Figure 1
From: Mucin CYS domain stiffens the mucus gel hindering bacteria and spermatozoa
Mucus permeability in MTX:MTX-rCYSx12 cocultures. (a) Schematic representation of a monomer of the intestinal mucin Muc2 and the recombinant protein rCYSx12 (not to scale). The mucin CYS domain is depicted in blue and the S/T/P repeats carrying the numerous O-glycans are in grey. The recombinant protein rCYSx12 is made of 12 consecutive CYS domains. (b) Study design to obtain and to characterize mucus enriched in rCYSx12 from cell culture. MTX cells were transfected with a 20.2-kb vector carrying the first two exons, first intron, and 5 part of intron No. 2 of mouse Tff3. Intron No. 2 is followed by a third exon coding rCYSx12. The transgene is driven by the Tff3 promoter. A floxed Neo cassette (orange) under the control of a hybrid promoter LacUV5-SV40 was inserted to select recombinant clones. The white rectangles represent the vector backbone. After stable transfection, the native MTX cell line and recombinant MTX-rCYSx12 clones were amplified and cocultured at five ratios to obtain a range of rCYSx12 production. Production and secretion of rCYSx12 in a dose-dependent manner was observed by immunofluorescence of cell cocultures and by immunohistochemistry. (c) Distribution of beads in the mucus layer from MTX and MTX-rCYSx12 cells after 45 min sedimentation. (d) Beads distribution as a function of the mucus depth in MTX and MTX-rCYSx12 cultures. The width of each blob is proportional to the number of beads in each mucus section.
