An intestinal secretory protein is found in most glands associated with the gastrointestinal tract: von Ebner's and salivary glands, gallbladder, and pancreas.

Abstract

We have previously shown that monoclonal antibodies (MAb) prepared against the duodenal mucosa of 4-day-old mice disclosed the presence of two antigens associated with the formation of intestinal crypts. One of these, MIM-1/39, was found in the apical cytoplasm of undifferentiated epithelial crypt cells of the duodenum and colon. We report here the immunolocalization of MIM-1/39 in different glands associated with the gastrointestinal tract, using a polyclonal antibody produced against antigen MIM-1/39. By indirect immunofluorescence on 1-micron thick Lowicryl K4M sections, MIM-1/39 was detected in secretory granules of serous 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 gastric glands. Liver, kidney, and Brunner's glands were not immunoreactive. Immunocytochemistry revealed the presence of antigen MIM-1/39 in small secretory granules of the gallbladder, duodenum, colon, and in the large secretory granules in serous cells of lingual and parotid glands, 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 duodenal mucosa, gallbladder and stomach, whereas only one (330 KD) was disclosed in pancreatic juice. However, two bands (330 and 350 KD) were detected in pancreatic juice with the polyclonal antibody. The distribution of MIM-1/39 was different from that reported for IgA, bound and free secretory components, cryptdin, and Tamm-Horsfall protein. Therefore, MIM-1/39 appears to be a unique protein. Its exact role remains to be elucidated.

Culture of human intestinal epithelial cell using the dissociating enzyme thermolysin and endothelin-3

“…And the presence of these intestinal functional markers in HIEC indicated that these cells have some potential for functional differentiation. As a crypt cell marker, the detection of the MIM-1/39 antigen provided strong evidence that serially passaged HIEC still retained their epithelial character, a feature that was absent in Caco-2 and HIM cells (21,23). This may also indicate that HIEC had the characteristics of crypt cells (31).…”

“…Above all, this method considerably improved the yield of epithelial cells in general and preserved cell viability, without destruction by the underlying stromal cells (16,21).…”

“…Production of a rabbit-specific anti-mouse intestinal mucosa (MIM) -1/39 antibody has been described elsewhere (21)(22)(23).…”

Tissue and Cell Distribution of the Multidrug Resistance-Associated Protein (MRP) in Mouse Intestine and Kidney

“…The population of crypt cells just above the Paneth cells had faint basolateral staining ( Figures 2B and 2E). The types of intestinal crypt cells containing MRP were identified by immunofluorescence studies on frozen sections of mouse jejunum using MRPr1 and MIM-1/39 MAb which reacts with the 330-and 350-kD proteins present in the secretory granules of intestinal crypt cells, but not in goblet and Paneth cells (Calvert et al 1993). In contrast to the gradient of labeling observed in crypt cells with MRPr1 (Figures 2A and 2E), there was intense cytoplasmic staining in the crypt epithelial cells with the MIM-1/ 39 MAb, which stopped abruptly at the crypt-villous junction ( Figure 2F).…”

“…Most of the apical membrane domain of the cells delimited by tight junctions, as detected by the anti-ZO-1 antibody ( Figure 6E) which binds to the tight junction-associated protein ZO-1 (Stevenson et al 1986), was not labeled with MRPr1. We then tested m-IC cl2 cells for the MIM-1/39 secreted antigen (Calvert et al 1993). CLSM analysis from optical sections (x-z plane) labeled with the anti-MIM-1/39 MAb alone ( Figure 6F) or double labeled with anti-MIM-1/39 MAb and MRPr1 ( Figure 6G) showed granular cytoplasmic staining of the antigenic protein within m-IC cl2 cells.…”