Expression of meningococcal epitopes in LamB of XXXX and the stimulation of serosubtype-specific antibody responses.

@entity535 @entity95 @entity214 @entity71359 @entity3631 @entity526
The class 1 outer membrane protein ( @entity71359 ), a major variable surface antigen of @entity3631 , is a component of novel meningococcal vaccines currently in field trials. Serological variants of the protein are also used to serosubtype meningococci. Most of the @entity535 changes that give rise to antigenic variants of the protein occur in two variable regions (VR1 and VR2) that are thought to form loops on the cell surface. The polymerase chain reaction (PCR) was used to amplify the nucleotide sequences encoding VR1 and VR2 from the chromosomal DNA of @entity3631 M1080. These were cloned in frame into the lamB gene of the @entity526 expression vector pAJC264. Whole-cell enzyme-linked immunosorbent assays (ELISAs), using monoclonal antibodies, and @entity214 -PAGE confirmed that, upon induction, strains of @entity526 carrying these constructs expressed hybrid LamB proteins containing the @entity3631 surface loops. These strains were used to immunize @entity95 and the resultant polyclonal antisera reacted specifically with the class 1 @entity71359 of reference strain M1080 (P1.7). Immunogold labelling of meningococcal cells and whole-cell dot-blot analyses with these antisera showed that the variable epitopes were exposed on the cell surface and confirmed that this approach could be used to obtain serosubtype-specific antisera. The binding profiles of the antisera were determined from their reactions with overlapping synthetic peptides and their reactivity compared with that of relevant serosubtype-specific monoclonal antibodies. This approach was used successfully to raise antisera against two other class 1 @entity71359 VR2s. A fourth antiserum raised against a VR2, including the P1.1 epitope, was not subtype specific.
