Human gut-specific homeostatic dendritic cells are generated from blood precursors by the gut microenvironment.

Background: Dendritic cells (DC) dictate not only the type of T-cell immunity, but also homing patterns of T cells in mice. In humans, we characterized normal human gut DC and tested whether gut-specific homeostatic DC could be generated from blood precursors by factors in the gut microenvironment.

Methods: We characterized the phenotype and function of healthy human gut DC compared with blood and skin DC, and studied whether conditioning of blood DC in the presence of colonic biopsy supernatants (Bx-SN) induced gut-like phenotype and functions.

Vitamin D and gastrointestinal diseases: inflammatory bowel disease and colorectal cancer.

Over the past 5 years, there has been a rapid resurgence of interest in vitamin D outside of its traditional role in metabolic bone disease. Some nontraditional roles ascribed to vitamin D include anti-inflammatory and immune-modulating effects. These effects have led to possible implications in the pathophysiology of immune-mediated diseases including multiple sclerosis and inflammatory bowel disease (IBD).

Is rosiglitazone a promising treatment for ulcerative colitis?

In this Practice Point commentary, we discuss the findings and limitations of a randomized, placebo-controlled trial conducted by Lewis and colleagues that examined the efficacy of rosiglitazone for the treatment of patients with mild-to-moderately active ulcerative colitis. The results show that rosiglitazone had superior efficacy to placebo for inducing clinical response and remission. However, the efficacy of rosiglitazone in this setting was modest.