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Increased production of fetal hemoglobin (HbF) can ameliorate the severity of sickle cell disease and beta-thalassemia(1). BCL11A represses the genes encoding HbF and regulates human hemoglobin switching through variation in its expression during development(2-7). However, the mechanisms underlying the developmental expression of BCL11A remain mysterious. Here we show that BCL11A is regulated at the level of messenger RNA (mRNA) translation during human hematopoietic development. Despite decreased BCL11A protein synthesis earlier in development, BCL11A mRNA continues to be associated with ribosomes. Through unbiased genomic and proteomic analyses, we demonstrate that the RNA-binding protein LIN28B, which is developmentally expressed in a pattern reciprocal to that of BCL11A, directly interacts with ribosomes and BCL11A mRNA. Furthermore, we show that BCL11A mRNA translation is suppressed by LIN28B through direct interactions, independently of its role in regulating let-7 microRNAs, and that BCL11A is the major target of LIN28B-mediated HbF induction. Our results reveal a previously unappreciated mechanism underlying human hemoglobin switching that illuminates new therapeutic opportunities. Experiments in developing human erythroid cells show that LIN28B controls hemoglobin switching by directly suppressing BCL11A translation, independently of its role in regulating let-7 microRNA biogenesis.

Since its discovery, the face-processing network in the brain of the macaque monkey has emerged as a model system that allowed for major neural mechanisms of face recognition to be identified - with implications for object recognition at large. Populations of face cells encode faces through broad tuning curves, whose shapes change over time. Face representations differ qualitatively across faces areas, and we not only understand the global organization of these specializations, but also some of the transformations between face areas, both feed-forward and feed-back, and the computational principles behind face representations and transformations. Facial information is combined with physical features and mnemonic features in extensions of the core network, which forms an early part of the primate social brain.

BackgroundAtopic dermatitis is a chronic inflammatory condition with substantial burden and limited treatment options for adolescents with moderate-to-severe disease. Significantly more patients treated with dupilumab vs. placebo achieved Investigator's Global Assessment 0/1 at week 16.ObjectiveThe objective of this study was to assess the impact of dupilumab treatment vs. placebo on the achievement of clinically meaningful improvements in atopic dermatitis signs, symptoms and quality of life.MethodsR668-AD-1526 LIBERTY AD ADOL was a randomized, double-blinded, parallel-group, phase III clinical trial. Two hundred and fifty-one adolescents with moderate-to-severe atopic dermatitis received dupilumab 300 mg every 4 weeks (q4w; n=84), dupilumab 200 or 300 mg every 2 weeks (q2w; n=82), or placebo (n=85). A post-hoc subgroup analysis was performed on 214 patients with Investigator's Global Assessment >1 at week 16. Measures of atopic dermatitis signs, symptoms, and quality of life were assessed. Clinically meaningful improvement in one or more of three domains of signs, symptoms, and quality of life was defined as an improvement of >= 50% in Eczema Area and Severity Index, >= 3 points in Peak Pruritus Numerical Rating Scale, or >= 6 points in the Children's Dermatology Life Quality Index from baseline.ResultsOf patients receiving dupilumab q2w, 80.5% [66/82] experienced clinically meaningful improvements in atopic dermatitis signs, symptoms, or quality of life at week 16 (vs. placebo, 20/85 [23.5%], difference 57.0% [95% confidence interval 44.5-69.4]; q4w vs. placebo, 53/84 [63.1%], difference 39.6% [95% confidence interval 25.9-53.3]; both p<0.0001). Results were similar in adolescents with Investigator's Global Assessment >1 at week 16 (q2w, 46/62 [74.2%] vs. placebo, 18/83 [21.7%], difference 52.5% [95% confidence interval 38.5-66.6]; q4w, 38/69 [55.1%] vs. placebo, difference 33.4% [95% confidence interval 18.7-48.1]; both p<0.0001).ConclusionsDupilumab provided clinically meaningful improvements in signs, symptoms, and quality of life in adolescents with moderate-to-severe atopic dermatitis among patients with Investigator's Global Assessment >1 at week 16. Treatment responses should be interpreted in the context of such clinically relevant patient-reported outcome measures.

Staphylococcal bi-component pore-forming toxins, also known as leukocidins, target and lyse human phagocytes in a receptor-dependent manner. S-components of the leukocidins Panton-Valentine leukocidin (PVL), gamma-haemolysin (HlgAB) and CB (HlgCB), and leukocidin ED (LukED) specifically employ receptors that belong to the class of G-protein coupled receptors (GPCRs). Although these receptors share a common structural architecture, little is known about the conserved characteristics of the interaction between leukocidins and GPCRs. In this study, we investigated host cellular pathways contributing to susceptibility towards S. aureus leukocidin cytotoxicity. We performed a genome-wide CRISPR/Cas9 library screen for toxin-resistance in U937 cells sensitized to leukocidins by ectopic expression of different GPCRs. Our screen identifies post-translational modification (PTM) pathways involved in the sulfation and sialylation of the leukocidin-receptors. Subsequent validation experiments show differences in the impact of PTM moieties on leukocidin toxicity, highlighting an additional layer of refinement and divergence in the staphylococcal host-pathogen interface. Leukocidin receptors may serve as targets for anti-staphylococcal interventions and understanding toxin-receptor interactions will facilitate the development of innovative therapeutics. Variations in the genes encoding PTM pathways could provide insight into observed differences in susceptibility of humans to infections with S. aureus.

Purpose Caspase-associated recruitment domain-9 (CARD9) deficiency is an inborn error of immunity that typically predisposes otherwise healthy patients to single fungal infections and the occurrence of multiple invasive fungal infections is rare. It has been described as the first known condition that predisposes to extrapulmonary Aspergillus infection with preserved lungs. We present a patient that expands the clinical variability of CARD9 deficiency. Materials and methods Genetic analysis was performed by Sanger sequencing. Neutrophils and mononuclear phagocyte response to fungal stimulation were evaluated through luminol-enhanced chemiluminescence and whole blood production of the proinflammatory mediator interleukin (IL)-6, respectively. Results We report a 56-year-old Argentinean woman, whose invasive Exophiala spinifera infection at the age of 32 years was unexplained and reported in year 2004. At the age of 49 years, she presented with chronic pulmonary disease due to Aspergillus nomius. After partial improvement following treatment with caspofungin and posaconazole, right pulmonary bilobectomy was performed. Despite administration of multiple courses of antifungals, sustained clinical remission could not be achieved. We recently found that the patient's blood showed an impaired production of IL-6 when stimulated with zymosan. We also found that she is homozygous for a previously reported CARD9 loss-of-function mutation (Q289*). Conclusions This is the first report of a patient with inherited CARD9 deficiency and chronic invasive pulmonary aspergillosis (IPA) due to A. nomius. Inherited CARD9 deficiency should be considered in otherwise healthy children and adults with one or more invasive fungal diseases.

The surface and lining tissues of our body are exposed to the external environment, and as such these epithelial tissues must form structural barriers able to defend against microbes, environmental toxins, and mechanical stress. Their cells are equipped to detect a diverse array of surface perturbations, and then launch signaling relays to the immune system. The aim of these liaisons is to coordinate the requisite immune cell response needed to preserve and/or restore barrier integrity and defend the host. It has been recently appreciated that epithelial cells learn from these experiences. Following inflammatory exposure, long-lived stem cells within the tissue retain an epigenetic memory that endows them with heightened responsiveness to subsequent encounters with stress. Here, we review the recent literature on how epithelial cells sense signals from microbes, allergens, and injury at the tissue surface, and transmit this information to immune cells, while embedding a memory of the experience within their chromatin.

Interferon gamma (IFN-gamma) was shown to be a macrophage activating factor already in 1984. Consistently, inborn errors of IFN-gamma immunity underlie Mendelian Susceptibility to Mycobacterial Disease (MSMD). MSMD is characterized by genetic predisposition to disease caused by weakly virulent mycobacterial species. Paradoxically, macrophages from patients with MSMD were little tested. Here, we report a disease modeling platform for studying IFN-gamma related pathologies using macrophages derived from patient specific induced pluripotent stem cells (iPSCs). We used iPSCs from patients with autosomal recessive complete- and partial IFN-gamma R2 deficiency, partial IFN-gamma R1 deficiency and complete STAT1 deficiency. Macrophages from all patient iPSCs showed normal morphology and IFN-gamma-independent functionality like phagocytic uptake of bioparticles and internalization of cytokines. For the IFN-gamma-dependent functionalities, we observed that the deficiencies played out at various stages of the IFN-gamma pathway, with the complete IFN-gamma R2 and complete STAT1 deficient cells showing the most severe phenotypes, in terms of upregulation of surface markers and induction of downstream targets. Although iPSC-derived macrophages with partial IFN-gamma R1 and IFN-gamma R2 deficiency still showed residual induction of downstream targets, they did not reduce the mycobacterial growth when challenged with Bacillus Calmette-Guerin. Taken together, we report a disease modeling platform to study the role of macrophages in patients with inborn errors of IFN-gamma immunity.

During implantation, cytotrophoblasts undergo epithelial-to-mesenchymal transition (EMT) as they differentiate into invasive extravillous trophoblasts (EVTs). The primate-specific microRNA cluster on chromosome 19 (C19MC) is exclusively expressed in the placenta, embryonic stem cells and certain cancers however, its role in EMT gene regulation is unknown. In situ hybridization for miR-517a/c, a C19MC cistron microRNA, in first trimester human placentas displayed strong expression in villous trophoblasts and a gradual decrease from proximal to distal cell columns as cytotrophoblasts differentiate into invasive EVTs. To investigate the role of C19MC in the regulation of EMT genes, we employed the CRISPR/dCas9 Synergistic Activation Mediator (SAM) system, which induced robust transcriptional activation of the entire C19MC cistron and resulted in suppression of EMT associated genes. Exposure of human iPSCs to hypoxia or differentiation of iPSCs into either cytotrophoblast-stem-like cells or EVT-like cells under hypoxia reduced C19MC expression and increased EMT genes. Furthermore, transcriptional activation of the C19MC cistron induced the expression of OCT4 and FGF4 and accelerated cellular reprogramming. This study establishes the CRISPR/dCas9 SAM as a powerful tool that enables activation of the entire C19MC cistron and uncovers its novel role in suppressing EMT genes critical for maintaining the epithelial cytotrophoblasts stem cell phenotype.

Identifying the environmental information and computations that drive sensory detection is key for understanding animal behavior. Using experimental and theoretical analysis of AWC(ON), a well-described olfactory neuron in C. elegans, here we derive a general and broadly useful model that matches stimulus history to odor sensation and behavioral responses. We show that AWC(ON) sensory activity is regulated by an absolute signal threshold that continuously adapts to odor history, allowing animals to compare present and past odor concentrations. The model predicts sensory activity and probabilistic behavior during animal navigation in different odor gradients and across a broad stimulus regime. Genetic studies demonstrate that the cGMP-dependent protein kinase EGL-4 determines the timescale of threshold adaptation, defining a molecular basis for a critical model feature. The adaptive threshold model efficiently filters stimulus noise, allowing reliable sensation in fluctuating environments, and represents a feedforward sensory mechanism with implications for other sensory systems.

The cerebral vasculature is a dense network of arteries, capillaries, and veins. Quantifying variations of the vascular organization across individuals, brain regions, or disease models is challenging. We used immunolabeling and tissue clearing to image the vascular network of adult mouse brains and developed a pipeline to segment terabyte-sized multi-channel images from light sheet microscopy, enabling the construction, analysis, and visualization of vascular graphs composed of over 100 million vessel segments. We generated datasets from over 20 mouse brains, with labeled arteries, veins, and capillaries according to their anatomical regions. We characterized the organization of the vascular network across brain regions, highlighting local adaptations and functional correlates. We propose a classification of cortical regions based on the vascular topology. Finally, we analysed brain-wide rearrangements of the vasculature in animal models of congenital deafness and ischemic stroke, revealing that vascular plasticity and remodeling adopt diverging rules in different models.