title: Haplotypic diversity in human CEACAM genes: effects on susceptibility to meningococcal disease.
abstract: Adhesion between the opacity-associated adhesin (Opa) proteins of Neisseria meningitidis and human carcino-embryonic antigen cell adhesion molecule (CEACAM) proteins is an important stage in the pathogenesis of meningococcal disease, a globally important bacterial infection. Most disease is caused by a small number of meningococcal genotypes known as hyperinvasive lineages. As these are also carried asymptomatically, acquisition of them alone cannot explain why only some hosts develop meningococcal disease. Our aim was to determine whether genetic diversity in CEACAM is associated with susceptibility to meningococcal disease. Frequency distributions of alleles, genotypes and haplotypes were compared in four CEACAM genes in 384 case samples and 190 controls. Linkage disequilibrium among polymorphic sites, haplotype structures and relationships were also analysed. A number of polymorphisms were observed in CEACAM genes but the diversity of CEACAM1, to which most Opa proteins bind, was lower, and a small number of high-frequency haplotypes were detected. Dose-dependent associations of three CEACAM haplotypes with meningococcal disease were observed, with the effect of carrying these haplotypes amplified in homozygous individuals. Two haplotypes were protective while one haplotype in CEACAM6 was associated with a twofold increase in disease susceptibility. These data imply that human CEACAM may be one determinant of human susceptibility to meningococcal disease.
authors.affiliation: Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Churchill Hospital, Headington, Oxford, Oxon, UK. martin.callaghan@paediatrics.ox.ac.uk
authors.forename: M J
authors.initials: MJ
authors.lastname: Callaghan
authors.forename: K
authors.initials: K
authors.lastname: Rockett
authors.forename: C
authors.initials: C
authors.lastname: Banner
authors.forename: E
authors.initials: E
authors.lastname: Haralambous
authors.forename: H
authors.initials: H
authors.lastname: Betts
authors.forename: S
authors.initials: S
authors.lastname: Faust
authors.forename: M C J
authors.initials: MC
authors.lastname: Maiden
authors.forename: J S
authors.initials: JS
authors.lastname: Kroll
authors.forename: M
authors.initials: M
authors.lastname: Levin
authors.forename: D P
authors.initials: DP
authors.lastname: Kwiatkowski
authors.forename: A J
authors.initials: AJ
authors.lastname: Pollard
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics* / Q000378:metabolism; D000483:Alleles; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism; D002272:Carcinoembryonic Antigen / Q000235:genetics*; D016022:Case-Control Studies; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006239:Haplotypes; D006720:Homozygote; D006801:Humans; D015810:Linkage Disequilibrium; D008589:Meningococcal Infections / Q000235:genetics* / Q000382:microbiology; D009345:Neisseria meningitidis / Q000472:pathogenicity; D020641:Polymorphism, Single Nucleotide; D012189:Retrospective Studies
chemical_list: D018829:Adhesins, Bacterial; D000942:Antigens, Bacterial; D002272:Carcinoembryonic Antigen; C050308:opacity proteins