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Immunostimulatory Agent Evaluation: Lymphoid Tissue Extraction and Injection Route-Dependent Dendritic Cell Activation
Published on: September 16, 2018
Low molecular-weight polyguluronate phosphate: An immunostimulant by activating splenocyte/macrophage invitro and
Quancai Li1, Wenwei Han2, Cheng Yang2
1Shandong Key Laboratory of Glycoscience and Glycoengineering, Key Laboratory of Marine Drugs of Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China; Laboratory of Marine Glycodrug Research and Development, Marine Biomedical Research Institute of Qingdao, Qingdao 266071, China.
Abstract:
The substituents and backbones are two main factors affecting immune activities of polysaccharides. In the present study, we firstly evaluated the immunostimulating effects of phosphorylated, sulfated, H-phosphonated and nitrated derivatives of low-molecular-weight polymannuronate (LPM) and polyguluronate (LPG) on splenocytes and peritoneal macrophages in vitro. The results showed that the phosphate group was the best substituent to enhance the immune activities, and LPG phosphate (LPGP) had much better activity than LPM phosphate (LPMP). Further studies showed that LPGP not only promoted the proliferation of mouse splenocytes in the presence of either LPS or Con A, but also acted as an excellent peritoneal macrophage activator to enhance the cell phagocytosis, energy metabolism, cytokines release and activities of intracellular enzymes. The studies in RAW264.7 cells revealed that LPGP activated the TBK1-IκBα-NF-κB and the TBK1-IRF3 pathway. Moreover, LPGP rescued the immune response in the Cyclophosphamide-treated mice in vivo. In conclusion, LPGP is a potential alginate-based biological response modifier (BRM).

