Studies on lymphocyte subpopulations in human colonic biopsy specimens by colonoscopy

Phenotypic and functional characterization of T-cell lines generated from colonoscopic biopsy specimens in patients with ulcerative colitis

Intestinal T-cell lines were generated from lamina propria mononuclear cells isolated from colonoscopic biopsies in ulcerative colitis patients and controls. In both ulcerative colitis and controls, expanded cells were constituted largely by T-cell receptor alpha beta+, CD4+, CD45RA- (helper), and CD8+, CD11b- (cytotoxic) phenotypes. T-cell receptor V beta gene usage was not significantly changed after cell expansion and no difference was observed between ulcerative colitis and controls. Ulcerative colitis cells, especially those derived from the patients with long-standing disease, showed significantly higher levels of cytotoxicity against the target cells, including those of colonic epithelial origin, and enhanced production of tumor necrosis factor-alpha and interferon-gamma after short incubation with anti-CD3 antibody. Generation of T-cell lines from colonoscopic biopsy specimens may be useful for detailed functional characterization of locally infiltrating T cells in ulcerative colitis patients.

Evidence of a local intestinal immunomodulatory effect of sulfasalazine in rheumatoid arthritis

OBJECTIVE

To analyze whether the intestinal mucosa in rheumatoid arthritis (RA) is immunologically abnormal and whether sulfasalazine (SSZ) possesses any local intestinal immunoregulatory effect.

METHODS

Lymphocyte subpopulations and HLA-DR expression were evaluated in biopsy specimens from the duodenal-jejunal mucosa and in peripheral blood samples obtained from 17 patients with RA, both before and after 16 weeks of SSZ treatment. The same mucosal assays were also performed in 7 controls.

RESULTS

The mucosa of the small intestine in RA patients showed no differences in morphology, HLA-DR expression, or the amounts and distribution of CD3+, CD4+, CD8+, and gamma/delta + lymphocytes compared with the control group. However, there was a reduction in mucosal CD3+ and gamma/delta + lymphocyte numbers after SSZ therapy, which did not correspond to a change in peripheral blood CD3+ lymphocyte number. SSZ treatment also tended to diminish the peripheral blood CD4+:CD8+ cell ratio (P = 0.05).

CONCLUSION

No signs of inflammation or immunologic abnormalities were seen in RA duodenal-jejunal mucosa. In this part of the intestine, however, SSZ exerted immunoregulatory effects that were not encountered in the peripheral blood.

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.

Immunohistological studies of surface antigen on colonic lymphoid cells in normal and inflamed mucosa. Comparison of follicular and lamina propria lymphocytes

Mucosal samples from 16 patients with idiopathic inflammatory bowel disease were examined immunohistologically using several monoclonal antibody combinations, and the results were compared with those obtained in other colonic inflammatory disorders and in normal mucosa. Within and around lymphoid follicles, most T cells expressed the restricted common leucocyte antigen (CD45R, displayed by unprimed T cells). Conversely, most lamina propria T cells were negative for CD45R but stained positively with UCHL1 (a monoclonal antibody recognizing an antigen displayed by primed T lymphocytes). The proportions of T-lymphocyte subpopulations in normal and inflamed mucosa were similar, except that CD6-negative, CD7-positive cells were significantly more frequent in inflammatory bowel disease. A characteristic feature of ulcerative colitis and Crohn's colitis was marked infiltration by CD45R+ lymphoid cells that did not coexpress T- or B-cell surface antigens; some stained positively with plasma cell reagents, suggesting that they may be activated B cells. The observations in the colitis sections are consistent with the interpretation that T and B cells alter their surface antigen expression as they emerge from follicles and enter the inflamed lamina propria.

Selective biopsy of human Peyer's patches during ileal endoscopy

During routine lower gastrointestinal endoscopy of children for suspected chronic inflammatory bowel disease, it is possible to visualize lymphoid follicles (Peyer's patches) in the last few centimeters of the terminal ileum. Biopsy specimens have been taken from these Peyer's patches and the lymphoid cells have been isolated by collagenase digestion. The mean cell yield of Peyer's patch cells was 1.7 x 10(8) lymphocytes/g tissue. Isolated Peyer's patch cells were 26%-54% CD3+ (pan T cells), 14%-34% CD4+ (helper/inducer T cells), and 9%-17% CD8+ (suppressor/cytotoxic T cells). Twenty six percent to 48% of the Peyer's patch cells were B cells; less than 1% contained cytoplasmic immunoglobulin A. When stimulated in vitro with phytohemagglutinin or pokeweed mitogen, cells from Peyer's patches proliferated. The successful isolation of functional cells from Peyer's patches will now allow studies to be done at the afferent limb of mucosal immunoregulation in humans.

Increased arachidonic acid composition of phospholipids in colonic mucosa from patients with active ulcerative colitis

The long chain fatty acid composition of phospholipids in colonic mucosa was determined by high performance liquid chromatography in nine patients with active ulcerative colitis and eight healthy controls. The arachidonic acid composition was 12.5 +/- 1.4 mol % (mean +/- 2 SEM) in the inflamed colonic mucosa from the patients with active ulcerative colitis and 6.8 +/- 1.2 mol % in the intact mucosa from healthy controls (p less than 0.001). In the inflamed colonic mucosa, oleic acid and palmitoleic acid were concomitantly decreased (p less than 0.001 and p less than 0.02, respectively), while docosahexaenoic acid was increased (p less than 0.05). Histopathological examination showed that there was a three fold increase in the cell density of inflammatory infiltrate in the lamina propria of the inflamed colonic mucosa (p less than 0.001). The cell density of inflammatory infiltrate correlated with the arachidonic acid composition of phospholipids in colonic mucosa (r = 0.89, p less than 0.005). These findings indicate that inflammation alters the long chain fatty acid composition of phospholipids in colonic mucosa. The observed increase in the arachidonic acid composition of phospholipids in inflamed colonic mucosa may contribute to the enhanced arachidonic acid metabolism in patients with active ulcerative colitis.