Clone, Expression And Immunological Analysis Of Neisseria Meningitidis Outer Membrane Protein NhhA

Neisseria meningitidis is an encapsulated, gram-negative bacterium which is known as the leading cause of bacterial meningitis worldwide. It is a rapid onset of disease and high morbidity and mortality. While conjugated capsular polysaccharide-based vaccines against serogroups A, C, Y, W-135 are showed very safe and effective in eliminating the disease, no universal vaccines are available for group B N. meningitidis (MenB). Since MenB differs from the others because it is decorated by a capsular polysaccharide identical to the polysialic acid [a(2-8) N-acetylneuraminic acid] present in many human glycoproteins. Therefore it is more important to foucus attention on out membrane protein of MenB.In this study, Neisseria meningitidis gene GNA0992 was amplified by polymerase chain reaction and cloned into the prokaryotic expression vector pET-20b. The recombinant plasmid was transformed into E.coli BL21(DE3), and the high expression strain was obtained by screening monoclones. The recombinant protein existed in soluble form, which accounted for 20% of the total cellular protein. The result of western blot showed it had immunogenic and antigenicity. Purified recombinant NhhA stimulated a significant antigen-specific humoral response following three intraperitoneal immunizations, while bactericidal assay showed that NhhA can elicit antibodies capable of inducing bactericidal activity against group B N. meningitidis strains. These results indicate that NhhA is a good candidate for vaccine development, and provide experimental data for further research.