Interleukin-1 (IL-1) is a key mediator of inflammation and immunity. Naturally-occurring IL-1 receptor antagonist (IL-1Ra) binds and blocks the IL-1 receptor-1 (IL-1R1), preventing signaling. Anakinra, a recombinant form of IL-1Ra, is used to treat a spectrum of inflammatory diseases. However, anakinra is rapidly cleared from the body and requires daily administration. To create a longer-lasting alternative, PASylated IL-1Ra (PAS-IL-1Ra) has been generated by in-frame fusion of a long, defined-length, N-terminal Pro/Ala/Ser (PAS) random-coil polypeptide with IL-1Ra. Here, we compared the efficacy of two PAS-IL-1Ra molecules, PAS600-IL-1Ra and PAS800-IL-1Ra (carrying 600 and 800 PAS residues, respectively), with that of anakinra in mice. PAS600-IL-1Ra displayed markedly extended blood plasma levels 3 days post-administration, whereas anakinra was undetectable after 24 h. We also studied PAS600-IL-1Ra and PAS800-IL-1Ra for efficacy in monosodium urate (MSU) crystal-induced peritonitis. 5 days post-administration, PAS800-IL-1Ra significantly reduced leukocyte influx and inflammatory markers in MSU-induced peritonitis, whereas equimolar anakinra administered 24 h before MSU challenge was ineffective. The 6-h pretreatment with equimolar anakinra or PAS800-IL-1Ra before MSU challenge similarly reduced inflammatory markers. In cultured A549 lung carcinoma cells, anakinra, PAS600-IL-1Ra, and PAS800-IL-Ra reduced IL-1α-induced IL-6 and IL-8 levels with comparable potency. In human peripheral blood mononuclear cells, these molecules suppressed Candida albicans-induced production of the cancer-promoting cytokine IL-22. Surface plasmon resonance analyses revealed significant binding between PAS-IL-1Ra and IL-1R1, although with a slightly lower affinity than anakinra. These results validate PAS-IL-1Ra as an active IL-1 antagonist with marked in vivo potency and a significantly extended half-life compared with anakinra.

中文翻译：

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在小鼠尿酸盐晶体诱发的腹膜炎中，IL-1受体拮抗剂（IL-1Ra）的PASylation保留了IL-1阻滞并延长了其持续时间。

白介素-1（IL-1）是炎症和免疫的关键介质。天然存在的IL-1受体拮抗剂（IL-1Ra）结合并阻断IL-1受体-1（IL-1R1），从而阻止信号传导。Anakinra，IL-1Ra的重组形式，用于治疗多种炎症性疾病。但是，anakinra会迅速从体内清除，需要每天服用。为了创建更持久的替代方案，已通过在框架内融合确定长度的N末端Pro / Ala / Ser（PAS）随机螺旋多肽，合成了PASyIL-1Ra（PAS-IL-1Ra）与IL-1Ra。在这里，我们比较了两种PAS-IL-1Ra分子PAS600-IL-1Ra和PAS800-IL-1Ra（分别带有600和800个PAS残基）与anakinra在小鼠中的功效。给药后3天，PAS600-IL-1Ra的血浆水平显着延长，而anakinra在24小时后无法检测到。我们还研究了PAS600-IL-1Ra和PAS800-IL-1Ra在尿酸钠（MSU）晶体引起的腹膜炎中的功效。给药后5天，PAS800-IL-1Ra显着减少了MSU诱发的腹膜炎中的白细胞流入和炎性标志物，而在MSU激发前24 h给予等摩尔的类似物则无效。在MSU攻击之前，用等摩尔的合成物或PAS800-IL-1Ra进行6小时预处理后，炎症标志物的含量也降低了。在培养的A549肺癌细胞中，anakinra，PAS600-IL-1Ra和PAS800-IL-Ra降低了IL-1α诱导的IL-6和IL-8水平，且具有可比的效力。在人类外周血单核细胞中，这些分子抑制了白色念珠菌诱导的促癌细胞因子IL-22的产生。表面等离振子共振分析表明，PAS-IL-1Ra和IL-1R1之间具有显着的结合，尽管亲和力比anakinra略低。这些结果证实了PAS-IL-1Ra是一种活性IL-1拮抗剂，与anakinra相比具有显着的体内效力和显着延长的半衰期。