[Screening of specific F4 IgE recombinant antibodies by phage display technology and development of a positive quality control].

Immunoglobulin E (IgE) plays a crucial role in allergic reactions and parasitic infections, and its accurate detection is of vital importance for the diagnosis and treatment of allergic diseases. Conventional enzyme-linked immunosorbent assay (ELISA) relies on positive quality control products, which depend on the preparation of high-concentration plasma samples, leading to a shortage of resources. This study aims to use phage display technology to screen antibodies that can specifically bind to the human wheat allergen F4. By screening the natural human phage display library, we identified 11 highly specific phage clones from 190 candidates. Three of them were selected for the preparation and construction of recombinant antibodies. Among them, the 1H7 and 6A8 recombinant IgE antibodies, after two-step purification, showed the purity higher than 93.0% by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and size-exclusion chromatography-high performance liquid chromatography (SEC-HPLC), and both could specifically bind to the natural F4 protein without cross-reaction with other common allergens. Surface plasmon resonance (SPR) detection indicated that both antibodies possessed high affinity at the nanomolar level. Stability analysis showed that the luminescence values of the two antibodies fluctuated by less than 10% under different storage conditions. The two antibodies showed the heat-accelerated matrix effect consistent with the performance of clinical samples, which suggested their potential value as positive quality control products for F4 IgE detection. This study reports for the first time on the construction and in vitro expression of IgE recombinant antibodies. The recombinant antibodies have higher stability, simpler preparation, and better cost-effectiveness than the quality control products prepared from high-value plasma, providing promising positive quality control product options for the development of new diagnostic tools for IgE detection.