Construction of a large human Fab phage display antibodies library and screening of phage antibodies against CD276

Objective To construct a large human Fab antibodies library and to screen and identify the anti-CD276 phage antibodies from the library. Methods Total RNA was extracted from peripheral blood lymphocytes of 10 healthy donors, and the Fab antibody genes were amplified by RT-PCR. The amplification products were sequentially cloned into phage vector pCANTAB5 E to construct a human Fab phage antibodies library. Antibodies against CD276 were screened using immobilized antigen. After three rounds of screening, 96 randomly selected clones were identified by phage-ELISA to select specific ones with high affinity for CD276. Results A large human Fab phage-display library consisting of 5 × 1010 members was successfully constructed. From the phage library, we obtained eleven positive clones which had specificity and binding reactivity towards CD276. By sequencing, all of the 11 clones had the same sequences, and their specificity was confirmed by ELISA. Conclusion We successfully constructed a large human Fab phage antibodies library and isolated the specific human anti-CD276 Fab antibodies, which provided an experimental foundation in future study and application.