title: Expression of KIR and C-type lectin receptors in Behcet's disease.
abstract: OBJECTIVE
  Behçet's disease (BD) is a multisystemic disorder with a possible underlying pathology of immune-mediated vasculitis. Genetic susceptibility associated with HLA-B*51 and B*2702 has been implicated in its pathogenesis. Considering the recently defined regulatory mechanisms of NK cells through HLA class I binding receptors, we hypothesized that interactions of NK and T cells through the NK receptors may be important in the pathogenesis of BD.
  
  
  METHODS
  The impact of different expression patterns of HLA-recognizing receptors on NK or T cells was analysed in 51 patients with BD and 32 healthy controls. We used flow cytometry to investigate the expression of KIR3DL1 from the polymorphic killer immunoglobulin-like receptor (KIR) family, which binds a shared HLA-Bw4 motif on HLA-B51 and *2702 alleles, and CD94 from the conserved C-type lectin receptor family, which binds HLA-E. Thirty-three of the BD patients and 19 of the controls carried the same HLA-Bw4 motif.
  
  
  RESULTS
  CD3(+) T cells were increased in patients with BD compared with controls (81 vs 75%, P = 0.001), whereas the NK cells did not show any difference between the two groups. Increased expression of CD94 in BD was observed on CD16(+)CD56(+) cells (66 vs 57, P = 0.04) and on CD3(+) (7.7 vs 4.0, P < 0.001) and CD3(+)CD56(+) (44 vs 35, P = 0.02) T cells. KIR3DL1 expression on the NK and T cells was not statistically different between the two groups. No effect of HLA-Bw4 motif was observed on the expression of CD94 and KIR3DL1 in both the patients and the controls.
  
  
  CONCLUSIONS
  The absence of a correlation between KIR3DL1 expression and HLA-Bw4 motif confirms previous work reporting that the expression of these molecules is regulated separately. Increased expression of CD94 may suggest that NK receptors play a pathogenic or regulatory role in BD.
authors.affiliation: Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, Turkey. gsaruhan@istanbul.edu.tr
authors.forename: G
authors.initials: G
authors.lastname: Saruhan-Direskeneli
authors.forename: F A
authors.initials: FA
authors.lastname: Uyar
authors.forename: A
authors.initials: A
authors.lastname: Cefle
authors.forename: S C
authors.initials: SC
authors.lastname: Onder
authors.forename: E
authors.initials: E
authors.lastname: Eksioglu-Demiralp
authors.forename: S
authors.initials: S
authors.lastname: Kamali
authors.forename: M
authors.initials: M
authors.lastname: Inanç
authors.forename: L
authors.initials: L
authors.lastname: Ocal
authors.forename: A
authors.initials: A
authors.lastname: Gül
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000097:blood; D001528:Behcet Syndrome / Q000276:immunology*; D005260:Female; D015235:HLA-B Antigens / Q000097:blood; D059949:HLA-B51 Antigen; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D037181:Lectins, C-Type / Q000097:blood*; D008297:Male; D008875:Middle Aged; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011971:Receptors, Immunologic / Q000097:blood*; D054340:Receptors, KIR; D054341:Receptors, KIR3DL1; D016176:T-Lymphocyte Subsets / Q000276:immunology
chemical_list: D015703:Antigens, CD; D015235:HLA-B Antigens; D059949:HLA-B51 Antigen; C042388:HLA-Bw4 antigen; C515083:KIR3DL1 protein, human; C497869:KLRD1 protein, human; D037181:Lectins, C-Type; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011971:Receptors, Immunologic; D054340:Receptors, KIR; D054341:Receptors, KIR3DL1