Tributyltin alters secretion of interleukin 1 beta from human immune cells
Tributyltin (TBT) is an organotin compound that has been used as a biocide in a variety of industrial applications such as wood preservation, antifouling paint, and antifungal agents. Known for contaminating the marine environment, it has been found in human blood samples, and mammals with TBT exposure have shown increased incidences of tumors. Interleukin 1 beta (IL-1β) is a pro-inflammatory cytokine that promotes cell growth, tissue repair, and immune response regulation. Produced predominately by both monocytes and macrophages, IL-1β appears to increase the invasiveness of certain tumors. This study shows that TBT modifies the secretion of IL-1β from increasingly reconstituted preparations of human immune cells. IL-1β secretion was examined after 24h, 48h, or 6 day exposures to TBT concentrations of 25 to 200 nM in a preparation of highly enriched human NK cells, a monocyte-depleted (MD) preparation of human peripheral blood mononuclear cells (MD-PBMCs), PBMCs, granulocytes, and a preparation combining both PBMCs and granulocytes. TBT altered IL-1β secretion from all of the cells preparations. The 200 nM concentration of TBT normally blocked the secretion of IL-1β, while some of the lower concentrations of TBT elevated secretion of IL-1β. The concentrations and lengths of exposure to TBT that caused statistically significant increases in IL-1β secretion from human immune cells varied from one donor to the next. MD-PBMCs were further studied to determine if TBT-induced increases in IL-1β secretion were due to TBT-induced alterations of the ILβ processing enzyme (Caspase-1), mitogen-activated protein kinases (MAPKs), or nuclear factor kappa B (NFκB).
Shyretha D Brown,
"Tributyltin alters secretion of interleukin 1 beta from human immune cells"
ETD Collection for Tennessee State University.