Alterations in mitogen-induced calcium mobilization and intracellular free calcium produced by 7,12-dimethylbenz(a)anthracene in the Jurkat human T cell line

Dioxin-Mediated Up-Regulation of Aryl Hydrocarbon Receptor Target Genes Is Dependent on the Calcium/Calmodulin/CaMKIα Pathway

“…Elevation of [Ca 2ϩ ] i in response to AhR agonists has been reported in various cellular models, including lymphocytes (Burchiel et al, 1991;Pallardy et al, 1992;Archuleta et al, 1993), macrophages (NЈDiaye et al, 2006;Pappas et al, 2003), intestinal (Le Ferrec et al, 2002), and mammary cells (Tannheimer et al, 1997) and can therefore be considered a hallmark of AhR agonist exposure. It is noteworthy that this change of [Ca 2ϩ ] i has been recently demonstrated to be required for regulation of the AhR target genes CYP1A1 and CCL1, in human Caco-2 intestinal cells (Le Ferrec et al, 2002) and human macrophages (NЈDiaye et al, 2006), respectively.…”

“…In addition to activation of AhR, TCDD and PAHs have been shown to increase intracellular concentration of Ca 2ϩ ([Ca 2ϩ ] i ) (Burchiel et al, 1991;Archuleta et al, 1993;Davila et al, 1995;Tannheimer et al, 1997;Le Ferrec et al, 2002). It is noteworthy that blocking these [Ca 2ϩ ] i changes through the use of intracellular Ca 2ϩ chelator or store-operated channel blockers prevents induction of CYP1A1 (NЈDiaye et al, 2006), thus suggesting cross-talk between Ca 2ϩ variations and AhR-dependent regulatory pathways.…”

7,12-Dimethylbenz[a]anthracene activates protein-tyrosine kinases Fyn and Lck in the HPB-ALL human T-cell line and increases tyrosine phosphorylation of phospholipase C-gamma 1, formation of inositol 1,4,5-trisphosphate, and mobilization of intracellular calcium.

“…HPB-ALL cells were activated at 37°C by incubation for 5 min with biotin-conjugated anti-CD3/anti-CD4 antibodies (1 ,g/ml), followed by crosslinking with streptavidin (2 ,ug/ml, Sigma), as described (11). Intracellular levels of free cytosolic Ca2+ were examined by flow cytometry with published methods (9,17). Briefly, HPB-ALL cells were suspended at 106 per ml for indo-1 loading and exposure to DMBA.…”

“…nin-induced Ca2+ mobilization in the Jurkat human T-cell line and that this effect is accompanied by a rise in baseline Ca2+ in unstimulated cells (9). Murine spleen cells treated with DMBA in vitro or in vivo also demonstrated a decreased Ca2+ mobilization response to phytohemagglutinin (6,7), and murine B cells were significantly inhibited in their Ca2+ mobilization response to anti-IgD antibodies, whereas Ca2+-independent pathways of B cell activation appeared to be relatively unaffected by DMBA (10).…”

Assessment of Immunotoxicity by Multiparameter Flow Cytometry

“…Activation and Apoptosis by Flow Cytometry-S. W. Burchiel, B. J. Mounho, F. T. Lauer, L. Seamer, and D. R. Davila Previous studies in this laboratory have shown that polycyclic aromatic hydrocarbons (PAHs) alter calcium homeostasis in murine lymphocytes and human lymphoid T cell lines (Burchiel et al, 1991;Archuleta et al, 1993;Krieger et al, 1994Krieger et al, , 1995 (Krieger et al, 1994). There appear to be at least two mechanisms whereby PAHs increase intracellular Ca 2+ : (1) an increase in tyrosine phosphorylation of Src kinases (Archuleta et al, 1993), and (2) an inhibition of sarcoendoplasmic reticulum ATPases (Krieger et al, 1995).…”