title: CD146+ T lymphocytes are increased in both the peripheral circulation and in the synovial effusions of patients with various musculoskeletal diseases and display pro-inflammatory gene profiles.
abstract: Twenty-eight synovial effusions (SE) were obtained from 24 patients, paired samples of peripheral blood (PB) from 10 of these patients, and PB from 36 healthy individuals for analysis of CD146 on T-lymphocytes by flow cytometry. CD146+ or CD146- T-lymphocytes were sorted from three SE to study gene expression profiles and selected genes revalidated using QPCR assays. We found more CD3+CD146+ and CD4+CD146+ T-lymphocytes in PB from patients compared with PB of healthy individuals (4.71% +/- 2.48% vs. 2.53% +/- 1.08%, P = 0.028) and (6.29% +/- 2.74% vs. 2.41% +/- 0.96%, P = 0.0017), respectively, whereas CD8+CD146+ T-lymphocytes were not significantly different (2.55% +/- 1.65% vs. 3.18% +/- 2.59%, P = 0.5008). SE displayed CD146 staining on 16.32% +/- 6.06% of CD3+ cells. This expression was skewed toward CD4+ T-lymphocytes, with CD146 present on 24.06% +/- 8.20% of the CD4+ T-lymphocytes compared with 6.19% +/- 5.22% of the CD8+ T-lymphocytes. CD146 on CD3+, CD4+ and CD8+ T-lymphocytes in SE was significantly higher compared with PB in patients (P < 0.0001, P < 0.0001 and P = 0.0036, respectively). Gene expression profiles of sorted CD146+CD4+CD3+ vs. CD146-CD4+CD3+ T-lymphocytes (n = 2) and CD2+CD146+ vs. CD2+CD 146- (n = 1) from SE, displayed increased CD146, LAIR2, CXCL13, CD109, IL6ST, IL6R, TNFRsf18, and TNFRsf4 genes, whereas decreased CCR7, CCL5, and cytotoxicity-associated genes including granzymes b, h, and k, perforin were found with the CD146- T-lymphocytes. By QPCR higher mRNA expression of CXCL13, CD146 and CD109 was also noted in the CD146+ subset, compared with the CD146- subset, in PB of healthy individuals and in PB and SE from patients. Our study establishes increased CD146+ T-lymphocytes in diseases with joint effusions, and demonstrates pro-inflammatory gene profiles in these cells.
authors.affiliation: Flow Cytometry Core Facility, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892, USA.
authors.forename: Pradeep Kumar
authors.initials: PK
authors.lastname: Dagur
authors.forename: Gulnaz
authors.initials: G
authors.lastname: Tatlici
authors.forename: Mark
authors.initials: M
authors.lastname: Gourley
authors.forename: Leigh
authors.initials: L
authors.lastname: Samsel
authors.forename: Nalini
authors.initials: N
authors.lastname: Raghavachari
authors.forename: Poching
authors.initials: P
authors.lastname: Liu
authors.forename: Delong
authors.initials: D
authors.lastname: Liu
authors.forename: J Philip
authors.initials: JP
authors.lastname: McCoy
mesh_terms: D051929:CD146 Antigen / Q000378:metabolism*; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006801:Humans; D007249:Inflammation / Q000235:genetics* / Q000276:immunology; D009140:Musculoskeletal Diseases / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013582:Synovial Fluid / Q000166:cytology* / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*
chemical_list: D051929:CD146 Antigen