French Institute of Health and Medical Research

About: French Institute of Health and Medical Research is a government organization based out in Paris, France. It is known for research contribution in the topics: Population & Receptor. The organization has 109367 authors who have published 174236 publications receiving 8365503 citations.

Tumor-derived exosomes are a source of shared tumor rejection antigens for CTL cross-priming.

Abstract: The initiation of T-cell-mediated antitumor immune responses requires the uptake and processing of tumor antigens by dendritic cells and their presentation on MHC-I molecules. Here we show in a human in vitro model system that exosomes, a population of small membrane vesicles secreted by living tumor cells, contain and transfer tumor antigens to dendritic cells. After mouse tumor exosome uptake, dendritic cells induce potent CD8+ T-cell-dependent antitumor effects on syngeneic and allogeneic established mouse tumors. Therefore, exosomes represent a novel source of tumor-rejection antigens for T-cell cross priming, relevant for immunointerventions.

HiC-Pro: an optimized and flexible pipeline for Hi-C data processing

Abstract: HiC-Pro is an optimized and flexible pipeline for processing Hi-C data from raw reads to normalized contact maps. HiC-Pro maps reads, detects valid ligation products, performs quality controls and generates intra- and inter-chromosomal contact maps. It includes a fast implementation of the iterative correction method and is based on a memory-efficient data format for Hi-C contact maps. In addition, HiC-Pro can use phased genotype data to build allele-specific contact maps. We applied HiC-Pro to different Hi-C datasets, demonstrating its ability to easily process large data in a reasonable time. Source code and documentation are available at http://github.com/nservant/HiC-Pro .

neurogenin3 is required for the development of the four endocrine cell lineages of the pancreas

Abstract: In the mammalian pancreas, the endocrine cell types of the islets of Langerhans, including the α-, β-, δ-, and pancreatic polypeptide cells as well as the exocrine cells, derive from foregut endodermal progenitors. Recent genetic studies have identified a network of transcription factors, including Pdx1, Isl1, Pax4, Pax6, NeuroD, Nkx2.2, and Hlxb9, regulating the development of islet cells at different stages, but the molecular mechanisms controlling the specification of pancreatic endocrine precursors remain unknown. neurogenin3 (ngn3) is a member of a family of basic helix–loop–helix transcription factors that is involved in the determination of neural precursor cells in the neuroectoderm. ngn3 is expressed in discrete regions of the nervous system and in scattered cells in the embryonic pancreas. We show herein that ngn3-positive cells coexpress neither insulin nor glucagon, suggesting that ngn3 marks early precursors of pancreatic endocrine cells. Mice lacking ngn3 function fail to generate any pancreatic endocrine cells and die postnatally from diabetes. Expression of Isl1, Pax4, Pax6, and NeuroD is lost, and endocrine precursors are lacking in the mutant pancreatic epithelium. Thus, ngn3 is required for the specification of a common precursor for the four pancreatic endocrine cell types.

Coherent plane-wave compounding for very high frame rate ultrasonography and transient elastography

Abstract: The emergence of ultrafast frame rates in ultrasonic imaging has been recently made possible by the development of new imaging modalities such as transient elastography. Data acquisition rates reaching more than thousands of images per second enable the real-time visualization of shear mechanical waves propagating in biological tissues, which convey information about local viscoelastic properties of tissues. The first proposed approach for reaching such ultrafast frame rates consists of transmitting plane waves into the medium. However, because the beamforming process is then restricted to the receive mode, the echographic images obtained in the ultrafast mode suffer from a low quality in terms of resolution and contrast and affect the robustness of the transient elastography mode. It is here proposed to improve the beamforming process by using a coherent recombination of compounded plane-wave transmissions to recover high-quality echographic images without degrading the high frame rate capabilities. A theoretical model is derived for the comparison between the proposed method and the conventional B-mode imaging in terms of contrast, signal-to-noise ratio, and resolution. Our model predicts that a significantly smaller number of insonifications, 10 times lower, is sufficient to reach an image quality comparable to conventional B-mode. Theoretical predictions are confirmed by in vitro experiments performed in tissue-mimicking phantoms. Such results raise the appeal of coherent compounds for use with standard imaging modes such as B-mode or color flow. Moreover, in the context of transient elastography, ultrafast frame rates can be preserved while increasing the image quality compared with flat insonifications. Improvements on the transient elastography mode are presented and discussed.