Figure 8.
Bacterial-mediated induction of matrilysin in mouse small intestine. Immunostaining for mouse matrilysin and proCRS1C was done on frozen sections of the small intestine prepared from conventionally housed, germ-free, and ex-germ-free NMRI mice. Positive staining for matrilysin (blue) was seen in the Paneth cells located at the base of the intestinal crypts in mice with a normal intestinal microflora but was not detected in the small intestine of germ-free mice. Paneth cell expression of matrilysin was induced within 10 d after contamination with B. thetaiotaomicron. No changes in the staining pattern or intensity of procryptdin-related sequences (proCRS1C), a marker of Paneth cell differentiation, were seen in any samples studied.