Thyrocytes--not innocent bystanders in autoimmune disease.

Possible Pathogenetic Relevance of Interleukin-1beta in "Destructive" Organ-specific Autoimmune Disease (Hashimoto's Thyroiditis)

Thyroid follicular cells (TFC) abundantly express a variety of immunologically relevant surface molecules in Hashimoto's thyroiditis (HT), for example, MHC antigens and adhesion molecules such as ICAM-1. Cytokines produced by infiltrating type 1 helper and cytotoxic T cells are importantly involved in de novo expression or up-regulation of such molecules. We recently demonstrated that TFC from HT patients almost invariably bear on their surface two additive functional molecules: Fas/Apo1/CD95, an important participant in apoptosis, and B7.1, a member of a family of "co-stimulatory" molecules that are crucial for efficient antigen presentation. To date, 12 out of 14 surgical HT thyroid speci…

Regulation of Apoptosis in Endocrine Autoimmunity

Dysregulation of apoptosis is associated with the pathogenesis of organ-specific autoimmune diseases, through altered target organ susceptibility. Apoptosis signaling pathways can be initiated through activation of death receptors such as Fas. A comparative analysis of the expression of Fas and FasL, the antiapoptotic molecule Bcl-2, and apoptosis in both thyrocytes and thyroid-infiltrating lymphocytes (TILs) from patients with either Graves' disease (GD) or Hashimoto's thyroiditis (HT) was performed. GD thyrocytes expressed less Fas than HT thyrocytes, whereas GD TILs had higher levels of Fas and FasL than HT TILs. GD thyrocytes expressed higher levels of Bcl-2 compared with HT thyrocytes.…