Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

One potential vaccine strategy in the fight against meningococcal disease involves the exploitation of outer-membrane components of Neisseria lactamica, a commensal bacterium closely related to the meningococcus, Neisseria meningitidis. Although N. lactamica shares many surface structures with the meningococcus, little is known about the antigenic diversity of this commensal bacterium or the antigenic relationships between N. lactamica and N. meningitidis. Here, the N. lactamica porin protein (Por) was examined and compared to the related PorB antigens of N. meningitidis, to investigate potential involvement in anti-meningococcal immunity. Relationships among porin sequences were determined using distance-based methods and F(ST), and maximum-likelihood analyses were used to compare the selection pressures acting on the encoded proteins. These analyses demonstrated that the N. lactamica porin was less diverse than meningococcal PorB and although it was subject to positive selection, this was not as strong as the positive selection pressures acting on the meningococcal porin. In addition, the N. lactamica porin gene sequences and the protein sequences of the loop regions predicted to be exposed to the human immune system were dissimilar to the corresponding sequences in the meningococcus. This suggests that N. lactamica Por, contrary to previous suggestions, may have limited involvement in the development of natural immunity to meningococcal disease and might not be effective as a meningococcal vaccine component.

Original publication

DOI

10.1099/mic.0.2007/015479-0

Type

Journal article

Journal

Microbiology

Publication Date

05/2008

Volume

154

Pages

1525 - 1534

Keywords

Amino Acid Sequence, Cluster Analysis, DNA, Bacterial, Female, Humans, Infant, Male, Models, Molecular, Molecular Sequence Data, Neisseria lactamica, Neisseria meningitidis, Pharynx, Polymorphism, Genetic, Porins, Selection, Genetic, Sequence Analysis, DNA, Sequence Homology, Amino Acid