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- NK cells (23)
- PBMCs (7)
- Dibutyltin (6)
- Lytic function (6)
- Hexabromocyclododecane (5)
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- Pentachlorophenol (5)
- Tributyltin (5)
- Binding function (4)
- CD16 (4)
- CD56 (4)
- Granulocytes (4)
- P44/42 (4)
- Tetrabromobisphenol A (4)
- ATP (3)
- Dichlorodiphenyltrichloroethane (3)
- Interleukin 1 beta (3)
- Interleukin 1β (3)
- Interleukin 6 (3)
- MAPK (3)
- MD-PBMCs (3)
- ATP levels (2)
- Butyltin (2)
- DDT (2)
- Flavonoids (2)
- Glioblastoma (2)
- Glutathione (2)
- Immune cells (2)
- Interferon gamma (2)
- MAP kinases (2)
- MRNA (2)
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Articles 31 - 45 of 45
Full-Text Articles in Cell Biology
Role Of Protein Kinase C In Tbt-Induced Inhibition Of Lytic Function And Mapk Activation In Human Natural Killer Cells, Abraham B. Abraha, Krupa Rana, Margaret M. Whalen
Role Of Protein Kinase C In Tbt-Induced Inhibition Of Lytic Function And Mapk Activation In Human Natural Killer Cells, Abraham B. Abraha, Krupa Rana, Margaret M. Whalen
Chemistry Faculty Research
Human natural killer (NK) cells are lymphocytes that destroy tumor and virally infected cells. Previous studies have shown that exposure of NK cells to tributyltin (TBT) greatly diminishes their ability to destroy tumor cells (lytic function) while activating mitogen-activated protein kinases (MAPK) (p44/42, p38, and JNK) in NK cells. The signaling pathway that regulates NK lytic function appears to include activation of protein kinase C (PKC) as well as MAPK activity. TBT-induced activation of MAPKs would trigger a portion of the NK lytic signaling pathway, which would then leave the NK cell unable to trigger this pathway in response to …
Effects Of Butyltin Exposures On Map Kinase-Dependent Transcription Regulators In Human Natural Killer Cells, Rachel J. Person, Margaret M. Whalen
Effects Of Butyltin Exposures On Map Kinase-Dependent Transcription Regulators In Human Natural Killer Cells, Rachel J. Person, Margaret M. Whalen
Chemistry Faculty Research
Natural killer (NK) cells are a major immune defense mechanism against cancer development and viral infection. The butyltins (BTs), tributyltin (TBT) and dibutyltin (DBT), have been widely used in industrial and other applications and significantly contaminate the environment. Both TBT and DBT have been detected in human blood. These compounds inhibit the lytic and binding function of human NK cells and thus could increase the incidence of cancer and viral infections. Butyltin (BT)-induced loss of NK function is accompanied by activation of mitogen activated protein kinases (MAPKs) and decreases in expression of cell-surface and cytolytic proteins. MAPKs activate components of …
Dibutyltin Activates Map Kinases In Human Natural Killer Cells, In Vitro, Sabah O. Odman-Ghazi, Abraham Abraha, Erica Taylor Isom, Margaret M. Whalen
Dibutyltin Activates Map Kinases In Human Natural Killer Cells, In Vitro, Sabah O. Odman-Ghazi, Abraham Abraha, Erica Taylor Isom, Margaret M. Whalen
Chemistry Faculty Research
Previous studies have shown that dibutyltin (DBT) interferes with the function of human natural killer (NK) cells, diminishing their capacity to destroy tumor cells, in vitro. DBT is a widespread environmental contaminant and has been found in human blood. As NK cells are our primary immune defense against tumor cells, it is important to understand the mechanism by which DBT interferes with their function. The current study examines the effects of DBT exposures on key enzymes in the signaling pathway that regulates NK responsiveness to tumor cells. These include several protein tyrosine kinases (PTKs), mitogen-activated protein kinases (MAPKs), and mitogen-activated …
Immunosuppressive Effects Of Triclosan, Nonylphenol, And Ddt On Human Natural Killer Cells In Vitro, Felicia Udoji, Tamara Martin, Rachel Etherton, Margaret M. Whalen
Immunosuppressive Effects Of Triclosan, Nonylphenol, And Ddt On Human Natural Killer Cells In Vitro, Felicia Udoji, Tamara Martin, Rachel Etherton, Margaret M. Whalen
Chemistry Faculty Research
Human natural killer (NK) cells are a first-line immune defense against tumor cells and virally-infected cells. If their function is impaired, it leaves an individual more susceptible to cancer development or viral infection. The ability of compounds that contaminate the environment to suppress the function of NK cells could contribute to the increased risk of cancer development. There are a wide spectrum of compounds that significantly contaminate water and food that are consumed by humans, leading to accumulation of some of these compounds in human tissues. In the current study, we examined the ability of three such compounds to diminish …
Activation Of P44/42 Mapk Plays A Role In The Tbt-Induced Loss Of Human Natural Killer (Nk) Cell Function, Fred D. Dudimah, Denisha Griffey, Xiaofei Wang, Margaret M. Whalen
Activation Of P44/42 Mapk Plays A Role In The Tbt-Induced Loss Of Human Natural Killer (Nk) Cell Function, Fred D. Dudimah, Denisha Griffey, Xiaofei Wang, Margaret M. Whalen
Chemistry Faculty Research
Natural killer (NK) cells destroy (lyse) tumor cells, virally infected cells, and antibody-coated cells. Previous studies indicated that exposure to the environmental contaminant tributyltin (TBT) decreases the lytic function of NK cells and activates mitogen-activated protein kinases (MAPK), including p44/42 (Aluoch and Whalen Toxicology 209:263–277, 2005). If activation of p44/42 is required for TBT-induced decreases of lytic function, then activation of p44/42 to similar extents by pharmacological agents such as phorbol 12-myristate 13-acetate (PMA) should mimic to some extent changes induced in NK cells with TBT exposures. NK cells were exposed to PMA concentrations between 0.25 and 10 nM for …
Hexabromocyclododecane Decreases Tumor-Cell-Binding Capacity And Cell-Surface Protein Expression Of Human Natural Killer Cells, Natasha C. Hinkson, Margaret M. Whalen
Hexabromocyclododecane Decreases Tumor-Cell-Binding Capacity And Cell-Surface Protein Expression Of Human Natural Killer Cells, Natasha C. Hinkson, Margaret M. Whalen
Chemistry Faculty Research
Hexabromocyclododecane (HBCD) is a flame retardant that decreases the lytic function of human natural killer (NK) cells. NK cells defend against tumor cells and virally infected cells. Thus, HBCD has the potential to increase cancer incidence and viral infections. NK cells must bind to their targets for lysis to occur. Thus, concentrations of HBCD that decrease lytic function were examined for their ability to alter NK binding to tumor targets. Levels of HBCD that caused a loss of binding function were examined for effects on expression of cell surface proteins needed for binding. NK cells exposed to HBCD for 24 …
Tetrabromobisphenol A Has Immunosuppressive Effects On Human Natural Killer Cells, Esther Caroline Kibakaya, Krishna Stephen, Margaret M. Whalen
Tetrabromobisphenol A Has Immunosuppressive Effects On Human Natural Killer Cells, Esther Caroline Kibakaya, Krishna Stephen, Margaret M. Whalen
Chemistry Faculty Research
Human natural killer (NK) cells are lymphocytes that destroy tumor cells, virally-infected cells, and antibody-coated cells. Tetrabromobisphenol A (TBBPA) is used both as a reactive and as an additive flame retardant in a variety of materials and appears to contaminate the environment. TBBPA has been found in human blood samples and if it interferes with NK cell function, this could increase the risk of tumor development and/or viral infection. The present study examines the effects of exposure to various concentrations of TBBPA for 24 hr, 48 hr, and 6 days on the lytic function, tumor-target-binding function, and ATP levels of …
Hexabromocyclododecane Decreases The Lytic Function And Atp Levels Of Human Natural Killer Cells, Natasha C. Hinkson, Margaret M. Whalen
Hexabromocyclododecane Decreases The Lytic Function And Atp Levels Of Human Natural Killer Cells, Natasha C. Hinkson, Margaret M. Whalen
Chemistry Faculty Research
This study investigates the effect of hexabromocyclododecane (HBCD) on the lytic function of human natural killer (NK) cells and on ATP levels in NK cells. NK cells are capable of lysing tumor cells, virally infected cells, and antibody-coated cells. HBCD is a brominated cyclic alkane used primarily as an additive flame retardant. If HBCD interferes with NK cell function, this could increase risk of tumor development and/or viral infection. NK cells were exposed to various concentrations of HBCD for 24 and 48 h and 6 days before determining lytic function and ATP levels. ATP levels and lytic function were also …
Increases In Cytosolic Calcium Ion Levels In Human Natural Killer Cells In Response To Butyltin Exposure, Rhonda Lane, Sabah O. Ghazi, Margaret M. Whalen
Increases In Cytosolic Calcium Ion Levels In Human Natural Killer Cells In Response To Butyltin Exposure, Rhonda Lane, Sabah O. Ghazi, Margaret M. Whalen
Chemistry Faculty Research
This study investigated whether exposures to butyltins (BTs), tributylin (TBT), and dibutyltin (DBT) were able to alter cytosolic calcium levels in human natural killer (NK) cells. Additionally, the effects of cytosolic calcium ion increases on the activation state of mitogen-activated protein kinases (MAPKs) in NK cells were also investigated. NK cells are an intital immune defense against the development of tumors or viral infections. TBT and DBT are widespread environmental contaminants, due to their various industrial applications. Both TBT and DBT have been shown to decrease the ability of NK cells to lyse tumor cells (lytic function). TBT has also …
Glutathione Diminishes Tributyltin- And Dibutyltin-Induced Loss Of Lytic Function In Human Natural Killer Cells, Jeralyn J. Powell, Mclisa V. Davis, Margaret M. Whalen
Glutathione Diminishes Tributyltin- And Dibutyltin-Induced Loss Of Lytic Function In Human Natural Killer Cells, Jeralyn J. Powell, Mclisa V. Davis, Margaret M. Whalen
Chemistry Faculty Research
This study investigated whether reduced glutathione (GSH) was able to alter the negative effects of tributyltin (TBT) or dibutyltin (DBT) on the lytic function of human natural killer (NK) cells. NK cells are an initial immune defense against the development of tumors or viral infections. TBT and DBT are widespread environmental contaminants, due to their various industrial applications. Both TBT and DBT have been shown to decrease the ability of NK cells to lyse tumor cells (lytic function). The results indicated that the presence of GSH during the exposure of NK cells to TBT or DBT diminished the negative effect …
The Role Of P44/42 Activation In Tributyltin-Induced Inhibition Of Human Natural Killer Cells: Effects Of Mek Inhibitors, Abraham B. Abraha, Margaret M. Whalen
The Role Of P44/42 Activation In Tributyltin-Induced Inhibition Of Human Natural Killer Cells: Effects Of Mek Inhibitors, Abraham B. Abraha, Margaret M. Whalen
Chemistry Faculty Research
Destruction of tumor cells is a key function of natural killer (NK) cells. Previous studies have shown that tributyltin (TBT) can significantly reduce the lytic function of the human NK cells with accompanying increases in the phosphorylation (activation) states of the mitogen activated protein kinases (MAPKs), p44/42. The current studies examine the role of p44/42 activation in the TBT-induced reduction of NK-lytic function, by using MAPK kinase (MEK) inhibitors, PD98059 and U0126. A 1 h treatment with PD98059 or U0126 or both decreased the ability of NK cells to lyse K562 tumor cells. PD98059, U0126 or a combination of both …
Effects Of Ziram On Tumor-Cell-Binding Capacity, Cell-Surface Marker Expression, And Atp Levels Of Human Natural Killer Cells, Thyneice R. Taylor, Margaret M. Whalen
Effects Of Ziram On Tumor-Cell-Binding Capacity, Cell-Surface Marker Expression, And Atp Levels Of Human Natural Killer Cells, Thyneice R. Taylor, Margaret M. Whalen
Chemistry Faculty Research
Human natural killer (NK) cells are central in immune defense against tumor and virally infected cells. Ziram is used as an accelerating agent in latex production and as an agricultural fungicide. Previous studies showed that continuous exposure to ziram inhibits NK lytic function. Additionally, they showed that a brief (1 h) exposure to ziram caused persistent loss of lytic function. This study examined whether decreases in lytic function were accompanied by decreases in the target-binding function of NK cells and found that some, but not all, exposures to ziram caused significant decreases in binding function. Ziram exposures that caused a …
Pentachlorophenol Decreases Atp Levels In Human Natural Killer Cells, Ugochukwu Nnodu, Margaret M. Whalen
Pentachlorophenol Decreases Atp Levels In Human Natural Killer Cells, Ugochukwu Nnodu, Margaret M. Whalen
Chemistry Faculty Research
Pentachlorophenol (PCP) is used as a wood preservative and is found in human blood and urine. PCP causes significant decreases in the tumor-killing (lytic) function of human natural killer (NK) cells, a critical immune defense. The current study examined the association between decreased lytic function and decreased ATP levels, as well as the ability of antioxidants (vitamin E and reduced glutathione) to prevent PCP-induced decreases in either ATP levels or lytic function. Exposure of NK cells to 10 µm PCP decreased ATP levels by 15% at 24 h, and exposure to 5 µm PCP decreased ATP levels by 32% at …
Effects Of A Series Of Triorganotins On Atp Levels In Human Natural Killer Cells, Laurin N. Holloway, Keith H. Pannell, Margaret M. Whalen
Effects Of A Series Of Triorganotins On Atp Levels In Human Natural Killer Cells, Laurin N. Holloway, Keith H. Pannell, Margaret M. Whalen
Chemistry Faculty Research
Natural killer (NK) cells are our initial immune defense against viral infections and cancer development. Thus, agents that are able to interfere with their function increase the risk of cancer and/or infection. A series of triorganotins (trimethyltin (TMT), dimethylphenyltin (DMPT), methyldiphenyltin (MDPT), and triphenyltin (TPT)) have been shown to decrease the lytic function of human NK cells. TPT and MDPT were much more effective than DMPT or TMT at reducing lytic function. This study investigates the role that decreased ATP levels may play in decreases in the lytic function of NK cells induced by these organotins (OTs). A 24h exposure …
Cadmium Toxicity On Arterioles Vascular Smooth Muscle Cells Of Spontaneously Hypertensive Rats, Benny Washington, Shunta Williams, Patrice Armstrong, Charlie Mtshali, John T. Robinson, Elbert L. Myles
Cadmium Toxicity On Arterioles Vascular Smooth Muscle Cells Of Spontaneously Hypertensive Rats, Benny Washington, Shunta Williams, Patrice Armstrong, Charlie Mtshali, John T. Robinson, Elbert L. Myles
Biology Faculty Research
Cadmium (Cd) is frequently used in various industrial applications and is a ubiquitous environmental toxicant, also present in tobacco smoke. An important route of exposure is the circulatory system whereas blood vessels are considered to be main stream organs of Cd toxicity. Our previous results indicate that cadmium chloride (CdCl2) affects mean arterial blood pressure in hypertensive rats. We hypothesized that Cd alters the intracellular calcium transient mechanism, by cadmium-induced stimulation of MAPKs (ERK 1 & 2) which is mediated partially through calcium-dependent PKC mechanism. To investigate this hypothesis, we exposed primary cultures of vascular smooth muscle cells (VSMCs) from …