title: Decreased expression of T lymphocyte co-stimulatory molecule CD26 on invariant natural killer T cells in systemic lupus erythematosus.
abstract: CD26, a T cell co-stimulatory molecule and dipeptidyl peptidase IV for the degradation of interferon-gamma-induced chemokine, participates in multiple immunopathological roles in leukocyte homing and inflammation. Decreased circulating concentration of soluble (s)CD26 in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis and murine model of arthritis and encephalomyelitis have been reported. In the present study, the plasma concentration of sCD26 and chemokines, and cell surface expression of CD26 on monocytes, CD4+T lymphocytes, CD8+T lymphocytes, CD19+B lymphocytes and invariant natural killer T (iNKT) lymphocytes were analyzed using ELISA and flow cytometry, respectively, in 23 SLE patients and 14 sex- and age-matched control subjects. Although there was no significant difference between plasma concentrations of soluble CD26 in SLE patients with controls (p > 0.05), there was significant elevated Th1 chemokines CXCL10 and CXCL9 but not Th2 chemokine CCL2, and down-regulation in iNKT lymphocytes number and cell surface expression of CD26 on CD4+T and iNKT lymphocytes of SLE patients compared with controls (all p < 0.05). Decreased circulating number of iNKT cells and CD26 on iNKT cells can be important for the immunopathogenesis by exacerbating Th1-related inflammation in SLE.
authors.affiliation: Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: P T Y
authors.initials: PT
authors.lastname: Wong
authors.forename: C K
authors.initials: CK
authors.lastname: Wong
authors.forename: L S
authors.initials: LS
authors.lastname: Tam
authors.forename: E K
authors.initials: EK
authors.lastname: Li
authors.forename: D P
authors.initials: DP
authors.lastname: Chen
authors.forename: C W K
authors.initials: CW
authors.lastname: Lam
mesh_terms: D000328:Adult; D018932:Chemokine CCL2 / Q000096:biosynthesis; D054357:Chemokine CXCL10 / Q000096:biosynthesis; D054370:Chemokine CXCL9 / Q000096:biosynthesis; D018819:Dipeptidyl Peptidase 4 / Q000096:biosynthesis / Q000276:immunology*; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000378:metabolism; D055611:Natural Killer T-Cells / Q000276:immunology* / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism
chemical_list: D018932:Chemokine CCL2; D054357:Chemokine CXCL10; D054370:Chemokine CXCL9; D018819:Dipeptidyl Peptidase 4