Semi-quantitative analysis of interleukin-1α, interleukin-6 and interleukin-8 mRNA expression by human thyrocytes

Abstract

It has been suggested that the thyroid itself may contribute to the inflammatory process observed in autoimmune thyroiditis by releasing the cytokines interleukin-1 alpha (IL-1 alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8), but studies of cytokine gene expression in thyrocytes have been limited and conflicting. A semi-quantitative reverse transcription-PCR technique has been used to investigate the expression of IL-1 alpha, IL-6 and IL-8 mRNA in the human thyroid cell line HTori3 and in cultures of primary human thyroid follicular cells (TFCs). Cytokine mRNA levels were examined over a 24-h period, and the modulatory effects of exogenous IL-1 alpha, interferon-gamma (IFN-gamma) and TSH investigated. Basal expression of IL-1 alpha, IL-6 and IL-8 mRNA was detected in HTori3 and primary TFC cultures. Stimulation with IL-1 (10 U/ml) for 12 h produced an increase in the level of IL-1 alpha mRNA in both primary TFC and HTori3 cultures. IL-6 and IL-8 mRNA levels were increased by the addition of IL-1 in both cell types, and this effect was detected throughout the 24-h time-course. IFN-gamma (100 U/ml) had no significant effect on cytokine gene expression. A higher concentration of IFN-gamma (500 U/ml) had no significant effect on the expression of IL-1 alpha or IL-8 but produced an increase in the level of IL-6 mRNA in primary cultures and in HTori3 cells. Addition of TSH (1 mU/ml) produced an increase in the level of IL-1 alpha mRNA in primary TFC and HTori3 cells, at 12 and 24 h. TSH had no significant effect on the expression of IL-6 or IL-8 mRNA. These results demonstrate that human TFCs constitutively express IL-1 alpha, IL-6 and IL-8 mRNA and that this expression can be modulated by IL-1, IFN-gamma and TSH.

Increased levels of serum interleukin-12 in Graves' disease

“…Serum thyrotropin (TSH) levels were measured with an IRMA kit (Eiken Chemical Co. Ltd, Tokyo, Japan) and free T 4 and free T 3 were measured with RIA kits (Ortho Clinical Diagnostics, Tokyo, Japan), while the serum thyroid-binding inhibiting immunoglobulin (TBII) was assessed with an RRA kit (Kodak diagnostics, Tokyo, Japan). Thyroglobulin antibody (TGAb) and microsomal antibody (MCAb) were measured by haemagglutination using commercial kits (Fuji Rebio Inc., Tokyo, Japan).…”

“…These molecules, produced by both inflammatory cells and thyroid follicular cells (1)(2)(3)(4)(5), are essential for T and B cell growth and differentiation, and may affect thyroid follicular cells directly, inducing expression of major histocompatibility complex (MHC) class II molecules and adhesion molecules (6)(7)(8)(9)(10)(11). Interleukin-12 (IL-12) is a recently defined cytokine that was originally identified and purified from condition medium of Epstein-Barr virus (EBV)-transformed human lymphoblastoid cell lines (12,13).…”

Intrathyroidal cytokine gene expression in Hashimoto's thyroiditis

“…In addition, CD4 + , CD8 + lymphocyte separation was carried out in stimulated PBMC and RT-PCR performed in each subset to insure the validity of the separation protocol. cDNA samples were equilibrated on the basis of the yield of -actin-specific PCR product, using a method previously described [16]. The primer sequences for IL-1, IL-1, IL-2, IL-4, IL-6, IL-8, IL-10, IFN-, TNF-and -actin have been described previously [20][21][22].…”

“…Infiltrating lymphocytes are not the only source of cytokines in thyroiditis, as TFC constitutively express IL-1, IL-6 and IL-8 in vitro [15,16], and TNF is secreted by TFC in vivo [17]. Thus, TFC could also have a role in the inflammatory process through the production of various cytokines.…”

Methimazole inhibits CXC chemokine ligand 10 secretion in human thyrocytes

“…The cytokine production in AITDs has been ascribed to infiltrating T cells, macrophages (Weetman 2003), thyrocytes (Watson et al 1995, Weetman 2004, and endothelial cells (Romagnani et al 2002). The active phase of the disease is characterized by the presence of proinflammatory and Th1-derived cytokines in the thyroid gland, whereas Th2-derived cytokines do not seem to be involved (Wakelkamp et al 2003).…”