Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University, Homburg, Germany; INM - Leibniz Institute for New Materials, Saarbrücken, Germany.
INM - Leibniz Institute for New Materials, Saarbrücken, Germany; Chemistry Department, Saarland University, 66123 Saarbrücken, Germany.
Biomater Adv. 2023 Oct;153:213554. doi: 10.1016/j.bioadv.2023.213554. Epub 2023 Jul 13.
In living therapeutic materials (LTMs), organisms genetically programmed to produce and deliver drugs are encapsulated in porous matrices acting as physical barriers between the therapeutic organisms and the host cells. LTMs consisting of engineered E. coli encapsulated in Pluronic F127-based hydrogels have been frequently used in LTM designs but their immunogenicity has not been tested. In this study, we investigate the response of human peripheral blood mononuclear cells (PBMCs) exposed to this bacteria/hydrogel combination. The release of inflammation-related cytokines and cytotoxic proteins and the subsets of natural killer cells and T cells were examined. Encapsulation of the bacteria in hydrogels considerably lowers their immunogenicity. ClearColi, an endotoxin-free variant of E. coli, did not polarize NK cells into the more cytolytic CD16 subset as E. coli. Our results demonstrate that ClearColi-encapsulated hydrogels generate low immunogenic response and are suitable candidates for the development of LTMs for in vivo testing to assess a potential clinical use. Nevertheless, we observed a stronger immune response (elevated levels of IFNγ, IL-6 and cytotoxic proteins) in pro-inflammatory PBMCs characterized by a high spontaneous release of IL-2. This highlights the need to identify recipients who have a higher likelihood of experiencing undesired immune responses to LTMs with IL-2 serving as a potential predictive marker. Additionally, including anti-inflammatory measures in living therapeutic material designs could be beneficial for such recipients.
在活体治疗材料（LTMs）中，经过基因编程以产生和递药的生物体被封装在多孔基质中，该基质充当治疗生物体与宿主细胞之间的物理屏障。由封装在基于 Pluronic F127 的水凝胶中的工程化大肠杆菌组成的 LTMs 经常用于 LTM 设计中，但尚未测试其免疫原性。在这项研究中，我们研究了暴露于这种细菌/水凝胶组合的人外周血单核细胞（PBMCs）的反应。检查了炎症相关细胞因子和细胞毒性蛋白的释放以及自然杀伤细胞和 T 细胞的亚群。将细菌封装在水凝胶中可大大降低其免疫原性。ClearColi 是大肠杆菌的无内毒素变体，它不会像大肠杆菌那样将 NK 细胞极化到更具细胞毒性的 CD16 亚群。我们的结果表明，ClearColi 封装的水凝胶产生低免疫原性反应，是用于体内测试以评估潜在临床用途的 LTMs 的合适候选物。然而，我们观察到在促炎 PBMC 中产生了更强的免疫反应（IFNγ、IL-6 和细胞毒性蛋白水平升高），其特征是 IL-2 的自发释放水平较高。这突出表明需要识别出更有可能对具有 IL-2 作为潜在预测标志物的 LTMs 产生不良免疫反应的接受者。此外，在活体治疗材料设计中加入抗炎措施可能对这些接受者有益。
