Background: Population control of domestic, wild, invasive, and captive animal species
is a global issue of importance to public health, animal welfare and the economy. There is
pressing need for effective, safe, and inexpensive contraceptive technologies to address this problem.
Contraceptive vaccines, designed to stimulate the immune system in order to block critical
reproductive events and suppress fertility, may provide a solution. Filamentous bacteriophages
can be used as platforms for development of such vaccines.
Objective: In this review authors highlight structural and immunogenic properties of filamentous
phages, and discuss applications of phage-peptide vaccines for advancement of immunocontraception
technology in animals.
Results: Phages can be engineered to display fusion (non-phage) peptides as coat proteins. Such
modifications can be accomplished via genetic manipulation of phage DNA, or by chemical conjugation
of synthetic peptides to phage surface proteins. Phage fusions with antigenic determinants
induce humoral as well as cell-mediated immune responses in animals, making them attractive
as vaccines. Additional advantages of the phage platform include environmental stability,
low cost, and safety for immunized animals and those administering the vaccines.
Conclusion: Filamentous phages are viable platforms for vaccine development that can be engineered
with molecular and organismal specificity. Phage-based vaccines can be produced in
abundance at low cost, are environmentally stable, and are immunogenic when administered via
multiple routes. These features are essential for a contraceptive vaccine to be operationally practical
in animal applications. Adaptability of the phage platform also makes it attractive for design
of human immunocontraceptive agents.