TY  - JOUR
A1  - Rauschenberger, Tabea
A1  - Schmitt, Viola
A1  - Azeem, Muhammad
A1  - Klein-Hessling, Stefan
A1  - Murti, Krisna
A1  - Grän, Franziska
A1  - Goebeler, Matthias
A1  - Kerstan, Andreas
A1  - Klein, Matthias
A1  - Bopp, Tobias
A1  - Serfling, Edgar
A1  - Muhammad, Khalid
T1  - T cells control chemokine secretion by keratinocytes
JF  - Frontiers in Immunology
N2  - The massive infiltration of lymphocytes into the skin is a hallmark of numerous human skin disorders. By co-culturing murine keratinocytes with splenic T cells we demonstrate here that T cells affect and control the synthesis and secretion of chemokines by keratinocytes. While pre-activated CD8\(^+\)T cells induce the synthesis of CXCL9 and CXCL10 in keratinocytes and keep in check the synthesis of CXCL1, CXCL5, and CCL20, keratinocytes dampen the synthesis of CCL3 and CCL4 in pre-activated CD8\(^+\)T cells. One key molecule is IFN-γ that is synthesized by CD8\(^+\)T cells under the control of NFATc1 and NFATc2. CD8\(^+\)T cells deficient for both NFAT factors are unable to induce CXCL9 and CXCL10 expression. In addition, CD8\(^+\)T cells induced numerous type I IFN-inducible “defense genes” in keratinocytes encoding the PD1 and CD40 ligands, TNF-α and caspase-1. The enhanced expression of type I IFN-inducible genes resembles the gene expression pattern at the dermal/epidermal interface in lichen planus, an inflammatory T lymphocyte-driven skin disease, in which we detected the expression of CXCL10 in keratinocytes in close vicinity to the infiltration front of T cells. These data reflect the multifaceted interplay of lymphocytes with keratinocytes at the molecular level.
KW  - chemokine
KW  - keratinocytes
KW  - IFN
KW  - lichen planus
KW  - T cells
KW  - Nfatc1
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195695
SN  - 1664-3224
VL  - 10
IS  - 1917
ER  - 
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  - Baur, Johannes
A1  - Otto, Christoph
A1  - Steger, Ulrich
A1  - Klein-Hessling, Stefan
A1  - Muhammad, Khalid
A1  - Pusch, Tobias
A1  - Murti, Krisna
A1  - Wismer, Rhoda
A1  - Germer, Christoph-Thomas
A1  - Klein, Ingo
A1  - Müller, Nora
A1  - Serfling, Edgar
A1  - Avots, Andris
T1  - The transcription factor NFaTc1 supports the rejection of heterotopic heart allografts
JF  - Frontiers in Immunology
N2  - The immune suppressants cyclosporin A (CsA) and tacrolimus (FK506) are used worldwide in transplantation medicine to suppress graft rejection. Both CsA and FK506 inhibit the phosphatase calcineurin (CN) whose activity controls the immune receptor-mediated activation of lymphocytes. Downstream targets of CN in lymphocytes are the nuclear factors of activated T cells (NFATs). We show here that the activity of NFATc1, the most prominent NFAT factor in activated lymphocytes supports the acute rejection of heterotopic heart allografts. While ablation of NFATc1 in T cells prevented graft rejection, ectopic expression of inducible NFATc1/αA isoform led to rejection of heart allografts in recipient mice. Acceptance of transplanted hearts in mice bearing NFATc1-deficient T cells was accompanied by a reduction in number and cytotoxicity of graft infiltrating cells. In CD8\(^+\) T cells, NFATc1 controls numerous intracellular signaling pathways that lead to the metabolic switch to aerobic glycolysis and the expression of numerous lymphokines, chemokines, and their receptors, including Cxcr3 that supports the rejection of allogeneic heart transplants. These findings favors NFATc1 as a molecular target for the development of new strategies to control the cytotoxicity of T cells upon organ transplantation.
KW  - NFATc1
KW  - transplantation
KW  - heterologous
KW  - CD8+ T cells
KW  - ChIPseq
KW  - metabolism
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-221530
VL  - 9
ER  -