title: Profiling and validation of individual and patterns of Chlamydia trachomatis-specific antibody responses in trachomatous trichiasis.
abstract: BACKGROUND
  Ocular Chlamydia trachomatis (Ct) infection causes trachoma, the leading infectious cause of blindness. A Ct D/UW3 proteome microarray and sera from Gambian adults with trachomatous trichiasis (TT) or healthy matched controls previously identified several novel antigens, which suggested differential recognition in adults with TT.
  
  
  METHODS
  We re-analysed this serological microarray data using more robust microarray analysis techniques accounting for typical problems associated with highly dimensional data. We examined the Ct-specific antibody profile concerning the overall diversity of responses, antigen expression stage and cellular localisation of antigens. We tested differentially recognised antigens by further serological testing of the screened sera and used larger independent sample sets for validation.
  
  
  RESULTS
  Antibody responses identified High-Performance on antigens expressed early and late in the Ct developmental cycle and those secreted or localised to the outer membrane. Eight antigens were preferentially recognised by scarred individuals and one antigen by healthy individuals. Three of these antigens, two associated with scarring (CT667 and CT706) and one healthy-associated (CT442), were not associated with the presence or absence of scarring following specific serological testing of the arrayed sera and sera from larger, independent case-control cohorts.
  
  
  CONCLUSIONS
  This study identified focussed Ct-specific antibody profiles targeting proteins expressed during entry and exit from cells and localised to interact with the host. A small panel of antibody responses could discriminate between adults with and without TT in a trachoma-endemic community. Heterogenous responses in the independent validation of these antibody targets highlighted the need for large sample sizes, clearly defined clinical phenotypes and follow-up work.
authors.affiliation: Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK. harry.pickering@lshtm.ac.uk.
authors.forename: Harry
authors.initials: H
authors.lastname: Pickering
authors.affiliation: Disease Control and Elimination Theme, Medical Research Council, The Gambia Unit, Fajara, Banjul, Gambia.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Burr
authors.affiliation: Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK.
authors.forename: Tamsyn
authors.initials: T
authors.lastname: Derrick
authors.affiliation: Disease Control and Elimination Theme, Medical Research Council, The Gambia Unit, Fajara, Banjul, Gambia.
authors.forename: Pateh
authors.initials: P
authors.lastname: Makalo
authors.affiliation: Disease Control and Elimination Theme, Medical Research Council, The Gambia Unit, Fajara, Banjul, Gambia.
authors.forename: Hassan
authors.initials: H
authors.lastname: Joof
authors.affiliation: Institute of Structural and Molecular Biology, Birkbeck and University College London, Malet Street, London, UK.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Hayward
authors.affiliation: Clinical Research Department, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Holland
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology*; D001766:Blindness / Q000382:microbiology; D002648:Child; D002692:Chlamydia trachomatis / Q000276:immunology*; D005260:Female; D005714:Gambia / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D040901:Proteomics / Q000379:methods; D014141:Trachoma / Q000453:epidemiology / Q000276:immunology* / Q000382:microbiology; D058457:Trichiasis / Q000453:epidemiology / Q000276:immunology* / Q000382:microbiology; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial
keywords: Antibodies; Chlamydia trachomatis; Microarray; Trachoma; Trachomatous scarring; Trachomatous trichiasis