title: Increased expression of plasma and cell surface co-stimulatory molecules CTLA-4, CD28 and CD86 in adult patients with allergic asthma.
abstract: The co-stimulatory interactions of the B7 family molecules CD80 and CD86 on antigen-presenting cells, together with their T cell counter receptors CD28 and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), modulate T lymphocyte-mediated immune responses in a reciprocal manner. To investigate whether there is altered expression and the clinical significance of soluble co-stimulatory molecules in asthmatic patients, plasma concentrations of sCTLA-4, sCD28, sCD80 and sCD86 in 51 adult allergic asthmatic adults with or without steroid treatment, and 35 sex- and age-matched control subjects were measured by enzyme-linked immunosorbent assay (ELISA). Cell surface expression of CTLA-4 and CD28 on peripheral blood mononuclear cells (PBMC) were analysed by flow cytometry. Results showed that the plasma sCTLA-4 concentration was significantly higher in all asthmatic patients while sCD28 and sCD86 concentrations were significantly higher in steroid and non-steroid treated asthmatic patients, respectively, compared with control subjects (all P < 0.01). Significantly increased cell surface expression of CD28 but not CTLA-4 on PBMC was found in asthmatic patients compared with controls (P < 0.05). The plasma concentration and cell surface expression of CTLA-4 were found to exhibit positive and significant correlations with those of CD28 (both P < 0.05). Serum total IgE concentration correlated positively and significantly with sCTLA-4 and sCD28 concentrations in allergic asthmatic patients (both P < 0.05). The increased expression of these soluble co-stimulatory molecules may reflect the dysregulation of T cell activation, thereby contributing to the immunopathogenesis of allergic asthma.
authors.affiliation: Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
authors.forename: C K
authors.initials: CK
authors.lastname: Wong
authors.forename: S W M
authors.initials: SW
authors.lastname: Lun
authors.forename: F W S
authors.initials: FW
authors.lastname: Ko
authors.forename: W K
authors.initials: WK
authors.lastname: Ip
authors.forename: D S C
authors.initials: DS
authors.lastname: Hui
authors.forename: C W K
authors.initials: CW
authors.lastname: Lam
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000097:blood*; D000943:Antigens, Differentiation / Q000097:blood*; D001249:Asthma / Q000188:drug therapy / Q000276:immunology* / Q000503:physiopathology; D051940:B7-2 Antigen; D018106:CD28 Antigens / Q000097:blood; D060908:CTLA-4 Antigen; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D047150:Eosinophil Cationic Protein / Q000097:blood; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D005541:Forced Expiratory Volume; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood; D008875:Middle Aged; D012995:Solubility; D013256:Steroids / Q000627:therapeutic use; D014797:Vital Capacity
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D051940:B7-2 Antigen; D018106:CD28 Antigens; C497964:CD86 protein, human; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D008562:Membrane Glycoproteins; D013256:Steroids; D007073:Immunoglobulin E; D047150:Eosinophil Cationic Protein