Histamine Induces the Generation of Monocyte-Derived Dendritic Cells that Express CD14 but not CD1a

Abstract

The local cytokine environment and the presence of stimulatory signals determine whether monocytes acquire dendritic cell or macrophage characteristics and functions. In this study, we examined the effect of histamine, a prototypic mediator of allergic inflammation, on the granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4-driven differentiation of monocytes into monocyte-derived dendritic cells (MoDC), which typically showed CD1a+CD14- phenotype. Monocytes from healthy adult donors were cultured with GM-CSF and IL-4 in the presence or absence of histamine, and the phenotypes and function of these cells were analyzed. Histamine induced the generation of CD1a-CD14+ cells, which exhibited cytological and phenotypical characteristics of dendritic cells (DC), showed enhanced phagocytic activity and cytokine-producing capacity, but demonstrated weak allo-stimulatory capacity compared with CD1a+CD14- MoDC. The inhibitory effects of histamine on CD1a+CD14- MoDC differentiation were antagonized by cimetidine, an H2 receptor antagonist, but not by H1 and H3 receptor blockers, and were mimicked by an H2 receptor agonist. Culture supernatant of histamine-treated monocytes also inhibited CD1a+CD14- MoDC differentiation, which was restored by the removal of IL-10. These results suggest that histamine-driven CD1a-CD14+ DC amplify their antigen-independent inflammatory reaction and may contribute to the exacerbation of allergic diseases.

Effect of serotonin on the differentiation of human monocytes into dendritic cells

“…By contrast, CD1a – CD14 + skin migratory DC were weak for allogeneic CD4 + T cells with the low expression of HLA‐DR and co‐stimulatory molecules. Recently, we showed that monocytes cultured in the presence of IL‐4, GM‐CSF and histamine differentiated into CD1a – CD14 + DC, in which histamine‐induced endogenous production of IL‐10 by monocytes plays a certain role [12]. 5‐HT also induces CD1a – CD14 + DC, although its effect on monocytic differentiation into CD1a – CD14 + DC was weaker than that of histamine.…”

Platelets as versatile regulators of cutaneous inflammation

“…They also showed that these effects are mediated by soluble protein factors that are excreted from activated platelets. When human monocytes are cultured with IL-4 and GM-CSF in the presence of 5-HT or histamine, they differentiate into CD1aÀCD14+ dendritic cells [51,52]. These DC exhibit enhanced phagocytic activity and cytokine-producing capacity including that for IL-10 but not IL-12, and show a weak allo-stimulatory capacity compared with CD1a+CD14À classical monocyte-derived DC.…”

Effects of PVA coated nanoparticles on human immune cells

“…These cells primarily ingest the pathogens for rapid killing and elimination and further regulate inflammatory reactions by producing proinflammatory or anti-inflammatory cytokines. [74][75][76] Incubation with nanoparticles clearly triggers an activation process, whereas monocyte survival is not influenced. But when considering macrophages, it became obvious that the number of differentiated, viable cells was increased by a-PVA-SPION contact.…”