Abstract
Dendritic cells (DCs) are specialized antigen-presenting cells that orchestrate the innate and adaptive immune response. The aim of this study was to prepare nanoemulsions and investigate their role in controlling DCs phenotype expression, apoptosis, and cytokine secretion. Three nanoemulsions (NEs) were produced by mixing essential oils, surfactants, and water with droplet sizes of NEs formulations in the range of 25-62nm. DCs were generated in vitro from peripheral blood mononuclear cells of healthy donors, followed by stimulation with lipopolysaccharide (LPS), Vitamin D and NEs. DCs morphology was determined using a bright field inverted microscope. Phenotype characteristics and apoptosis were investigated using flow cytometry, and ELISA technique to determine IL-10 and IL-12 (p70) production. NEs showed significantly lower expression of maturation marker CD83 compared to LPS which stimulated DCs. Also, costimulatory molecules CD80 showed higher expression and CD86 showed significantly lower expression compared with unstimulated DCs. In addition, NEs showed a non-significant effect on the viability and apoptosis of DCs at high concentrations, beside secretion of significantly low levels of IL-12 (p70) and high levels of IL-10. In conclusion, the result suggested that NEs may have a tolerogenic effect on Dendritic cells.