TY  - JOUR
AB  - A direct regulation of adaptive immunity by the coagulation protease activated protein C (aPC) has recently been established. Preincubation of T cells with aPC for 1 hour before transplantation increases FOXP3+ regulatory T cells (Tregs) and reduces acute graft-versushost disease (aGVHD) in mice, but the underlying mechanism remains unknown. Because cellular metabolism modulates epigenetic gene regulation and plasticity in T cells, we hypothesized that aPC promotes FOXP3+ expression by altering T-cell metabolism. To this end, T-cell differentiation was assessed in vitro using mixed lymphocyte reaction or plate-bound α-CD3/CD28 stimulation, and ex vivo using T cells isolated from mice with aGVHD without and with aPC preincubation, or analyses of mice with high plasma aPC levels. In stimulated CD4+CD25- cells, aPC induces FOXP3 expression while reducing expression of T helper type 1 cell markers. Increased FOXP3 expression is associated with altered epigenetic markers (reduced 5-methylcytosine and H3K27me3) and reduced Foxp3 promoter methylation and activity. These changes are linked to metabolic quiescence, decreased glucose and glutamine uptake, decreased mitochondrial metabolism (reduced tricarboxylic acid metabolites and mitochondrial membrane potential), and decreased intracellular glutamine and α-ketoglutarate levels. In mice with high aPC plasma levels, T-cell subpopulations in the thymus are not altered, reflecting normal T-cell development, whereas FOXP3 expression in splenic T cells is reduced. Glutamine and α-ketoglutarate substitution reverse aPC-mediated FOXP3+ induction and abolish aPC-mediated suppression of allogeneic T-cell stimulation. These findings show that aPC modulates cellular metabolism in T cells, reducing glutamine and α-ketoglutarate levels, which results in altered epigenetic markers, Foxp3 promoter demethylation and induction of FOXP3 expression, thus favoring a Treg-like phenotype.
AU  - Gupta, D.*
AU  - Elwakiel, A.*
AU  - Ranjan, S.*
AU  - Pandey, M.K.*
AU  - Krishnan, S.*
AU  - Ambreen, S.*
AU  - Henschler, R.*
AU  - Rana, R.*
AU  - Keller, M.
AU  - Ceglarek, U.*
AU  - Shahzad, K.*
AU  - Kohli, S.*
AU  - Isermann, B.*
C1  - 68261
C2  - 54696
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
SP  - 5055-5068
TI  - Activated protein C modulates T-cell metabolism and epigenetic FOXP3 induction via α-ketoglutarate.
JO  - Blood Adv.
VL  - 7
IS  - 17
PB  - Elsevier
PY  - 2023
SN  - 2473-9529
ER  - 

TY  - JOUR
AB  - Expression of ZAP-70 in a subset of CLL patients positively correlates with the absence of IGHV mutations and is indicative of a more active disease and shorter treatment free survival. We recently demonstrated that ZAP-70 regulates the constitutive expression of CCL3 and CCL4, activation of AKT and expression of MYC in the absence of an overt BCR signal, bona fide functions of BCR activation. We here provide evidence that these features relate to the presence of a constitutive tonic BCR signal, exclusively found in IGHV unmutated CLL and dependent on the ZAP-70 mediated activation of AKT and its downstream target GSK3b. These findings are associated with increased steady state activation of CD19 and SRC. Notably this tonic BCR signal is not present in IGHV mutated CLL cells, discordantly expressing ZAP-70. Quantitative mass spectrometry and phosphoprotein-analyses indicate that this ZAP-70-dependent, tonic BCR-signal regulates CLL cell migration through phosphorylation of LCP1 on serine-5. Indeed, we show that CCL19- and CCL21-induced chemotaxis is regulated by and dependent on the expression of ZAP-70 through its function to enhance CCR7 signaling to LCP1. Thus, our data demonstrate that ZAP-70 converges a tonic BCR signal, exclusively present in IGHV unmutated CLL, and CCR7-mediated chemotaxis.
AU  - Ringshausen, I.*
AU  - Chen, J.*
AU  - Sathiaseelan, V.*
AU  - Chilamakuri, C.S.*
AU  - Jakwerth, C.A.
AU  - D'Santos, C.S.*
AU  - Roamio Franklin, V.N.*
C1  - 69063
C2  - 53839
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
SP  - 1167-1178
TI  - ZAP-70 augments tonic B-cell receptor and CCR7 signaling in IGHV unmutated chronic lymphocytic leukemia.
JO  - Blood Adv.
VL  - 8
IS  - 5
PB  - Elsevier
PY  - 2023
SN  - 2473-9529
ER  - 

TY  - JOUR
AU  - Lazaro-Navarro, J.*
AU  - Pimentel-Gutiérrez, H.J.*
AU  - Gauert, A.*
AU  - Hagemann, A.I.H.*
AU  - Eisenschmid, J.*
AU  - Goekbuget, N.*
AU  - Vick, B.
AU  - Jeremias, I.
AU  - Seyfried, F.*
AU  - Meyer, L.H.*
AU  - Debatin, K.M.*
AU  - Richer, K.*
AU  - Bultman, M.*
AU  - Neumann, M.*
AU  - Hanzelmann, S.*
AU  - Serve, H.*
AU  - Astrahantseff, K.*
AU  - Rieger, M.A.*
AU  - Eckert, C.*
AU  - Baldus, C.D.*
AU  - Bastian, L.*
C1  - 64045
C2  - 51651
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
SP  - 5501-5506
TI  - Inhibiting casein kinase 2 sensitizes acute lymphoblastic leukemia cells to venetoclax via MCL1 degradation.
JO  - Blood Adv.
VL  - 5
IS  - 24
PB  - Elsevier
PY  - 2021
SN  - 2473-9529
ER  - 

TY  - JOUR
AB  - Prediction of resistant disease at initial diagnosis of acute myeloid leukemia (AML) can be achieved with high accuracy by using cytogenetic data and 29 gene expression markers (PS29MRC). Our aim was to establish PS29MRC as a clinically usable assay by using the widely implemented NanoString platform and further validate the classifier in a more recently treated patient cohort. 351 patients with newly diagnosed AML intensively treated within the AMLCG registry were analyzed. As a continuous variable, PS29MRC performed best in predicting induction failure in comparison to previously published risk models (OR=2.37; p=1.20·10-9). The classifier was strongly associated with overall survival (HR=1.38; p=2.62·10-6). We were able to establish a previously defined cut-off that allows a classifier dichotomization (PS29MRCdic). PS29MRCdic significantly identified induction failure with 59% sensitivity, 77% specificity and 72% overall accuracy (OR=4.81; p=4.15·10-10). PS29MRCdic was able to improve the ELN-2017 risk classification within every category (favorable: OR=5.44; p=0.017; intermediate: OR=4.43; p=0.011; adverse: OR=2.52; p=0.034). Median patients' overall survival with high PS29MRCdic was 1.8 years compared to 4.3 years of low-risk patients. In multivariate analysis including ELN-2017, clinical and genetic markers, only age and PS29MRCdic were independent predictors of refractory disease. In patients aged 60 or older, only PS29MRCdic was left as significant variable. In summary, we confirmed PS29MRC as a valuable classifier that can be calculated and reproduced on a widely available platform to identify high-risk patients in AML. Risk classification can still be refined beyond ELN-2017 and predictive classifiers might facilitate clinical trials focusing on these high-risk AML patients.
AU  - Moser, C.*
AU  - Jurinovic, V.*
AU  - Sagebiel-Kohler, S.*
AU  - Ksienzyk, B.*
AU  - Batcha, A.M.N.*
AU  - Dufour, A.*
AU  - Schneider, S.*
AU  - Rothenberg-Thurley, M.*
AU  - Sauerland, C.M.*
AU  - Görlich, D.
AU  - Berdel, W.E.*
AU  - Krug, U.*
AU  - Mansmann, U.R.*
AU  - Hiddemann, W.*
AU  - Braess, J.*
AU  - Spiekermann, K.*
AU  - Greif, P.A.*
AU  - Vosberg, S.*
AU  - Metzeler, K.H.*
AU  - Kumbrink, J.
AU  - Herold, T.
C1  - 63043
C2  - 51229
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
SP  - 4752-4761
TI  - A clinically applicable gene expression based score predicts resistance to induction treatment in acute myeloid leukemia.
JO  - Blood Adv.
VL  - 5
IS  - 22
PB  - Elsevier
PY  - 2021
SN  - 2473-9529
ER  - 

TY  - JOUR
AB  - Peritoneal adhesions are pathological fibroses that ensnare organs after abdominal surgery. This dense connective tissue can cause small bowel obstruction, female infertility, and chronic abdominal pain. The pathogenesis of adhesions is a fibrotic response to tissue damage coordinated between mesothelial cells, fibroblasts, and immune cells. We have previously demonstrated that peritoneal adhesions are a consequence of mechanical injury to the mesothelial layer sustained during surgery. Neutrophils are among the first leukocytes involved in the early response to tissue damage. Here, we show that when subjected to mechanical stress, activated mesothelial cells directly recruit neutrophils and monocytes through upregulation of chemokines such as CXCL1 and monocyte chemoattractant protein 1 (MCP-1). We find that neutrophils within the adhesion sites undergo cell death and form neutrophil extracellular traps (NETosis) that contribute to pathogenesis. Conversely, tissue-resident macrophages were profoundly depleted throughout the disease time course. We show that this is distinct from traditional inflammatory kinetics such as after sham surgery or chemically induced peritonitis, and suggest that adhesions result from a primary difference in inflammatory kinetics. We find that transient depletion of circulating neutrophils significantly decreases adhesion burden, and further recruitment of monocytes with thioglycolate or MCP-1 also improves outcomes. Our findings suggest that the combination of neutrophil depletion and monocyte recruitment is sufficient to prevent adhesion formation, thus providing insight for potential clinical interventions.
AU  - Tsai, J.M.*
AU  - Shoham, M.*
AU  - Fernhoff, N.B.*
AU  - George, B.M.*
AU  - Marjon, K.D.*
AU  - McCracken, M.N.*
AU  - Kao, K.S.*
AU  - Sinha, R.*
AU  - Volkmer, A.K.*
AU  - Miyanishi, M.*
AU  - Seita, J.*
AU  - Rinkevich, Y.
AU  - Weissman, I.L.*
C1  - 56957
C2  - 47454
SP  - 2713-2721
TI  - Neutrophil and monocyte kinetics play critical roles in mouse peritoneal adhesion formation.
JO  - Blood Adv.
VL  - 3
IS  - 18
PY  - 2019
SN  - 2473-9529
ER  - 

TY  - JOUR
AB  - Receptor tyrosine kinase (RTK)-dependent signaling has been implicated in the pathogenesis of acute lymphoblastic leukemia (ALL) of childhood. However, the RTK-dependent signaling state and its interpretation with regard to biological behavior are often elusive. To decipher signaling circuits that link RTK activity with biological output in vivo, we established patient-derived xenograft ALL (PDX-ALL) models with dependencies on fms-like tyrosine kinase 3 (FLT3) and platelet-derived growth factor receptor β (PDGFRB), which were interrogated by phosphoproteomics using iTRAQ mass spectrometry. Signaling circuits were determined by receptor type and cellular context with few generic features, among which we identified group I p21-activated kinases (PAKs) as potential therapeutic targets. Growth factor stimulation markedly increased catalytic activities of PAK1 and PAK2. RNA interference (RNAi)-mediated or pharmacological inhibition of PAKs using allosteric or adenosine triphosphate (ATP)-competitive compounds attenuated cell growth and increased apoptosis in vitro. Notably, PAK1- or PAK2-directed RNAi enhanced the antiproliferative effects of the type III RTK and protein kinase C inhibitor midostaurin. Treatment of FLT3- or PDGFRB-dependent ALLs with ATP-competitive PAK inhibitors markedly decreased catalytic activities of both PAK isoforms. In FLT3-driven ALL, this effect was augmented by coadministration of midostaurin resulting in synergistic effects on growth inhibition and apoptosis. Finally, combined treatment of PDX-ALL with the ATP-competitive group I PAK inhibitor FRAX486 and midostaurin in vivo significantly prolonged leukemia progression-free survival compared with midostaurin monotherapy or control. Our study establishes PAKs as potential downstream targets in RTK-dependent ALL of childhood, the inhibition of which might help prevent the selection or acquisition of resistance mutations toward tyrosine kinase inhibitors.
AU  - Siekmann, I.-K.*
AU  - Dierck, K.*
AU  - Prall, S.*
AU  - Klokow, M.*
AU  - Strauss, J.*
AU  - Buhs, S.*
AU  - Wrzeszcz, A.*
AU  - Bockmayr, M.*
AU  - Beck, F.*
AU  - Trochimiuk, M.*
AU  - Gottschling, K.*
AU  - Martens, V.*
AU  - Khosh-Naucke, M.*
AU  - Gerull, H.*
AU  - Müller, J.*
AU  - Behrmann, L.*
AU  - Blohm, M.*
AU  - Zahedi, R.P.*
AU  - Jeremias, I.
AU  - Sickmann, A.*
AU  - Nollau, P.*
AU  - Horstmann, M.A.*
C1  - 54505
C2  - 45643
SP  - 2554-2567
TI  - Combined inhibition of receptor tyrosine and p21-activated kinases as a therapeutic strategy in childhood ALL.
JO  - Blood Adv.
VL  - 2
IS  - 19
PY  - 2018
SN  - 2473-9529
ER  -