379 research outputs found

    An HLA-G/SPAG9/STAT3 axis promotes brain metastases

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    Brain metastases (BM) are the most common brain neoplasm in adults. Current BM therapies still offer limited efficacy and reduced survival outcomes, emphasizing the need for a better understanding of the disease. Herein, we analyzed the transcriptional profile of brain metastasis initiating cells (BMICs) at two distinct stages of the brain metastatic cascade-the "premetastatic" or early stage when they first colonize the brain and the established macrometastatic stage. RNA sequencing was used to obtain the transcriptional profiles of premetastatic and macrometastatic (non-premetastatic) lung, breast, and melanoma BMICs. We identified that lung, breast, and melanoma premetastatic BMICs share a common transcriptomic signature that is distinct from their non-premetastatic counterparts. Importantly, we show that premetastatic BMICs exhibit increased expression of HLA-G, which we further demonstrate functions in an HLA-G/SPAG9/STAT3 axis to promote the establishment of brain metastatic lesions. Our findings suggest that unraveling the molecular landscape of premetastatic BMICs allows for the identification of clinically relevant targets that can possibly inform the development of preventive and/or more efficacious BM therapies

    Cell-intrinsic differences between human airway epithelial cells from children and adults

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    Summary The airway epithelium is a protective barrier that is maintained by the self-renewal and differentiation of basal stem cells. Increasing age is a principle risk factor for chronic lung diseases, but few studies have explored age-related molecular or functional changes in the airway epithelium. We retrieved epithelial biopsies from histologically normal tracheobronchial sites from pediatric and adult donors and compared their cellular composition and gene expression profile (in laser capture-microdissected whole epithelium, fluorescence-activated cell-sorted basal cells and basal cells in cell culture). Histologically, pediatric and adult tracheobronchial epithelium were similar in composition. We observed age-associated changes in RNA sequencing studies, including higher interferon-associated gene expression in pediatric epithelium. In cell culture, pediatric cells had higher colony-formation ability, sustained in vitro growth and out-competed adult cells in a direct competitive proliferation assay. Our results demonstrate cell-intrinsic differences between airway epithelial cells from children and adults in both homeostatic and proliferative states

    Allele-Specific HLA Loss and Immune Escape in Lung Cancer Evolution

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    Immune evasion is a hallmark of cancer. Losing the ability to present neoantigens through human leukocyte antigen (HLA) loss may facilitate immune evasion. However, the polymorphic nature of the locus has precluded accurate HLA copy-number analysis. Here, we present loss of heterozygosity in human leukocyte antigen (LOHHLA), a computational tool to determine HLA allele-specific copy number from sequencing data. Using LOHHLA, we find that HLA LOH occurs in 40% of non-small-cell lung cancers (NSCLCs) and is associated with a high subclonal neoantigen burden, APOBEC-mediated mutagenesis, upregulation of cytolytic activity, and PD-L1 positivity. The focal nature of HLA LOH alterations, their subclonal frequencies, enrichment in metastatic sites, and occurrence as parallel events suggests that HLA LOH is an immune escape mechanism that is subject to strong microenvironmental selection pressures later in tumor evolution. Characterizing HLA LOH with LOHHLA refines neoantigen prediction and may have implications for our understanding of resistance mechanisms and immunotherapeutic approaches targeting neoantigens. Video Abstract [Figure presented] Development of the bioinformatics tool LOHHLA allows precise measurement of allele-specific HLA copy number, improves the accuracy in neoantigen prediction, and uncovers insights into how immune escape contributes to tumor evolution in non-small-cell lung cancer

    Fc-Optimized Anti-CD25 Depletes Tumor-Infiltrating Regulatory T Cells and Synergizes with PD-1 Blockade to Eradicate Established Tumors

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    CD25 is expressed at high levels on regulatory T (Treg) cells and was initially proposed as a target for cancer immunotherapy. However, anti-CD25 antibodies have displayed limited activity against established tumors. We demonstrated that CD25 expression is largely restricted to tumor-infiltrating Treg cells in mice and humans. While existing anti-CD25 antibodies were observed to deplete Treg cells in the periphery, upregulation of the inhibitory Fc gamma receptor (FcγR) IIb at the tumor site prevented intra-tumoral Treg cell depletion, which may underlie the lack of anti-tumor activity previously observed in pre-clinical models. Use of an anti-CD25 antibody with enhanced binding to activating FcγRs led to effective depletion of tumor-infiltrating Treg cells, increased effector to Treg cell ratios, and improved control of established tumors. Combination with anti-programmed cell death protein-1 antibodies promoted complete tumor rejection, demonstrating the relevance of CD25 as a therapeutic target and promising substrate for future combination approaches in immune-oncology

    Phylogenetic ctDNA analysis depicts early-stage lung cancer evolution.

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    The early detection of relapse following primary surgery for non-small-cell lung cancer and the characterization of emerging subclones, which seed metastatic sites, might offer new therapeutic approaches for limiting tumour recurrence. The ability to track the evolutionary dynamics of early-stage lung cancer non-invasively in circulating tumour DNA (ctDNA) has not yet been demonstrated. Here we use a tumour-specific phylogenetic approach to profile the ctDNA of the first 100 TRACERx (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy (Rx)) study participants, including one patient who was also recruited to the PEACE (Posthumous Evaluation of Advanced Cancer Environment) post-mortem study. We identify independent predictors of ctDNA release and analyse the tumour-volume detection limit. Through blinded profiling of postoperative plasma, we observe evidence of adjuvant chemotherapy resistance and identify patients who are very likely to experience recurrence of their lung cancer. Finally, we show that phylogenetic ctDNA profiling tracks the subclonal nature of lung cancer relapse and metastasis, providing a new approach for ctDNA-driven therapeutic studies

    Fc Effector Function Contributes to the Activity of Human Anti-CTLA-4 Antibodies.

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    With the use of a mouse model expressing human Fc-gamma receptors (FcγRs), we demonstrated that antibodies with isotypes equivalent to ipilimumab and tremelimumab mediate intra-tumoral regulatory T (Treg) cell depletion in vivo, increasing the CD8+ to Treg cell ratio and promoting tumor rejection. Antibodies with improved FcγR binding profiles drove superior anti-tumor responses and survival. In patients with advanced melanoma, response to ipilimumab was associated with the CD16a-V158F high affinity polymorphism. Such activity only appeared relevant in the context of inflamed tumors, explaining the modest response rates observed in the clinical setting. Our data suggest that the activity of anti-CTLA-4 in inflamed tumors may be improved through enhancement of FcγR binding, whereas poorly infiltrated tumors will likely require combination approaches

    Physics case for an LHCb Upgrade II - Opportunities in flavour physics, and beyond, in the HL-LHC era

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    The LHCb Upgrade II will fully exploit the flavour-physics opportunities of the HL-LHC, and study additional physics topics that take advantage of the forward acceptance of the LHCb spectrometer. The LHCb Upgrade I will begin operation in 2020. Consolidation will occur, and modest enhancements of the Upgrade I detector will be installed, in Long Shutdown 3 of the LHC (2025) and these are discussed here. The main Upgrade II detector will be installed in long shutdown 4 of the LHC (2030) and will build on the strengths of the current LHCb experiment and the Upgrade I. It will operate at a luminosity up to 2×1034 cm−2s−1, ten times that of the Upgrade I detector. New detector components will improve the intrinsic performance of the experiment in certain key areas. An Expression Of Interest proposing Upgrade II was submitted in February 2017. The physics case for the Upgrade II is presented here in more depth. CP-violating phases will be measured with precisions unattainable at any other envisaged facility. The experiment will probe b → sl+l−and b → dl+l− transitions in both muon and electron decays in modes not accessible at Upgrade I. Minimal flavour violation will be tested with a precision measurement of the ratio of B(B0 → μ+μ−)/B(Bs → μ+μ−). Probing charm CP violation at the 10−5 level may result in its long sought discovery. Major advances in hadron spectroscopy will be possible, which will be powerful probes of low energy QCD. Upgrade II potentially will have the highest sensitivity of all the LHC experiments on the Higgs to charm-quark couplings. Generically, the new physics mass scale probed, for fixed couplings, will almost double compared with the pre-HL-LHC era; this extended reach for flavour physics is similar to that which would be achieved by the HE-LHC proposal for the energy frontier

    LHCb upgrade software and computing : technical design report

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    This document reports the Research and Development activities that are carried out in the software and computing domains in view of the upgrade of the LHCb experiment. The implementation of a full software trigger implies major changes in the core software framework, in the event data model, and in the reconstruction algorithms. The increase of the data volumes for both real and simulated datasets requires a corresponding scaling of the distributed computing infrastructure. An implementation plan in both domains is presented, together with a risk assessment analysis

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Angular analysis of the B-0 -> K*(0) e(+) e(-) decay in the low-q(2) region

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    An angular analysis of the B0K0e+eB^0 \rightarrow K^{*0} e^+ e^- decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in pppp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q2q^2) interval between 0.002 and 1.120GeV2 ⁣/c4{\mathrm{\,Ge\kern -0.1em V^2\!/}c^4}. The angular observables FLF_{\mathrm{L}} and ATReA_{\mathrm{T}}^{\mathrm{Re}} which are related to the K0K^{*0} polarisation and to the lepton forward-backward asymmetry, are measured to be FL=0.16±0.06±0.03F_{\mathrm{L}}= 0.16 \pm 0.06 \pm0.03 and ATRe=0.10±0.18±0.05A_{\mathrm{T}}^{\mathrm{Re}} = 0.10 \pm 0.18 \pm 0.05, where the first uncertainty is statistical and the second systematic. The angular observables AT(2)A_{\mathrm{T}}^{(2)} and ATImA_{\mathrm{T}}^{\mathrm{Im}} which are sensitive to the photon polarisation in this q2q^2 range, are found to be AT(2)=0.23±0.23±0.05A_{\mathrm{T}}^{(2)} = -0.23 \pm 0.23 \pm 0.05 and ATIm=0.14±0.22±0.05A_{\mathrm{T}}^{\mathrm{Im}} =0.14 \pm 0.22 \pm 0.05. The results are consistent with Standard Model predictions.An angular analysis of the B0^{0} → K^{*}^{0} e+^{+} e^{−} decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 fb1^{−1}, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q2^{2}) interval between 0.002 and 1.120 GeV2^{2} /c4^{4}. The angular observables FL_{L} and ATRe_{T}^{Re} which are related to the K^{*}^{0} polarisation and to the lepton forward-backward asymmetry, are measured to be FL_{L} = 0.16 ± 0.06 ± 0.03 and ATRe_{T}^{Re}  = 0.10 ± 0.18 ± 0.05, where the first uncertainty is statistical and the second systematic. The angular observables AT(2)_{T}^{(2)} and ATIm_{T}^{Im} which are sensitive to the photon polarisation in this q2^{2} range, are found to be AT(2)_{T}^{(2)}  = − 0.23 ± 0.23 ± 0.05 and ATIm_{T}^{Im}  = 0.14 ± 0.22 ± 0.05. The results are consistent with Standard Model predictions.An angular analysis of the B0K0e+eB^0 \rightarrow K^{*0} e^+ e^- decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in pppp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q2q^2) interval between 0.002 and 1.120GeV2 ⁣/c4{\mathrm{\,Ge\kern -0.1em V^2\!/}c^4}. The angular observables FLF_{\mathrm{L}} and ATReA_{\mathrm{T}}^{\mathrm{Re}} which are related to the K0K^{*0} polarisation and to the lepton forward-backward asymmetry, are measured to be FL=0.16±0.06±0.03F_{\mathrm{L}}= 0.16 \pm 0.06 \pm0.03 and ATRe=0.10±0.18±0.05A_{\mathrm{T}}^{\mathrm{Re}} = 0.10 \pm 0.18 \pm 0.05, where the first uncertainty is statistical and the second systematic. The angular observables AT(2)A_{\mathrm{T}}^{(2)} and ATImA_{\mathrm{T}}^{\mathrm{Im}} which are sensitive to the photon polarisation in this q2q^2 range, are found to be AT(2)=0.23±0.23±0.05A_{\mathrm{T}}^{(2)} = -0.23 \pm 0.23 \pm 0.05 and ATIm=0.14±0.22±0.05A_{\mathrm{T}}^{\mathrm{Im}} =0.14 \pm 0.22 \pm 0.05. The results are consistent with Standard Model predictions
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