours, with 11B12-1 induced significantly better (p<0.05) tumour growth control than isotype control by day 12. 12F1-1 did not induce significant tumour growth control. The combination of 11B12-1 with oncolytic adenovirus TILT-123 improved tumour growth control further, when compared to monotherapy (p<0.05) by day 26.
CONCLUSIONS
Novel Syrian hamster anti-PD-L1 clone 11B12-1 induces tumour growth control in a hamster model of PDAC. Combining 11B12-1 with oncolytic adenovirus TILT-123 improves tumour growth control further and demonstrates good safety and toxicity profiles.
简介
免疫检查点抑制剂（ICIs）彻底改变了癌症的治疗方式，但由于物种不兼容等问题，对联合治疗等假设的临床前测试变得复杂。例如，少数已知的可用于溶瘤腺病毒的允许动物模型之一是叙利亚仓鼠，此前该动物模型没有可用的 ICI，主要是抗 PD-L1 单克隆抗体（mAb）。在这项研究中，我们开发了一种抗叙利亚仓鼠 PD-L1 mAb，以能够评估安全性和疗效，当将抗 PD-L1 与编码肿瘤坏死因子 alpha（TNFα）和白细胞介素-2（IL-2）的溶瘤腺病毒（Ad5/3-E2F-D24-hTNFα-IRES-hIL-2 或 TILT-123）联合使用时。
方法
使用杂交瘤技术表达重组叙利亚仓鼠 PD-L1，并对小鼠进行免疫以形成 mAb。通过体外、体内和计算机结合结合和功能研究进行克隆选择，确定抗 PD-L1 克隆 11B12-1 作为免疫治疗模型的主要 mAb 候选物。然后，在叙利亚仓鼠胰腺导管腺癌（PDAC）模型中，使用 11B12-1 和 TILT-123 评估溶瘤病毒（OV）和 ICI 联合治疗方法。
结果
杂交瘤亲本亚克隆 11B12B4 的上清液在叙利亚仓鼠 PBMC 和三种癌细胞系（HT100、HapT1 和 HCPC1）上提供了最高的阳性 PD-L1 信号。体外共培养显示，当使用 7G2、11B12 和 12F1 的亚克隆时，与细胞系匹配的 HT100 肿瘤浸润淋巴细胞具有更好的免疫调节谱。使用 AlphaFold2 和 ColabFold 进行表位分组和表位预测，揭示了克隆 11B12-1 和 12F1-1 的两个独特功能表位。用 11B12-1 治疗携带 HapT1 肿瘤的叙利亚仓鼠，与同型对照相比，第 12 天肿瘤生长控制明显更好（p<0.05）。12F1-1 并未诱导明显的肿瘤生长控制。与单药治疗相比，11B12-1 与溶瘤腺病毒 TILT-123 的联合治疗进一步改善了肿瘤生长控制，在第 26 天（p<0.05）。
结论
新型叙利亚仓鼠抗 PD-L1 克隆 11B12-1 在叙利亚仓鼠 PDAC 模型中诱导肿瘤生长控制。将 11B12-1 与溶瘤腺病毒 TILT-123 联合使用可进一步改善肿瘤生长控制，并显示出良好的安全性和毒性特征。
Zotero 插件