[Preparation of anti-lymphocyte activation gene 3 (LAG-3) fully human antibodies]

Objective Lymphocyte activation gene 3 (LAG-3) is a potential therapeutic target of tumor. This work aims to screen for anti-LAG-3 human scFvs from a human phage antibody library, and transform them into fully human antibodies. Methods The human phage antibody library was screened for anti-LAG-3 human scFvs. The specificity and affinity of phage scFvs were determined by ELISA and surface plasmon resonance (SPR), respectively. The anti-LAG-3 full human antibodies were obtained using eukaryotic expression system. Results Through 3 rounds of screening, we obtained 4 phage scFv clones that could bind to human LAG-3 recombinant protein. Affinity determination showed that the highest affinity reached 3.48×10^-10. Then through the construction of whole human antibody expression vector, expression in eukaryotic cells, and purification, 3 clones of anti-LAG-3 full human antibodies were harvested finally. Conclusion Using a large-capacity human antibody phage display library, we obtained three anti-LAG-3 full human antibodies with high affinity.