Polysaccharide of Dendrobium huoshanense activates macrophages via toll-like receptor 4-mediated signaling pathways.
The present work aimed at investigating the pattern recognition receptor (PRR) and immunostimulatory mechanism of a purified Dendrobium huoshanense polysaccharide (DHP). We found that DHP could bind to the surface of macrophages and stimulate macrophages to secrete NO, TNF-α and IL-1β. To unravel the mechanism for the binding of DHP to macrophages, flow cytometry, confocal laser-scanning microscopy, affinity electrophoresis, SDS-PAGE and western blotting were employed to verify the type of PRR responsible for the recognition of DHP by RAW264.7 macrophages and peritoneal macrophages of C3H/HeN and C3H/HeJ macrophages. Results showed that toll-like receptor 4 (TLR4) was an essential receptor for macrophages to directly bind DHP. Further, the phosphorylation of ERK, JNK, Akt and p38 were observed to be time-dependently promoted by DHP, as well as the nuclear translocation of NF-κB p65. These results suggest that DHP activates macrophages via its direct binding to TLR4 to trigger TLR4 signaling pathways.
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China.
Song-Zi
SZ
Xie
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China.
Ran
R
Hao
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China.
Xue-Qiang
XQ
Zha
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China.
Li-Hua
LH
Pan
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China.
Jian
J
Liu
School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, China. Electronic address: jianpingluo@hfut.edu.cn.
Jian-Ping
JP
Luo
D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D031667:Dendrobium / Q000737:chemistry*; D008262:Macrophage Activation / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects; D017737:Macrophages, Peritoneal / Q000187:drug effects; D051379:Mice; D011134:Polysaccharides / Q000737:chemistry* / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
D011134:Polysaccharides; D051197:Toll-Like Receptor 4
Dendrobium huoshanense; Macrophage; Polysaccharide; Signaling pathway; Toll-like receptor 4