TY  - JOUR
A1  - Rinaldetti, Sébastien
A1  - Pfirrmann, Markus
A1  - Manz, Kirsi
A1  - Guilhot, Joelle
A1  - Dietz, Christian
A1  - Panagiotidis, Panayiotidis
A1  - Spiess, Birgit
A1  - Seifarth, Wolfgang
A1  - Fabarius, Alice
A1  - Müller, Martin
A1  - Pagoni, Maria
A1  - Dimou, Maria
A1  - Dengler, Jolanta
A1  - Waller, Cornelius F.
A1  - Brümmendorf, Tim H.
A1  - Herbst, Regina
A1  - Burchert, Andreas
A1  - Janßen, Carsten
A1  - Goebeler, Maria Elisabeth
A1  - Jost, Philipp J.
A1  - Hanzel, Stefan
A1  - Schafhausen, Philippe
A1  - Prange-Krex, Gabriele
A1  - Illmer, Thomas
A1  - Janzen, Viktor
A1  - Klausmann, Martine
A1  - Eckert, Robert
A1  - Büschel, Gerd
A1  - Kiani, Alexander
A1  - Hofmann, Wolf-Karsten
A1  - Mahon, François-Xavier
A1  - Saussele, Susanne
T1  - Effect of ABCG2, OCT1, and ABCB1 (MDR1) Gene Expression on Treatment-Free Remission in a EURO-SKI Subtrial
JF  - Clinical Lymphoma, Myeloma & Leukemia
N2  - Within the EURO-SKI trial, 132 chronic phase CML patients discontinued imatinib treatment. RNA was isolated from peripheral blood in order to analyze the expression of MDR1, ABCG2 and OCT1. ABCG2 was predictive for treatment-free remission in Cox regression analysis. High transcript levels of the ABCG2 efflux transporter (>4.5 parts per thousand) were associated with a twofold higher risk of relapse. Introduction: Tyrosine kinase inhibitors (TKIs) can safely be discontinued in chronic myeloid leukemia (CML) patients with sustained deep molecular response. ABCG2 (breast cancer resistance protein), OCT1 (organic cation transporter 1), and ABCB1 (multidrug resistance protein 1) gene products are known to play a crucial role in acquired pharmacogenetic TKI resistance. Their influence on treatment-free remission (TFR) has not yet been investigated. Materials and Methods: RNA was isolated on the last day of TKI intake from peripheral blood leukocytes of 132 chronic phase CML patients who discontinued TKI treatment within the European Stop Tyrosine Kinase Inhibitor Study trial. Plasmid standards were designed including subgenic inserts of OCT1, ABCG2, and ABCB1 together with GUSB as reference gene. For expression analyses, quantitative real-time polymerase chain reaction was used. Multiple Cox regression analysis was performed. In addition, gene expression cutoffs for patient risk stratification were investigated. Results: The TFR rate of 132 patients, 12 months after TKI discontinuation, was 54% (95% confidence interval [CI], 46%-62%). ABCG2 expression (parts per thousand) was retained as the only significant variable (P=.02; hazard ratio, 1.04; 95% CI, 1.01-1.07) in multiple Cox regression analysis. Only for the ABCG2 efflux transporter, a significant cutoff was found (P=.04). Patients with an ABCG2/GUSB transcript level >4.5 parts per thousand (n=93) showed a 12-month TFR rate of 47% (95% CI, 37%-57%), whereas patients with low ABCG2 expression (<= 4.5 parts per thousand; n=39) had a 12-month TFR rate of 72% (95% CI, 55%-82%). Conclusion: In this study, we investigated the effect of pharmacogenetics in the context of a CML treatment discontinuation trial. The transcript levels of the efflux transporter ABCG2 predicted TFR after TKI discontinuation. (C) 2018 The Authors. Published by Elsevier Inc.
KW  - ABCG2
KW  - Biomarker
KW  - CML
KW  - Imatinib
KW  - Prediction
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226281
VL  - 18
IS  - 4
ER  - 
TY  - JOUR
A1  - Rhodes, David A.
A1  - Chen, Hung-Chang
A1  - Williamson, James C.
A1  - Hill, Alfred
A1  - Yuan, Jack
A1  - Smith, Sam
A1  - Rhodes, Harriet
A1  - Trowsdale, John
A1  - Lehner, Paul J.
A1  - Herrmann, Thomas
A1  - Eberl, Matthias
T1  - Regulation of Human γδ T Cells by BTN3A1 Protein Stability and ATP-Binding Cassette Transporters
JF  - Frontiers in Immunology
N2  - Activation of human Vγ9/Vδ2 T cells by “phosphoantigens” (pAg), the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP) and the endogenous isoprenoid intermediate isopentenyl pyrophosphate, requires expression of butyrophilin BTN3A molecules by presenting cells. However, the precise mechanism of activation of Vγ9/Vδ2 T cells by BTN3A molecules remains elusive. It is not clear what conformation of the three BTN3A isoforms transmits activation signals nor how externally delivered pAg accesses the cytosolic B30.2 domain of BTN3A1. To approach these problems, we studied two HLA haplo-identical HeLa cell lines, termed HeLa-L and HeLa-M, which showed marked differences in pAg-dependent stimulation of Vγ9/Vδ2 T cells. Levels of IFN-γ secretion by Vγ9/Vδ2 T cells were profoundly increased by pAg loading, or by binding of the pan-BTN3A specific agonist antibody CD277 20.1, in HeLa-M compared to HeLa-L cells. IL-2 production from a murine hybridoma T cell line expressing human Vγ9/Vδ2 T cell receptor (TCR) transgenes confirmed that the differential responsiveness to HeLa-L and HeLa-M was TCR dependent. By tissue typing, both HeLa lines were shown to be genetically identical and full-length transcripts of the three BTN3A isoforms were detected in equal abundance with no sequence variation. Expression of BTN3A and interacting molecules, such as periplakin or RhoB, did not account for the functional variation between HeLa-L and HeLa-M cells. Instead, the data implicate a checkpoint controlling BTN3A1 stability and protein trafficking, acting at an early time point in its maturation. In addition, plasma membrane profiling was used to identify proteins upregulated in HMB-PP-treated HeLa-M. ABCG2, a member of the ATP-binding cassette (ABC) transporter family was the most significant candidate, which crucially showed reduced expression in HeLa-L. Expression of a subset of ABC transporters, including ABCA1 and ABCG1, correlated with efficiency of T cell activation by cytokine secretion, although direct evidence of a functional role was not obtained by knockdown experiments. Our findings indicate a link between members of the ABC protein superfamily and the BTN3A-dependent activation of γδ T cells by endogenous and exogenous pAg.
KW  - butyrophilins
KW  - T cells
KW  - phosphoantigens
KW  - mevalonate pathway
KW  - ABCG2
KW  - NRF2
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-197054
SN  - 1664-3224
VL  - 9
IS  - 662
ER  -