Characterization of a peptide vaccine candidate mimicking an oligosaccharide epitope of Neisseria gonorrhoeae and resultant immune responses and function

• Published in: Vaccine 2006-01, Vol.24 (2), p.157-170
• Main Authors: Ngampasutadol, Jutamas, Rice, Peter A., Walsh, Mary T., Gulati, Sunita
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antibodies, Bacterial - biosynthesis; Applied microbiology; Bacterial Vaccines - chemistry; Bacteriology; Base Sequence; Biological and medical sciences; DNA Primers; Enzyme-Linked Immunosorbent Assay; Epitopes - chemistry; Epitopes - immunology; Flow Cytometry; Fundamental and applied biological sciences. Psychology; Immune response; Mice; Microbiology; Miscellaneous; Molecular Sequence Data; Neisseria gonorrhoeae; Neisseria gonorrhoeae - immunology; Oligosaccharide epitope; Oligosaccharides - chemistry; Peptide vaccine candidate; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects)
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2005.07.065

The 2C7 epitope is a conserved oligosaccharide structure, a part of lipooligosaccharide (LOS) on Neisseria gonorrhoeae, present in 95% of clinical gonococcal isolates. 2C7 may represent a potential candidate for an anti-gonococcal vaccine. To circumvent the limitations of saccharide immunogens in producing long lived immune responses, we identified a peptide that mimics the 2C7 epitope using a random peptide library, characterizing linear and cyclic forms and formulating a multiple antigenic peptide. The multiple antigenic peptide Octa-MAP1 was used for immunization, and elicited ≥4-fold increase in cross-reactive anti-LOS antibodies in 26 of 30 mice (87%). IgG anti-LOS antibody elicited by Octa-MAP1 immunization possessed dose-responsive direct complement (C)-dependent bactericidal activity against gonococcal strains that expressed the 2C7 epitope. These data indicate that a peptide can mimic an oligosaccharide epitope and may form the basis for the development of a vaccine candidate for human immunization against N. gonorrhoeae.