Filamentous phage (genus Inovirus) infect almost invariably Gram-negative bacteria. They are distinct from all other bacteriophage not only by morphology, but also by the mode of their assembly, a secretion-like process that does not kill the host. “Classic” Escherichia coli filamentous phage Ff (f1, fd and M13) are used in display technology and bio/nano/technology, whereas filamentous phage in general have been put to use by their bacterial hosts for adaptation to environment, pathogenesis, biofilm formation, horizontal gene transfer and bacterial genome stability.
Many filamentous phage have a “symbiotic” life style that is often manifested by inability to form plaques, preventing their identification by standard phage-hunting techniques; while the absence or very low sequence conservation between phage infecting different species often complicates their identification through bioinformatics. Nevertheless, the number of discovered filamentous phage is increasing rapidly, along with realisation of their significance. “Temperate” filamentous phage whose genomes are integrated into the bacterial chromosome of pathogenic bacteria often affect virulence of the host. The Vibrio cholearae phage CTXφ genome encodes cholera toxin, whereas many filamentous prophage influence virulence without encoding virulence factors. The nature of their effect on the virulence and overall physiology is the next frontier in understanding intricate relationship between the filamentous phage and their bacterial host.
Phage display has been combinatorial technology of choice for discovery of therapeutic antibodies and peptide leads for vaccines, diagnostics and drug design over the past thirty years. Recent applications of Ff filamentous phage extend into protein evolution, synthetic biology and nanotechnology. In many applications, phage serves as monodisperse long-aspect scaffold of well-defined shape. Chemical or chenetic modification of this scaffold introduces necessary functioalities, such as peptides that promote formation of nanostructures, labels, ligands that target specific proteins. We anticipate development of new strategies for site-specific modification of phage, multi-functional modification and improvement of existing modifications to make them simpler, faster and higher yielding.
Virion proteins of filamentous phage are integral membrane proteins prior to assembly; hence they are ideal for display of bacterial surface and secreted proteins. Phage display has been used to identify bacterial surface proteins that interact with their hosts at a single species level. The use of this technology at the scale of microbial community has potential to identify host-interacting proteins of uncultivable or poorly represented community members. This is very useful, as a large volume of microbial community sequencing must be offset by identifying key functionalities that keep the community together and mediate interactions with the environment or plant/animal/human host.
This topic will focus on most recent developments in
• Identification of novel filamentous phage, deciphering their replication, interaction with their host and their roles in physiology, ecology and virulence.
• Innovation in phage display technology, in particular directed evolution, synthetic biology, vaccine development and nanotechnology.
• Application of phage display in understanding interactions between bacteria and host.
• New strategies for modification of phage coat proteins using genetic or chemical approaches
Original research, hypothesis and theory, methods or review articles are welcome.
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.
total views article views article downloads topic views