Thioredoxin expression is reduced at the plasma membrane of CD4+ T-cells in mid-life adults compared to young adults

C.R. Dunston, S.J. Bennett, H.R. Griffiths

Research output: Contribution to journalMeeting abstract

Abstract

Thioredoxin is a 2-cys oxidoreductase enzyme involved in maintaining cellular redox state. A number of human thioredoxin isoforms have been described; Trx1 is located in the cytoplasm, on the exofacial surface and as a secreted protein whereas Trx2 is located in the mitochondria. Secreted Trx1 has previously been implicated in T-cell signaling. As T-cell regulation declines with age we have investigated the age effects on T-cell Trx1. In the present study, we demonstrate an increase in Trx1 expression (p=0.0317; n=9) on total lymphocytes from healthy mid-life adults (age, 50-78) when compared to young adults (age, 25-30), however, a decrease in the level of Trx1 (p=0.0024) on the cell surface of CD4+ T-cells was observed. To further investigate the mechanisms underpinning the age-related decrease in cell surface Trx1, Jurkat T-cell line was treated with or without the addition of buthionine sulfoximine (BSO) to modulate intracellular GSH levels. BSO reduced cellular GSH content in a dose dependent manner with a 50% decrease after 25μ M BSO for 24 hours. BSO treatment is also associated with an increase in Trx1 expression (1.5-fold increase) as measured by western blot analysis. However, with a selective pull-down of cell surface proteins we observed a decrease in thioredoxin expression (3-fold decrease) at the plasma membrane. Furthermore, BSO treatment decreased mitogenic activation of Jurkats as measured by PHA-induced interleukin-2 secretion. These data suggest that in response to GSH depletion Jurkat T-cells increase cellular levels of Trx1 and alter subcellular localization resulting in decreased surface expression of Trx1. This may reflect adaptation by retention of thioredoxin in the cytoplasm to maintain intracellular protein integrity. Redox homeostasis within the immune synapse is vital for efficient antigen mediated T-cell activation; the impact of decreased expression of thioredoxin with age is currently unclear but it could impact on T-cell function.
Original languageEnglish
Article number0570
Pages (from-to)S82-S83
Number of pages2
JournalFree Radical Biology and Medicine
Volume53
Issue numberSupplement 1
DOIs
Publication statusPublished - Sep 2012
EventSociety for Free Radical Research International 16th Biennial Meeting - Imperial College London, London, United Kingdom
Duration: 6 Sep 20129 Sep 2012

Fingerprint

Thioredoxins
T-cells
Cell membranes
Buthionine Sulfoximine
Young Adult
Cell Membrane
T-Lymphocytes
Jurkat Cells
Oxidation-Reduction
Cytoplasm
CD27 Antigens
Chemical activation
Cell signaling
Mitochondria
Lymphocytes
Synapses
Interleukin-2
Oxidoreductases
Protein Isoforms
Membrane Proteins

Cite this

Dunston, C.R. ; Bennett, S.J. ; Griffiths, H.R. / Thioredoxin expression is reduced at the plasma membrane of CD4+ T-cells in mid-life adults compared to young adults. In: Free Radical Biology and Medicine. 2012 ; Vol. 53, No. Supplement 1. pp. S82-S83.
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abstract = "Thioredoxin is a 2-cys oxidoreductase enzyme involved in maintaining cellular redox state. A number of human thioredoxin isoforms have been described; Trx1 is located in the cytoplasm, on the exofacial surface and as a secreted protein whereas Trx2 is located in the mitochondria. Secreted Trx1 has previously been implicated in T-cell signaling. As T-cell regulation declines with age we have investigated the age effects on T-cell Trx1. In the present study, we demonstrate an increase in Trx1 expression (p=0.0317; n=9) on total lymphocytes from healthy mid-life adults (age, 50-78) when compared to young adults (age, 25-30), however, a decrease in the level of Trx1 (p=0.0024) on the cell surface of CD4+ T-cells was observed. To further investigate the mechanisms underpinning the age-related decrease in cell surface Trx1, Jurkat T-cell line was treated with or without the addition of buthionine sulfoximine (BSO) to modulate intracellular GSH levels. BSO reduced cellular GSH content in a dose dependent manner with a 50{\%} decrease after 25μ M BSO for 24 hours. BSO treatment is also associated with an increase in Trx1 expression (1.5-fold increase) as measured by western blot analysis. However, with a selective pull-down of cell surface proteins we observed a decrease in thioredoxin expression (3-fold decrease) at the plasma membrane. Furthermore, BSO treatment decreased mitogenic activation of Jurkats as measured by PHA-induced interleukin-2 secretion. These data suggest that in response to GSH depletion Jurkat T-cells increase cellular levels of Trx1 and alter subcellular localization resulting in decreased surface expression of Trx1. This may reflect adaptation by retention of thioredoxin in the cytoplasm to maintain intracellular protein integrity. Redox homeostasis within the immune synapse is vital for efficient antigen mediated T-cell activation; the impact of decreased expression of thioredoxin with age is currently unclear but it could impact on T-cell function.",
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Thioredoxin expression is reduced at the plasma membrane of CD4+ T-cells in mid-life adults compared to young adults. / Dunston, C.R.; Bennett, S.J.; Griffiths, H.R.

In: Free Radical Biology and Medicine, Vol. 53, No. Supplement 1, 0570, 09.2012, p. S82-S83.

Research output: Contribution to journalMeeting abstract

TY - JOUR

T1 - Thioredoxin expression is reduced at the plasma membrane of CD4+ T-cells in mid-life adults compared to young adults

AU - Dunston, C.R.

AU - Bennett, S.J.

AU - Griffiths, H.R.

PY - 2012/9

Y1 - 2012/9

N2 - Thioredoxin is a 2-cys oxidoreductase enzyme involved in maintaining cellular redox state. A number of human thioredoxin isoforms have been described; Trx1 is located in the cytoplasm, on the exofacial surface and as a secreted protein whereas Trx2 is located in the mitochondria. Secreted Trx1 has previously been implicated in T-cell signaling. As T-cell regulation declines with age we have investigated the age effects on T-cell Trx1. In the present study, we demonstrate an increase in Trx1 expression (p=0.0317; n=9) on total lymphocytes from healthy mid-life adults (age, 50-78) when compared to young adults (age, 25-30), however, a decrease in the level of Trx1 (p=0.0024) on the cell surface of CD4+ T-cells was observed. To further investigate the mechanisms underpinning the age-related decrease in cell surface Trx1, Jurkat T-cell line was treated with or without the addition of buthionine sulfoximine (BSO) to modulate intracellular GSH levels. BSO reduced cellular GSH content in a dose dependent manner with a 50% decrease after 25μ M BSO for 24 hours. BSO treatment is also associated with an increase in Trx1 expression (1.5-fold increase) as measured by western blot analysis. However, with a selective pull-down of cell surface proteins we observed a decrease in thioredoxin expression (3-fold decrease) at the plasma membrane. Furthermore, BSO treatment decreased mitogenic activation of Jurkats as measured by PHA-induced interleukin-2 secretion. These data suggest that in response to GSH depletion Jurkat T-cells increase cellular levels of Trx1 and alter subcellular localization resulting in decreased surface expression of Trx1. This may reflect adaptation by retention of thioredoxin in the cytoplasm to maintain intracellular protein integrity. Redox homeostasis within the immune synapse is vital for efficient antigen mediated T-cell activation; the impact of decreased expression of thioredoxin with age is currently unclear but it could impact on T-cell function.

AB - Thioredoxin is a 2-cys oxidoreductase enzyme involved in maintaining cellular redox state. A number of human thioredoxin isoforms have been described; Trx1 is located in the cytoplasm, on the exofacial surface and as a secreted protein whereas Trx2 is located in the mitochondria. Secreted Trx1 has previously been implicated in T-cell signaling. As T-cell regulation declines with age we have investigated the age effects on T-cell Trx1. In the present study, we demonstrate an increase in Trx1 expression (p=0.0317; n=9) on total lymphocytes from healthy mid-life adults (age, 50-78) when compared to young adults (age, 25-30), however, a decrease in the level of Trx1 (p=0.0024) on the cell surface of CD4+ T-cells was observed. To further investigate the mechanisms underpinning the age-related decrease in cell surface Trx1, Jurkat T-cell line was treated with or without the addition of buthionine sulfoximine (BSO) to modulate intracellular GSH levels. BSO reduced cellular GSH content in a dose dependent manner with a 50% decrease after 25μ M BSO for 24 hours. BSO treatment is also associated with an increase in Trx1 expression (1.5-fold increase) as measured by western blot analysis. However, with a selective pull-down of cell surface proteins we observed a decrease in thioredoxin expression (3-fold decrease) at the plasma membrane. Furthermore, BSO treatment decreased mitogenic activation of Jurkats as measured by PHA-induced interleukin-2 secretion. These data suggest that in response to GSH depletion Jurkat T-cells increase cellular levels of Trx1 and alter subcellular localization resulting in decreased surface expression of Trx1. This may reflect adaptation by retention of thioredoxin in the cytoplasm to maintain intracellular protein integrity. Redox homeostasis within the immune synapse is vital for efficient antigen mediated T-cell activation; the impact of decreased expression of thioredoxin with age is currently unclear but it could impact on T-cell function.

U2 - 10.1016/j.freeradbiomed.2012.08.172

DO - 10.1016/j.freeradbiomed.2012.08.172

M3 - Meeting abstract

VL - 53

SP - S82-S83

JO - Free Radical Biology and Medicine

JF - Free Radical Biology and Medicine

SN - 0891-5849

IS - Supplement 1

M1 - 0570

ER -