TY  - JOUR
A1  - Jost, Priska
A1  - Klein, Franziska
A1  - Brand, Benjamin
A1  - Wahl, Vanessa
A1  - Wyatt, Amanda
A1  - Yildiz, Daniela
A1  - Boehm, Ulrich
A1  - Niemeyer, Barbara A.
A1  - Vaeth, Martin
A1  - Alansary, Dalia
T1  - Acute downregulation but not genetic ablation of murine MCU impairs suppressive capacity of regulatory CD4 T cells
JF  - International Journal of Molecular Sciences
N2  - By virtue of mitochondrial control of energy production, reactive oxygen species (ROS) generation, and maintenance of Ca\(^{2+}\) homeostasis, mitochondria play an essential role in modulating T cell function. The mitochondrial Ca\(^{2+}\) uniporter (MCU) is the pore-forming unit in the main protein complex mediating mitochondrial Ca\(^{2+}\) uptake. Recently, MCU has been shown to modulate Ca\(^{2+}\) signals at subcellular organellar interfaces, thus fine-tuning NFAT translocation and T cell activation. The mechanisms underlying this modulation and whether MCU has additional T cell subpopulation-specific effects remain elusive. However, mice with germline or tissue-specific ablation of Mcu did not show impaired T cell responses in vitro or in vivo, indicating that ‘chronic’ loss of MCU can be functionally compensated in lymphocytes. The current work aimed to specifically investigate whether and how MCU influences the suppressive potential of regulatory CD4 T cells (Treg). We show that, in contrast to genetic ablation, acute siRNA-mediated downregulation of Mcu in murine Tregs results in a significant reduction both in mitochondrial Ca\(^{2+}\) uptake and in the suppressive capacity of Tregs, while the ratios of Treg subpopulations and the expression of hallmark transcription factors were not affected. These findings suggest that permanent genetic inactivation of MCU may result in compensatory adaptive mechanisms, masking the effects on the suppressive capacity of Tregs.
KW  - mitochondrial calcium uniporter
KW  - regulatory T cells
KW  - suppressive capacity
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313621
SN  - 1422-0067
VL  - 24
IS  - 9
ER  - 
TY  - JOUR
A1  - Wu, Hao
A1  - Zhao, Xiufeng
A1  - Hochrein, Sophia M.
A1  - Eckstein, Miriam
A1  - Gubert, Gabriela F.
A1  - Knöpper, Konrad
A1  - Mansilla, Ana Maria
A1  - Öner, Arman
A1  - Doucet-Ladevèze, Remi
A1  - Schmitz, Werner
A1  - Ghesquière, Bart
A1  - Theurich, Sebastian
A1  - Dudek, Jan
A1  - Gasteiger, Georg
A1  - Zernecke, Alma
A1  - Kobold, Sebastian
A1  - Kastenmüller, Wolfgang
A1  - Vaeth, Martin
T1  - Mitochondrial dysfunction promotes the transition of precursor to terminally exhausted T cells through HIF-1α-mediated glycolytic reprogramming
JF  - Nature Communications
N2  - T cell exhaustion is a hallmark of cancer and persistent infections, marked by inhibitory receptor upregulation, diminished cytokine secretion, and impaired cytolytic activity. Terminally exhausted T cells are steadily replenished by a precursor population (Tpex), but the metabolic principles governing Tpex maintenance and the regulatory circuits that control their exhaustion remain incompletely understood. Using a combination of gene-deficient mice, single-cell transcriptomics, and metabolomic analyses, we show that mitochondrial insufficiency is a cell-intrinsic trigger that initiates the functional exhaustion of T cells. At the molecular level, we find that mitochondrial dysfunction causes redox stress, which inhibits the proteasomal degradation of hypoxia-inducible factor 1α (HIF-1α) and promotes the transcriptional and metabolic reprogramming of Tpex cells into terminally exhausted T cells. Our findings also bear clinical significance, as metabolic engineering of chimeric antigen receptor (CAR) T cells is a promising strategy to enhance the stemness and functionality of Tpex cells for cancer immunotherapy.
KW  - cytotoxic T cells
KW  - infection
KW  - lymphocyte differentiation
KW  - translational research
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-358052
VL  - 14
ER  -