Functional analysis of intercellular adhesion molecule-1-expressing human thyroid cells.
We have tested the potential role of thyroid cell intercellular adhesion molecule-1 (ICAM-1) expression by in vitro assays of cell clustering and cytotoxicity. Increased ICAM-1 appeared within 24 h of thyroid cell stimulation with cytokines and was not inhibited by the antithyroid drug methimazole. Autologous and allogeneic lymphocyte-thyroid cell cluster formation, assessed by flow cytometry, was reduced by about one-third in the presence of a monoclonal antibody against ICAM-1, regardless of whether thyroid cells were expressing basal levels of ICAM-1 or had been stimulated with interferon-gamma. The cytotoxicity produced by interleukin 2-stimulated allogeneic lymphocytes was not consistently inhibited by anti-ICAM-1 antibody, but phytohemagglutinin-stimulated lymphocytes showed a reduction of 23%-28% in cytotoxicity against untreated or interferon-gamma stimulated thyroid cells when the anti-ICAM-1 monoclonal antibody was present. Finally, thyroid cells could be infected by rhinovirus, confirming the presence of fully functional ligand. These results show that ICAM-1 expression by thyroid cells may enhance immune cell recognition and play some role in cytotoxicity, features which could be important in the initiation or perpetuation of autoimmune thyroiditis.
Weetman
A P
AP
Department of Medicine, University of Cambridge Clinical School, Addenbrooke's Hospital, Cambridge, GB.
Freeman
M
M
Borysiewicz
L K
LK
Makgoba
M W
MW
D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000032:analysis* / Q000502:physiology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D006111:Graves Disease / Q000503:physiopathology; D006801:Humans; D066298:In Vitro Techniques; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma / Q000494:pharmacology; D008214:Lymphocytes / Q000276:immunology*; D010850:Picornaviridae Infections / Q000382:microbiology; D012229:Rhinovirus / Q000472:pathogenicity; D013961:Thyroid Gland / Q000166:cytology* / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D015815:Cell Adhesion Molecules; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma