Homology modeling and topology prediction of GNA1870 protein inNeisseria meningitidis

Neisseria meningitides is a gram negative, encapsulated bacterium which at any time colonizes the upper respiratory tract of 10% of human population. Colonizing strains belong to hypervirulent lineages and carriage strains, which are frequently or rarely associated with disease, respectively. Although effective in adults, polysaccharide vaccines are less efficacious ininfants and young children and do not induce immunologicalmemory, so that they have not been used for universalvaccination. Recently, conjugate vaccines against serogroupC have been introduced in the UK, Ireland, and Canada. To develop avaccine against serogroup B, surface-exposed proteins containedin outer membrane vesicles (OMVs)*have been used. These vaccines elicit serum bactericidal antibodyresponses and protect against meningococcal disease. However, while they induce complement-mediated bactericidal antibodies against the homologous strain,they fail to induce bactericidal antibodies against heterologous strains.In the year 2000 our laboratory published the use of the genomic sequence of MC58 to discover novel antigens capable of inducing protection against serogroup BN. meningitidis. Here we describe the topology and 3D structure of a novel antigen which was discovered by mining the bacterial genome and that is very effective in inducing bactericidal antibodies. This antigen is a very good candidate for inclusion in universal vaccines against N.meningitidis.

Keywords:

Neisseria meningitides , GNA1870 , Topology and 3D structure