Study on Expression of Recombinant Full-Length Antibodies Against Zearalenone Based on Expi 293F Cells

Abstract:

Immunoassay technology plays an important role in the field of rapid detection of food safety, with antibodies being the core component of immunoassay. However, the current detection of antibodies used in foods is mainly based on polyclonal antibodies or monoclonal antibodies obtained in large quantities through the in vivo cultivation of hybridoma cells, which not only face animal welfare and viral contamination, but also face problems, such as non-targeted antibody contamination and loss of cellular antibody genes. This study focused on the common fungal toxin zearalenone (ZEN) in foods. Based on the self-made anti-ZEN monoclonal hybridoma cell line (Z14) in our laboratory, sub-type specific primers were used to amplify the full-length gene sequences of the heavy and light chains of the anti-ZEN antibody. The expression vector of the ZEN recombinant full-length antibody was constructed and the PEI mediated transient transfection expression of the ZEN recombinant full-length antibody in Expi 293F cells was achieved. The results of the indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) showed that the half inhibitory mass concentration (IC₅₀) of the ZEN inhibition standard curve established was based on recombinant full-length antibodies, which was 2.43 ng/mL. Moreover, the mass concentration in the linear range (IC₂₀~IC₈₀) was 0.66~8.88 ng/mL, while the affinity constant (K_a) was 3.87×10¹⁰ L/mol. The performance of the ZEN monoclonal antibodies prepared from ascites was superior to that of traditional ascites, providing a basis for a large-scale production of recombinant full-length antibodies against ZEN based on in vitro cell culture in the later stage.