LIPOPOLYSACCHARIDE STIMULATION OF DENDRITIC CELLS INDUCES INTERLEUKIN-10 PRODUCING ALLERGEN-SPECIFIC T CELLS IN VITRO BUT FAILS TO PREVENT ALLERGIC AIRWAY DISEASE

Dendritic cells (DCs) play an important role in directing naive T cells towards a Th1/Th2 or regulatory T cells (Treg) cell phenotype. In this context, interleukin (IL)-10 has been shown to exhibit immune regulatory capacities. The aim of this study was to delineate the influence of high-IL-10–producing DCs on DC–T-cell interactions in inhibiting allergen-induced airway inflammation and hyperreactivity in a murine model of allergic airway disease. Bone marrow–derived dendritic cells (BMDCs) were generated from hemopoietic progenitors by culture with granulocte-macrophage colony-stimulating factor (GM-CSF), and stimulated with ovalbumin (OVA) ± lipopolysaccharide (LPS). The effects of ovalbumin-pulsed BMDCs on cytokine production by allergen-specific naive T cells were studied in vitro. The development of airway inflammation in Balb/c mice was determined after intranasal administration of BMDCs in vivo. LPS stimulation of BMDCs strongly enhanced IL-10 production. Coculture of LPS-modulated DCs exhibiting i...