title: Increased expression of human leucocyte antigen class I free heavy chains on monocytes of patients with spondyloarthritis and cells transfected with HLA-B27.
abstract: Human leucocyte antigen (HLA)-B27 expression is correlated with spondyloarthritis (SpA), but its role in disease pathogenesis remains unclear. The aim of the study was to determine whether HLA-B27 free heavy chain (FHC) contributes to SpA pathogenesis. Flow cytometry was used to analyse the FHC expression on CD3+ and CD14+ cells in the peripheral blood (PB) and synovial fluid (SF) from SpA patients, healthy controls, and rheumatoid arthritis (RA) patients. Human monocytic U937 cell lines stably expressing enhanced green fluorescence protein (EGFP)/HLA-B27, EGFP/HLA-A2 or EGFP alone were created to further investigate the relation between HLA-B27 and FHC expression. The relative FHC level on CD14+ PB cells was significantly higher in SpA patients than in controls, but lower than on the SF cells of SpA patients. No significant correlation was found for relative FHC expression with HLA-B27 or β2-microglobulin expression. HLA-B27-transfected U937 cells expressed higher FHC levels than either EGFP/HLA-A2- or EGFP-transfected cells. HLA class I FHC expression was significantly increased on monocytes of SpA patients and HLA-B27-transfected cells, implying that FHC, perhaps mostly derived from HLA-B27, plays an important role in SpA pathogenesis.
authors.affiliation: Department of Clinical Immunology, State Key Discipline of Cell Biology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Ding
authors.forename: Yuan
authors.initials: Y
authors.lastname: Feng
authors.forename: Zhao Hui
authors.initials: ZH
authors.lastname: Zheng
authors.forename: Xue Yi
authors.initials: XY
authors.lastname: Li
authors.forename: Zhen Biao
authors.initials: ZB
authors.lastname: Wu
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D000328:Adult; D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000473:pathology; D017252:CD3 Complex / Q000378:metabolism; D045744:Cell Line, Tumor; D005260:Female; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D015796:HLA-B27 Antigen / Q000235:genetics / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000096:biosynthesis*; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology*; D025242:Spondylarthropathies / Q000276:immunology* / Q000473:pathology; D013582:Synovial Fluid / Q000166:cytology; D014162:Transfection; D020298:U937 Cells; D055815:Young Adult; D001613:beta 2-Microglobulin / Q000096:biosynthesis
chemical_list: D017252:CD3 Complex; D015796:HLA-B27 Antigen; D015395:Histocompatibility Antigens Class I; D007143:Immunoglobulin Heavy Chains; D018950:Lipopolysaccharide Receptors; D001613:beta 2-Microglobulin; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins