A study on the immune receptors for polysaccharides from the roots of Astragalus membranaceus, a Chinese medicinal herb
A study on the immune receptors for polysaccharides from the roots of Astragalus membranaceus, a Chinese medicinal herb
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DOI：
10.1016/j.bbrc.2004.06.065
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发表时间：
2004-08-06
影响因子：
3.1
通讯作者：
Gao, XM
中科院分区：
文献类型：
--
作者：
Shao, BM;Xu, W;Gao, XM
黄芪是一种中草药，其免疫增强作用与其多糖组分(APS)有关。在此，我们证明APS能激活小鼠B细胞和巨噬细胞，但不能激活T细胞。在增殖或细胞因子产生方面。荧光标记APS(FL-APS)能选择性地对小鼠B细胞进行染色。巨噬细胞和人类肿瘤细胞系THP-1，通过流式细胞仪分析和激光共聚焦扫描显微镜进行检测。细菌脂多糖竞争性抑制APS与B细胞和巨噬细胞的特异性结合。兔抗鼠免疫球蛋白(Ig)抗体能抑制APS诱导的小鼠B细胞增殖及其与APS的结合。此外，APS有效地刺激了C3H/HeJ小鼠的脾B细胞的增殖，这些小鼠的TLR4分子突变而不能进行信号转导。这些结果表明，APS通过膜Ig以TLR4不依赖的方式激活B细胞。有趣的是，C3H/HeJ小鼠的巨噬细胞不能对APS刺激做出反应，这表明TLR4分子积极参与了APS介导的巨噬细胞激活。抗小鼠TLR4的单抗部分抑制APS与巨噬细胞的结合，提示APS与TLR4在细胞表面有直接的相互作用。这些结果可能对我们理解中草药多糖免疫增强的分子机制有重要意义。(C)2004 Elsevier Inc.保留所有权利。
The immunopotentiating effect of the roots of Astragalus membranaceus, a medicinal herb, has been associated with its polysaccharide fractions (Astragalus polysaccharides, APS). We herein demonstrate that APS activates mouse B cells and macrophages, but not T cells. in terms of proliferation or cytokine production. Fluorescence-labeled APS (fl-APS) was able to selectively stain murine B cells. macrophages and a also human tumor cell line, THP-1, as determined in flow cytometric analysis and confocal laser scanning microscopy. The specific binding of APS to B cells and macrophages was competitively inhibited by bacterial lipopolysaccharides. Rabbit-anti-mouse immunoglobulin (Ig) antibody was able to inhibit APS-induced proliferation of, and APS binding to, mouse B cells. Additionally, APS effectively stimulated the proliferation of splenic B cells from C3H/HeJ mice that have a mutated TLR4 molecule incapable of signal transduction. These results indicate that APS activates B cells via membrane Ig in a TLR4-independent manner. Interestingly, macrophages from C3H/HeJ mice were unable to respond to APS stimulation, suggesting a positive involvement of the TLR4 molecule in APS-mediated macrophage activation. Monoclonal Ab against mouse TLR4 partially inhibited APS binding with macrophages, implying direct interaction between APS and TLR4 on cell surface. These results may have important implications for our understanding on the molecular mechanisms of immunopotentiating polysaccharides from medicinal herbs. (C) 2004 Elsevier Inc. All rights reserved.