Dichlorodiphenyltrichloroethane and Pentachlorophenol alter secretion of tumor necrosis factor alpha from human immune cells
Pentachlorophenol (PCP) and Dichlorodiphenyltrichloroethane (DDT) are both classified as "probable carcinogens". PCP was used as a wood preservative and has been found in human blood at levels as high as 5 μM. DDT is widely used as an insecticide in the developing world and is also found in human blood at levels as high as 0.26 μM. Tumor necrosis factor alpha is an inflammatory cytokine secreted by key immune cells such as NK cells, T cells, macrophages and monocytes. It is responsible for inhibiting tumor-induced vascularization (angiogenesis) by damaging the vascular endothelial cells in the vicinity of a tumor, thus decreasing the flow of blood and oxygen that is integral for tumor growth and increases growth for tumor invasiveness. However, inappropriately elevated levels of TNF alpha can cause chronic inflammation which promotes malignant transformation. The objective of this study is to determine whether exposures to PCP and DDT alter the secretion of TNF alpha; from human immune cells. We examined highly purified natural killer (NK) cells, monocyte-depleted (MD) peripheral blood mononuclear cells (PBMCs) and PBMCs exposed to PCP (0, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, and 10 μM) and DDT (0, 0.025, 0.05, 0.1, 0.25, 0.5, 1, and 2.5 μM) for 24h, 48h, and 6 days for changes in TNF alpha secretion. Secretion of TNF alpha was measured utilizing the enzyme-linked immunosorbent assay (ELISA). Data indicate that both PCP and DDT alter the secretion of TNF alpha; by causing increases or decreases of TNF alpha in immune cells, however, the effects vary from donor to donor.
"Dichlorodiphenyltrichloroethane and Pentachlorophenol alter secretion of tumor necrosis factor alpha from human immune cells"
ETD Collection for Tennessee State University.