Chiewchengchol Direkrit, Midgley Angela, Sodsai Pimpayao, Deekajorndech Tawatchai, Hirankarn Nattiya, Beresford Michael W, Edwards Steven W
Center of Excellence in Immunology and Immune-mediated Disease, Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand,
Clin Rheumatol. 2015 Jan;34(1):85-91. doi: 10.1007/s10067-014-2800-2. Epub 2014 Oct 26.
Juvenile systemic lupus erythematosus (JSLE) is one of the most common autoimmune diseases in children and can affect multiple organs and systems. The etiology remains unclear, and current management only suppresses rather than eliminates the disease. The pathogenesis is triggered by autoantigens that induce autoantibody production. Apoptotic neutrophils may be one source of autoantigens in JSLE, and increased numbers of apoptotic neutrophils in JSLE have been reported. This study aimed to determine if factor(s) in JSLE serum induce neutrophil apoptosis, to identify the most potent cytokine in delaying neutrophil apoptosis, and to investigate whether this cytokine can reverse the pro-apoptotic effects of JSLE serum. Blood neutrophils and sera were collected from JSLE patients, healthy children and adult controls. Neutrophils from healthy adult controls were incubated with 10 % serum from either JSLE patients or pediatric controls. Neutrophils from healthy adult controls were also incubated with 10 % JSLE serum with or without granulocyte-macrophage colony-stimulating factor (GM-CSF) supplementation. Neutrophil apoptosis was measured by flow cytometry (annexin-V/propidium iodide staining). Caspase-3, caspase-7 and caspase-8 protein expression was detected using Western blotting. Neutrophils incubated with JSLE sera had significantly increased apoptosis at 6 h compared to those incubated with control sera. Cleaved (active) forms of caspase-3, caspase-7 and caspase-8 were identified in neutrophils incubated with JSLE sera (that showed high rates of apoptosis) compared to control sera. GM-CSF had the most protective effect on neutrophil apoptosis, significantly preventing neutrophil apoptosis and caspase activation induced by JSLE serum. JSLE serum significantly induced neutrophil apoptosis in healthy adult neutrophils, activating the extrinsic pathway of apoptosis. The observation that GM-CSF prevents activation of apoptosis in response to JSLE serum should prompt further studies to evaluate the therapeutic potential of this cytokine for the treatment of JSLE.
青少年系统性红斑狼疮（JSLE）是儿童中最常见的自身免疫性疾病之一，可累及多个器官和系统。其病因尚不清楚，目前的治疗方法只能抑制而非消除该疾病。发病机制由诱导自身抗体产生的自身抗原引发。凋亡的中性粒细胞可能是JSLE中自身抗原的来源之一，并且已有报道称JSLE中凋亡中性粒细胞数量增加。本研究旨在确定JSLE血清中的因子是否诱导中性粒细胞凋亡，鉴定延迟中性粒细胞凋亡最有效的细胞因子，并研究该细胞因子是否能逆转JSLE血清的促凋亡作用。从JSLE患者、健康儿童和成人对照中采集血液中性粒细胞和血清。将健康成人对照的中性粒细胞与JSLE患者或儿科对照的10%血清孵育。健康成人对照的中性粒细胞也与添加或不添加粒细胞-巨噬细胞集落刺激因子（GM-CSF）的10% JSLE血清孵育。通过流式细胞术（膜联蛋白-V/碘化丙啶染色）检测中性粒细胞凋亡。使用蛋白质印迹法检测半胱天冬酶-3、半胱天冬酶-7和半胱天冬酶-8蛋白表达。与用对照血清孵育的中性粒细胞相比，用JSLE血清孵育的中性粒细胞在6小时时凋亡显著增加。与对照血清相比，在与JSLE血清孵育（显示高凋亡率）的中性粒细胞中鉴定出半胱天冬酶-3、半胱天冬酶-7和半胱天冬酶-8的裂解（活性）形式。GM-CSF对中性粒细胞凋亡具有最显著的保护作用，可显著预防JSLE血清诱导的中性粒细胞凋亡和半胱天冬酶激活。JSLE血清显著诱导健康成人中性粒细胞凋亡，激活凋亡的外源性途径。GM-CSF可预防对JSLE血清反应的凋亡激活这一观察结果应促使进一步研究以评估该细胞因子治疗JSLE的治疗潜力。
