Gattorno Marco, Tassi Sara, Carta Sonia, Delfino Laura, Ferlito Francesca, Pelagatti Maria Antonietta, D'Osualdo Andrea, Buoncompagni Antonella, Alpigiani Maria Giannina, Alessio Maria, Martini Alberto, Rubartelli Anna
Second Division of Pediatrics, IRCCS, Istituto G. Gaslini, Genoa, Italy.
Arthritis Rheum. 2007 Sep;56(9):3138-48. doi: 10.1002/art.22842.
To examine the synthesis, processing, and secretion of interleukin-1beta (IL-1beta), as well as the clinical and biologic effects of IL-1 blockade, in patients with chronic infantile neurologic, cutaneous, articular (CINCA) syndrome and Muckle-Wells syndrome (MWS), in an effort to understand the molecular mechanisms linking mutations of the CIAS1 gene and IL-1beta hypersecretion, and the underlying response to IL-1 receptor antagonist (IL-1Ra).
Six patients with CINCA syndrome or MWS were treated with IL-1Ra and followed up longitudinally. Monocytes obtained from the patients and from 24 healthy donors were activated with lipopolysaccharide (LPS) for 3 hours, and intracellular and secreted IL-1beta levels were determined by Western blotting and enzyme-linked immunosorbent assay before and after exposure to exogenous ATP.
LPS-induced IL-1beta secretion was markedly increased in monocytes from patients with CIAS1 mutations. However, unlike in healthy subjects, secretion of IL-1beta was not induced by exogenous ATP. Treatment with IL-1Ra resulted in a dramatic clinical improvement, which was paralleled by an early and strong down-regulation of LPS-induced IL-1beta secretion by the patients' cells in vitro.
Our results showed that the requirements of ATP stimulation for IL-1beta release observed in healthy individuals are bypassed in patients bearing CIAS1 mutations. This indicates that cryopyrin is the direct target of ATP and that the mutations release the protein from the requirement of ATP for activation. In addition, the dramatic amelioration induced by IL-1Ra treatment is at least partly due to the strong decrease in IL-1beta secretion that follows the first injections of the antagonist. These findings may have implications for other chronic inflammatory conditions characterized by increased IL-1beta.
研究慢性婴儿神经皮肤关节综合征(CINCA)和穆克-韦尔斯综合征(MWS)患者白细胞介素-1β(IL-1β)的合成、加工和分泌,以及IL-1阻断的临床和生物学效应,以了解连接CIAS1基因突变与IL-1β分泌过多的分子机制,以及对IL-1受体拮抗剂(IL-1Ra)的潜在反应。
6例CINCA综合征或MWS患者接受IL-1Ra治疗并进行纵向随访。从患者和24名健康供体获取的单核细胞用脂多糖(LPS)激活3小时,在暴露于外源性ATP之前和之后,通过蛋白质印迹法和酶联免疫吸附测定法测定细胞内和分泌的IL-1β水平。
CIAS1基因突变患者的单核细胞中,LPS诱导的IL-1β分泌显著增加。然而,与健康受试者不同,外源性ATP未诱导IL-1β分泌。IL-1Ra治疗导致临床显著改善,同时患者细胞在体外对LPS诱导的IL-1β分泌出现早期且强烈的下调。
我们的结果表明,携带CIAS1基因突变的患者绕过了健康个体中观察到的ATP刺激对IL-1β释放的需求。这表明冷吡啉是ATP的直接靶点,并且这些突变使该蛋白无需ATP激活。此外,IL-1Ra治疗诱导的显著改善至少部分归因于首次注射拮抗剂后IL-1β分泌的强烈减少。这些发现可能对以IL-1β增加为特征的其他慢性炎症性疾病具有启示意义。