title: Secretion of interferon gamma from human immune cells is altered by exposure to tributyltin and dibutyltin.
abstract: Tributyltin (TBT) and dibutyltin (DBT) are widespread environmental contaminants found in food, beverages, and human blood samples. Both of these butyltins (BTs) interfere with the ability of human natural killer (NK) cells to lyse target cells and alter secretion of the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) from human immune cells in vitro. The capacity of BTs to interfere with secretion of other pro-inflammatory cytokines has not been examined. Interferon gamma (IFNγ) is a modulator of adaptive and innate immune responses, playing an important role in overall immune competence. This study shows that both TBT and DBT alter secretion of IFNγ from human immune cells. Peripheral blood cell preparations that were increasingly reconstituted were used to determine if exposures to either TBT or DBT affected IFNγ secretion and how the makeup of the cell preparation influenced that effect. IFNγ secretion was examined after 24 h, 48 h, and 6 day exposures to TBT (200 - 2.5 nM) and DBT (5 - 0.05 µM) in highly enriched human NK cells, a monocyte-depleted preparation of PBMCs, and monocyte-containing PBMCs. Both BTs altered IFNγ secretion from immune cells at most of the conditions tested (either increasing or decreasing secretion). However, there was significant variability among donors as to the concentrations and time points that showed changes as well as the baseline secretion of IFNγ. The majority of donors showed an increase in IFNγ secretion in response to at least one concentration of TBT or DBT at a minimum of one length of exposure.
authors.affiliation: Department of Biological Sciences, Tennessee State University, 3500 John A. Merritt Blvd., Nashville, Tennessee, 37209, USA.
authors.forename: Shanieek
authors.initials: S
authors.lastname: Lawrence
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Reid
authors.forename: Margaret
authors.initials: M
authors.lastname: Whalen
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D009947:Organotin Compounds / Q000633:toxicity*; D014220:Trialkyltin Compounds / Q000633:toxicity*
chemical_list: D009947:Organotin Compounds; D014220:Trialkyltin Compounds; C056189:di-n-butyltin; C011559:tributyltin; D007371:Interferon-gamma
keywords: NK cells; PBMCs; dibutyltin; interferon gamma; tributyltin