硬皮病抗体和人免疫球蛋白对肛门括约肌和结肠平滑肌功能的影响。
Effects of scleroderma antibodies and pooled human immunoglobulin on anal sphincter and colonic smooth muscle function.
机构信息
Department of Medicine, Division of Gastroenterology and Hepatology, Thomas Jefferson University, Philadelphia, Pennsylvania.
Jefferson Institute of Molecular Medicine and Scleroderma Center, Thomas Jefferson University, Philadelphia, Pennsylvania.
出版信息
Gastroenterology. 2012 Nov;143(5):1308-1318. doi: 10.1053/j.gastro.2012.07.109. Epub 2012 Aug 1.
BACKGROUND & AIMS: Patients with systemic sclerosis (SSc) have impairments in gastrointestinal smooth muscle function. The disorder has been associated with circulating antibodies to cholinergic muscarinic the type-3 receptor (M(3)-R). We investigated whether it is possible to neutralize these antibodies with pooled human IgGs (pooledhIgG).
METHODS
We studied the effects of IgGs purified from patients with SSc (SScIgGs) on cholinergic nerve stimulation in rat colon tissues. We also examined the effects of SScIgGs on M(3)-R activation by bethanechol (BeCh), M(3)-R occupancy, and receptor binding using immunofluorescence, immunoblot, and enzyme-linked immunosorbent analyses of human internal anal sphincter (IAS) smooth muscle cells, before and after administration of pooledhIgG. Functional displacement of M(3)-R occupancy by the SScIgGs was compared with that of other IgGs during the sustained phase of BeCh-induced contraction of intact smooth muscles from rats.
RESULTS
SScIgG significantly attenuated neurally mediated contraction and acetylcholine release in rat colon as well as BeCh-induced sustained contraction of the IAS smooth muscle. In immunofluorescence analysis, SScIgG co-localized with M(3)-R. In immunoblot and enzyme-linked immunosorbent analyses, M(3)-R loop-2 peptide and human IAS SMC membrane lysates bound significant amounts of SScIgG, compared with IgGs from healthy individuals and pooledhIgG. Binding was attenuated significantly by application of pooledhIgG, which by itself had no significant effect. Incubation of samples with pooledhIgG, or mixing pooledhIgG with SScIgG before administration to tissues, significantly reduced binding of SScIgG, indicating that pooledhIgG prevents SScIgG blockade of M(3)-R.
CONCLUSIONS
In studies of rat and human tissues, pooled human IgG prevent and reverses the cholinergic dysfunction associated with the progressive gastrointestinal manifestations of SSc by neutralizing functional M(3)-R antibodies present in the circulation of patients with SSc.
背景与目的
系统性硬化症（SSc）患者存在胃肠道平滑肌功能障碍。该疾病与循环中针对毒蕈碱型乙酰胆碱 M3 受体（M3-R）的抗体有关。我们研究了是否可以使用人免疫球蛋白（pooledhIgG）中和这些抗体。
方法
我们研究了来自 SSc 患者的 IgG（SScIgGs）对大鼠结肠组织中胆碱能神经刺激的影响。我们还研究了 SScIgGs 对 Bethanechol（BeCh）激活 M3-R、M3-R 占据和受体结合的影响，使用免疫荧光、免疫印迹和酶联免疫吸附分析，对人类肛门内括约肌（IAS）平滑肌细胞进行了分析，在给予 pooledhIgG 前后。在完整平滑肌 BeCh 诱导收缩的持续期，通过 SScIgGs 与其他 IgGs 比较 M3-R 占据的功能置换。
结果
SScIgG 显著减弱了大鼠结肠的神经介导收缩和乙酰胆碱释放，以及 IAS 平滑肌的 BeCh 诱导持续收缩。在免疫荧光分析中，SScIgG 与 M3-R 共定位。在免疫印迹和酶联免疫吸附分析中，与健康个体和 pooledhIgG 的 IgG 相比，M3-R 环 2 肽和人 IAS SMC 膜裂解物结合了大量的 SScIgG。应用 pooledhIgG 显著减弱了结合，pooledhIgG 本身没有显著影响。用 pooledhIgG 孵育样品，或在给予组织前将 pooledhIgG 与 SScIgG 混合，显著减少了 SScIgG 的结合，表明 pooledhIgG 可预防 SScIgG 阻断 M3-R。
结论
在对大鼠和人类组织的研究中，pooledhIgG 通过中和 SSc 患者循环中存在的功能性 M3-R 抗体，预防和逆转与 SSc 进行性胃肠道表现相关的胆碱能功能障碍。
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