title: Differential expression of HLA class II genes associated with disease susceptibility and progression in rheumatoid arthritis.
abstract: OBJECTIVE
  Rheumatoid arthritis (RA)-associated HLA class II genes are assumed to promote susceptibility to and/or progression of the disease. Among the various modes of action proposed so far is the effect of the differential expression of HLA class II genes in different types of antigen-presenting cells on the Th1/Th2 balance. The aim of this study was to investigate the differential expression of genes encoded within the RA-associated HLA-DR4 superhaplotype and within the neutral DR7 and DR9 superhaplotypes.
  
  
  METHODS
  The promoters encoded within these 3 haplotypes were first analyzed for sequence polymorphisms. To test for functional consequences, we assumed that the binding of nuclear factors to the promoter elements was correlated with the transcription activity, and we used surface plasmon resonance technology. To that end, oligonucleotides representing the polymorphic regulatory sequences and nuclear extracts from a monocyte cell line and a B cell line were used.
  
  
  RESULTS
  While the promoters of the highly polymorphic HLA-DRB1*04, *07, and *09 alleles showed comparable binding of nuclear factors, differential binding was observed for the 2 promoters that drive the relatively nonpolymorphic DRB4 alleles in linkage disequilibrium with DRB1. Interestingly, analysis of RA patients positive for DR4, DR7, and DR9 revealed the segregation of radiographic progression with the stronger of the 2 DRB4 promoters, independent of the DRB1 allele. Moreover, DRB1*04 alleles in RA patients showed a reduced association with the DRB4 splice variant, completely preventing DRB4 expression.
  
  
  CONCLUSIONS
  Our findings represent the first evidence of a correlation between the differential expression of HLA class II genes and both the susceptibility and the progression of RA.
authors.affiliation: Deutsches RheumaForschungs-Zentrum, Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Heldt
authors.forename: Joachim
authors.initials: J
authors.lastname: Listing
authors.forename: Osman
authors.initials: O
authors.lastname: Sözeri
authors.forename: Franca
authors.initials: F
authors.lastname: Bläsing
authors.forename: Stefan
authors.initials: S
authors.lastname: Frischbutter
authors.forename: Brigitte
authors.initials: B
authors.lastname: Müller
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000235:genetics* / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D018450:Disease Progression; D004198:Disease Susceptibility / Q000276:immunology; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology*; D006684:HLA-DR Antigens / Q000235:genetics; D059810:HLA-DR Serological Subtypes; D015809:HLA-DR7 Antigen / Q000235:genetics; D059811:HLA-DRB1 Chains; D059845:HLA-DRB4 Chains; D006239:Haplotypes; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000187:drug effects / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000276:immunology; D011859:Radiography; D016385:TATA Box / Q000235:genetics / Q000276:immunology
chemical_list: D006684:HLA-DR Antigens; D059810:HLA-DR Serological Subtypes; D015809:HLA-DR7 Antigen; C038988:HLA-DR9 antigen; D059811:HLA-DRB1 Chains; D059845:HLA-DRB4 Chains; D000949:Histocompatibility Antigens Class II; D007371:Interferon-gamma