@article{SerflingRudolfBuschetal.2014, author = {Serfling, Edgar and Rudolf, Ronald and Busch, Rhoda and Patra, Amiya K. and Muhammad, Khalid and Avots, Andris and Andrau, Jean-Christophe and Klein-Hessling, Stefan}, title = {Architecture and expression of the Nfatc1 gene in lymphocytes}, doi = {10.3389/fimmu.2014.00021}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112718}, year = {2014}, abstract = {In lymphocytes, the three NFAT factors NFATc1 (also designated as NFAT2), NFATc2 (NFAT1), and NFATc3 (NFAT4 or NFATx) are expressed and are the targets of immune receptor signals, which lead to a rapid rise of intracellular Ca++, the activation of phosphatase calcineurin, and to the activation of cytosolic NFATc proteins. In addition to rapid activation of NFAT factors, immune receptor signals lead to accumulation of the short NFATc1/αA isoform in lymphocytes which controls their proliferation and survival. In this mini-review, we summarize our current knowledge on the structure and transcription of the Nfatc1 gene in lymphocytes, which is controlled by two promoters, two poly A addition sites and a remote downstream enhancer. The Nfatc1 gene resembles numerous primary response genes (PRGs) induced by LPS in macrophages. Similar to the PRG promoters, the Nfatc1 promoter region is organized in CpG islands, forms DNase I hypersensitive sites, and is marked by histone tail modifications before induction. By studying gene induction in lymphocytes in detail, it will be important to elucidate whether the properties of the Nfatc1 induction are not only typical for the Nfatc1 gene but also for other transcription factor genes expressed in lymphocytes.}, language = {en} } @article{KleinHesslingMuhammadKleinetal.2017, author = {Klein-Hessling, Stefan and Muhammad, Khalid and Klein, Matthias and Pusch, Tobias and Rudolf, Ronald and Fl{\"o}ter, Jessica and Qureischi, Musga and Beilhack, Andreas and Vaeth, Martin and Kummerow, Carsten and Backes, Christian and Schoppmeyer, Rouven and Hahn, Ulrike and Hoth, Markus and Bopp, Tobias and Berberich-Siebelt, Friederike and Patra, Amiya and Avots, Andris and M{\"u}ller, Nora and Schulze, Almut and Serfling, Edgar}, title = {NFATc1 controls the cytotoxicity of CD8\(^{+}\) T cells}, series = {Nature Communications}, volume = {8}, journal = {Nature Communications}, number = {511}, doi = {10.1038/s41467-017-00612-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170353}, year = {2017}, abstract = {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.}, language = {en} } @article{KleinHesslingRudolfMuhammadetal.2016, author = {Klein-Hessling, Stefan and Rudolf, Ronald and Muhammad, Khalid and Knobeloch, Klaus-Peter and Maqbool, Muhammad Ahmad and Cauchy, Pierre and Andrau, Jean-Christophe and Avots, Andris and Talora, Claudio and Ellenrieder, Volker and Screpanti, Isabella and Serfling, Edgar and Patra, Amiya Kumar}, title = {A threshold level of NFATc1 activity facilitates thymocyte differentiation and opposes notch-driven leukaemia development}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, doi = {10.1038/ncomms11841}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172974}, year = {2016}, abstract = {NFATc1 plays a critical role in double-negative thymocyte survival and differentiation. However, the signals that regulate Nfatc1 expression are incompletely characterized. Here we show a developmental stage-specific differential expression pattern of Nfatc1 driven by the distal (P1) or proximal (P2) promoters in thymocytes. Whereas, preTCR-negative thymocytes exhibit only P2 promoter-derived Nfatc1β expression, preTCR-positive thymocytes express both Nfatc1β and P1 promoter-derived Nfatc1α transcripts. Inducing NFATc1α activity from P1 promoter in preTCR-negative thymocytes, in addition to the NFATc1β from P2 promoter impairs thymocyte development resulting in severe T-cell lymphopenia. In addition, we show that NFATc1 activity suppresses the B-lineage potential of immature thymocytes, and consolidates their differentiation to T cells. Further, in the pTCR-positive DN3 cells, a threshold level of NFATc1 activity is vital in facilitating T-cell differentiation and to prevent Notch3-induced T-acute lymphoblastic leukaemia. Altogether, our results show NFATc1 activity is crucial in determining the T-cell fate of thymocytes.}, language = {en} } @article{AlrefaiMuhammadRudolfetal.2016, author = {Alrefai, Hani and Muhammad, Khalid and Rudolf, Ronald and Pham, Duong Anh Thuy and Klein-Hessling, Stefan and Patra, Amiya K. and Avots, Andris and Bukur, Valesca and Sahin,, Ugur and Tenzer, Stefan and Goebeler, Matthias and Kerstan, Andreas and Serfling, Edgar}, title = {NFATc1 supports imiquimod-induced skin inflammation by suppressing IL-10 synthesis in B cells}, series = {Nature Communications}, volume = {7}, journal = {Nature Communications}, doi = {10.1038/ncomms11724}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173053}, year = {2016}, abstract = {Epicutaneous application of Aldara cream containing the TLR7 agonist imiquimod (IMQ) to mice induces skin inflammation that exhibits many aspects of psoriasis, an inflammatory human skin disease. Here we show that mice depleted of B cells or bearing interleukin (IL)-10-deficient B cells show a fulminant inflammation upon IMQ exposure, whereas ablation of NFATc1 in B cells results in a suppression of Aldara-induced inflammation. In vitro, IMQ induces the proliferation and IL-10 expression by B cells that is blocked by BCR signals inducing NFATc1. By binding to HDAC1, a transcriptional repressor, and to an intronic site of the Il10 gene, NFATc1 suppresses IL-10 expression that dampens the production of tumour necrosis factor-α and IL-17 by T cells. These data indicate a close link between NFATc1 and IL-10 expression in B cells and suggest NFATc1 and, in particular, its inducible short isoform, NFATc1/αA, as a potential target to treat human psoriasis.}, language = {en} } @article{BarahonadeBritoKleinHesslingSerflingetal.2022, author = {Barahona de Brito, Carlotta and Klein-Hessling, Stefan and Serfling, Edgar and Patra, Amiya Kumar}, title = {Hematopoietic stem and progenitor cell maintenance and multiple lineage differentiation is an integral function of NFATc1}, series = {Cells}, volume = {11}, journal = {Cells}, number = {13}, issn = {2073-4409}, doi = {10.3390/cells11132012}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-278809}, year = {2022}, abstract = {Hematopoietic stem and progenitor cell (HSPC) maintenance and the differentiation of various lineages is a highly complex but precisely regulated process. Multiple signaling pathways and an array of transcription factors influence HSPC maintenance and the differentiation of individual lineages to constitute a functional hematopoietic system. Nuclear factor of activated T cell (NFAT) family transcription factors have been studied in the context of development and function of multiple mature hematopoietic lineage cells. However, until now their contribution in HSPC physiology and HSPC differentiation to multiple hematopoietic lineages has remained poorly understood. Here, we show that NFAT proteins, specifically NFATc1, play an indispensable role in the maintenance of HSPCs. In the absence of NFATc1, very few HSPCs develop in the bone marrow, which are functionally defective. In addition to HSPC maintenance, NFATc1 also critically regulates differentiation of lymphoid, myeloid, and erythroid lineage cells from HSPCs. Deficiency of NFATc1 strongly impaired, while enhanced NFATc1 activity augmented, the differentiation of these lineages, which further attested to the vital involvement of NFATc1 in regulating hematopoiesis. Hematopoietic defects due to lack of NFATc1 activity can lead to severe pathologies such as lymphopenia, myelopenia, and a drastically reduced lifespan underlining the critical role NFATc1 plays in HSPC maintenance and in the differentaion of various lineages. Our findings suggest that NFATc1 is a critical component of the myriad signaling and transcriptional regulators that are essential to maintain normal hematopoiesis.}, language = {en} }