Coffea arabica, an allotetraploid hybrid of Coffea eugenioides and Coffea canephora, is the source of approximately 60% of coffee products worldwide, and its cultivated accessions have undergone several population bottlenecks. We present chromosome-level assemblies of a di-haploid C. arabica accession and modern representatives of its diploid progenitors, C. eugenioides and C. canephora. The three species exhibit largely conserved genome structures between diploid parents and descendant subgenomes, with no obvious global subgenome dominance. We find evidence for a founding polyploidy event 350,000-610,000 years ago, followed by several pre-domestication bottlenecks, resulting in narrow genetic variation. A split between wild accessions and cultivar progenitors occurred similar to 30.5 thousand years ago, followed by a period of migration between the two populations. Analysis of modern varieties, including lines historically introgressed with C. canephora, highlights their breeding histories and loci that may contribute to pathogen resistance, laying the groundwork for future genomics-based breeding of C. arabica.
Despite major improvements in immunotherapeutic strategies, the immunosuppressive tumor microenvironment remains a major obstacle for the induction of efficient antitumor responses. In this study, we show that local delivery of a bispecific Clec9A-PD-L1 targeted type I interferon (AcTaferon, AFN) overcomes this hurdle by reshaping the tumor immune landscape.Treatment with the bispecific AFN resulted in the presence of pro-immunogenic tumor-associated macrophages and neutrophils, increased motility and maturation profile of cDC1 and presence of inflammatory cDC2. Moreover, we report empowered diversity in the CD8+ T cell repertoire and induction of a shift from naive, dysfunctional CD8+ T cells towards effector, plastic cytotoxic T lymphocytes together with increased presence of NK and NKT cells as well as decreased regulatory T cell levels. These dynamic changes were associated with potent antitumor activity. Tumor clearance and immunological memory, therapeutic immunity on large established tumors and blunted tumor growth at distant sites were obtained upon co-administration of a non-curative dose of chemotherapy.Overall, this study illuminates further application of type I interferon as a safe and efficient way to reshape the suppressive tumor microenvironment and induce potent antitumor immunity; features which are of major importance in overcoming the development of metastases and tumor cell resistance to immune attack. The strategy described here has potential for application across to a broad range of cancer types.
AbstractCoffea arabica, an allotetraploid hybrid ofC. eugenioidesandC. canephora, is the source of approximately 60% of coffee products worldwide, and its cultivated accessions have undergone several population bottlenecks. We present chromosome-level assemblies of a di-haploidC. arabicaaccession and modern representatives of its diploid progenitors,C. eugenioidesandC. canephora. The three species exhibit largely conserved genome structures between diploid parents and descendant subgenomes, with no obvious global subgenome dominance. We find evidence for a founding polyploidy event 350,000-610,000 years ago, followed by several pre-domestication bottlenecks, resulting in narrow genetic variation. A split between wild accessions and cultivar progenitors occurred ∼30.5 kya, followed by a period of migration between the two populations. Analysis of modern varieties, including lines historically introgressed withC. canephora, highlights their breeding histories and loci that may contribute to pathogen resistance, laying the groundwork for future genomics-based breeding ofC. arabica.
One important facet of glaucoma pathophysiology is axonal damage, which ultimately disrupts the connection between the retina and its postsynaptic brain targets. The concurrent loss of retrograde support interferes with the functionality and survival of the retinal ganglion cells (RGCs). Previous research has shown that stimulation of neuronal activity in a primary retinal target area—i.e., the superior colliculus—promotes RGC survival in an acute mouse model of glaucoma. To build further on this observation, we applied repeated chemogenetics in the superior colliculus of a more chronic murine glaucoma model—i.e., the microbead occlusion model—and performed bulk RNA sequencing on collicular lysates and isolated RGCs. Our study revealed that chronic target stimulation upon glaucomatous injury phenocopies the a priori expected molecular response: growth factors were pinpointed as essential transcriptional regulators both in the locally stimulated tissue and in distant, unstimulated RGCs. Strikingly, and although the RGC transcriptome revealed a partial reversal of the glaucomatous signature and an enrichment of pro-survival signaling pathways, functional rescue of injured RGCs was not achieved. By postulating various explanations for the lack of RGC neuroprotection, we aim to warrant researchers and drug developers for the complexity of chronic neuromodulation and growth factor signaling.
Background Clinical success of therapeutic cancer vaccines depends on the ability to mount strong and durable antitumor T cell responses. To achieve this, potent cellular adjuvants are highly needed. Interleukin-1β (IL-1β) acts on CD8 + T cells and promotes their expansion and effector differentiation, but toxicity and undesired tumor-promoting side effects hamper efficient clinical application of this cytokine. Methods This ‘cytokine problem’ can be solved by use of AcTakines ( Ac tivity-on- Ta rget cyto kines ), which represent fusions between low-activity cytokine mutants and cell type-specific single-domain antibodies. AcTakines deliver cytokine activity to a priori selected cell types and as such evade toxicity and unwanted off-target side effects. Here, we employ subcutaneous melanoma and lung carcinoma models to evaluate the antitumor effects of AcTakines. Results In this work, we use an IL-1β-based AcTakine to drive proliferation and effector functionality of antitumor CD8 + T cells without inducing measurable toxicity. AcTakine treatment enhances diversity of the T cell receptor repertoire and empowers adoptive T cell transfer. Combination treatment with a neovasculature-targeted tumor necrosis factor (TNF) AcTakine mediates full tumor eradication and establishes immunological memory that protects against secondary tumor challenge. Interferon-γ was found to empower this AcTakine synergy by sensitizing the tumor microenvironment to TNF. Conclusions Our data illustrate that anticancer cellular immunity can be safely promoted with an IL-1β-based AcTakine, which synergizes with other immunotherapies for efficient tumor destruction.
BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a very lethal disease that can develop therapy resistance over time. The dense stroma in PDAC plays a critical role in tumor progression and resistance. How this stroma interacts with the tumor cells and how this is influenced by chemotherapy remain poorly understood. METHODS: The backbone of this study is the parallel transcriptome analysis of human tumor and mouse stroma in two molecular and clinical representative patient-derived tumor xenografts models. Mice (8 animals per group) were treated for 4 weeks with gemcitabine or control. We studied tumor growth, RNA expression in the stroma, tumor-associated macrophages (TAMs) with immunofluorescence, and cytokines in the serum. RESULTS: A method for parallel transcriptome analysis was optimized. We found that the tumor (differentiation, gene expression) determines the infiltration of macrophages into the stroma. In aggressive PDAC (epithelial-to-mesenchymal transition high), we find more M2 polarized TAMs and the activation of cytokines and growth factors (TNFα, TGFβ1, and IL6). There are increased stromal glycolysis, reduced fatty acid oxidation, and reduced mitochondrial oxidation (tricarboxylic acid cycle and oxidative phosphorylation). Treatment with gemcitabine results in a shift of innate immune cells, especially additional infiltration of protumoral M2 TAMs (P < .001) and metabolic reprogramming. CONCLUSIONS: Gemcitabine treatment of PDAC xenografts stimulates a protumoral macrophage phenotype, and this, in combination with a shift of the tumor cells to a mesenchymal phenotype that we reported previously, contributes to tumor progression and therapeutic resistance. Targeting M2-polarized TAMs may benefit PDAC patients at risk to become refractory to current anticancer regimens.
DSCAM and DSCAML1 are immunoglobulin and cell adhesion-type receptors serving important neurodevelopmental functions including control of axon growth, branching, neurite self-avoidance, and neuronal cell death. The signal transduction mechanisms or effectors of DSCAM receptors, however, remain poorly characterized. We used a human ORFeome library to perform a high-throughput screen in mammalian cells and identified novel cytoplasmic signaling effector candidates including the Down syndrome kinase Dyrk1a, STAT3, USP21, and SH2D2A. Unexpectedly, we also found that the intracellular domains (ICDs) of DSCAM and DSCAML1 specifically and directly interact with IPO5, a nuclear import protein of the importin beta family, via a conserved nuclear localization signal. The DSCAM ICD is released by γ-secretase-dependent cleavage, and both the DSCAM and DSCAML1 ICDs efficiently translocate to the nucleus. Furthermore, RNA sequencing confirms that expression of the DSCAM as well as the DSCAML1 ICDs alone can profoundly alter the expression of genes associated with neuronal differentiation and apoptosis, as well as synapse formation and function. Gain-of-function experiments using primary cortical neurons show that increasing the levels of either the DSCAM or the DSCAML1 ICD leads to an impairment of neurite growth. Strikingly, increased expression of either full-length DSCAM or the DSCAM ICD, but not the DSCAML1 ICD, significantly decreases synapse numbers in primary hippocampal neurons. Taken together, we identified a novel membrane-to-nucleus signaling mechanism by which DSCAM receptors can alter the expression of regulators of neuronal differentiation and synapse formation and function. Considering that chromosomal duplications lead to increased DSCAM expression in trisomy 21, our findings may help uncover novel mechanisms contributing to intellectual disability in Down syndrome.
Motivation: The Bionano Genomics platform allows for the optical detection of short sequence patterns in very long DNA molecules (up to 2.5 Mbp). Molecules with overlapping patterns can be assembled to generate a consensus optical map of the entire genome. In turn, these optical maps can be used to validate or improve de novo genome assembly projects or to detect large-scale structural variation in genomes. Simulated optical map data can assist in the development and benchmarking of tools that operate on those data, such as alignment and assembly software. Additionally, it can help to optimize the experimental setup for a genome of interest. Such a simulator is currently not available.Results: We have developed a simulator, OMSim, that produces synthetic optical map data that mimics real Bionano Genomics data. These simulated data have been tested for compatibility with the Bionano Genomics Irys software system and the Irys-scaffolding scripts. OMSim is capable of handling very large genomes (over 30 Gbp) with high throughput and low memory requirements.
Although p53 protein aggregates have been observed in cancer cell lines and tumour tissue, their impact in cancer remains largely unknown. Here, we extensively screened for p53 aggregation phenotypes in tumour biopsies, and identified nuclear inclusion bodies (nIBs) of transcriptionally inactive mutant or wild‐type p53 as the most frequent aggregation‐like phenotype across six different cancer types. p53‐positive nIBs co‐stained with nuclear aggregation markers, and shared molecular hallmarks of nIBs commonly found in neurodegenerative disorders. In cell culture, tumour‐associated stress was a strong inducer of p53 aggregation and nIB formation. This was most prominent for mutant p53, but could also be observed in wild‐type p53 cell lines, for which nIB formation correlated with the loss of p53's transcriptional activity. Importantly, protein aggregation also fuelled the dysregulation of the proteostasis network in the tumour cell by inducing a hyperactivated, oncogenic heat‐shock response, to which tumours are commonly addicted, and by overloading the proteasomal degradation system, an observation that was most pronounced for structurally destabilized mutant p53. Patients showing tumours with p53‐positive nIBs suffered from a poor clinical outcome, similar to those with loss of p53 expression, and tumour biopsies showed a differential proteostatic expression profile associated with p53‐positive nIBs. p53‐positive nIBs therefore highlight a malignant state of the tumour that results from the interplay between (1) the functional inactivation of p53 through mutation and/or aggregation, and (2) microenvironmental stress, a combination that catalyses proteostatic dysregulation. This study highlights several unexpected clinical, biological and therapeutically unexplored parallels between cancer and neurodegeneration. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The HEK293 human cell lineage is widely used in cell biology and biotechnology. Here we use whole-genome resequencing of six 293 cell lines to study the dynamics of this aneuploid genome in response to the manipulations used to generate common 293 cell derivatives, such as transformation and stable clone generation (293T); suspension growth adaptation (293S); and cytotoxic lectin selection (293SG). Remarkably, we observe that copy number alteration detection could identify the genomic region that enabled cell survival under selective conditions (i.c. ricin selection). Furthermore, we present methods to detect human/vector genome breakpoints and a user-friendly visualization tool for the 293 genome data. We also establish that the genome structure composition is in steady state for most of these cell lines when standard cell culturing conditions are used. This resource enables novel and more informed studies with 293 cells, and we will distribute the sequenced cell lines to this effect.
The Ashkenazi Jewish (AJ) population is a genetic isolate close to European and Middle Eastern groups, with genetic diversity patterns conducive to disease mapping. Here we report high-depth sequencing of 128 complete genomes of AJ controls. Compared with European samples, our AJ panel has 47% more novel variants per genome and is eightfold more effective at filtering benign variants out of AJ clinical genomes. Our panel improves imputation accuracy for AJ SNP arrays by 28%, and covers at least one haplotype in ≈67% of any AJ genome with long, identical-by-descent segments. Reconstruction of recent AJ history from such segments confirms a recent bottleneck of merely ≈350 individuals. Modelling of ancient histories for AJ and European populations using their joint allele frequency spectrum determines AJ to be an even admixture of European and likely Middle Eastern origins. We date the split between the two ancestral populations to ≈12–25 Kyr, suggesting a predominantly Near Eastern source for the repopulation of Europe after the Last Glacial Maximum. Ashkenazi Jews are a genetically isolated population with distinct patterns of genetic diversity. Here, the authors sequence the genomes of 128 Ashkenazi Jewish individuals and use the sequence information to provide insight into the population's European and Middle Eastern origins.
Summary The importance of the blood- and lymph vessels in the transport of essential fluids, gases, macromolecules and cells in vertebrates warrants optimal insight into the regulatory mechanisms underlying their development. Mouse and zebrafish models of lymphatic development are instrumental for gene discovery and gene characterization but are challenging for certain aspects, e.g. no direct accessibility of embryonic stages, or non-straightforward visualization of early lymphatic sprouting, respectively. We previously demonstrated that the Xenopus tadpole is a valuable model to study the processes of lymphatic development. However, a fluorescent Xenopus reporter directly visualizing the lymph vessels was lacking. Here, we created transgenic Tg(Flk1:eGFP) Xenopus laevis reporter lines expressing green fluorescent protein (GFP) in blood- and lymph vessels driven by the Flk1 (VEGFR-2) promoter. We also established a high-resolution fluorescent dye labeling technique selectively and persistently visualizing lymphatic endothelial cells, even in conditions of impaired lymph vessel formation or drainage function upon silencing of lymphangiogenic factors. Next, we applied the model to dynamically document blood and lymphatic sprouting and patterning of the initially avascular tadpole fin. Furthermore, quantifiable models of spontaneous or induced lymphatic sprouting into the tadpole fin were developed for dynamic analysis of loss-of-function and gain-of-function phenotypes using pharmacologic or genetic manipulation. Together with angiography and lymphangiography to assess functionality, Tg(Flk1:eGFP) reporter tadpoles readily allowed detailed lymphatic phenotyping of live tadpoles by fluorescence microscopy. The Tg(Flk1:eGFP) tadpoles represent a versatile model for functional lymph/angiogenomics and drug screening.
A more detailed insight into disease mechanisms of multiple sclerosis (MS) is crucial for the development of new and more effective therapies. MS is a chronic inflammatory autoimmune disease of the central nervous system. The aim of this study is to identify novel disease associated proteins involved in the development of inflammatory brain lesions, to help unravel underlying disease processes. Brainstem proteins were obtained from rats with MBP induced acute experimental autoimmune encephalomyelitis (EAE), a well characterized disease model of MS. Samples were collected at different time points: just before onset of symptoms, at the top of the disease and following recovery. To analyze changes in the brainstem proteome during the disease course, a quantitative proteomics study was performed using two-dimensional difference in-gel electrophoresis (2D-DIGE) followed by mass spectrometry. We identified 75 unique proteins in 92 spots with a significant abundance difference between the experimental groups. To find disease-related networks, these regulated proteins were mapped to existing biological networks by Ingenuity Pathway Analysis (IPA). The analysis revealed that 70% of these proteins have been described to take part in neurological disease. Furthermore, some focus networks were created by IPA. These networks suggest an integrated regulation of the identified proteins with the addition of some putative regulators. Post-synaptic density protein 95 (DLG4), a key player in neuronal signalling and calcium-activated potassium channel alpha 1 (KCNMA1), involved in neurotransmitter release, are 2 putative regulators connecting 64% of the identified proteins. Functional blocking of the KCNMA1 in macrophages was able to alter myelin phagocytosis, a disease mechanism highly involved in EAE and MS pathology. Quantitative analysis of differentially expressed brainstem proteins in an animal model of MS is a first step to identify disease-associated proteins and networks that warrant further research to study their actual contribution to disease pathology.
Most bacteria control oxidative stress through the H(2)O(2)-responsive transactivator OxyR, a member of the LTTR family (LysR Type Transcriptional Regulators), which activates the expression of defensive genes such as those encoding catalases, alkyl hydroperoxide reductases and superoxide dismutases. In the human opportunistic pathogen Pseudomonas aeruginosa, OxyR positively regulates expression of the oxidative stress response genes katA, katB, ahpB and ahpCF. To identify additional targets of OxyR in P. aeruginosa PAO1, we performed chromatin immunoprecipitation in combination with whole genome tiling array analyses (ChIP-chip). We detected 56 genes including all the previously identified defensive genes and a battery of novel direct targets of OxyR. Electrophoretic mobility shift assays (EMSAs) for selected newly identified targets indicated that ∼70% of those were bound by purified oxidized OxyR and their regulation was confirmed by quantitative real-time polymerase chain reaction. Furthermore, a thioredoxin system was identified to enzymatically reduce OxyR under oxidative stress. Functional classification analysis showed that OxyR controls a core regulon of oxidative stress defensive genes, and other genes involved in regulation of iron homeostasis (pvdS), quorum-sensing (rsaL), protein synthesis (rpsL) and oxidative phosphorylation (cyoA and snr1). Collectively, our results indicate that OxyR is involved in oxidative stress defense and regulates other aspects of cellular metabolism as well.
Abstract Growth arrest-specific gene 6 (Gas6) binds to the TAM family of receptor tyrosine kinases (TAMRs) and exerts pleiotropic functions in health and disease. TAMRs, in particular Axl, have transforming properties, and are highly expressed in human tumor cells. In contrast, little is known about the role of Gas6 in cancer. Previous studies indicate that Gas6 stimulates proliferation of cancer cells in vitro and that it is present in human tumor tissue. By using Gas6-deficient mice, we explored the role of Gas6 in tumor biology in vivo in detail and here unravel a previously unknown mechanism, how malignant cells educate infiltrating leukocytes, in particular macrophages, to upregulate Gas6 and as such promote their growth. By analyzing Gas6 expression, we found that in murine syngeneic tumor models (colonic CT26, pancreatic Panc02 and breast 4T1 tumors) Gas6 is exclusively expressed in host cells, most notably in tumor-infiltrating leukocytes, and to a lesser extent in tumor endothelial cells, but was beyond threshold of detection in tumor cells. Investigation of Gas6 expression in different intratumoral leukocyte subfractions (macrophages, monocytes, granulocytes, T-cells, B-cells, dendritic cells, NK cells) revealed highest Gas6 expression in tumor-associated macrophages (TAMs) and dendritic cells. Importantly, by comparing Gas6 expression in TAMs to resident tissue macrophages (isolated from spleen, lung and peritoneum), we found that tumors specifically educate TAMs to upregulate Gas6, which is mediated by IL-10. To analyze a potential impact of Gas6 on tumor progression, we studied growth of different tumor models (see above) in Gas6-/- mice, and found impaired tumor growth and metastasis in all studied models, including one resistant to VEGF inhibitors (lymphoma EL4), by 35-55%. Phenotypic analyses of tumors grown in wt mice in comparison to Gas6-deficient mice revealed reduced proliferation of tumor cells in Gas6-/- hosts. Angiogenesis, lymphangiogenesis, apoptosis and intra-tumoral coagulation were similar in both genotypes. Based on these findings we put forward the hypothesis that tumors educate infiltrating leukocytes to upregulate Gas6, which stimulates their growth. To functionally proof this concept, we performed cross-over bone marrow transplantation (BMT) studies in 3 different tumor models. These experiments revealed that transplantation of wt bone marrow into Gas6-/- hosts rescues impaired tumor growth, conversely transplantation of Gas6-/- bone marrow into wt hosts phenocopies decreased tumor growth in Gas6-/- mice. Hence, bone marrow-derived cells indeed deliver growth-promoting Gas6 into tumors, which stimulates their growth. This concept was further underscored by strongly reduced capability of Gas6-/- TAMs to stimulate proliferation of tumor cells compared to wt TAMs. In summary, our studies identify Gas6 as potential novel target in cancer. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1353.
The transforming and tumor growth-promoting properties of Axl, a member of the Tyro3, Axl, and Mer (TAM) family of receptor tyrosine kinases (TAMRs), are well recognized. In contrast, little is known about the role of the TAMR ligand growth arrest-specific gene 6 (Gas6) in tumor biology. By using Gas6-deficient (Gas6(-/-)) mice, we show that bone marrow-derived Gas6 promotes growth and metastasis in different experimental cancer models, including one resistant to vascular endothelial growth factor inhibitors. Mechanistic studies reveal that circulating leukocytes produce minimal Gas6. However, once infiltrated in the tumor, leukocytes up-regulate Gas6, which is mitogenic for tumor cells. Consistent herewith, impaired tumor growth in Gas6(-/-) mice is rescued by transplantation of wild-type bone marrow and, conversely, mimicked by transplantation of Gas6(-/-) bone marrow into wild-type hosts. These findings highlight a novel role for Gas6 in a positive amplification loop, whereby tumors promote their growth by educating infiltrating leukocytes to up-regulate the production of the mitogen Gas6. Hence, inhibition of Gas6 might offer novel opportunities for the treatment of cancer.