MacNeil S, Munro D S, Metcalfe R, Cotterell S, Ruban L, Davies R, Weetman A P
Department of Medicine, University of Sheffield, Northern General Hospital, UK.
J Endocrinol. 1994 Dec;143(3):527-40. doi: 10.1677/joe.0.1430527.
The purpose of this study was to determine if immunoglobulin G preparations (IgGs) from patients with Graves' disease can increase intracellular calcium in thyroid cells, as has been reported for TSH. Both TSH and Graves' IgGs (prepared by protein G affinity chromatography) increased calcium in a range of thyroid cells; however, the response seen, using Fura-2-loaded coverslips of cell monolayers, varied considerably. Chinese hamster ovary (CHO/JPO9) cells transfected with a high number of human TSH receptors showed the greatest response: TSH (10 mU/ml) increased calcium in 46% of experiments and 18 out of 25 (72%) Graves' IgGs increased calcium at 0.1 mg/ml (significantly greater, P < 0.001, than for control IgGs where cells responded to 2 out of 13 preparations). Rat FRTL-5 cells only responded to TSH in 22% of experiments and to 2 out of 8 (25%) of Graves' IgGs. Similarly, human thyroid cells responded to TSH in 22% of experiments and to 2 out of 9 (22%) of Graves' IgGs. (When studying cyclic AMP responses in JPO9 cells, much higher concentrations of Graves' IgGs were required (1-3 mg/ml). However, higher concentrations (0.3 mg/ml) of both Graves' IgGs, and to a lesser extent of control IgGs, were capable of increasing calcium in cells both with and without TSH receptors (control CHO cells and normal human dermal fibroblasts). We conclude that relatively low concentrations of patient IgGs can be distinguished from control IgGs in JPO9 cells on the basis of their ability to increase calcium, but that additionally all IgG preparations possibly contain another factor which can increase calcium in a range of cells independent of the presence of the TSH receptor.
本研究的目的是确定格雷夫斯病患者的免疫球蛋白G制剂（IgGs）是否能像促甲状腺激素（TSH）那样增加甲状腺细胞内的钙含量。TSH和格雷夫斯病IgGs（通过蛋白G亲和层析制备）均可使一系列甲状腺细胞内的钙含量增加；然而，使用负载Fura-2的细胞单层盖玻片观察到的反应差异很大。转染了大量人TSH受体的中国仓鼠卵巢（CHO/JPO9）细胞反应最为强烈：TSH（10 mU/ml）在46%的实验中使钙含量增加，25份格雷夫斯病IgGs中有18份（72%）在0.1 mg/ml时使钙含量增加（显著高于对照IgGs，P < 0.001，对照IgGs中13份制剂仅有2份能使细胞反应）。大鼠FRTL-5细胞仅在22%的实验中对TSH有反应，对8份格雷夫斯病IgGs中的2份（25%）有反应。同样，人甲状腺细胞在22%的实验中对TSH有反应，对9份格雷夫斯病IgGs中的2份（22%）有反应。（在研究JPO9细胞中的环磷酸腺苷反应时，需要更高浓度的格雷夫斯病IgGs（1 - 3 mg/ml）。然而，更高浓度（0.3 mg/ml）的格雷夫斯病IgGs以及浓度稍低的对照IgGs，无论细胞有无TSH受体（对照CHO细胞和正常人皮肤成纤维细胞），都能够增加细胞内的钙含量。我们得出结论，在JPO9细胞中，基于其增加钙含量的能力，相对低浓度的患者IgGs可与对照IgGs区分开来，但此外所有IgG制剂可能都含有另一种因子，该因子可在一系列细胞中增加钙含量，而与TSH受体的存在无关。
