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
bioRxiv. 2024 Oct 8:2024.10.07.617024. doi: 10.1101/2024.10.07.617024.
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 excited 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.
NMR and molecular dynamics simulations revealed distinct conformational dynamics and allosteric networks in computationally re-designed IL-2 superkines compared to wild-type IL-2, despite their similar crystal structures.The superkines S1 and S15 exhibit altered sampling of excited state conformations at an intermediate timescale, with slower conformational exchange rates compared to wild-type IL-2.A rationally designed mutation (L56A) in the S1 superkine's core allosteric network partially reverted its dynamics, receptor binding affinity, and T cell signaling behavior towards that of wild-type IL-2.Our study demonstrates that IL-2 core dynamics play a critical role in receptor binding and signaling function, providing a foundation for engineering more selective IL-2-based immunotherapies.
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，导致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，这两种突变体对效应T细胞表现出偏向性信号传导。使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变体在核心动态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变构网络和激发态构象。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动力学和核心变构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。
核磁共振和分子动力学模拟揭示，与野生型IL-2相比，在计算重新设计的IL-2超级细胞因子中存在不同的构象动力学和变构网络，尽管它们具有相似的晶体结构。超级细胞因子S1和S15在中间时间尺度上表现出激发态构象采样的改变，与野生型IL-2相比，构象交换速率较慢。在S1超级细胞因子的核心变构网络中合理设计的突变（L56A）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。我们的研究表明，IL-2核心动力学在受体结合和信号传导功能中起关键作用，为设计更具选择性的基于IL-2的免疫疗法奠定了基础。
