Journal: eLife
Article Title: Peptidoglycan-Chi3l1 interaction shapes gut microbiota in intestinal mucus layer
doi: 10.7554/eLife.92994
Figure Lengend Snippet: ( A ) Structural comparison between chitin and PGN. Both chitin and PGN contain N-acetylglucosamine (GlcNAc) and have β–1,4-glycosidic bonds in their structures. However, chitin is purely a polysaccharide, while PGN includes a peptide component that forms cross-links between chains . ( B ) Gram-positive bacteria ( E. faecalis , S. saprophyticus ) and Gram-negative bacteria ( E. coli ) were incubated with 1 μg of recombinant mouse Chi3l1 protein (rmChi3l1), respectively. Proteins bound to indicated bacteria were precipitated by centrifugation. Western blot was used to detect rmChi3l1 in Pellet, Supernatant (unbound proteins) and Last Wash (last wash unbound proteins). ( C ) Insoluble PGN were incubated with either recombinant mouse Chi3l1 protein (rmChi3l1) or bovine serum albumin (BSA). Proteins bound to PGN were precipitated by centrifugation. Silver staining was used to detect rmChi3l1 in Input, Supernatant (unbound proteins), Pellet and Last Wash (last wash unbound proteins). ( D ) Insoluble PGN were incubated with recombinant human Chi3l1 protein (rhChi3l1). Proteins bound to PGN were precipitated by centrifugation. Silver staining was used to detect rhChi3l1 in Input, Supernatant (unbound proteins), Pellet and Last Wash (last wash unbound proteins). All data above represent at least three independent experiments. ( E ) Insoluble PGN or chitin was incubated with rmChi3l1. Chi3l1 bound to PGN (upper panel) and chitin (lower panel) was precipitated and detected by silver staining. The supernatant represents the last wash, and the pellet contains proteins precipitated by either PGN or chitin. ( F ) Relative DLD-1 bacterial binding preference after treatment with K12 or GlmM, a PGN synthesis-deficient mutant. Colony-forming units (CFU) were counted, and GlmM CFU were normalized to 1. ( G ) Relative K12 bacterial adhesion preference after DLD-1 cells were transfected without (Mock), or with scramble shRNA (shCK), or with sh Chil1 . CFU were counted, and the Mock group were normalized to 1. *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001, ns: no significant difference, error bar indicates SEM. Figure 2—source data 1. File containing original western blots for and silver staining for , indicating the relevant bands. Figure 2—source data 2. Original files for western blot analysis displayed in and silver staining for . Figure 2—source data 3. Numerical data of .
Article Snippet: Transfected construct (human) , sh Chil1 (constructed from pLKO.1 – TRC) , This paper , Constructed from RRID: Addgene_10878 , Lentiviral construct to transfect and express the shRNA.
Techniques: Comparison, Bacteria, Incubation, Recombinant, Centrifugation, Western Blot, Silver Staining, Binding Assay, Mutagenesis, Transfection, shRNA