College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
Phytomedicine. 2024 Feb;124:155302. doi: 10.1016/j.phymed.2023.155302. Epub 2023 Dec 19.
Extensive investigation has been undertaken about the utilization of saponin adjuvants in vaccines intended for veterinary and human applications. AB4 is the main constituent of the traditional Chinese medicine, Pulsatilla chinensis (Bunge) Regel, and has immunomodulatory activity. However, there is a paucity of reports on AB4 as a potential adjuvant.
The objective of this work was to clarify the adjuvant role of AB4 and the molecular mechanisms that underlie its immunomodulatory actions.
The immunomodulatory effects of AB4 were investigated using network pharmacological analyses. These effects were validated by evaluating the developmental status of the immune organs and by using the following techniques: ELISA for the quantification of serum-specific antibodies to determine immune-related cytokine levels; the MTS method for the assessment of proliferative activity of splenic lymphocytes; flow cytometry to analyze lymphocyte and dendritic cell activation status; and western blotting for mechanistic analysis at the protein level.
The network pharmacological analysis predicted a total of 52 targets and 12 pathways for AB4 to exert immunomodulatory effects. In a mouse model with immunity to OVA, the introduction of AB4 resulted in the enhancement of immunological organ growth and maturation, elevation of blood antibodies targeting OVA, and amplification of the production of cytokines associated with Th1 and Th2 immune responses. Additionally, the administration of AB4 resulted in a notable augmentation of lymphocyte proliferation and an elevation in the CD4+/CD8+ T lymphocyte ratios. Furthermore, the administration of AB4 enhanced the maturation process of DCs in the draining LNs and increased the production of co-stimulatory factors and MHC II molecules. AB4 induces the upregulation of TLR4 and IKK proteins, as well as the phosphorylation of NF-κB p65 protein within the TLR4/NF-κB signaling cascade, while concurrently suppressing the expression of IκBα protein.
The specific immunoadjuvant effects of AB4 have been demonstrated to modulate the growth and maturation of immune organs and enhance the secretion and cellular activity of pertinent immune molecules. The utilization of network pharmacology, combined within and in vivo vitro assays, clarified the adjuvant function of AB4, which potentially involves the regulation of the TLR4/NF-κB signaling pathway.
人们对皂苷佐剂在兽医和人类应用疫苗中的应用进行了广泛的研究。AB4 是中药白头翁（Bunge）Regel 的主要成分，具有免疫调节活性。然而，关于 AB4 作为一种潜在佐剂的报道很少。
本工作的目的是阐明 AB4 的佐剂作用及其免疫调节作用的分子机制。
采用网络药理学分析研究 AB4 的免疫调节作用。通过评估免疫器官的发育状况，以及使用 ELISA 定量测定血清中针对 OVA 的特异性抗体以确定免疫相关细胞因子水平、MTS 法评估脾淋巴细胞的增殖活性、流式细胞术分析淋巴细胞和树突状细胞的激活状态以及 Western blot 进行机制分析等技术验证 AB4 的作用。
网络药理学分析预测 AB4 发挥免疫调节作用的共有 52 个靶点和 12 条通路。在对 OVA 具有免疫性的小鼠模型中，引入 AB4 可增强免疫器官的生长和成熟，提高针对 OVA 的血液抗体，放大与 Th1 和 Th2 免疫反应相关的细胞因子的产生。此外，AB4 的给药显著增强了淋巴细胞的增殖，并提高了 CD4+/CD8+T 淋巴细胞比值。此外，AB4 增强了引流淋巴结中 DC 的成熟过程，并增加了共刺激因子和 MHC II 分子的产生。AB4 诱导 TLR4 和 IKK 蛋白的上调，以及 TLR4/NF-κB 信号通路中 NF-κB p65 蛋白的磷酸化，同时抑制 IκBα 蛋白的表达。
AB4 的特异性免疫佐剂作用被证明可调节免疫器官的生长和成熟，并增强相关免疫分子的分泌和细胞活性。利用网络药理学结合体内和体外实验，阐明了 AB4 的佐剂功能，其可能涉及 TLR4/NF-κB 信号通路的调节。
