Woodward Claire H, Solieva Shahlo O, Hwang Daniel, De Paula Viviane S, Fabilane Charina S, Young Michael C, Trent Tony, Teeley Ella C, Majumdar Ananya, Spangler Jamie B, Bowman Gregory R, Sgourakis Nikolaos G
Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA; Center for Computational and Genomic Medicine, Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
J Mol Biol. 2025 Jan 15;437(2):168892. doi: 10.1016/j.jmb.2024.168892. Epub 2024 Dec 9.
Human interleukin-2 (IL-2) is a crucial cytokine for T cell regulation, with therapeutic potential in cancer and autoimmune diseases. However, IL-2's pleiotropic effects across different immune cell types often lead to toxicity and limited efficacy. Previous efforts to enhance IL-2's therapeutic profile have focused on modifying its receptor binding sites. Yet, the underlying dynamics and intramolecular networks contributing to IL-2 receptor recognition remain unexplored. This study presents a detailed characterization of IL-2 dynamics compared to two engineered IL-2 mutants, "superkines" S15 and S1, which exhibit biased signaling towards effector T cells. Using NMR spectroscopy and molecular dynamics simulations, we demonstrate significant variations in core dynamic pathways and conformational exchange rates across these three IL-2 variants. We identify distinct allosteric networks and minor state conformations in the superkines, despite their structural similarity to wild-type IL-2. Furthermore, we rationally design a mutation (L56A) in the S1 superkine's core network, which partially reverts its dynamics, receptor binding affinity, and T cell signaling behavior towards that of wild-type IL-2. Our results reveal that IL-2 superkine core dynamics play a critical role in their enhanced receptor binding and function, suggesting that modulating IL-2 dynamics and core allostery represents an untapped approach for designing immunotherapies with improved immune cell selectivity profiles.
人白细胞介素-2（IL-2）是T细胞调节的关键细胞因子，在癌症和自身免疫性疾病中具有治疗潜力。然而，IL-2对不同免疫细胞类型的多效性作用常常导致毒性和疗效有限。以往增强IL-2治疗特性的努力主要集中在修饰其受体结合位点。然而，促成IL-2受体识别的潜在动力学和分子内网络仍未得到探索。本研究详细表征了IL-2与两种工程化IL-2突变体“超级细胞因子”S15和S1的动力学差异，这两种突变体对效应T细胞表现出偏向性信号传导。利用核磁共振光谱和分子动力学模拟，我们证明了这三种IL-2变体在核心动力学途径和构象交换速率上存在显著差异。尽管超级细胞因子与野生型IL-2结构相似，但我们在其中识别出了不同的别构网络和次要状态构象。此外，我们在S1超级细胞因子的核心网络中合理设计了一个突变（L56A），该突变部分恢复了其动力学、受体结合亲和力以及T细胞信号传导行为，使其向野生型IL-2的方向转变。我们的结果表明，IL-2超级细胞因子的核心动力学在其增强的受体结合和功能中起关键作用，这表明调节IL-2动力学和核心别构作用是一种尚未开发的方法，可用于设计具有改善免疫细胞选择性的免疫疗法。
