Phage Landscape Libraries as a Source of Substitute Antibodies for Detection Platforms

摘要

The authors introduced new formats of phage display -- landscape phage and mosaic landscape phage, in which all 4,000 copies of the major coat protein in the phage bear one or two foreign peptides. Libraries of landscape and mosaic landscape phages contain billions of clones with different peptides. This work demonstrated the great potential of the landscape phage probes as elements of biosensors and threat agent detectors. The authors learned that landscape phages' affinity selected against various agents (bacteria, spores, proteins) demonstrate high specificity, selectivity, and extreme robustness that commend them well as candidate probes for separation, concentration, and continuous monitoring of biological threats. They showed that selected bacterium- and virus-binding phages may be used as probes for identification of surface components of these pathogens -- potential targets for vaccines and drug development. It is significant, too, that this work represented the first test of a phage evolution strategy that may have broad applicability in any system where directed enhancement of the probe's performance is required. In particular, it may improve the operational affectivity of already existing detection and monitoring devices. It also suggests a new strategy of genetically directed nano-manipulation, which may be beneficial in creating new materials for nano-electronics, medicine, and fundamental research. Objectives were as follows: construct of filamentous phage landscape libraries displaying randomized peptides in various formats on every copy of the major coat protein, create libraries of mosaic phage on whose surface displays a mixture of two different peptides, use various model antigens to select phage that bind antigens with high affinity, characterize the specific binding between selected phage and antigen, use test pathogens to select binding landscape phage, and identify target receptors on the bacterial and viral particles.