PROTECTIVE IMMUNE-RESPONSES INDUCED BY THE IMMUNIZATION OF MICE WITH A RECOMBINANT BACTERIOPHAGE DISPLAYING AN EPITOPE OF THE HUMAN RESPIRATORY SYNCYTIAL VIRUS

We investigated whether a recombinant bacteriophage displaying a disea se-specific protective epitope could be experimentally used as a vacci ne to confer protection of immunized animals against infection. We gen etically engineered a recombinant phage, fd, displaying at its surface a chimeric pill coat protein fused to the previously identified prote ctive epitope 173-187 from the glycoprotein G of the human respiratory syncytial virus (RSV). A selected recombinant fd phage elicited a str ong immune response in mice, inducing a high level of circulating RSV- specific antibodies Mice immunized with the recombinant phage acquired a complete resistance to RSV infection as evidenced by the lack of de tectable virus particles in their lungs following intranasal challenge with live RSV. In contrast, a high level of virus particles was found in the lungs of either animals immunized with the wild-type fd phage or nonimmunized mice. To our knowledge, this is the first study to rep ort the ability of a phage presenting an immunogenic peptide to preven t infection of immunized animals by a pathogen. This finding should fa cilitate the identification of pathogen-specific protective epitopes s elected from random phage peptide libraries, as it is simpler and less expensive than the conventional method of synthesis and coupling of p hage-specific peptide ligand sequences for immunization. (C) 1997 Acad emic Press.