Characterisation of mucosal lymphoid aggregates in ulcerative colitis: immune cell phenotype and TcR-gamma delta expression

Abstract

Background and aims-A histopathological feature considered indicative of ulcerative colitis (UC) is the so-called basal lymphoid aggregates. Their relevance in the pathogenesis of UC is, however, unknown. We have performed a comprehensive analysis of the immune cells in these aggregates most likely corresponding to the lymphoid follicular hyperplasia also described in other colitides. Methods-Resection

Morphology of colorectal lymphoid aggregates in cancer, diverticular and inflammatory bowel diseases

“…7,16,17 The increase of density in active inflammatory bowel diseases exceeds by two to four folds the aggregate proliferation seen close to inflamed diverticula. Moreover, most of aggregates in Crohn's disease and a substantial part of them in ulcerative colitis is positioned deeply in the submucosa or even transmurally.…”

Inhibitory Effect of Recombinant IL-25 on the Development of Dextran Sulfate Sodium-Induced Experimental Colitis in Mice

“…A recent study on Mycobacterium tuberculosis infection described a domination of production of IL-17 by T cells and other non-CD4 + /CD8 + T cells (34). T cells have been shown to increase in the mucosa of ulcerative colitis patients (35). While T cells have been shown to provide mucosal protection at the early phase of intestinal inflammation (36), the production of IL-17 by CD4 + /CD8 + T cells was suggested to occur at the late phase (34,37).…”

Prenatal Blockage of Lymphotoxin β Receptor and TNF Receptor p55 Signaling Cascade Resulted in the Acceleration of Tissue Genesis for Isolated Lymphoid Follicles in the Large Intestine

“…Furthermore, dextran sodium sulfate-induced colitis accelerated additional formation of these lymphoid follicles (24). In all cases of ulcerative colitis patients, the colonic LP contain numerous basal lymphoid aggregates composed of T and B lymphocytes and dendritic cells (35). Furthermore, these lymphoid aggregates increase in number and size with severity of disease (35).…”

“…In all cases of ulcerative colitis patients, the colonic LP contain numerous basal lymphoid aggregates composed of T and B lymphocytes and dendritic cells (35). Furthermore, these lymphoid aggregates increase in number and size with severity of disease (35). Overall, it seems likely that LI-ILF could be site for the generation of regulatory and/or pathogenic lymphocytes.…”