Expression of adhesion molecules and HLA-DR by macrophages and dendritic cells in aphthoid lesions of Crohn's disease: an immunocytochemical study

Ileocecal involvement in intestinal Behçet's disease and Crohn's disease: comparison of clinicopathological and immunophenotypic features

OBJECTIVES

Intestinal Behçet's disease (BD) predominantly affects the ileocecal region and is currently diagnosed based on endoscopic features and clinical manifestations. It is difficult to distinguish between intestinal BD and Crohn's disease (CD) due to similar patient populations, gastrointestinal involvement, extraintestinal manifestations, and long-term recurrent course. In this study we aimed to compare the clinicopathological and immunophenotypic features of intestinal BD to CD.

METHODS

The medical and pathological records of 29 cases of intestinal BD and 120 cases of CD diagnosed at Sir Run Run Shaw Hospital were retrospectively analyzed. Immunohistochemistry for CD3, CD20, FOXP3, myeloperoxidase, and quantitative analysis of the infiltrating inflammatory cells was conducted.

RESULTS

Intestinal BD with ileocecal ulcer had a higher incidence of abdominal pain and a higher erythrocyte sedimentation rate than CD, while chronic diarrhea was more common in CD. Excessive neutrophils in the mucosal lamina propria, neutrophilic exudate on the ulcer surface, and prominent lymphocytic infiltration in ulcer tissues were statistically more frequent in intestinal BD than in CD. The numbers of FOXP3+ T cells, CD3+ T cells, and CD20+ B cells in biopsy tissue from intestinal BD were significantly higher than CD, but the ratio of FOXP3+ T cells to CD3+ T cells was not statistically different.

CONCLUSION

Besides the typical clinical and endoscopic findings, diagnostic biopsies from the ileocecal region in intestinal BD show some histological and immunophenotypic features that are different from CD, which may be useful in distinguishing these two entities.

Crohn's disease with ankylosing spondylitis in an adolescent patient who had undergone long ileo-colonic anastomosis for Hirschsprung's disease as an infant

Crohn's disease (CD) is a chronic, idiopathic, inflammatory disorder of the gastrointestinal tract. In rare cases, CD has been associated with Hirschsprung's disease (HD); however, the underlying pathophysiology of this and other comorbidities is not yet fully understood. In this report, we describe the case of a 17-year-old patient who was diagnosed with both CD and ankylosing spondylitis (AS), having undergone a long ileo-colonic anastomosis to treat HD at 12 months of age. To our knowledge, this is the first documented case of CD combined with AS in a patient with HD.

Initiation of an inflammatory response in resident intestinal lamina propria cells -use of a human organ culture model

Resident human lamina propria immune cells serve as powerful effectors in host defense. Molecular events associated with the initiation of an intestinal inflammatory response in these cells are largely unknown. Here, we aimed to characterize phenotypic and functional changes induced in these cells at the onset of intestinal inflammation using a human intestinal organ culture model. In this model, healthy human colonic mucosa was depleted of epithelial cells by EDTA treatment. Following loss of the epithelial layer, expression of the inflammatory mediators IL1B, IL6, IL8, IL23A, TNFA, CXCL2, and the surface receptors CD14, TLR2, CD86, CD54 was rapidly induced in resident lamina propria cells in situ as determined by qRT-PCR and immunohistology. Gene microarray analysis of lamina propria cells obtained by laser-capture microdissection provided an overview of global changes in gene expression occurring during the initiation of an intestinal inflammatory response in these cells. Bioinformatic analysis gave insight into signalling pathways mediating this inflammatory response. Furthermore, comparison with published microarray datasets of inflamed mucosa in vivo (ulcerative colitis) revealed a significant overlap of differentially regulated genes underlining the in vivo relevance of the organ culture model. Furthermore, genes never been previously associated with intestinal inflammation were identified using this model. The organ culture model characterized may be useful to study molecular mechanisms underlying the initiation of an intestinal inflammatory response in normal mucosa as well as potential alterations of this response in inflammatory bowel disease.

Promoting MPhi transepithelial migration by stimulating the epithelial cell P2Y(2) receptor

In intestine, neutrophils are recruited in response to bacterial infiltration and their anti-cellular activities contribute to inflammatory bowel diseases. In contrast, little is known regarding the recruitment of MPhi to the intestinal epithelium. Extracellular adenosine and uridine 5'-triphosphate (ATP and UTP) can function as leukocyte chemoattractants. We investigated the effects of these nucleotides on the ability of intestinal epithelial cells (IEC) to promote MPhi transepithelial migration and adhesion. ATP and UTP promoted the migration of neutrophil-like PLB-985 cells and MPhi across a Caco-2 monolayer. The MPhi-like U-937 cells adhered to nucleotide-stimulated IEC monolayers. In mice with intestinal inflammation, there were infiltrating CD68(+) MPhi in the colonic epithelium and CD68(+) MPhi present at the apical surface of colonocytes. We determined that ATP and UTP activated the P2Y(2) receptor P (P2Y(2)R) to increase ICAM-1 expression, which mediated the adhesion of MPhi to the apical surface of IEC. Intriguingly, stimulation of IEC with nucleotides did not increase the adhesion of neutrophils. However, in the presence of adherent MPhi, there was adhesion of neutrophils, suggesting that MPhi may serve as anchors for neutrophil adhesion. These studies provide insight into the inflammatory mechanisms that contribute to inflammatory bowel diseases and identify potential therapeutic targets for the treatment of gastrointestinal disorders.

Induction and cellular expression of tartrate resistant acid phosphatase during dextran sodium sulphate induced colitis in rats

The aim of this study was to investigate the cellular and molecular expression of tartrate resistant acid phosphatase (TRAP) as a marker of activated macrophages in macrophage dependent dextran sulphate sodium (DSS)-induced colitis in rats. In normal colon, TRAP+/CX(3)CR(1)+ macrophages were located in the upper part of the lamina propria. In the early stage (day 1-3) of acute colitis prior to histopathological changes, induction of the cytokines TNFalpha, IL-12 and IFN gamma occurred concomitant with increased mRNA and enzyme activity of TRAP along with a slight increase of TRAP immunolabelling in macrophages of the upper lamina propria, suggesting induction of TRAP in resident macrophages. Among these cytokines, TNFalpha up-regulated TRAP expression in the RAW 264.7 monocyte/macrophage cell line. In a later phase (day 7) with fulminant colitis, a massive infiltration of macrophages including recruited TRAP+/CCR2+ cells was observed also in the lower part of the lamina propria as well as in the submuscular layer. Additionally, differentiated cellular expression of pro- and mature TRAP also suggest that mucosal macrophages in the lower part of lamina propria bordering the sub-mucosa provide a source of replenishment of macrophages situated in the upper lamina propria. In conclusion, induction of TRAP provides an early sign of macrophage responsiveness in DSS induced colitis.

Alterations in myeloid dendritic cell innate immune responses in the Galphai2-deficient mouse model of colitis

BACKGROUND

The G protein alpha subunit type-2 (Galpha(i)2)-deficient mouse develops inflammatory bowel disease (IBD) with increased severity in mice on a 129SvEv (129) background compared to the C57BL/6 (B6) background. Since dendritic cells (DCs) are key cells of innate immunity, we determined whether Galpha(i)2(-/-) DCs have functional defects, influenced by strain background, that predispose to IBD.

METHODS

By breeding these strains to homozygosity for the first time, it became possible to study innate immunity in this animal model with more precision than ever before. Immature DCs were generated using bone marrow monoblasts cultured in the presence of GM-CSF (BMDCs), DC subsets sorted and responses to TLR9 activation were assayed.

RESULTS

In contrast to Galpha(i)2(-/-) B6, Galpha(i)2(-/-) 129 mice display accelerated onset and increased severity of colitis, abnormal mucosal DC distribution, accompanied by preponderance for Th1 and Th17-associated gut cytokine expression. TLR9 activation of BMDCs induces sustained p38 MAPK activation and greater Th1- and Th17-type cytokine secretion in both strains of Galpha(i)2-deficient compared to wildtype BMDCs. However, only B6 Galpha(i)2(-/-) BMDCs concomitantly produces IL-10 while Galpha(i)2(-/-) 129 BMDCs do not.

CONCLUSIONS

Loss of Galpha(i)2 promotes a Th1/Th17 phenotype and relative IL-10 insufficiency in Galpha(i)2(-/-) 129 BMDCs may account for the striking difference in disease.

Colonic epithelial cell expression of ICAM-1 relates to loss of surface continuity: a comparative study of inflammatory bowel disease and colonic neoplasms

OBJECTIVE

Intercellular adhesion molecule-1 (ICAM-1) is important in ulcerative colitis (UC) by mediating the arrest and further migration of neutrophils. In vitro studies have shown that colonocytes from chronically inflamed colon and cultured colon cancer cells are capable of expressing ICAM-1. The aim of this study was to assess the ICAM-1 expression in human colonic tissue representing UC, Crohn's disease (CD), adenomas, and adenocarcinomas, with special attention to the epithelium.

MATERIAL AND METHODS

Formalin-fixed and paraffin-embedded tissue from the archives of the Department of Pathology of Rigshospitalet University of Copenhagen was examined. Colonic tissue from 10 patients with UC, 10 with CD, 32 adenomas, 27 adenocarcinomas, and 10 lymph node metastases were included. The expression of ICAM-1 was assessed by using the EnVision(+)technique (DakoCytomation).

RESULTS

Endothelial ICAM-1 was up-regulated in areas with dense lymphocyte infiltration and near crypt abscesses and ulcerations. Ulcerations were covered by a continuous layer of macrophages and epithelial cells expressing ICAM-1. Similar observations were made in the case of adenomas and adenocarcinomas, but in adenocarcinomas the epithelial ICAM-1 was more diffuse and not related solely to sites of surface destruction.

CONCLUSIONS

In the colon, endothelial cells, macrophages, and epithelial cells are in certain conditions capable of expressing ICAM-1. Although the ICAM-1 expression was related to both the degree and the nature of inflammation, the data indicate increased susceptibility of cancer cells to express ICAM-1. Epithelial and macrophage ICAM-1 might be involved in the immune surveillance and the first-line defense of the diseased colon.

Expression of ICAM-1 in colon epithelial cells: an ultrastructural study performed on in vivo and in vitro models

BACKGROUND

Studies have suggested that in ulcerative colitis (UC), intercellular adhesion molecule-1 (ICAM-1) is involved in migration of leukocytes toward the colonic epithelium. A suitable in vitro model of chronic colonic inflammation does not exist, and the role of the epithelium is based on monolayers of cancer cells. Conflicting results exist on epithelial ICAM-1 expression, and the aim of this study was to compare the expression in various models of colonic epithelium.

MATERIALS AND METHODS

Colonic biopsies from four UC patients and four controls were examined by cryoimmuno-electron microscopy using ICAM-1-antibodies. In four other controls, the epithelium was isolated from colonic biopsies, embedded in collagen, and evaluated similarly. Isolated crypts and cultured cancer cells were stimulated with interferon-gamma (IFN-gamma) or tumor necrosis factor-alpha (TNF-alpha).

RESULTS

ICAM-1 was not expressed in the biopsies. In contrast, HT29 cells and the collagen-embedded crypts expressed ICAM-1 on the apical membranes proximal to the junctional complexes when stimulated with IFN-gamma or TNF-alpha in a dose-related manner.

CONCLUSIONS

ICAM-1 is not expressed on colonic epithelium in vivo. However, both colonocytes and HT29 cells were capable of expressing ICAM-1 on their apical membranes in response to supraphysiologic cytokine concentrations. These observations question the justification of extrapolating observations from colon cancer cell lines to in vivo inflammatory conditions.

Connections between psoriasis and Crohn's disease

The prevalence of psoriasis in patients with Crohn's disease (CD) is higher than chance would allow if they were mutually exclusive diseases. A close examination reveals genetic and pathologic connections between these diseases. An appreciation for the role of tumor necrosis factor-alpha in both diseases has proven very important. Increased levels of this inflammatory cytokine have been measured in CD lesions, and in 1997 a clinical trial demonstrated the response of this disease to infliximab, a monoclonal antibody specific for tumor necrosis factor-alpha. A subsequent clinical trial evaluated infliximab in a patient with CD and psoriasis, another disease in which increased levels of tumor necrosis factor-alpha are seen in lesions. Scientists noticed the marked skin improvement of this patient and later demonstrated the efficacy of infliximab for psoriasis in a randomized, double-blind, placebo-controlled trial. Thus, an appreciation for connections between psoriasis and CD can suggest novel therapeutic strategies with ensuing benefits to patients. This article reviews epidemiologic, genetic, and pathologic connections between psoriasis and CD and discusses pharmaceuticals targeting inflammatory mediators common to each disease. (J Am Acad Dermatol 2003;48:805-21.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should understand how psoriasis and Crohn's disease are related at epidemiologic, genetic, and pathological levels and should appreciate how to use this knowledge to treat these diseases.

Differentiation between ulcerative colitis and Crohn's disease by a quantitative immunohistochemical evaluation of T lymphocytes, neutrophils, histiocytes and mast cells

Mucosal biopsy criteria has limited validity in terms of discrimination between ulcerative colitis (UC) and Crohn's disease (CD). The aim of this study was to set up quantitative immunohistochemical criteria, with a special focus on inflammatory cell distribution within individual specimens and throughout the large bowel. Quantitative evaluation was performed for the density of CD8+, CD45RO+, neutrophil elastase+, CD68+ and mast cell tryptase+ cells in affected and unaffected mucosa taken from 41 patients with UC and 61 patients with CD. Each slide was examined at the highest and lowest density fields, which were further divided into the upper and deeper half of mucosa. Multiple logistic regression analysis using 51 features as independent variables constructed a predictive equation finding the probability of UC (PUC), and the diagnostic categories were subsequently defined based on a receiver-operating characteristic curve. The analysis disclosed five significant features suggesting UC; these implied intense infiltration of CD8+ and mast cell tryptase+ cells, diffuse infiltration of neutrophil elastase+ and CD68+ cells, and continuous infiltration of CD45RO+ cells. The criteria consisted of three diagnostic categories, 'suggestive of UC (PUC > or = 0.7)', 'indeterminate (0.3 < PUC < 0.7)', and 'suggestive of CD (PUC < or = 0.3)'; the criteria had values for sensitivity and specificity exceeding 95%. The immunohistochemical criteria distinguishing UC from CD may help to confirm the diagnosis in patients with ambiguous endoscopic and histological diagnosis.

Efficacy of the inflammatory cell infiltration inhibitor IS-741 on colitis induced by dextran sulfate sodium in the rat

We examined the therapeutic effects of the inflammatory cell infiltration inhibitor IS-741 (N-(2-((ethylsulfonyl)amino)-5-(trifluoromethyl)-3-pyridinyl)-cyclohexanecarboxamide monosodium salt monohydrate) on a rat colitis model. As a result of its effects on leukocyte infiltration, IS-741 inhibits cell adhesion, alleviates symptoms and signs of pancreatitis and multiple organ failure and demonstrates a life-saving effect in a model of severe acute pancreatitis. A rat model was prepared by inducing colitis with 3% dextran sodium sulfate (DSS) and maintaining pathology with 1% DSS. Repeated oral administration of IS-741 at 1, 10 or 100 mg/kg per day was conducted for 2 weeks (during treatment with 1% DSS). IS-741 at each dose decreased the area of erosion in the large intestine, thickening of the wall of the large intestine and anemia caused by melena. Some effects of IS-741 were nearly equivalent to those of the control compound salazosulfapyridine. Furthermore, IS-741 markedly alleviated inflammatory cell infiltration into the intestinal wall. IS-741 improved lesions in a rat DSS model by inhibiting leukocyte infiltration, suggesting the possibility of clinical application of this drug for IBD.

Role of cell adhesion molecules in inflammatory bowel diseases

Infiltration of leukocytes into the bowel wall is a landmark of the inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD). The leukocyte movement is dependent on physical contact (adhesion) between the leukocytes and activated endothelial cells and can be divided into capturing, rolling, leukocyte flattening, and extra-vasation. The molecules shown to form the basis of leukocyte-endothelial binding are referred to as cell adhesion molecules (CAMs). Several of these molecules have additional properties, including interaction between leukocytes and proteins in the extracellular matrix, collaen in basement membranes, and stromal cells in lymphoid tissue and bone marrow. Furthermore, studies have indicated that CAMs interfere with the tumor cell's ability to metastasize. This paper will focus on a description of those CAMs that are either known or believed to be involved in the pathogenesis of IBD. Investigations of the presence and functions of these CAMs in IBD is reviewed, and potential new treatments are discussed.

Pathogenesis of aphthoid ulcers in Crohn's disease: correlative findings by magnifying colonoscopy, electron microscopy, and immunohistochemistry

BACKGROUND

The mechanism of ulceration in Crohn's disease remains unknown.

AIMS

To clarify the role of the follicle associated epithelium (FAE) of colonic lymphoid nodules in the formation of ulcers in Crohn's disease.

METHODS

After identification of colonic lymphoid nodules and aphthoid lesions by magnifying colonoscopy, 76 biopsy specimens were obtained from 10 patients with Crohn's disease and three patients with colonic lymphoid hyperplasia. This study correlated magnifying colonoscopic, electron microscopic, and immunohistochemical findings of biopsy specimens.

RESULTS

In Crohn's disease, scanning electron microscopy of lymphoid nodules surrounded by a red halo without visible erosions by magnifying colonoscopy, showed surface erosions 150-200 microns in size. These lymphoid nodules with red halos had small erosions either light microscopically or electron microscopically in 18 of 21 specimens (86%). Correlation of scanning and transmission electron microscopy showed residues of FAE including M cells at the edges of the erosions. In immunohistochemical studies, HLA-DR antigen was limited in M cells of FAE in the patients with lymphoid hyperplasia without inflammatory bowel disease. In Crohn's disease patients in remission, however, HLA-DR antigen was strongly expressed over the entire FAE of lymphoid nodules with a red halo endoscopically, while the expression was weak and irregular in the mucosa surrounding the lymphoid nodules. HLA-DR was strongly expressed in the entire inflamed colonic mucosa in the active stage.

CONCLUSION

The red halo appearance surrounding lymphoid follicles seems to precede visible aphthoid ulcers and suggests that ulcerations in Crohn's disease originate from FAE, possibly related to its physiological role as a portal of entry for potentially pathogenic agents.