Department of Microbiology and Immunology, University of Otago, Dunedin, 9016, New Zealand.
The Children's Hospital Westmead, The Children's Hospital Westmead CRN Hawksbury Road and Hainsworth Street, Westmead, NSW, 2145, Australia.
Cancer Immunol Immunother. 2024 Aug 6;73(10):195. doi: 10.1007/s00262-024-03778-3.
The efficacy of antibody-targeted therapy of solid cancers is limited by the lack of consistent tumour-associated antigen expression. However, tumour-associated antigens shared with non-malignant cells may still be targeted using conditionally activated-antibodies, or by chimeric antigen receptor (CAR) T cells or CAR NK cells activated either by the tumour microenvironment or following 'unlocking' via multiple antigen-recognition. In this study, we have focused on tissue factor (TF; CD142), a type I membrane protein present on a range of solid tumours as a basis for future development of conditionally-activated BiTE or CAR T cells. TF is frequently upregulated on multiple solid tumours providing a selective advantage for growth, immune evasion and metastasis, as well as contributing to the pathology of thrombosis via the extrinsic coagulation pathway.
Two well-characterised anti-TF monoclonal antibodies (mAb) were cloned into expression or transposon vectors to produce single chain (scFv) BiTE for assessment as CAR and CD28-CD3-based CAR or CD3-based BiTE. The affinities of both scFv formats for TF were determined by surface plasmon resonance. Jurkat cell line-based assays were used to confirm the activity of the BiTE or CAR constructs.
The anti-TF mAb hATR-5 and TF8-5G9 mAb were shown to maintain their nanomolar affinities following conversion into a single chain (scFv) format and could be utilised as CD28-CD3-based CAR or CD3-based BiTE format.
Because of the broad expression of TF on a range of solid cancers, anti-TF antibody formats provide a useful addition for the development of conditionally activated biologics for antibody and cellular-based therapy.
抗体靶向治疗实体瘤的疗效受到缺乏一致的肿瘤相关抗原表达的限制。然而，与非恶性细胞共享的肿瘤相关抗原仍然可以使用条件激活抗体，或通过嵌合抗原受体 (CAR) T 细胞或 CAR NK 细胞进行靶向治疗，这些细胞可以被肿瘤微环境激活，也可以通过多种抗原识别进行“解锁”后激活。在这项研究中，我们专注于组织因子 (TF; CD142)，它是一种存在于多种实体瘤中的 I 型膜蛋白，作为未来开发条件激活 BiTE 或 CAR T 细胞的基础。TF 在多种实体瘤中经常上调，为生长、免疫逃避和转移提供了选择性优势，并通过外源性凝血途径导致血栓形成的病理学变化。
将两种经过充分表征的抗 TF 单克隆抗体 (mAb) 克隆到表达或转座子载体中，以产生用于评估 CAR 和 CD28-CD3 为基础的 CAR 或 CD3 为基础的 BiTE 的单链 (scFv) BiTE。通过表面等离子体共振测定两种 scFv 形式对 TF 的亲和力。使用 Jurkat 细胞系测定来确认 BiTE 或 CAR 构建体的活性。
抗 TF mAb hATR-5 和 TF8-5G9 mAb 在转化为单链 (scFv) 形式后仍保持其纳摩尔亲和力，可以用作 CD28-CD3 为基础的 CAR 或 CD3 为基础的 BiTE 形式。
由于 TF 在多种实体瘤中的广泛表达，抗 TF 抗体形式为开发用于抗体和细胞为基础的治疗的条件激活生物制剂提供了有用的补充。
