@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{GiampaoloWojcikKleinHesslingetal.2019, author = {Giampaolo, Sabrina and W{\´o}jcik, Gabriela and Klein-Hessling, Stefan and Serfling, Edgar and Patra, Amiya K.}, title = {B cell development is critically dependent on NFATc1 activity}, series = {Cellular \& Molecular Immunology}, volume = {16}, journal = {Cellular \& Molecular Immunology}, doi = {10.1038/s41423-018-0052-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233006}, pages = {508-520}, year = {2019}, abstract = {B cell development in bone marrow is a precisely regulated complex process. Through successive stages of differentiation, which are regulated by a multitude of signaling pathways and an array of lineage-specific transcription factors, the common lymphoid progenitors ultimately give rise to mature B cells. Similar to early thymocyte development in the thymus, early B cell development in bone marrow is critically dependent on IL-7 signaling. During this IL-7-dependent stage of differentiation, several transcription factors, such as E2A, EBF1, and Pax5, among others, play indispensable roles in B lineage specification and maintenance. Although recent studies have implicated several other transcription factors in B cell development, the role of NFATc1 in early B cell developmental stages is not known. Here, using multiple gene-manipulated mouse models and applying various experimental methods, we show that NFATc1 activity is vital for early B cell differentiation. Lack of NFATc1 activity in pro-B cells suppresses EBF1 expression, impairs immunoglobulin gene rearrangement, and thereby preBCR formation, resulting in defective B cell development. Overall, deficiency in NFATc1 activity arrested the pro-B cell transition to the pre-B cell stage, leading to severe B cell lymphopenia. Our findings suggest that, along with other transcription factors, NFATc1 is a critical component of the signaling mechanism that facilitates early B cell differentiation.}, language = {en} } @article{GiampaoloWojcikSerflingetal.2017, author = {Giampaolo, Sabrina and W{\´o}jcik, Gabriela and Serfling, Edgar and Patra, Amiya K.}, title = {Interleukin-2-regulatory T cell axis critically regulates maintenance of hematopoietic stem cells}, series = {Oncotarget}, volume = {8}, journal = {Oncotarget}, number = {18}, doi = {10.18632/oncotarget.16377}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170947}, pages = {29625-29642}, year = {2017}, abstract = {The role of IL-2 in HSC maintenance is unknown. Here we show that Il2\(^{-/-}\) mice develop severe anomalies in HSC maintenance leading to defective hematopoiesis. Whereas, lack of IL-2 signaling was detrimental for lympho- and erythropoiesis, myelopoiesis was enhanced in Il2\(^{-/-}\) mice. Investigation of the underlying mechanisms of dysregulated hematopoiesis in Il2\(^{-/-}\) mice shows that the IL-2-T\(_{reg}\) cell axis is indispensable for HSC maintenance and normal hematopoiesis. Lack of T\(_{reg}\) activity resulted in increased IFN-γ production by activated T cells and an expansion of the HSCs in the bone marrow (BM). Though, restoring T\(_{reg}\) population successfully rescued HSC maintenance in Il2\(^{-/-}\) mice, preventing IFN-γ activity could do the same even in the absence of T\(_{reg}\) cells. Our study suggests that equilibrium in IL-2 and IFN-γ activity is critical for steady state hematopoiesis, and in clinical conditions of BM failure, IL-2 or anti-IFN-γ treatment might help to restore hematopoiesis.}, 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} }