title: MetQ of Neisseria gonorrhoeae Is a Surface-Expressed Antigen That Elicits Bactericidal and Functional Blocking Antibodies.
abstract: Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection (STI) gonorrhea, is a growing public health threat for which a vaccine is urgently needed. We characterized the functional role of the gonococcal MetQ protein, which is the methionine binding component of an ABC transporter system, and assessed its potential as a candidate antigen for inclusion in a gonococcal vaccine. MetQ has been found to be highly conserved in all strains investigated to date, it is localized on the bacterial surface, and it binds l-methionine with a high affinity. MetQ is also involved in gonococcal adherence to cervical epithelial cells. Mutants lacking MetQ have impaired survival in human monocytes, macrophages, and serum. Furthermore, antibodies raised against MetQ are bactericidal and are able to block gonococcal adherence to epithelial cells. These data suggest that MetQ elicits both bactericidal and functional blocking antibodies and is a valid candidate antigen for additional investigation and possible inclusion in a vaccine for prevention of gonorrhea.
authors.affiliation: Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia.
authors.forename: Evgeny A
authors.initials: EA
authors.lastname: Semchenko
authors.affiliation: Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Day
authors.affiliation: Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia k.seib@griffith.edu.au.
authors.forename: Kate L
authors.identifier: http://orcid.org/0000-0002-7094-3528
authors.initials: KL
authors.lastname: Seib
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial / Q000276:immunology*; D019138:Antibodies, Blocking / Q000276:immunology*; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D001422:Bacterial Adhesion; D001428:Bacterial Vaccines / Q000276:immunology; D055786:Gene Knockout Techniques; D023061:Gene Order; D006069:Gonorrhea / Q000276:immunology* / Q000382:microbiology; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D008715:Methionine; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D009344:Neisseria gonorrhoeae / Q000276:immunology* / Q000378:metabolism; D016366:Open Reading Frames; D011485:Protein Binding
chemical_list: D018528:ATP-Binding Cassette Transporters; D000907:Antibodies, Bacterial; D019138:Antibodies, Blocking; D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D008715:Methionine
keywords: ABC transporters; MetQ; Neisseria gonorrhoeae; adhesins; gonorrhea; methionine; vaccine candidate