Generation of human monoclonal antibody Fab fragments against respiratory syncytial virus (RSV) using phage display technology
Objective To develop a safe and effective medicine for RSV infection.Methods The hu- man IgG Fab genes of heavy and light chains were amplified from peripheral lymphocytes of four infants in conva- lescent phase of asthma-like pneumonia caused by RSV infection in an outbreak in Henan province,and cloned in- to phage display system (pComb3/VCSM13).The combinatorial phage Fab antibody library was constructed and followed by screening with purified RSV virions.The specific human antibody Fab fragments against RSV were se- lected and expressed in XL1-Blu,and the specificity of the expressed RSV Fabs were characterized by ELISA.Fi- nally the sequence of Fab genes from the positive clones were analyzed by alignment with GenBank.Results The human antibody library consists of 10~8 independent clones.Six rounds of selection against McAb captured RSV par- ticles showed specific enrichment of phage antibodies.Direct ELISA verified that the positive phage antibodies were specific against RSV.Analysis of the DNA sequence indicates that the human immunoglobulin Fab sequence was identified and confirmed.Conclusion Human IgG Fab fragments anti-RSV were obtained with phage display technique.