Production of Tumor Necrosis Factor Alpha (TNFα) and Interferon Gamma (IFNᵧ) in Human Immune Cells Exposed to the Brominated Flame Retardant, Hexabromocyclododecane
Interferon-gamma (IFNᵧ) and tumor necrosis factor (TNF) are both pro-inflammatory cytokines secreted by immune cells. As such, they can cause chronic inflammation if they are secreted in the absence of injury or infection. Chronic inflammation relates to various disease states, such as cancer. Hexabromocyclododecane (HBCD) is a brominated flame retardant used in polystyrene insulation as well as other products such as upholstery and has been found in human blood and other tissues. HBCD has been shown to increase the secretion of both IFNᵧ and TNFα from human immune cells. This study examines whether the increased secretion of these 2 cytokines from immune cells that were exposed to HBCD is due to increased production (intracellular plus secreted levels) of the cytokine or simply due to release of pre-existing cytokine. Monocyte-depleted (MD) human peripheral blood mononuclear cells (PBMCs) were exposed to 0-5 µM HBCD for 1 h, 6 h, and 24 h. The enzyme-linked immunosorbent assay (ELISA) technique was followed to measure the secretion of TNFα or IFNᵧ and to measure the intracellular levels of both cytokines, the western blot technique was used. Results show that when MD-PBMCs were exposed to HBCD, it increases the production of both TNF and IFNᵧ in immune cells. The ability of HBCD to increase production, rather than simulate release, of these cytokines could lead to sustained elevation of IFNᵧ and TNFα contributing to chronic inflammation.
Syeda Raika Shahid,
"Production of Tumor Necrosis Factor Alpha (TNFα) and Interferon Gamma (IFNᵧ) in Human Immune Cells Exposed to the Brominated Flame Retardant, Hexabromocyclododecane"
ETD Collection for Tennessee State University.