Background: Lignin fractions of Lentinus edodes mycelia extract (LEM) have shown anti-HIV and immunopotentiating activity. However, the action point of lignin-carbohydrate complex has not been elucidated. In order to elucidate their action point, DNA microarray analysis was performed, using mouse macrophage-like J774.1 cells.
Materials and methods: RNA was isolated with Qiagen RNeasy Plus Mini kit, hydridized with GeneChip MouseGene 1.0 ST arrays, and scanned with Affymetrix GeneChip Command Console software.
Results: One of the seven lignin-carbohydrate fractions isolated from LEM (Fr4) enhanced the expression of dectin-2 (4.2-fold) and toll-like receptor (TLR)-2 (2.5-fold) prominently, but only slightly modified the expression of dectin-1 (0.8-fold), complement receptor 3 (0.9-fold), TLR1, 3, 4, 9 and 13 (0.8- to 1.7-fold), spleen tyrosine kinase (Syk)b, zeta-chain (TCR) associated 70 kDa protein kinase (Zap70), Janus tyrosine kinase (Jak)2 (1.0- to 1.2-fold), nuclear factor (Nf)кb1, NFкb2, reticuloendotheliosis viral oncogene homolog (Rel)a, Relb (1.0- to 1.6-fold), Nfкbia, Nfкbib, Nfкbie, Nfкbil2 and Nfкbiz (0.8- to 2.3-fold). On the other hand, lipopolysaccharide did not affect the expression of dectin-2 or TLR-2.
Conclusion: These data suggest the significant role of the activation of the dectin-2 signaling pathway in the action of lignin-carbohydrate complex on macrophages.