title: Dendritic cell activation by glucan isolated from umbilicaria esculenta.
abstract: BACKGROUND
  Lichen-derived glucans have been known to stimulate the functions of immune cells. However, immunostimulatory activity of glucan obtained from edible lichen, Umbilicaria esculenta, has not been reported. Thus we evaluated the phenotype and functional maturation of dendritic cells (DCs) following treatment of extracted glucan (PUE).
  
  
  METHODS
  The phenotypic and functional maturation of PUE-treated DCs was assessed by flow cytometric analysis and cytokine production, respectively. PUE-treated DCs was also used for mixed leukocyte reaction to evaluate T cell-priming capacity. Finally we detected the activation of MAPK and NF-κB by immunoblot.
  
  
  RESULTS
  Phenotypic maturation of DCs was shown by the elevated expressions of CD40, CD80, CD86, and MHC class I/II molecules. Functional activation of DCs was proved by increased cytokine production of IL-12, IL-1β, TNF-α, and IFN-α/β, decreased endocytosis, and enhanced proliferation of allogenic T cells. Polymyxin B, specific inhibitor of lipopolysaccharide (LPS), did not affect PUE activity, which suggested that PUE was free of LPS contamination. As a mechanism of action, PUE increased phosphorylation of ERK, JNK, and p38 MAPKs, and enhanced nuclear translocation of NF-κB p50/p65 in DCs.
  
  
  CONCLUSIONS
  These results indicate that PUE induced DC maturation via MAPK and NF-κB signaling pathways.
authors.affiliation: College of Pharmacy and Medical Research Center (CICT), Chungbuk National University, Cheongju 361-763, Korea.
authors.forename: Hyung Sook
authors.initials: HS
authors.lastname: Kim
authors.forename: Jee Youn
authors.initials: JY
authors.lastname: Kim
authors.forename: Hong Kyung
authors.initials: HK
authors.lastname: Lee
authors.forename: Moo Sung
authors.initials: MS
authors.lastname: Kim
authors.forename: Sang Rin
authors.initials: SR
authors.lastname: Lee
authors.forename: Jong Soon
authors.initials: JS
authors.lastname: Kang
authors.forename: Hwan Mook
authors.initials: HM
authors.lastname: Kim
authors.forename: Kyung-Ae
authors.initials: KA
authors.lastname: Lee
authors.forename: Jin Tae
authors.initials: JT
authors.lastname: Hong
authors.forename: Youngsoo
authors.initials: Y
authors.lastname: Kim
authors.forename: Sang-Bae
authors.initials: SB
authors.lastname: Han