Production of corticotropin-releasing factor and urocortin from human monocyte-derived dendritic cells is stimulated by commensal bacteria in intestine.

Abstract

To examine whether commensal bacteria are a contributing cause of stress-related mucosal inflammation. Human peripheral blood monocyte-derived dendritic cells (MoDCs) were stimulated by commensal bacterial strains, including Escherichia coli, Clostridium clostridioforme, Bacteroides vulgatus (B. vulgatus), Fusobacterium varium (F. varium), and Lactobacillus delbrueckii subsp. bulgaricus. After incubation, corticotropin-releasing factor (CRF) and urocortin 1 (UCN1) mRNA in the cells was examined by real-time reverse transcription polymerase chain reaction. Supernatants from the cells were tested for CRF and UCN1 using an enzyme-linked immunosorbent assay. Both CRF and UCN1 were significantly augmented by B. vulgatus and F. varium at both the mRNA and protein levels. In particular, B. vulgatus stimulated human MoDCs, resulting in extremely high levels of CRF and UCN1. Stimulation of MoDCs by B. vulgatus and F. varium may be associated with CRF/UCN1-related intestinal disorders, such as irritable bowel syndrome and inflammatory bowel disease.