Human Monocyte-Derived Dendritic Cell Metabolic Phenotype

Abstract

Lead (Pb) is an environmental contaminant associated with adverse health problems across the world that affects multiple body systems. Previous studies demonstrate chronic inflammation of intestinal, respiratory, and integumentary systems with even nominal levels of exposure. Monocyte-derived dendritic cells play an important role in innate and adaptive immunity because they have the ability to stimulate CD4+ and CD8+ T-cell responses and regulate B-cell immunoglobulin production. Successful development of a protocol for monocyte-derived dendritic cells from human peripheral blood mononuclear cells and isolation using anti-CD14 conjugated with magnetic particles. Flow cytometry was used to analyze surface cell markers of cultured cells and was consistent with phenotypical characteristics of dendritic cells. Increased expression of CD209 and CD1c on day 7 of cell culture was observed. In addition, reduced expression of CD14 and increased expression of costimulatory factors CD83/CD86 was also observed. It is our effort to determine the effects of lead acetate on the immune cell function by analyzing the ability of these monocyte-derived dendritic cells to metabolize vitamin A from the circulating form, retinol, to the steroid hormone transcription factor ligand, all-trans retinoic acid. We expect that in the presence of Pb, dendritic cells will produce more bioactive vitamin A resulting in more inflammatory immune response. In future efforts, our laboratory will determine the effects of Pb on STRA6 (stimulated by retinoic acid 6) expression, which is known as the receptor for retinol binding protein (RBP) and transports vitamin A to tissues, and use the Aldefluor assay as a marker for aldehyde dehydrogenase activity in monocyte-derived dendritic cells.