Two different methods result in the selection of peptides that induce a protective antibody response to XXXX serogroup C.

@entity1 @entity19 @entity535 @entity10217 @entity1735 @entity3631 @entity734
@entity3631 is a leading cause of morbidity and mortality worldwide. The presently available capsular polysaccharide vaccine is poorly immunogenic in @entity1 under the age of 2 due to its T-independent (TI) nature. Efforts to overcome the TI response elicited by the polysaccharide vaccine have led to the development of polysaccharide-protein conjugate vaccines. Although a @entity734 ( @entity734 ) response can be achieved in young @entity1 , the response to the polysaccharide still retains characteristics of a TI antibody response. An alternative method of potentially inducing a @entity734 response to a @entity1735 antigen is through peptides that mimic the capsular polysaccharide. Our laboratory, through the production of an anti-idiotypic (anti-id) monoclonal antibody, designated 6F9, has previously identified a peptide mimic of the @entity10217 ( @entity10217 ). Using the same selecting monoclonal antibody (mAb), 1E4, we have screened a phage display library and identified 13 unique peptides that bound specifically to mAb1E4. Two peptides, Pep1C and Pep2C, that demonstrated the highest binding to mAb1E4, were selected, complexed to proteosomes, and used to immunize Balb/c @entity19 . Of the 13 peptide motifs, only one peptide motif, that of Pep2C, was found to resemble the immunogenic peptide sequence of the anti-id selected with the same mAb, although many contained several similar @entity535 residues. Immunization with Pep2C, but not Pep1C, induced a significant and functional anti- @entity10217 antibody response that conferred protection from a lethal challenge with meningococci. Our results indicate that immunization with a peptide of @entity3631 serogroup C, screened with the same mAb that selected an anti-id of @entity10217 , induces a functional and protective anti- @entity10217 immune response similar to that of the anti-id. This study demonstrates that two different selection methods, production of an anti-id and biopanning using a phage display library, can be used to select functional and protective peptides of @entity10217 with similar moieties.
