Phage display: applications, innovations, and issues in phage and host biology.

In the 7 years since the first publications describing phage-displayed peptide libraries, phage display has been successfully employed in a variety of research. Innovations in vector design and methods to identify target clones account for much of this success. At the same time, not all ventures have been entirely successful and it appears that phage and host biology play important roles in this. A key issue concerns the role played by a displayed peptide or protein in its successful expression and incorporation into virions. While few studies have examined these issues specifically in context of phage display, the literature as a whole provides insight. Accordingly, we review phage biology, relevant aspects of host biology, and phage display applications with the goals of illustrating (i) relevant aspects of the interplay between phage-host biology and successful phage display and (ii) the limitations and considerable potential of this important technology.