IgG-like Bispecific Antibody CD3×EpCAM Generated by Split Intein Against Colorectal Cancer

Yu Qiao,Jie Chen,Jianwei Zhu,ZhiDi Pan,Lei Han,Lei Wang,Yong Ke,Tianlei Ying,Baohong Zhang,Huifang Zong,Jinyao Li,Jun Lu

doi:10.3389/fphar.2022.803059

Abstract

Background: Colorectal cancer is a commonly diagnosed cancer with high mortality worldwide. Postoperative recidivation and metastasis still are the main challenges in clinical treatments. Thus, it is urgent to develop new therapies against colorectal cancer. Epithelial Cell Adhesion Molecule (EpCAM) is overexpressed in colorectal cancer cells and strongly associated with cancer development. Bispecific antibody (BsAb) is a kind of promising immunotherapy, which could recognize T cells and cancer cells simultaneously to achieve the anti-tumor effects. Methods: A bispecific antibody targeting EpCAM and CD3 with IgG format was genereated by split intein based on the Bispecific Antibody by Protein Splicing” platform. In vitro, the affinity of CD3×EpCAM BsAb was determined by Biolayer interferometry, its cytotoxicity was detected by LDH release assay, T cell recruitment and activation was detected by Flow Cytometry. In vivo, its pharmacokinetic parameters were detected, and anti-tumor effects were evaluated on the tumor cell xenograft mouse model. Results: The results showed that the CD3×EpCAM BsAb could activate and recruit T cells via binding colorectal cells and T cells, which could lead to more potent cytotoxicity to various colorectal cell lines than its parent EpCAM monoclonal antibody (mAb) in vitro. The CD3×EpCAM BsAb had similar pharmacokinetic parameters with EpCAM mAb and inhibits tumor growth on the SW480 tumor cell xenograft mouse model. Conclusion: The CD3×EpCAM BsAb could be a promising candidate for colorectal cancer treatment.

Highlights

Colorectal cancer (CRC) is one of the most common cancers with a low 5-years survival rate worldwide (Siegel et al, 2021; Sung et al, 2021)
The affinity of CD3×Epithelial Cell Adhesion Molecule (EpCAM) bispecific antibodies (BsAb) was determined by Biolayer interferometry, its cytotoxicity was detected by LDH release assay, T cell recruitment and activation was detected by Flow Cytometry
The results showed that the CD3×EpCAM BsAb could activate and recruit T cells via binding colorectal cells and T cells, which could lead to more potent cytotoxicity to various colorectal cell lines than its parent EpCAM monoclonal antibody in vitro

Summary

Introduction

Colorectal cancer (CRC) is one of the most common cancers with a low 5-years survival rate worldwide (Siegel et al, 2021; Sung et al, 2021). Immunotherapies for CRC have been developed, including bispecific antibodies (BsAb), checkpoint inhibitors, cancer vaccines, and oncolytic virus therapy (Ciardiello et al, 2019). The bispecific antibody is an engineering antibody with two different binding targets or epitopes for multiple applications (Brinkmann and Kontermann, 2021) It could exhibit a novel action or mechanism that cannot be achieved by combining separate antibodies with the same targets (Labrijn et al, 2019), such as redirecting T cells to tumor cells (Bargou et al, 2008), activating or inhibiting two receptors (Schaefer et al, 2011), serving as cofactor mimetic (Sampei et al, 2013), or even delivering a protein across the blood-brain barrier (Yu et al, 2011; Yu et al, 2014). Bispecific antibody (BsAb) is a kind of promising immunotherapy, which could recognize T cells and cancer cells simultaneously to achieve the anti-tumor effects

Methods

Results

Conclusion