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Intercellular adhesion molecule-1 (ICAM-1) in Graves' disease: contrast between in vivo and in vitro results.
Intercellular adhesion molecule-1 (ICAM-1) in Graves' disease: contrast between in vivo and in vitro results.
- Source :
-
Clinical & Experimental Immunology . Dec1993, Vol. 94 Issue 3, p478-485. 8p. - Publication Year :
- 1993
-
Abstract
- We have reassessed the possible role of the adhesion molecule ICAM-1 in the pathogenesis of thyroid autoimmunity. In order to do that, we have investigated its expression in eight Graves' thyroids both in vivo (i.e. on cryostat sections and on cell suspensions), and in vitro (i.e. on cells cultured in monolayers for 3 days), and the results were compared with those obtained with similar preparations from lour normal glands. On cryostat sections, the expression of ICAM-1, and for comparison that of HLA Class I and Class II molecules, was studied by immunofluorescence (IFL), but the former were also assessed by a distinct immunohistochemical technique. ICAM-I was not detected in thyrocytes in vivo of both normal and Graves' glands, but solely in endothelial ceils and antigen-presenting cells (APC), This selective reaction was confirmed by a four-layer technique using specific markers which identify endothelial cells and thyrocytes. HLA Class II molecules were confirmed to be inappropriately expressed in thyrocytes of Graves' glands, but there was no co-expression of these products and ICAM-I in the same cells. In contrast, ICAM-I appeared de novo in a proportion of Graves' and normal thyrocytes soon after the attachment and spreading of these cells in monolayer cultures (36-48 h). Graves' thyrocytes showed a quantitively higher degree of expression compared with that detected on normal thyroid cells (40-70% versus 12-20%). Under these experimental conditions, the four-layer staining with thyroid microsomal antibodies confirmed that thyrocytes were indeed the positive cells which expressed ICAM-1. Blocking experiments with cultured thyrocytes from two Graves' glands and MoAbs to tumour necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) did not prevent the occurrence of ICAM-1 expression, As a result of our study, we failed to demonstrate that Graves' thyrocytes express ICAM-1 in vivo. The unexpected ease of inducing ICAM-1 on thyroid cells under certain in vitro conditions remains intriguing. The phenomenon could be the simple consequence of a mechanical effect rather than exerted by specific biological processes. Further investigations arc, therefore, needed to establish whether ICAM-1 is really involved in the pathogenesis of Graves' disease. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00099104
- Volume :
- 94
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Clinical & Experimental Immunology
- Publication Type :
- Academic Journal
- Accession number :
- 16186849