Nakasuji-Togi Misa, Togi Sumihito, Saeki Keita, Kojima Yasuhiko, Ozato Keiko
Division of Developmental Biology, Eunice Kennedy Institute of Child Health and Human Development, National Institutes of Health, MD, USA.
Department of Regenerative Medicine, School of Medicine, Kanazawa Medical University, Ishikawa, Japan.
Food Nutr Res. 2022 Jan 28;66. doi: 10.29219/fnr.v66.5524. eCollection 2022.
A mixture of five herbal extracts called internatural (INT), which is prepared from pumpkin seeds, purple turmeric, pearl barley, corn pistil, and cinnamon, is widely used by people in Japan and elsewhere for its immunity-enhancing effects and general health. Although anecdotal evidence indicates its efficacy, the mechanisms by which INT boosts immunity have remained unknown.
The aim of this study was to investigate whether INT induces type I interferons (IFNs) in murine bone marrow-derived macrophages (BMDMs) and by what mechanism.
We measured induction of type I IFNs (IFNβ and IFNα) in BMDMs treated with INT or other Toll-like receptor ligands: bacterial lipopolysaccharides (LPS), dsRNA, poly(I:C), and CpG oligonucleotides. To investigate whether INT signals through Toll-like receptor 4 (TLR4), we tested TLR4-specific inhibitor. We also tested if INT utilizes TLR4 adaptors, toll/IL-1 receptor (TIR) domain-containing adaptor (TRIF), or myeloid differentiation factor 88 (MyD88), we examined INT induction of IFNβ in TRIF-KO and MyD88-KO BMDMs. We then investigated whether INT provides an antiviral effect upon fibroblasts either directly or indirectly using the encephalomyocarditis virus (EMCV) model.
We first observed that INT, when added to BMDMs, potently induces type I IFNs (IFNβ and IFNα) within 2 h. INT induction of IFN expression was mediated by TLR4, which signaled through the TRIF/MyD88 adaptors, similar to LPS. A high-molecular-weight fraction (MW > 10,000) of INT extracts contained IFN-inducing activity. Supernatants from INT-treated BMDMs protected untreated fibroblast from EMCV infection as reduced viral titers.
INT induced type I IFN mRNA and proteins in BMDMs and other cell types. This induction was mediated by TLR4, which transduces signals using the TRIF/MyD88 pathway. The high-MW component of INT contained type I IFN inducing activity. The supernatants from INT-treated cells displayed antiviral activity and protected cells from EMCV infection. These findings indicate that INT is a novel natural IFN inducer that strengthens host's innate immunity.
一种名为internatural（INT）的由南瓜籽、紫姜黄、珍珠大麦、玉米雌蕊和肉桂制成的五种草药提取物混合物，因其增强免疫力的作用和对整体健康的益处，在日本及其他地区被人们广泛使用。尽管有传闻证据表明其功效，但INT增强免疫力的机制仍不清楚。
本研究旨在调查INT是否能在小鼠骨髓来源的巨噬细胞（BMDM）中诱导I型干扰素（IFN）以及通过何种机制诱导。
我们测量了用INT或其他Toll样受体配体（细菌脂多糖（LPS）、双链RNA、聚肌苷酸-聚胞苷酸（poly(I:C)）和CpG寡核苷酸）处理的BMDM中I型IFN（IFNβ和IFNα）的诱导情况。为了研究INT是否通过Toll样受体4（TLR4）发出信号，我们测试了TLR4特异性抑制剂。我们还测试了INT是否利用TLR4接头、含Toll/IL-1受体（TIR）结构域的接头（TRIF）或髓样分化因子88（MyD88），我们检测了INT在TRIF基因敲除（KO）和MyD88-KO BMDM中对IFNβ的诱导情况。然后，我们使用脑心肌炎病毒（EMCV）模型研究INT是直接还是间接对成纤维细胞产生抗病毒作用。
我们首先观察到，当将INT添加到BMDM中时，它能在2小时内有效诱导I型IFN（IFNβ和IFNα）。INT对IFN表达的诱导是由TLR4介导的，其通过TRIF/MyD88接头发出信号，与LPS类似。INT提取物的高分子量部分（分子量>10,000）具有IFN诱导活性。INT处理的BMDM的上清液可保护未处理的成纤维细胞免受EMCV感染，因为病毒滴度降低。
INT在BMDM和其他细胞类型中诱导I型IFN mRNA和蛋白质。这种诱导是由TLR4介导的，TLR4通过TRIF/MyD88途径转导信号。INT的高分子量成分具有I型IFN诱导活性。INT处理细胞的上清液具有抗病毒活性，并能保护细胞免受EMCV感染。这些发现表明INT是一种新型的天然IFN诱导剂，可增强宿主的先天免疫力。
