AN INTESTINAL SECRETORY PROTEIN IS FOUND IN MOST GLANDS ASSOCIATED WITH THE GASTROINTESTINAL-TRACT - VONEBNERS AND SALIVARY-GLANDS, GALLBLADDER, AND PANCREAS
R. Calvert et al., AN INTESTINAL SECRETORY PROTEIN IS FOUND IN MOST GLANDS ASSOCIATED WITH THE GASTROINTESTINAL-TRACT - VONEBNERS AND SALIVARY-GLANDS, GALLBLADDER, AND PANCREAS, The Journal of histochemistry and cytochemistry, 41(8), 1993, pp. 1223-1231
We have previously shown that monoclonal antibodies (MAb) prepared aga
inst the duodenal mucosa of 4-day-old mice disclosed the presence of t
wo antigens associated with the formation of intestinal crypts. One of
these, MIM-1/39, was found in the apical cytoplasm of undifferentiate
d epithelial crypt cells of the duodenum and colon. We report here the
immunolocalization of MIM-1/39 in different glands associated with th
e gastrointestinal tract, using a polyclonal antibody produced against
antigen MIM-1/39. By indirect immunofluorescence on 1-mum thick Lowic
ryl K4M sections, MIM-1/39 was detected in secretory granules of serou
s cells in lingual (von Ebner's gland), sublingual, submandibular and
parotid glands, and in pancreas; it was also found in epithelial cells
of the gallbladder and in the secretory granules of chief cells of ga
stric glands. Liver, kidney, and Brunner's glands were not immunoreact
ive. Immunocytochemistry revealed the presence of antigen MIM-1/39 in
small secretory granules of the gallbladder, duodenum, colon, and in t
he large secretory granules in serous cells of lingual and parotid gla
nds, in pancreas, and in gastric chief cells. In Western blotting, the
MIM-1/39 MAb revealed two bands (330 and 350 KD) in adult mouse duode
nal mucosa, gallbladder and stomach, whereas only one (330 KD) was dis
closed in pancreatic juice. However, two bands (330 and 350 KD) were d
etected in pancreatic juice with the polyclonal antibody. The distribu
tion of MIM-1/39 was different from that reported for IgA, bound and f
ree secretory components, cryptdin, and Tamm-Horsfall protein. Therefo
re, MIM-1/39 appears to be a unique protein. Its exact role remains to
be elucidated.