R. Calvert et al., IMMUNOLOCALIZATION OF A MESENCHYMAL ANTIGEN-SPECIFIC TO THE GASTROINTESTINAL-TRACT, The Anatomical record, 240(3), 1994, pp. 358-366
Background: The aim of the present study was to localize, at the fine
structural level, a protein found by indirect immunofluorescence to be
associated with the mesenchymal tissue 1) closely applied to the inte
rvillus epithelium before the formation of intestinal crypts in the mo
use fetus and 2) around intestinal crypts during and after their forma
tion. Methods: We used a pre-embedding immunolabeling technique for ex
tracellular matrix molecules, and a monoclonal antibody (Mab) directed
against antigen MIM-1/130. Results: Immunofluorescence disclosed the
presence of antigen 1/130 in the connective tissue closely applied to
the epithelium of the gallbladder, pyloric glands, and intestinal and
colonic crypts in adult mice. The antigen was absent in all salivary g
lands, kidney, liver, lung, spleen, and pancreas. At the fine structur
al level, gold particles in positive organs were associated with the i
nterstitial matrix around collagen fibrils underneath the epithelia; g
old particles were completely absent in the basement membranes. In the
small intestine, labeling was seen only around crypts from cell posit
ion 1 up to the crypt-villus junction; it was totally absent under the
villus epithelium. In order to confirm this particular localization i
n vivo, Mab 1/130 was administered orogastrically to 9-day-old mice: a
fter 3 hours the antibody was found lining the immediate periphery of
duodenal crypts as seen by indirect immunofluorescence. In control ani
mals, an anti-mouse laminin Mab of the same subclass as Mab 1/130 was
orogastrically fed using the same protocol: basal laminae were labeled
under the epithelium of duodenal villi and crypts and also in the lam
ina propria, with a decreasing gradient from the top of the villi to t
he bottom of the crypts. Conclusion: These observations indicate that
the extracellular matrix associated with the epithelium of pyloric gla
nds, of intestinal and colonic crypts, and of gallbladder contains a n
ew antigen whose function remains to be determined. The neonatal mouse
hence constitutes a good model to study the role of extracellular mat
rix components in determining organ differentiation in vivo. (C) 1994
Wiley-Liss, Inc.