Screening,Preparation And Identification Of TIGIT Specific Single Domain Antibody

In tumor microenvironment,TIGIT is an inhibitory receptor expressed on the surface of NK cells and T cells.When combined with ligands CD 155 and CD112,TIGIT will cause NK cells and T cells depletion,thus promoting tumor growth.By studying the targeted TIGIT monocellular antibody,blocking the TIGIT/CD155 signaling pathway will enhance the anti-tumor response of cytotoxic T lymphocytes and NK cells,and delay tumor growth.Compared with the traditional monoclonal antibody,monocellular antibodies have the advantages of small molecular weight,can pass through the blood-brain barrier,and are easy to be modified and expressed by recombination.It will lay a solid foundation for tumor diagnosis and treatment as well as drug research and development,and has potential application prospects in the future.In this study,the TIGIT gene was cloned and the TIGIT expression vector was constructed.The Expression system was escherichia coli,and the TIGIT protein was expressed and purified.With TIGIT protein as antigen immune adult health bactrian camel,build TIGIT specificity of Phage antibody library,using the commercialization,eukaryotic expression TIGIT protein to build good antibody library for three rounds of enrichment,screening,the Phage ELISA TIGIT protein identification combined with the specific positive clones,connect the positive clone genes to the prokaryotic expression vector pET-25b-SBP,adopting low temperature induction of engineering bacteria for soluble expression,get soluble anti TIGIT specificity of single domain antibodies,the affinity activity were determined by ELISA.In this experiment,single-domain antibody against TIGIT was successfully obtained by phage display technology,and the affinity and biological activity of single-domain antibody were preliminarily studied in subsequent experiments,laying a foundation for the development of single-domain antibody and tumor immunotherapy drugs.