Effect of human serum on de-N-acetyl sialic acid epitope expression and antibody activity against N. meningitidis group B

• Published in: Vaccine 2010-08, Vol.28 (37), p.5967-5972
• Main Authors: Flitter, Becca A, Ing, Jessica Y, Moe, Gregory R
• Format: Article
• Language: English
• Subjects: Acids; Allergy and Immunology; Animal models; Animals; Antibodies, Bacterial - immunology; Antibodies, Bacterial - isolation & purification; Antibodies, Monoclonal - immunology; Antibodies, Monoclonal - isolation & purification; Antigens, Bacterial - immunology; Applied microbiology; Bacteria; Bactericidal activity; Bacteriology; Biological and medical sciences; Blood Bactericidal Activity; Complement System Proteins - immunology; De-N-acetyl sialic acid; Epitopes - immunology; Fundamental and applied biological sciences. Psychology; Humans; Mice; Microbiology; Miscellaneous; Neisseria meningitidis; Neisseria meningitidis, Serogroup B - immunology; Polysialic acid; Proteins; Rats; Sialic Acids - immunology; Studies; Tetanus; Vaccines; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects)
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2010.06.119

Abstract Antibody-mediated complement-dependent bactericidal activity (BCA) against Neisseria meningitidis (Nm) is correlated with protection against invasive disease. Recently, we showed that murine antibodies elicited by neuraminic acid-containing polysialic acid (NeuPSA) antigens conferred protection against Nm group B (NmB) strains in an infant rat model of meningococcal bacteremia [Moe GR, Bhandari TS, Flitter BA. Vaccines containing de-N-acetyl sialic acid elicit antibodies protective against neisseria meningitidis groups B and C. J Immunol 2009;182(10):6610–7]. However, NeuPSA antibodies did not mediate BCA against NmB strains in vitro despite the presence of NmB-reactive IgG and IgM. Using monoclonal antibodies (mAbs) SEAM 2 and 3, which are reactive with two distinctive NeuPSA epitopes, and an NmB anticapsular mAb, we show that growth in human serum affects expression of NeuPSA epitopes by NmB and is necessary for evaluating anti-NeuPSA functional activity.