TY  - JOUR
A1  - Manukjan, Georgi
A1  - Ripperger, Tim
A1  - Venturini, Letizia
A1  - Stadler, Michael
A1  - Göhring, Gudrun
A1  - Schambach, Axel
A1  - Schlegelberger, Brigitte
A1  - Steinemann, Doris
T1  - GABP is necessary for stem/progenitor cell maintenance and myeloid differentiation in human hematopoiesis and chronic myeloid leukemia
JF  - Stem Cell Research
N2  - Maintenance of hematopoietic stem cells and their potential to give rise to progenitors of differentiated lymphoid and myeloid cells are accomplished by a network of regulatory processes. As a part of this network, the heteromeric transcription factor GA-binding protein (GABP) plays a crucial role in self-renewal of murine hematopoietic and leukemic stem cells. Here, we report the consequences of functional impairment of GABP in human hematopoietic and in leukemic stem/progenitor cells. Ectopic overexpression of a dominant-negative acting GABP mutant led to impaired myeloid differentiation of CD34\(^{+}\) hematopoietic stem/progenitor cells obtained from healthy donors. Moreover, drastically reduced clonogenic capacity of leukemic stem/progenitor cells isolated from bone marrow aspirates of chronic myeloid leukemia (CML) patients underlines the importance of GABP on stem/progenitor cell maintenance and confirms the relevance of GABP for human myelopoiesis in healthy and diseased states.
KW  - GABP
KW  - stem cells
KW  - human hematopoiesis
KW  - leukemia
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168165
VL  - 16
IS  - 3
ER  - 
TY  - JOUR
A1  - Berges, Carsten
A1  - Kerkau, Thomas
A1  - Werner, Sandra
A1  - Wolf, Nelli
A1  - Winter, Nadine
A1  - Hünig, Thomas
A1  - Einsele, Hermann
A1  - Topp, Max S.
A1  - Beyersdorf, Niklas
T1  - Hsp90 inhibition ameliorates CD4\(^{+}\) T cell-mediated acute Graft versus Host disease in mice
JF  - Immunity, Inflammation and Disease
N2  - Introduction:
For many patients with leukemia only allogeneic bone marrow transplantion provides a chance of cure. Co‐transplanted mature donor T cells mediate the desired Graft versus Tumor (GvT) effect required to destroy residual leukemic cells. The donor T cells very often, however, also attack healthy tissue of the patient inducing acute Graft versus Host Disease (aGvHD)—a potentially life‐threatening complication.

Methods:
Therefore, we used the well established C57BL/6 into BALB/c mouse aGvHD model to evaluate whether pharmacological inhibition of heat shock protein 90 (Hsp90) would protect the mice from aGvHD.

Results:
Treatment of the BALB/c recipient mice from day 0 to +2 after allogeneic CD4\(^{+}\) T cell transplantation with the Hsp90 inhibitor 17‐(dimethylaminoethylamino)‐17‐demethoxygeldanamycin (DMAG) partially protected the mice from aGvHD. DMAG treatment was, however, insufficient to prolong overall survival of leukemia‐bearing mice after transplantation of allogeneic CD4\(^{+}\) and CD8\(^{+}\) T cells. Ex vivo analyses and in vitro experiments revealed that DMAG primarily inhibits conventional CD4\(^{+}\) T cells with a relative resistance of CD4\(^{+}\) regulatory and CD8\(^{+}\) T cells toward Hsp90 inhibition.

Conclusions:
Our data, thus, suggest that Hsp90 inhibition might constitute a novel approach to reduce aGvHD in patients without abrogating the desired GvT effect.
KW  - Hsp90
KW  - leukemia
KW  - acute Graft versus Host Disease
KW  - Graft versus Tumor
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168318
VL  - 4
IS  - 4
ER  -