Structural and Biological Evaluations of a Non-Nucleoside STING Agonist Specific for Human STINGA230 Variants.
Structural and Biological Evaluations of a Non-Nucleoside STING Agonist Specific for Human STINGA230 Variants.
复制标题
针对人类 STINGA230 变体的非核苷 STING 激动剂的结构和生物学评估。
DOI：
10.1101/2023.07.02.547363
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Wang,Jingxin
中科院分区：
文献类型：
--
作者：
Tang,Zhichao;Zhao,Junxing;Li,Ying;Tomer,Shallu;Selvaraju,Manikandan;Tien,Nicholas;Sun,Diyun;Johnson,DavidK;Zhen,Anjie;Li,Pingwei;Wang,Jingxin
此前，我们在人单核细胞系(THP-1)中发现了一种非核苷酸三环激动剂BDW568，它可以激活含有A230的人刺激物(干扰素基因刺激物)基因变体。STINGA230等位基因，包括HAQ和AQ，在人类群体中是不太常见的刺变异体。为了进一步研究BDW568的作用机制，我们获得了BDW568的活性代谢物BDW-OH与STINGA230的C-末端结构域以1.95？分辨率络合的晶体结构，并发现BDW-OH中的平面三环结构在STING结合口袋中二聚，并模拟内源性STING配体2‘，3’-cGAMP的两个碱基。这种结合模式也类似于已知的人刺的合成配体MSA-2，但不同于另一种三环小鼠刺激动剂DMXAA。结构-活性-关系(SAR)研究表明，BDW568中的所有三个杂环和S-乙酸酯侧链是保持化合物活性的关键。BDW568可显著激活携带STINGA230基因的健康人外周血单个核细胞(PBMC)的STING通路。我们还观察到BDW568可以在表达STINGA230的慢病毒转导的纯化的人原代巨噬细胞中有力地激活I型干扰素信号，这表明它在基于巨噬细胞的途径中选择性激活基因工程巨噬细胞的潜在用途，如嵌合抗原受体(CAR)-巨噬细胞免疫疗法。
Previously we identified a non-nucleotide tricyclic agonist BDW568 that activates human STING (stimulator of interferon genes) gene variant containing A230 in a human monocyte cell line (THP-1). STINGA230 alleles, including HAQ and AQ, are less common STING variants in human population. To further characterize the mechanism of BDW568, we obtained the crystal structure of the C-terminal domain of STINGA230 complexed with BDW-OH (active metabolite of BDW568) at 1.95 Å resolution and found the planar tricyclic structure in BDW-OH dimerizes in the STING binding pocket and mimics the two nucleobases of the endogenous STING ligand 2’,3’-cGAMP. This binding mode also resembles a known synthetic ligand of human STING, MSA-2, but not another tricyclic mouse STING agonist DMXAA. Structure-activity-relationship (SAR) studies revealed that all three heterocycles in BDW568 and the S-acetate side chain are critical for retaining the compound’s activity. BDW568 could robustly activate the STING pathway in human primary peripheral blood mononuclear cells (PBMCs) with STINGA230 genotype from healthy individuals. We also observed BDW568 could robustly activate type I interferon signaling in purified human primary macrophages that were transduced with lentivirus expressing STINGA230, suggesting its potential use to selectively activate genetically engineered macrophages in macrophage-based approaches, such as chimeric antigen receptor (CAR)-macrophage immunotherapies.