title: The regulation of FasL expression--a distinquishing feature between monocytes and T lymphocytes/NK cells with possible implications for SLE.
abstract: Monocytes and lymphocytes from patients with systemic lupus erythematosus (SLE) had a higher cell surface expression of FasL than the corresponding cells from healthy individuals. Inhibitors of metalloproteases upregulated the surface expression of FasL in peripheral blood lymphocytes (PBL), indicating that a metalloprotease is responsible for the cleavage of FasL. The level of sFasL in serum was slightly increased in the patient group compared to the controls. Therefore, the possible contribution of various mononuclear cell types to the release of FasL was analyzed. Isolated NK cells and T lymphocytes released FasL into the medium and the release was prevented by inhibitors of metalloproteases. In contrast, isolated monocytes did not release FasL. FasR expression was elevated in patients with inverted CD4/CD8 ratio, while FasL expression showed no relationship to CD4/CD8 ratio. The absence of FasL release by isolated cells and a high level of surface expression of FasL distinguish monocytes and T lymphocytes/NK cells.
authors.affiliation: Department of Clinical Immunology, Umeå University, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Eneslätt
authors.forename: S
authors.initials: S
authors.lastname: Rantapää-Dahlqvist
authors.forename: A
authors.initials: A
authors.lastname: Uddhammar
authors.forename: K G
authors.initials: KG
authors.lastname: Sundqvist
mesh_terms: D000328:Adult; D000954:Antigens, Surface / Q000378:metabolism; D017209:Apoptosis; D016516:CD4-CD8 Ratio; D016022:Case-Control Studies; D053222:Fas Ligand Protein; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology* / Q000473:pathology; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology* / Q000473:pathology; D011480:Protease Inhibitors / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism
chemical_list: D000954:Antigens, Surface; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D011480:Protease Inhibitors; D019014:fas Receptor