Immunisation with phage-displayed variable region 2 from meningococcal PorA outer membrane protein induces bactericidal antibodies against Neisseria meningitidis

The immunogenicity and functional activity of antibodies raised in mice against the cyclic disulphide peptide corresponding to the variable region 2 of PorA outer membrane protein from Neisseria meningitidis strain B385 (serosubtype P1.15), displayed on filamentous phage, were evaluated. The epitope, flanked either by cysteine or cysteine and three glycine residues, was expressed as a fusion to PVIII protein from M13. Immunisation of Balb/C mice with either phage generated antibody specific responses. Sera raised against the phage exposing the cyclic peptide through the three-glycine linker recognised the native protein better than those raised against the peptide with no linker, Only the phage displaying the cyclic peptide with linker was capable of inducing antibodies with bactericidal activity. These results indicate the possibility of using phage display for conformational peptide expression for immunisation. to elicit functional antibody responses. (C) 2001 Elsevier Science B.V. All rights reserved.