Preparation of anti-human TIGIT monoclonal antibody and preliminary study of its biological activity

T cell immune receptor with Ig and ITIM domains (TIGIT), a promising new target in cancer immunotherapy, plays a critical role in limiting adaptive and innate immunity against tumors. The extracellular domain of human TIGIT was used to immune BALB/c mice, and a new anti-human TIGIT chimeric antibody (c7D3) was developed. The mice in this study were used in accordance with the international guidelines for the care and use of laboratory animals, and the animal study was approved by the Institutional Animal Ethics Committee of AbMax Biotechnology. The biological activity of c7D3 was studied. The results showed that c7D3 exhibited high affinity for TIGIT and effectively inhibited the interaction between TIGIT and its ligands. Cell-based assays indicated that c7D3 induced strong luciferase signaling in TIGIT/CD155 signaling reporter assay and enhanced cytokine secretion in a T cell stimulation assay. The data showed that c7D3 has high binding affinity and excellent blocking bioactivity, supporting the further advancement for therapeutic application.