Dendritic cells and veiled accessory macrophages : hormonal influences and autoimmune thyroid disease

Immune responses to thyroid specific autoantigens form the basis of autoimmune thyroid disease pathogenesis. Two polar forms of autoimmune reactivity of the thyroid gland exist in this disease spectrum: a catabolic form characterized by gradual inflammatory destruction of thyroid parenchyma leading to thyroid failure, and an anabolic form in which stimulation of the growth and metabolism of the thyroid parenchyma leads to goiter formation and hyperthyroidism. The catabolic form is best known as destructive autoimmune thyroiditis, whereas the anabolic form is generally referred to as Graves’ disease

Opposing effects of dehydroepiandrosterone and dexamethasone on the generation of monocyte-derived dendritic cells

BACKGROUND: Dehydroepiandrosterone (DHEA) has been suggested as an immunostimulating steroid hormone, of which the effects on the development of dendritic cells (DC) are unknown. The effects of DHEA often oppose those of the other adrenal glucocorticoid, cortisol. Glucocorticoids (GC) are known to suppress the immune response at different levels and have recently been shown to modulate the development of DC, thereby influencing the initiation of the immune response. Variations in the duration of exposure to, and doses of, GC (particularly dexamethasone (DEX)) however, have resulted in conflicting effects on DC development. AIM: In this study, we describe the effects of a continuous high level of exposure to the adrenal steroid DHEA (10 M) on the generation of immature DC from monocytes, as well as the effects of the opposing steroid DEX on this development. RESULTS: The continuous presence of DHEA (10 M) in GM-CSF/IL-4-induced monocyte-derived DC cultures resulted in immature DC with a morphology and functional capabilities similar to those of typical immature DC (T cell stimulation, IL-12/IL-10 production), but with a slightly altered phenotype of increased CD80 and decreased CD43 expression (markers of maturity). The continuous presence of DEX at a concentration of 10 M in the monocyte/DC cultures resulted in the generation of plastic-adherent macrophage-like cells in place of typical immature DC, with increased CD14 expression, but decreased expression of the typical DC markers CD1a, CD40 and CD80. These cells were strongly reactive to acid phosphatase, but equally capable of stimulating T cell prolifer