Phage display strategy against outbreaks of unknown pathogens

The experience with SARS-CoV-2 that spread rapidly throughout the world makes us realize we need protocols to act quickly against unknown pathogens. The immune system protects recovering patients from any pathogen by producing antibodies against their immunogenic epitopes. Therefore, the strategy presented here is based on convalescent blood samples and a phage display platform for antibody and peptide drug discovery. Peptide libraries are screened against purified convalescent antibodies to identify immunogenic epitopes of the pathogen. Furthermore, the B cells of the recovery patients are used to amplify variable domains of antibody heavy and light chains expressed during the infection. These domains are cloned in a phagemid and produce free phage particles expressing the antibody fragments on their surfaces to select binders to pathogen immunogenic epitopes. These findings are essential in the identification of the unknown pathogen and the design of therapeutic molecules. In conclusion, this report describes a phage display strategy to combat outbreaks of unknown pathogens such as SARS-CoV-2.