title: High avidity state of leukocyte function-associated antigen-1 on rheumatoid synovial fluid T lymphocytes.
abstract: The integrin LFA-1 (CD11a/CD18) is a cell surface adhesion molecule required for leukocyte extravasation and subsequent immune and inflammatory responses. Rapid transition between nonadherent and adherent states of LFA-1 is of key importance to Ag-specific recognition of T lymphocytes. In this paper, LFA-1-mediated adhesiveness of peripheral blood (PB) and synovial fluid (SF) T lymphocytes to affinity-purified ICAM-1-coated plates was studied in patients with rheumatoid arthritis (RA) and in patients with non-RA panels, including osteoarthritis, ankylosing spondylitis, erythema nodosum, pseudogout, and pustulosis. LFA-1-mediated adhesiveness of SF T lymphocytes was not observed in any of the 10 non-RA patients studied, although cross-linking of the TCR on lymphocytes from these patients rapidly converted LFA-1 to an adhesive state. In contrast, SF T lymphocytes from 10 of 12 RA patients exhibited LFA-1-mediated adhesiveness without a requirement for cross-linking of the TCR. No difference was seen in the cell surface density of LFA-1 between non-RA and RA T lymphocytes, suggesting that the difference in adhesiveness was due to a high avidity state of LFA-1 on SF T lymphocytes in RA. Furthermore, exposure of PB T lymphocytes, which showed a low avidity state of LFA-1, to whole SF from RA patients that was depleted of T lymphocytes could induce a high avidity state of LFA-1 in vitro. Cellfree SF from RA patients also could stimulate adhesiveness, although to a lesser extent. These data suggest the existence of a LFA-1-activating environment that is selectively found in SF from RA patients.
authors.affiliation: Department of Medicine III, Osaka University Medical School, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Yokota
authors.forename: N
authors.initials: N
authors.lastname: Murata
authors.forename: O
authors.initials: O
authors.lastname: Saiki
authors.forename: M
authors.initials: M
authors.lastname: Shimizu
authors.forename: T A
authors.initials: TA
authors.lastname: Springer
authors.forename: T
authors.initials: T
authors.lastname: Kishimoto
mesh_terms: D000328:Adult; D000368:Aged; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D005260:Female; D006801:Humans; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011485:Protein Binding; D013582:Synovial Fluid / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D016169:Lymphocyte Function-Associated Antigen-1