Flavoured jets with exact anti-ktk_t kinematics and tests of infrared and collinear safety

We propose extensions of the anti-$k_t$ and Cambridge/Aachen hierarchical jet clustering algorithms that are designed to retain the exact jet kinematics of these algorithms, while providing an infrared-and-collinear-safe definition of jet flavour at any fixed order in perturbation theory. Central to our approach is a new technique called Interleaved Flavour Neutralisation (IFN), whereby the treatment of flavour is integrated with, but distinct from, the kinematic clustering. IFN allows flavour information to be meaningfully accessed at each stage of the clustering sequence, which enables a consistent assignment of flavour both to individual jets and to their substructure. We validate the IFN approach using a dedicated framework for fixed-order tests of infrared and collinear safety, which also reveals unanticipated issues in earlier approaches to flavoured jet clustering. We briefly explore the phenomenological impact of IFN with anti-$k_t$ jets for benchmark tasks at the Large Hadron Collider.Comment: 36 pages, 27 figures, 1 table, code available from https://github.com/jetflav/IFNPlugi

239. Ocena efektu przeciwnowotworowego genetycznie modyfikowanej szczepionki komórkowej w mysim modelu raka nerki

CelGenetycznie modyfikowane szczepionki komórkowe (GMTV) mają za zadanie indukcję efektywnej odpowiedzi przeciwnowotworowej. Postanowiliśmy ocenić efekt protekcyjny dwóch różnych GMTV w mysim modelu raka jasnokomórkowego nerki, oraz rolę komórek dendrytycznych w fazie indukcji przeciwnowotworowej odpowiedzi komórkowej.MetodyPrzy wykorzystaniu wektorów retrowirusowych DCCMV-IRES-Neo-H-6 oraz DCCMV-IRES-Neo-IL-6 wprowadzono do komórek mysiego raka jasnokomórkowego (RenCa) skonstruowano dwa rodzaje GMTV: (i) Komórki RenCa wykazujące ekspresję genu Interleukiny-6, (ii) komórki RenCa wykazujące ekspresję genu Hyper-lnterleukiny-6 (sztuczna cytokina będąca białkiem fuzyjnym składającym się z IL-6 powiązanej sztucznym linkerem z agonistycznym rozpuszczalnym receptorem) W celu oceny efektu protekcyjnego GMTV, myszy Balb/c w wieku 8–12 tygodni (8 osobników w jednej grupie eksperymentalnej) immunizowano podając podskórnie w lewe udo, 1×10^6 naświetlonych (80 Gy) komórek (RenCa w/t, RenCa-IL-6, Renca-H6). Po 14 dniach myszom podawano podskórnie w prawe udo wyjściowe komórki RenCa w/t w ilości 5×10^5. Następnie oceniano dynamikę pojawiania się guzów oraz kinetykę ich wzrostu. W celu oceny mechanizmów indukcji odpowiedzi immunologicznej postanowiono ocenić in situ wpływ poszczególnych rodzajów GMTV na komórki dendrytyczne. Myszy Balb/c otrzymywały w okolicy śródbrzusza, podskórnie 2×10^6 napromienionych (80 Gy) komórek Renca w/t, Renca-IL-6, Renca H-6 zawieszonych w Matrigelu™. Po 7 dniach przy pomocy cytometru przepływowego analizowano komórki naciekające Matrigel.Wyniki i podsumowanieImmunizacja myszy komórkami RenCa-H6 okazała się najbardziej efektywna w porównaniu do komórek RenCa w/t i RenCa-IL-6. Jakkolwiek nie przeciwdziałała wzrostowi guzów. Aktywowane komórki DC naciekały najsilniej komórki RenCa-H6. Efekt protekcyjny wyraźnie korelował z ilością aktywowanych komórek DC naciekających miejsce podania GMTV. Intensywna infiltracja miejsca podania GMTV przez komórki DC o wysokim poziomie aktywacji wskazuje na silną role Hyper-Interleukiny-6 w procesie indukcji funkcjonalnej przeciwnowotworowej odpowiedzi immunologicznej

Increased Expression of Bcl11b Leads to Chemoresistance Accompanied by G1 Accumulation

BACKGROUND: The expression of BCL11B was reported in T-cells, neurons and keratinocytes. Aberrations of BCL11B locus leading to abnormal gene transcription were identified in human hematological disorders and corresponding animal models. Recently, the elevated levels of Bcl11b protein have been described in a subset of squameous cell carcinoma cases. Despite the rapidly accumulating knowledge concerning Bcl11b biology, the contribution of this protein to normal or transformed cell homeostasis remains open. METHODOLOGY/PRINCIPAL FINDINGS: Here, by employing an overexpression strategy we revealed formerly unidentified features of Bcl11b. Two different T-cell lines were forced to express BCL11B at levels similar to those observed in primary T-cell leukemias. This resulted in markedly increased resistance to radiomimetic drugs while no influence on death-receptor apoptotic pathway was observed. Apoptosis resistance triggered by BCL11B overexpression was accompanied by a cell cycle delay caused by accumulation of cells at G1. This cell cycle restriction was associated with upregulation of CDKN1C (p57) and CDKN2C (p18) cyclin dependent kinase inhibitors. Moreover, p27 and p130 proteins accumulated and the SKP2 gene encoding a protein of the ubiquitin-binding complex responsible for their degradation was repressed. Furthermore, the expression of the MYCN oncogene was silenced which resulted in significant depletion of the protein in cells expressing high BCL11B levels. Both cell cycle restriction and resistance to DNA-damage-induced apoptosis coincided and required the histone deacetylase binding N-terminal domain of Bcl11b. The sensitivity to genotoxic stress could be restored by the histone deacetylase inhibitor trichostatine A. CONCLUSIONS: The data presented here suggest a potential role of BCL11B in tumor survival and encourage developing Bcl11b-inhibitory approaches as a potential tool to specifically target chemoresistant tumor cells

Search for dark mesons decaying to top and bottom quarks in proton-proton collisions at s = 13 TeV with the ATLAS detector

A search for dark mesons originating from strongly-coupled, SU(2) dark flavor symmetry conserving models and decaying gaugephobically to pure Standard Model final states containing top and bottom quarks is presented. The search targets fully hadronic final states and final states with exactly one electron or muon and multiple jets. The analyzed data sample corresponds to an integrated luminosity of 140 fb−1 of proton-proton collisions collected at s = 13 TeV with the ATLAS detector at the Large Hadron Collider. No significant excess over the Standard Model background expectation is observed and the results are used to set the first direct constraints on this type of model. The two-dimensional signal space of dark pion masses mπD and dark rho-meson masses mρD is scanned. For mπD/mρD = 0.45, dark pions with masses mπD< 940 GeV are excluded at the 95% CL, while for mπD/mρD = 0.25 masses mπD< 740 GeV are excluded

Combination of searches for Higgs boson decays into a photon and a massless dark photon using pp collisions at s = 13 TeV with the ATLAS detector

A combination of searches for Higgs boson decays into a visible photon and a massless dark photon (H → γγd) is presented using 139 fb−1 of proton-proton collision data at a centre-of-mass energy of s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. The observed (expected) 95% confidence level upper limit on the Standard Model Higgs boson decay branching ratio is determined to be B(H → γγd) < 1.3% (1.5)%. The search is also sensitive to higher-mass Higgs bosons decaying into the same final state. The observed (expected) 95% confidence level limit on the cross-section times branching ratio ranges from 16 fb (20 fb) for mH = 400 GeV to 1.0 fb (1.5 fb) for mH = 3 TeV. Results are also interpreted in the context of a minimal simplified model

Search for a resonance decaying into a scalar particle and a Higgs boson in final states with leptons and two photons in proton-proton collisions at s = 13 TeV with the ATLAS detector

A search for a hypothetical heavy scalar particle, X, decaying into a singlet scalar particle, S, and a Standard Model Higgs boson, H, using 140 fb−1 of proton-proton collision data at the centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the LHC is presented. The explored mass range is 300 ≤ mX ≤ 1000 GeV and 170 ≤ mS ≤ 500 GeV. The signature of this search is one or two leptons (e or μ) from the decay of vector bosons originating from the S particle, S → W±W∓/ZZ, and two photons from the Higgs boson decay, H → γγ. No significant excess is observed above the expected Standard Model background. The observed (expected) upper limits at the 95% confidence level on the cross- section for gg → X → SH, assuming the same S → WW/ZZ branching ratios as for a SM-like heavy Higgs boson, are between 530 (800) fb and 120 (170) fb

NK-like homeodomain proteins activate NOTCH3-signaling in leukemic T-cells

<p>Abstract</p> <p>Background</p> <p>Homeodomain proteins control fundamental cellular processes in development and in cancer if deregulated. Three members of the NK-like subfamily of homeobox genes (NKLs), TLX1, TLX3 and NKX2-5, are implicated in T-cell acute lymphoblastic leukemia (T-ALL). They are activated by particular chromosomal aberrations. However, their precise function in leukemogenesis is still unclear. Here we screened further NKLs in 24 T-ALL cell lines and identified the common expression of MSX2. The subsequent aim of this study was to analyze the role of MSX2 in T-cell differentiation which may be disturbed by oncogenic NKLs.</p> <p>Methods</p> <p>Specific gene activity was examined by quantitative real-time PCR, and globally by expression profiling. Proteins were analyzed by western blot, immuno-cytology and immuno-precipitation. For overexpression studies cell lines were transduced by lentiviruses.</p> <p>Results</p> <p>Quantification of MSX2 mRNA in primary hematopoietic cells demonstrated higher levels in CD34+ stem cells as compared to peripheral blood cells and mature CD3+ T-cells. Furthermore, analysis of MSX2 expression levels in T-cell lines after treatment with core thymic factors confirmed their involvement in regulation. These results indicated that MSX2 represents an hematopoietic NKL family member which is downregulated during T-cell development and may functionally substituted by oncogenic NKLs. For functional analysis JURKAT cells were lentivirally transduced, overexpressing either MSX2 or oncogenic TLX1 and NKX2-5, respectively. These cells displayed transcriptional activation of NOTCH3-signaling, including NOTCH3 and HEY1 as analyzed by gene expression profiling and quantitative RT-PCR, and consistently attenuated sensitivity to gamma-secretase inhibitor as analyzed by MTT-assays. Furthermore, in addition to MSX2, both TLX1 and NKX2-5 proteins interacted with NOTCH-pathway repressors, SPEN/MINT/SHARP and TLE1/GRG1, representing a potential mechanism for (de)regulation. Finally, elevated expression of NOTCH3 and HEY1 was detected in primary TLX1/3 positive T-ALL cells corresponding to the cell line data.</p> <p>Conclusion</p> <p>Identification and analysis of MSX2 in hematopoietic cells implicates a modulatory role via NOTCH3-signaling in early T-cell differentiation. Our data suggest that reduction of NOTCH3-signaling by physiological downregulation of MSX2 expression during T-cell development is abrogated by ectopic expression of oncogenic NKLs, substituting MSX2 function.</p

The S phase checkpoint promotes the Smc5/6 complex dependent SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε

Replication fork stalling and accumulation of single-stranded DNA trigger the S phase checkpoint, a signalling cascade that, in budding yeast, leads to the activation of the Rad53 kinase. Rad53 is essential in maintaining cell viability, but its targets of regulation are still partially unknown. Here we show that Rad53 drives the hyper-SUMOylation of Pol2, the catalytic subunit of DNA polymerase ε, principally following replication forks stalling induced by nucleotide depletion. Pol2 is the main target of SUMOylation within the replisome and its modification requires the SUMO-ligase Mms21, a subunit of the Smc5/6 complex. Moreover, the Smc5/6 complex co-purifies with Pol ε, independently of other replisome components. Finally, we map Pol2 SUMOylation to a single site within the N-terminal catalytic domain and identify a SUMO-interacting motif at the C-terminus of Pol2. These data suggest that the S phase checkpoint regulate Pol ε during replication stress through Pol2 SUMOylation and SUMO-binding abilit