Lymphoid cell subsets in normal human small intestine

IgG subclass-containing cells around the lymph follicle in the human intestine

The authors previously reported the ring-like distribution of IgG-containing cells around the lymph follicle in both the small and large intestine. In the present study, the distribution of IgG subclass-containing cells around the lymph follicle was examined in both the small and large intestine, including Peyer's patches, by the indirect immunoperoxidase staining method. A ring-like distribution of IgG subclass-containing cells was observed in 14 out of 21 lymph follicles including 4 Peyer's patches (66.7%) in the terminal ileum, and 4 out of 7 (57.1%) in the large intestine. The percentages of IgG1-, IgG2-, IgG3-, and IgG4- containing cells around the lymph follicle in the terminal ileum were 27.6 +/- 11.6%, 51.9 +/- 15.4%, 16.5 +/- 10.2%, and 4.0 +/- 3.1%, respectively, and those in the large intestine were 22.9 +/- 15.4%, 47.4 +/- 14.9%, 11.2 +/- 4.1%, and 18.5 +/- 7.7%, respectively. Thus, among the IgG subclasses, IgG2-containing cells showed the most frequent ring-like distribution around the lymph follicle. The IgG2 predominance around the lymph follicle in the intestine was markedly different from reported IgG1 predominance in the lamina propria in the large intestine. This difference in IgG subclass distribution may suggest different origins of the IgG subclass-containing cells in the lamina propria and in areas around the lymph follicle.

Expression of MHC class II antigens (HLA-DR, -DP, and -DQ) on human gastric epithelium

Class II antigen expression on gastric epithelium was investigated using an immunoperoxidase method in relation to the degree of inflammatory cell infiltration in the lamina propria. Sixty-six biopsy specimens from 43 patients with chronic gastritis were examined. The frequency of HLA-DR expression in specimens with cell infiltration was 94%, while that in specimens without cell infiltration was 24%. There was significant difference in the frequency of HLA-DR expression between the two groups (P less than 0.01). HLA-DR was most intensely expressed in the glandular neck portion. The frequency and extent of class II antigen expression on gastric epithelium with cell infiltration were in the following order: DR greater than DP greater than DQ. The extent of DR and DP, but not DQ expression generally paralleled the degree of cell infiltration. Intestinal metaplasia was found in 13 specimens. In the area of intestinal metaplasia, epithelial class II staining was absent except for one specimen. These results suggest that the respective genes of three class II antigens are regulated by different mechanisms and that an immunological mechanism plays a role in the pathogenesis of gastritis.

Lymphoid cell subsets in colonic mucosa and HLA-DR antigens on colonic epithelia in colitis excluding ulcerative colitis and Crohn's disease

Lymphoid cell subsets, including T cells as well as Ig-containing cells in the colonic mucosa and HLA-DR antigens on colonic epithelia, were examined in non-IBD colitis (colitis excluding ulcerative colitis (UC) and Crohn's disease) by the indirect immunoperoxidase staining method. Mouse anti-CD5, CD8, CD4, IgG, IgA1, IgA2, IgM, IgD, IgE, HLA-DR, and NuIa monoclonal antibodies were used as the first antibody. The results were compared to those of the normal controls and UC. T cell subsets in non-IBD colitis were almost similar to those of the controls and UC. The number of Ig-containing cells of all classes, except for IgA, tended to be increased in non-IBD colitis. In particular, both IgG- and IgE-containing cells were significantly increased compared to those in the controls. Compared to UC, IgG-containing cells were decreased in non-IBD colitis. Namely, in non-IBD colitis, as well as in UC, the change of Ig-containing cells (B cell lineage) was more pronounced than that of T cells. The frequency of the expression of HLA-DR antigens on colonic epithelia in non-IBD colitis was 70%, which was significantly higher than that in controls (0%), but significantly lower than that in UC (100%). Whether the differences in the number of IgG-containing cells, and the frequency of epithelial HLA-DR expression between non-IBD colitis and UC was due to the differences of the degree of local inflammation or due to the differences of the nature of the two diseases was not elucidated in this study.

Class II (HLA-DR, -DP, and -DO) antigens on intestinal epithelia in ulcerative colitis, Crohn's disease, colorectal cancer and normal small intestine

Class II antigens in involved colonic epithelia of ulcerative colitis (UC), Crohn's disease (CD), colorectal cancer, and epithelia of normal small intestine were investigated using an immunoperoxidase method. Ten normal colonic mucosa served as normal controls. Ten specimens were studied for each group. Normal colonic epithelia did not express class II antigens. In colonic diseases; (1) with regard to the frequency and extent of class II antigens on epithelia. HLA-DR antigens were the most highly and greatly expressed, followed by HLA-DP and then HLA-DQ antigens. (2) The extent of HLA-DR and -DP, but not HLA-DQ, expression on epithelia of UC and colorectal cancer seemed to be positively correlated with the degree of mononuclear cell infiltration in the lesion. (3) The extent of class II antigen expression on colonic epithelia in CD was not related to the degree of mononuclear cell infiltration in the lesion. (4) The extent of HLA-DR and -DP expression on epithelia of colorectal cancer seemed to be positively correlated with increasing undifferentiation. In the normal small intestine, where HLA-DR antigens were physiologically expressed on epithelia. HLA-DQ antigens were not expressed. The heterogeneity among colonic diseases, and between the physiological and pathological status, may reflect differences in immunoregulation.

Colonic lymphoid cell subsets and epithelial HLA-DR antigens in familial polyposis coli

Although there has been some evidence suggesting that immunological mechanisms are involved in the pathophysiology of familial polyposis coli (FPC), there has not been any report as to whether there is any abnormality of lymphoid cell subsets as background, whether polyps (adenomas) show different lymphoid cell subsets from the normal mucosa, or whether HLA-DR antigens are expressed on the epithelia of adenomas. Lymphoid cell subsets (CD5, CD4, CD8, IgA1, IgA2, IgM, IgD, IgG, and IgE positive cells) in the lamina propria, and HLA-DR antigens on the epithelia were studied in 7 patients with FPC. From each patient, 2 specimens were obtained from both the normal (non-polypoid) area and the polyp. Normal colonic mucosa, taken from 15 patients with conventional polyps or colorectal cancer, served as the normal control mucosa. Lymphoid cell subsets and HLA-DR antigens were identified by indirect immunoperoxidase staining using mouse anti-human monoclonal antibodies. In the normal area of FPC, lymphoid cell subsets were similar to those of normal control mucosa except for an increase in IgD positive (IgD+) cells. However, definite alterations were observed in the polyp. There were significant increases in the number of CD4+ and IgG+ cells, and in the sum of five classes of Ig+ cells compared to the normal area or normal control mucosa. HLA-DR antigens were not expressed in the normal control mucosa or in the normal areas, and only on the epithelia of the polyp in 5 out of 7 specimens (71%). These results clearly demonstrate that immunological reactions are involved in FPC polyps.

HLA-DR antigen expression in macroscopically uninvolved areas of intestinal epithelia in Crohn's disease

HLA-DR antigens in small and large intestinal epithelia were examined in Crohn's disease (CD). Seventy-two biopsy specimens (10 from the duodenum, 18 from the terminal ileum, and 44 from various sites of the large intestine) were obtained from 5 patients with CD chronologically; before treatment, during elemental diet (ED) treatment, and during home elemental enteral hyperalimentation (HEEH). HLA-DR antigens on the intestinal epithelia were identified by the indirect immunoperoxidase staining method using two mouse anti-HLA-DR monoclonal antibodies. In the small intestine, HLA-DR antigens were expressed differently from normal controls in macroscopically or microscopically pathological areas, but not in macro- or microscopically normal areas. In the large intestine, when the disease was in full vigor before treatment, HLA-DR antigens were always aberrantly expressed even in the macroscopically uninvolved areas, as well as in macroscopically involved areas. However, when the disease was suppressed after ED followed by HEEH treatment, the antigens were not always expressed in the macroscopically uninvolved areas, or in the macroscopically involved areas. These findings suggest that HLA-DR antigens are not merely expressed as a non-specific response to inflammation, but may be expressed as a primary change which results in macroscopic lesions. The possible role of HLA-DR antigens in the immunological mechanism in CD is proposed.

Ubiquitous expression of HLA-DR antigens on human small intestinal epithelium

To clarify the frequency of the expression of HLA-DR antigens on the human small intestinal epithelium and the variation of such expression, 43 specimens (duodenum 16, jejunum 8, ileum 19; histologically normal 33, pathologic lesions 10) were studied for HLA-DR expression by indirect immunoperoxidase staining using monoclonal antibodies against HLA-DR antigens. All specimens reacted with anti-HLA-DR antibodies with minor variations. Most specimens showed decreasing intensity from the top of the villi toward the base of the villi and no staining in the crypt. In about half of the specimens, clear peripheral and cytoplasmic staining of the epithelial cells was observed. In some cases, the staining of the apical portion of the epithelium was patchy. The expression was unrelated to the lymph follicle. This ubiquitous expression of HLA-DR antigens on the small intestinal epithelium presents a striking contrast to an absence of the antigens on the normal large intestinal epithelium. A preliminary study on the pathologic lesions demonstrated the following changes in the expression of HLA-DR antigens; appearance of HLA-DR antigens on the crypt epithelium in Crohn's disease, loss of HLA-DR antigens on the epithelium covering the area of cell infiltration in macroglobulinemia and covering adenoma in familial polyposis coli.

Ring-like distribution of IgG-containing cells around the lymph follicle in the human intestine

Immunoglobulin (Ig)-containing cells were studied in the lamina propria of the normal human large bowel and around the lymph follicle, including Peyer's patches, in the normal intestine. Ig-containing cells were identified by the indirect immunoperoxidase staining method, using mouse anti-human Ig monoclonal antibodies. In the lamina propria in the large bowel, the mean percentage of IgA+ (IgA1+ cells and IgA2+ cells), IgM+, IgD+, IgG+ and IgE+ cells was 75.9, 8.5, 7.3, 5.8, 2.5, respectively (total 100), namely there was a marked preponderance of IgA+ cells in comparison to IgG+ cells. However, IgG+ cells were observed not only on the epithelial but also in the serosal side of lymph follicles, showing a ring-like pattern. Ig+ cells of the other four classes did not show such a pattern. The ring-like distribution of IgG+ cells around lymph follicles was observed in both the large and small intestine including Peyer's patches. This tendency was observed in 9 out of 14 follicles (64.3 per cent). A large number of IgG+ cells were observed outside lymph follicles, while a small number of IgG+ cells were observed at the most outer rim of lymph follicles which suggested a local maturation of IgG+ cells. The significance and the role of the newly recognized IgG+ cells in the vicinity of lymph follicles remain to be resolved.

Expression of HLA-DR antigens on colonic epithelium in ulcerative colitis

Although the expression of HLA-DR antigens on colonic epithelium in ulcerative colitis has been observed by several groups, the results of the expression in remission have been conflicting and there has been virtually no study concerning the expression in non-inflamed area in active ulcerative colitis. We studied systematically HLA-DR expression on colonic epithelium in 37 patients with ulcerative colitis chronologically, namely in remission as well as in the active stage and inflamed and non-inflamed areas simultaneously in the active stage. HLA-DR antigens were detected by indirect peroxidase staining using anti-HLA-DR monoclonal antibody. We confirmed the previous observation that epithelium from control colon does not express HLA-DR antigens, while epithelium from ulcerative colitis expresses the antigens with high frequency (83.3 percent). In addition, we demonstrated that HLA-DR expression on colonic epithelium in active ulcerative colitis disappeared in remission. Our new finding was that there is no HLA-DR expression on colonic epithelium in non-inflamed mucosa in active ulcerative colitis. Namely HLA-DR antigens were expressed only on inflamed epithelium of ulcerative colitis. These results lead to the conclusion that the expression of HLA-DR antigens on colonic epithelium in ulcerative colitis is closely related to the inflammation of mucosa.

Definite spontaneous cell-mediated cytotoxicity and HNK-1 cells in the human large intestine

Spontaneous cell-mediated cytotoxicity (SCMC) and the marker of natural killer (NK) cells mediating SCMC of the human large intestine were studied. Lamina proprial lymphoid cells (LPL) were isolated by sequential dithiothreitol-EDTA-collagenase treatment of the gut specimen. SCMC was measured by the chromium release method. Target cells included P4788 in monolayer, a cell line derived from colon cancer, Chang cells in monolayer, and K562 in suspension. Target cells in monolayer including colon cancer cell line were chosen because they were thought to be more appropriate to assess SCMC for lymphoid cells in the solid organ. While lower compared to cytotoxicities (CT) by peripheral blood lymphoid cells (PBL), define CT were observed in LPL against all three targets. NK cells marker was studied both on LPL by an indirect fluorescent antibody method and on the gut tissue by indirect immunoperoxidase staining using anti HNK-1 monoclonal antibody which defines virtually all NK cells. HNK-1 positive (HNK-1 +) cells were identified in both methods. HNK-1 + cells were observed in the epithelium, lamina propria, and lymph follicle with or without germinal centers. These results clearly demonstrated the presence of SCMC and HNK-1 + cells in the human large bowel.