Glycan sequence-dependent Nod2 activation investigated by using a chemically synthesized bacterial peptidoglycan fragment library.
Nucleotide oligomerization domain-containing protein 2 (Nod2), an innate immune receptor, recognizes bacterial cell-wall peptidoglycan (PGN), the minimum ligand of which is muramyl dipeptide (MDP). Enzymatic digestion of PGN appears to be important for Nod2 recognition. PGN is degraded by muramidase or glucosamidase through a process that produces two types of glycan sequence; glycans containing GlcNAcβ(1→4)MurNAc or MurNAcβ(1→4)GlcNAc. In this report, a range of disaccharide or tetrasaccharide fragments of each sequence were chemically synthesized, and their activities in stimulating human Nod2 (hNod2) were investigated. The results reveal that hNod2 recognitions is dependent on the glycan sequence, as demonstrated by comparing the activities of glycans with the same peptide moieties. (MurNAcβ(1→4)GlcNAc)(2) -containing structures exhibited stronger activity than those containing (GlcNAcβ(1→4)MurNAc)(2) . The results suggest that differences in the enzymatic degradation process affect the host's immunomodulation process.
Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
Ning
N
Wang
Cheng-Yuan
CY
Huang
Mizuho
M
Hasegawa
Naohiro
N
Inohara
Yukari
Y
Fujimoto
Koichi
K
Fukase
D002240:Carbohydrate Sequence; D006094:Gram-Positive Bacteria / Q000737:chemistry* / Q000276:immunology*; D057809:HEK293 Cells; D006801:Humans; D008969:Molecular Sequence Data; D053473:Nod2 Signaling Adaptor Protein / Q000276:immunology*; D010457:Peptidoglycan / Q000737:chemistry* / Q000276:immunology*
D053473:Nod2 Signaling Adaptor Protein; D010457:Peptidoglycan