Liu, LYang, XYuan, PCai, SBao, JZhao, YAimaier, AAipire, ALu, JLi, J2022-03-212022-03-21Marine Drugs, 20(3), 197. https://doi.org/10.3390/md200301971660-3397https://hdl.handle.net/10292/15008Low molecular weight fucoidan (LMWF) has been reported to have immunomodulation effects through the increase of the activation and function of macrophages. In this study, the regulating effect of LMWF from Undaria pinnatifida grown in New Zealand on dendritic cells (DCs) was investigated. We discovered that LMWF could stimulate DCs’ maturation and migration, as well as CD4+ and CD8+ T cells’ proliferation in vitro. We proved that this immune promoting activity is activated through TLR4 and its downstream MAPK and NF–κB signaling pathways. Further in vivo (mouse model) investigation showed that LMWF has a strong immunological boosting effect, such as facilitating the proliferation of immune cells and increasing the index of immune organs. These findings suggest that LMWF has a positive immunomodulatory effect and is a promising candidate to supplement cancer immunotherapy.© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).Low molecular weight fucoidan (LMWF); Dendritic cells; Immune stimulation; Undaria pinnatifida; New ZealandJournal ArticleOpenAccess10.3390/md20030197