title: Association of Pneumococcal Protein Antigen Serology With Age and Antigenic Profile of Colonizing Isolates.
abstract: Several Streptococcus pneumoniae proteins play a role in pathogenesis and are being investigated as vaccine targets. It is largely unknown whether naturally acquired antibodies reduce the risk of colonization with strains expressing a particular antigenic variant.
  
  
  
  Serum immunoglobulin G (IgG) titers to 28 pneumococcal protein antigens were measured among 242 individuals aged <6 months-78 years in Native American communities between 2007 and 2009. Nasopharyngeal swabs were collected >- 30 days after serum collection, and the antigen variant in each pneumococcal isolate was determined using genomic data. We assessed the association between preexisting variant-specific antibody titers and subsequent carriage of pneumococcus expressing a particular antigen variant.
  
  
  
  Antibody titers often increased across pediatric groups before decreasing among adults. Individuals with low titers against group 3 pneumococcal surface protein C (PspC) variants were more likely to be colonized with pneumococci expressing those variants. For other antigens, variant-specific IgG titers do not predict colonization.
  
  
  
  We observed an inverse association between variant-specific antibody concentration and homologous pneumococcal colonization for only 1 protein. Further assessment of antibody repertoires may elucidate the nature of antipneumococcal antibody-mediated mucosal immunity while informing vaccine development.
authors.affiliation: Center for Communicable Disease Dynamics, Department of Epidemiology, T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA.
authors.forename: Taj
authors.initials: T
authors.lastname: Azarian
authors.affiliation: Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Lindsay R
authors.initials: LR
authors.lastname: Grant
authors.affiliation: Center for Communicable Disease Dynamics, Department of Epidemiology, T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Georgieva
authors.affiliation: Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Hammitt
authors.affiliation: Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Raymond
authors.initials: R
authors.lastname: Reid
authors.affiliation: Wellcome Trust Sanger Institute, Cambridge, Hinxton, UK.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Bentley
authors.affiliation: Immunobiology Section, Institute of Child Health, University College London, UK.
authors.forename: David
authors.initials: D
authors.lastname: Goldblatt
authors.affiliation: Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Mathuran
authors.initials: M
authors.lastname: Santosham
authors.affiliation: Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Weatherholtz
authors.affiliation: Immunobiology Section, Institute of Child Health, University College London, UK.
authors.forename: Paula
authors.initials: P
authors.lastname: Burbidge
authors.affiliation: Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Novalene
authors.initials: N
authors.lastname: Goklish
authors.affiliation: Center for Communicable Disease Dynamics, Department of Epidemiology, T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA.
authors.forename: Claudette M
authors.initials: CM
authors.lastname: Thompson
authors.affiliation: Center for Communicable Disease Dynamics, Department of Epidemiology, T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA.
authors.forename: William P
authors.initials: WP
authors.lastname: Hanage
authors.affiliation: Center for American Indian Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Kate L
authors.initials: KL
authors.lastname: O'Brien
authors.affiliation: Center for Communicable Disease Dynamics, Department of Epidemiology, T. H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Lipsitch
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000097:blood* / Q000276:immunology; D001426:Bacterial Proteins / Q000097:blood; D002353:Carrier State / Q000276:immunology / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D005500:Follow-Up Studies; D006360:Heat-Shock Proteins / Q000097:blood; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D016015:Logistic Models; D008137:Longitudinal Studies; D008875:Middle Aged; D009305:Nasopharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000097:blood* / Q000276:immunology; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D007074:Immunoglobulin G; C110344:SpsA protein, Streptococcus pneumoniae; C069816:phage shock protein, Bacteria
keywords: PspA; PspC; Streptococcus pneumoniae; immunology; pilus; pneumococci; protein antigens; sera; vaccine; antibody