TY  - JOUR
A1  - Muhammad, Khalid
A1  - Rudolf, Ronald
A1  - Pham, Duong Anh Thuy
A1  - Klein-Hessling, Stefan
A1  - Takata, Katsuyoshi
A1  - Matsushita, Nobuko
A1  - Ellenrieder, Volker
A1  - Kondo, Eisaku
A1  -  Serfling, Edgar
T1  - Induction of Short NFATc1/αA Isoform Interferes with Peripheral B Cell Differentiation
JF  - Frontiers in Immunology
N2  - In lymphocytes, immune receptor signals induce the rapid nuclear translocation of preformed cytosolic NFAT proteins. Along with co-stimulatory signals, persistent immune receptor signals lead to high levels of NFATc1/αA, a short NFATc1 isoform, in effector lymphocytes. Whereas NFATc1 is not expressed in plasma cells, in germinal centers numerous centrocytic B cells express nuclear NFATc1/αA. When overexpressed in chicken DT40 B cells or murine WEHI 231 B cells, NFATc1/αA suppressed their cell death induced by B cell receptor signals and affected the expression of genes controlling the germinal center reaction and plasma cell formation. Among those is the Prdm1 gene encoding Blimp-1, a key factor of plasma cell formation. By binding to a regulatory DNA element within exon 1 of the Prdm1 gene, NFATc1/αA suppresses Blimp-1 expression. Since expression of a constitutive active version of NFATc1/αA interfered with Prdm1 RNA expression, LPS-mediated differentiation of splenic B cells to plasmablasts in vitro and reduced immunoglobulin production in vivo, one may conclude that NFATc1/αA plays an important role in controlling plasmablast/plasma cell formation.
KW  - B cells
KW  - DT40 cells
KW  - germinal center
KW  - NFATc1
KW  - plasmablasts
KW  - plasma cells
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-197501
SN  - 1664-3224
VL  - 9
IS  - 32
ER  - 
TY  - JOUR
A1  - Klein-Hessling, Stefan
A1  - Rudolf, Ronald
A1  - Muhammad, Khalid
A1  - Knobeloch, Klaus-Peter
A1  - Maqbool, Muhammad Ahmad
A1  - Cauchy, Pierre
A1  - Andrau, Jean-Christophe
A1  - Avots, Andris
A1  - Talora, Claudio
A1  - Ellenrieder, Volker
A1  - Screpanti, Isabella
A1  - Serfling, Edgar
A1  - Patra, Amiya Kumar
T1  - A threshold level of NFATc1 activity facilitates thymocyte differentiation and opposes notch-driven leukaemia development
JF  - Nature Communications
N2  - 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.
KW  - acute lymphocytic leukaemia
KW  - transcription factors
KW  - lymphocyte differentiation
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-172974
VL  - 7
ER  -