TY - JOUR A1 - Murti, Krisna A1 - Fender, Hendrik A1 - Glatzle, Carolin A1 - Wismer, Rhoda A1 - Sampere-Birlanga, Salvador A1 - Wild, Vanessa A1 - Muhammad, Khalid A1 - Rosenwald, Andreas A1 - Serfling, Edgar A1 - Avots, Andris T1 - Calcineurin-independent NFATc1 signaling is essential for survival of Burkitt lymphoma cells JF - Frontiers in Oncology N2 - In Burkitt lymphoma (BL), a tumor of germinal center B cells, the pro-apoptotic properties of MYC are controlled by tonic B cell receptor (BCR) signals. Since BL cells do not exhibit constitutive NF-κB activity, we hypothesized that anti-apoptotic NFATc1 proteins provide a major transcriptional survival signal in BL. Here we show that post-transcriptional mechanisms are responsible for the calcineurin (CN) independent constitutive nuclear over-expression of NFATc1 in BL and Eµ-MYC – induced B cell lymphomas (BCL). Conditional inactivation of the Nfatc1 gene in B cells of Eµ-MYC mice leads to apoptosis of BCL cells in vivo and ex vivo. Inhibition of BCR/SYK/BTK/PI3K signals in BL cells results in cytosolic re-location of NFATc1 and apoptosis. Therefore, NFATc1 activity is an integrated part of tonic BCR signaling and an alternative target for therapeutic intervention in BL. KW - apoptosis KW - Burkitt lymphoma KW - cyclosporin A KW - nuclear localization KW - NFATc1 KW - activated B cell-like diffuse large B-cell lymphoma (ABC-DLBCL) KW - B cell receptor (BCR) KW - Burkitt lymphoma (BL) Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-323103 VL - 13 ER - TY - JOUR A1 - Klein-Hessling, Stefan A1 - Muhammad, Khalid A1 - Klein, Matthias A1 - Pusch, Tobias A1 - Rudolf, Ronald A1 - Flöter, Jessica A1 - Qureischi, Musga A1 - Beilhack, Andreas A1 - Vaeth, Martin A1 - Kummerow, Carsten A1 - Backes, Christian A1 - Schoppmeyer, Rouven A1 - Hahn, Ulrike A1 - Hoth, Markus A1 - Bopp, Tobias A1 - Berberich-Siebelt, Friederike A1 - Patra, Amiya A1 - Avots, Andris A1 - Müller, Nora A1 - Schulze, Almut A1 - Serfling, Edgar T1 - NFATc1 controls the cytotoxicity of CD8\(^{+}\) T cells JF - Nature Communications N2 - Cytotoxic T lymphocytes are effector CD8\(^{+}\) T cells that eradicate infected and malignant cells. Here we show that the transcription factor NFATc1 controls the cytotoxicity of mouse cytotoxic T lymphocytes. Activation of Nfatc1\(^{-/-}\) cytotoxic T lymphocytes showed a defective cytoskeleton organization and recruitment of cytosolic organelles to immunological synapses. These cells have reduced cytotoxicity against tumor cells, and mice with NFATc1-deficient T cells are defective in controlling Listeria infection. Transcriptome analysis shows diminished RNA levels of numerous genes in Nfatc1\(^{-/-}\) CD8\(^{+}\) T cells, including Tbx21, Gzmb and genes encoding cytokines and chemokines, and genes controlling glycolysis. Nfatc1\(^{-/-}\), but not Nfatc2\(^{-/-}\) CD8\(^{+}\) T cells have an impaired metabolic switch to glycolysis, which can be restored by IL-2. Genome-wide ChIP-seq shows that NFATc1 binds many genes that control cytotoxic T lymphocyte activity. Together these data indicate that NFATc1 is an important regulator of cytotoxic T lymphocyte effector functions. KW - cytotoxic T cells KW - lymphocyte activation KW - signal transduction KW - gene regulation KW - immune cells KW - NFATc1 Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170353 VL - 8 IS - 511 ER -