title: Mechanisms of lymphocyte adhesion to endothelial cells: studies using a LFA-1-deficient cell line.
abstract: In order to investigate the role of lymphocyte function-associated antigen 1 (LFA-1) in lymphocyte adhesion to endothelial cells (EC), we have studied the adhesion of a LFA-1-deficient lymphoblastoid cell line, ICH-KM, which has < 10% of the cell surface LFA-1 expressed on a normal lymphoblastoid cell line, ICH-BJ. The adhesion of ICH-KM cells to unstimulated EC was 49.9 +/- 8.6% (mean +/- SD) that of ICH-BJ cells. Moreover, phorbol ester-stimulated ICH-KM cells showed a considerably weaker increase in adhesion to unstimulated EC compared with ICH-BJ cells (mean +/- SD increase in percentage adhesion, 3.8 +/- 2.3 compared with 18.5 +/- 8.0; P<0.025). In contrast, there was no significant difference between the enhanced adhesion of ICH-KM cells and ICH-BJ cells to interleukin-1 (IL-1)-stimulated EC. Thus ICH-KM cells showed a 22.7 +/- 11.0 (mean +/- SD) increase in percentage adhesion to IL-1-stimulated EC compared with the 24.8 +/- 8.5 increase in percentage adhesion of ICH-BJ cells. Anti-LFA-1 monoclonal antibodies had no effect on the enhanced adhesion of ICH-KM and ICH-BJ cells to IL-1-stimulated EC but abolished the differences in adhesion between the two cell lines. The study therefore indicates that although a major part of unstimulated and phorbol ester-stimulated lymphocyte-EC adhesion is dependent upon LFA-1, the enhanced adhesion due to stimulation of EC with IL-1 is not dependent upon this molecule. The data therefore supports the existence of cytokine-inducible LFA-1-independent adhesion molecules for lymphocytes on EC.
authors.affiliation: Rheumatology Unit, United Medical and Dental Schools, Guy's Hospital, London, UK.
authors.forename: D O
authors.initials: DO
authors.lastname: Haskard
authors.forename: S
authors.initials: S
authors.lastname: Strobel
authors.forename: M
authors.initials: M
authors.lastname: Thornhill
authors.forename: C
authors.initials: C
authors.lastname: Pitzalis
authors.forename: R J
authors.initials: RJ
authors.lastname: Levinsky
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002448:Cell Adhesion; D002460:Cell Line; D018920:Coculture Techniques; D042783:Endothelial Cells / Q000166:cytology*; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology*; D008214:Lymphocytes / Q000166:cytology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D007375:Interleukin-1; D016169:Lymphocyte Function-Associated Antigen-1; D013755:Tetradecanoylphorbol Acetate