The Antitumor Activity of Combinations of Cytotoxic Chemotherapy and Immune Checkpoint Inhibitors Is Model-Dependent

In spite of impressive response rates in multiple cancer types, immune checkpoint inhibitors (ICIs) are active in only a minority of patients. Alternative strategies currently aim to combine immunotherapies with conventional agents such as cytotoxic chemotherapies. Here, we performed a study of PD-1 or PDL-1 blockade in combination with reference chemotherapies in four fully immunocompetent mouse models of cancer. We analyzed both the in vivo antitumor response, and the tumor immune infiltrate 4 days after the first treatment. in vivo tumor growth experiments revealed variable responsiveness to ICIs between models. We observed enhanced antitumor effects of the combination of immunotherapy with chemotherapy in the MC38 colon and MB49 bladder models, a lack of response in the 4T1 breast model, and an inhibition of ICIs activity in the MBT-2 bladder model. Flow cytometry analysis of tumor samples showed significant differences in all models between untreated and treated mice. At baseline, all the tumor models studied were predominantly infiltrated with cells harboring an immunosuppressive phenotype. Early alterations of the tumor immune infiltrate after treatment were found to be highly variable. We found that the balance between effector cells and immunosuppressive cells in the tumor microenvironment could be altered with some treatment combinations, but this effect was not always correlated with an impact on in vivo tumor growth. These results show that the combination of cytotoxic chemotherapy with ICIs may result in enhanced, similar or reduced antitumor activity, in a model- and regimen-dependent fashion. The present investigations should help to select appropriate combination regimens for ICIs

Exposome and human induced pluripotent stem cells : modeling effect of air pollution on airway epithelium.

La pollution atmosphérique est responsable d’environ 7 millions de décès prématurés par an au niveau mondial. Les particules fines (PM2.5) en particulier, jouent un rôle majeur dans le développement de pathologies respiratoires chroniques telles que la bronchopneumopathie obstructive chronique et l’asthme. Plusieurs études ont récemment mis en évidence que ces maladies pouvaient prendre racine dès l’enfance, au cours du développement pulmonaire. Il existe cependant peu de modèles précliniques permettant d’étudier ces étapes précoces et critiques en santé respiratoire. Les cellules souches pluripotentes induites humaines (hiPSC) sont capables de se différencier vers tous les types cellulaires de l’organisme. Elles offrent ainsi une formidable opportunité de modéliser in vitro le développement pulmonaire et plus particulièrement celui de l’épithélium bronchique, dans le cadre de ces pathologies respiratoires chroniques.Grâce à un protocole de différenciation de hiPSC vers un épithélium bronchique fonctionnel, nous pouvons mimer les étapes clés de la morphogenèse bronchique in vitro en reproduisant les stades d’endoderme définitif, d’intestin primitif antérieur, de progéniteurs bronchiques jusqu’au stade d’épithélium bronchique composé de cellules multiciliées, à mucus, basales, club et neuroendocrines. En exposant à différents stades du protocole cet épithélium à des particules fines de pollution atmosphérique, nous avons pu mettre en évidence une cytotoxicité provoquée par de fortes doses de PM2.5, une induction de mécanismes de stress oxydant et d’inflammation, ainsi qu’un impact sur le processus de différenciation : diminution des marqueurs d’intestin primitif antérieur et de progéniteurs bronchiques aux étapes précoces ; modifications de la proportion des marqueurs de cellules terminales aux étapes tardives.Les résultats de ce travail ouvrent de nouvelles perspectives dans l’étude de l’impact de la pollution atmosphérique sur le développement pulmonaire. En enrichissant ce modèle d’autres compartiments cellulaires du poumon, en développant de nouveaux systèmes d’exposition et en variant le fond génétique des hiPSC, les propriétés d’auto-renouvellement virtuellement illimité de ces cellules souches pourraient permettre une évaluation à grande échelle de l’impact de nombreux facteurs environnementaux, au cours du développement.ABSTRACTAir pollution is one of the largest environmental cause of disease and every year, 7 millions of premature deaths are attributable to air pollution worldwide. Ambient fine particulate matter plays a major role in the development of chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD) or asthma. Recently, several studies have highlighted pediatric roots in the trajectories of these diseases. However, only few preclinical models are available to study these early developmental stages yet critical in respiratory health. Human induced pluripotent stem cells (hiPSC) are able to differentiate into all cell types of human body. Thus, they offer a great opportunity to recapitulate lung development in vitro, especially bronchial airway development.Thanks to our differentiation protocol of hiPSC into functional airway epithelium, we can mimic in vitro key bronchial development steps: definitive endoderm, anterior foregut endoderm, lung progenitors towards functional epithelial cells such as ciliated cells, goblet cells, basal cells, club cells and neuroendocrine cells. PM2.5 exposure performed at different steps of the protocol showed high doses related cytotoxicity, oxidative stress and inflammatory responses. An effect on differentiation process was also observed with a decrease of anterior foregut endoderm and lung progenitors markers along with a modification in differentiated cells proportion.These results open new possibilities to study air pollution impact on lung development. Thanks to hiPSC self-renewal property, high scale exposure studies of environmental factors impact on lung development could emerge by adding new cell types to this model, developing new exposure systems and modifying genetic background of hiPSC

Pipeline for the Generation and Characterization of Transgenic Human Pluripotent Stem Cells Using the CRISPR/Cas9 Technology

International audienceRecent advances in genome engineering based on the CRISPR/Cas9 technology have revolutionized our ability to manipulate genomic DNA. Its use in human pluripotent stem cells (hPSCs) has allowed a wide range of mutant cell lines to be obtained at an unprecedented rate. The combination of these two groundbreaking technologies has tremendous potential, from disease modeling to stem cell-based therapies. However, the generation, screening and molecular characterization of these cell lines remain a cumbersome and multi-step endeavor. Here, we propose a pipeline of strategies to efficiently generate, sub-clone, and characterize CRISPR/Cas9-edited hPSC lines in the function of the introduced mutation (indels, point mutations, insertion of large constructs, deletions)

The Risk of Thrombosis Around Pregnancy: Where Do We Stand?

International audiencePregnancy and puerperium increase the relative risk of venous thromboembolism (VTE) and the absolute risk remains low, around 1 per 1,000, with induced mortality of around 1 per 100,000. Analysis of large databases has helped specify the modes of presentation and risk factors (RF) whose impact is greater after than before childbirth, since VTE during pregnancy and post-partum obey different RFs. The evolution of the population concerned (mostly women over 35, obese, of multi-ethnicity undergoing medically assisted reproduction) affects the frequency of these RFs. Pulmonary embolism (PE) is over-represented after childbirth, but 30% of PE in pregnancy occurs without any RFs. Recommendations for prevention, mainly from expert groups, are heterogeneous and often discordant. Low molecular weight heparins (LMWH) are the mainstay of pharmacological thromboprophylaxis, in a field where randomized controlled studies are definitely lacking. VTE risk assessment in pregnancy must be systematic and repetitive. Risk assessment methods and scores are beginning to emerge to guide thromboprophylaxis and should be used more systematically. In the future, analyzing observational data from huge, nationwide registries and prospective cluster clinical trials may bring to light clinically relevant outcomes likely to feed comprehensive guidelines

Hemodiafiltration improves free light chain removal and normalizes κ/λ ratio in hemodialysis patients

International audienceSerum free light chain (FLC) levels are correlated with chronic kidney disease (CKD) stages and are highest in patients on hemodialysis (HD). Aim of this study was to assess the FLC removal efficiency of Elisio™-210H dialyzer using either high-flux HD or on line high efficiency hemodiafiltration (HDF) modalities in CKD-5D patients

Induced Pluripotent Stem Cells for Primary Ciliary Dyskinesia Modeling and Personalized Medicine

International audiencePrimary ciliary dyskinesia (PCD) is a rare and heterogeneous genetic disorder that affects the structure and function of motile cilia. In the airway epithelium, impaired ciliary motion results in reduced or absent mucociliary clearance that leads to the appearance of chronic airway infection, sinusitis and bronchiectasis. Currently, there is no effective treatment for PCD, and research is limited by the lack of convenient models to study this disease and investigate innovative therapies. Furthermore, the high heterogeneity of PCD genotypes is likely to hinder the development of a single therapy for all patients. The generation of patient-derived induced pluripotent stem cells (iPSC) and their differentiation into airway epithelium as well as genome editing technologies could represent major tools for in vitro PCD modelling and for developing personalized therapies. Here, we review PCD pathogenesis, and then discuss how human iPSC could be used to model this disease for the development of innovative patient-specific biotherapies

New erythrocyte parameters derived from the Coulter principle relate with red blood cell properties-A pilot study in diabetes mellitus.

In routine hematological instruments, blood cells are counted and sized by monitoring the impedance signals induced during their passage through a Coulter orifice. However, only signals associated with centered paths in the aperture are considered for analysis, while the rejected measurements, caused by near-wall trajectories, can provide additional information on red blood cells (RBC), as recent publications suggest. To assess usefulness of two new parameters in describing alterations in RBC properties, we performed a pilot study to compare blood samples from patients with diabetes mellitus (DM), frequent pathological condition associated with impairment in RBC deformability, versus controls. A total of 345 blood samples were analyzed: 225 in the DM group and 120 in the control group. A diagram of [Formula: see text] and [Formula: see text], the two new parameters derived from the analysis of impedancemetry pulses, was used to compare distribution of RBC subpopulations between groups. To discriminate RBC from DM and control individuals, based on our multiparametric analysis, we built a score from variables derived from [Formula: see text] matrix which showed good performances: area under the receiving operating characteristic curve 0.948 (0.920-0.970), p<0.0001; best discriminating value: negative predictive value 94.7%, positive predictive value was 78.4%. These results seem promising to approach RBC alterations in routine laboratory practice. The related potential clinically relevant outcomes remain to be investigated

Generation of four severe early-onset chronic obstructive pulmonary disease (COPD) patient-derived induced pluripotent stem cell lines from peripheral blood mononuclear cells

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Targeted therapy in eosinophilic chronic obstructive pulmonary disease

International audienceChronic obstructive pulmonary disease (COPD) is a common and preventable airway disease causing significant worldwide mortality and morbidity. Lifetime exposure to tobacco smoking and environmental particles are the two major risk factors. Over recent decades, COPD has become a growing public health problem with an increase in incidence. COPD is defined by airflow limitation due to airway inflammation and small airway remodelling coupled to parenchymal lung destruction. Most patients exhibit neutrophil-predominant airway inflammation combined with an increase in macrophages and CD8 + T-cells. Asthma is a heterogeneous chronic inflammatory airway disease. The most studied subtype is type 2 (T2) high eosinophilic asthma, for which there are an increasing number of biologic agents developed. However, both asthma and COPD are complex and share common pathophysiological mechanisms. They are known as overlapping syndromes as approximately 40% of patients with COPD present an eosinophilic airway inflammation. Several studies suggest a putative role of eosinophilia in lung function decline and COPD exacerbation. Recently, pharmacological agents targeting eosinophilic traits in uncontrolled eosinophilic asthma, especially monoclonal antibodies directed against interleukins (IL-5, IL-4, IL-13) or their receptors, have shown promising results. This review examines data on the rationale for such biological agents and assesses efficacy in T2-endotype COPD patients. @ERSpublications Patients with severe COPD and eosinophilic inflammation experience uncontrolled symptoms despite optimal pharmaceutical treatment. The development of new biomarkers is needed for better phenotyping of patients to propose innovative targeted therapy