Ezrin drives adaptation of monocytes to the inflamed lung microenvironment.

Ezrin, an actin-binding protein, orchestrates the organization of the cortical cytoskeleton and plasma membrane during cell migration, adhesion, and proliferation. Its role in monocytes/macrophages (MΦs) is less understood. Here, we used a monocyte/MΦ-specific ezrin knock-out mouse model to investigate the contribution of ezrin to monocyte recruitment and adaptation to the lung extracellular matrix (ECM) in response to lipopolysaccharide (LPS).

CCR2+ monocytes are dispensable to resolve acute pulmonary Pseudomonas aeruginosa infections in WT and Cystic Fibrosis mice.

Extravasation of CCR2-positive monocytes into tissue and to the site of injury is a fundamental immunological response to infections. Nevertheless, exuberant recruitment and/or activity of these monocytes and monocyte-derived macrophages can propagate tissue damage, especially in chronic inflammatory disease conditions. We have previously shown that inhibiting the recruitment of CCR2-positive monocytes ameliorates lung tissue damage caused by chronic neutrophilic inflammation in cystic fibrosis (CF) mouse models.

Aplastic anemia in association with multiple myeloma: clinical and pathophysiological insights.

We investigated immune cytopenia in multiple myeloma (MM) patients with concurrent acquired aplastic anemia (AA), focusing on three clinical cases treated with plasma cell-directed therapy. All three patients achieved partial response in MM and one patient experienced complete resolution of AA. Two patients had partial improvement in transfusion requirement but continued to suffer from severe AA, leading to immunosuppressive therapy (IST) with improvement of transfusion requirement in both patients.

CDK9 phosphorylates RUNX1 to promote megakaryocytic fate in megakaryocytic-erythroid progenitors.

The specification of megakaryocytic (Mk) or erythroid (E) lineages from primary human megakaryocytic-erythroid progenitors (MEPs) is crucial for hematopoietic homeostasis, yet the underlying mechanisms regulating fate specification remain elusive. In this study, we identify RUNX1 as a key modulator of gene expression during MEP fate specification. Overexpression of RUNX1 in primary human MEPs promotes Mk specification, whereas pan-RUNX inhibition favors E specification.

Single-cell analysis reveals transcriptional dynamics in healthy primary parathyroid tissue.

Studies on human parathyroids are generally limited to hyperfunctioning glands owing to the difficulty in obtaining normal human tissue. We therefore obtained non-human primate (NHP) parathyroids to provide a suitable alternative for sequencing that would bear a close semblance to human organs. Single-cell RNA expression analysis of parathyroids from four healthy adult reveals a continuous trajectory of epithelial cell states.

An immunophenotype-coupled transcriptomic atlas of human hematopoietic progenitors.

Analysis of the human hematopoietic progenitor compartment is being transformed by single-cell multimodal approaches. Cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) enables coupled surface protein and transcriptome profiling, thereby revealing genomic programs underlying progenitor states. To perform CITE-seq systematically on primary human bone marrow cells, we used titrations with 266 CITE-seq antibodies (antibody-derived tags) and machine learning to optimize a panel of 132 antibodies.

Core Needle Biopsies as an Alternative Source for Ex Vivo Expanded TIL for Adoptive Cell Therapy in Triple-Negative Breast Cancer.

Adoptive transfer of ex vivo expanded tumor-infiltrating lymphocytes (TILs) have produced long-term response in metastatic cancers. TILs have traditionally been expanded from surgically resected specimens. Ultrasound-guided core needle biopsy (CNB) is an alternative method that avoids the morbidity of surgery and have added benefits which may include patients not amenable to surgery as well as the potential to produce TILs from multiple lesions in the same patient.

Dysregulation of alternative splicing in spinocerebellar ataxia type 1.

Spinocerebellar ataxia type 1 is caused by an expansion of the polyglutamine tract in ATAXIN-1. Ataxin-1 is broadly expressed throughout the brain and is involved in regulating gene expression. However, it is not yet known if mutant ataxin-1 can impact the regulation of alternative splicing events.

Assay optimization for the objective quantification of human multilineage colony-forming units.

Colony-forming unit (CFU) assays are a powerful tool in hematopoietic research because they allow researchers to functionally test the lineage potential of individual stem and progenitor cells. Assaying for lineage potential is important for determining and validating the identity of progenitor populations isolated by methods such as fluorescence-activated cell sorting (FACS). However, current methods for CFU assays are limited in their ability to robustly assay multipotent progenitors with the ability to differentiate down the myeloid, erythroid, and megakaryocytic lineages because of the lack of specific growth factors necessary for certain lineage outputs.

Recruited monocytes/macrophages drive pulmonary neutrophilic inflammation and irreversible lung tissue remodeling in cystic fibrosis.

Persistent neutrophil-dominated lung inflammation contributes to lung damage in cystic fibrosis (CF). However, the mechanisms that drive persistent lung neutrophilia and tissue deterioration in CF are not well characterized. Starting from the observation that, in patients with CF, c-c motif chemokine receptor 2 (CCR2) monocytes/macrophages are abundant in the lungs, we investigate the interplay between monocytes/macrophages and neutrophils in perpetuating lung tissue damage in CF.

Longitudinal single-cell analysis of a patient receiving adoptive cell therapy reveals potential mechanisms of treatment failure.

Adoptive cell therapy (ACT) using tumor infiltrating lymphocytes (TIL) is being studied in multiple tumor types. However, little is known about clonal cell expansion in vitro and persistence of the ACT product in vivo. We performed single-cell RNA and T-Cell Receptor (TCR) sequencing on serial blood and tumor samples from a patient undergoing ACT, who did not respond.

Multiparameter analysis of timelapse imaging reveals kinetics of megakaryocytic erythroid progenitor clonal expansion and differentiation.

Single-cell assays have enriched our understanding of hematopoiesis and, more generally, stem and progenitor cell biology. However, these single-end-point approaches provide only a static snapshot of the state of a cell. To observe and measure dynamic changes that may instruct cell fate, we developed an approach for examining hematopoietic progenitor fate specification using long-term (> 7-day) single-cell time-lapse imaging for up to 13 generations with in situ fluorescence staining of primary human hematopoietic progenitors followed by algorithm-assisted lineage tracing.

Structure-function analysis of the role of megakaryoblastic leukemia 1 in megakaryocyte polyploidization.

Not available.

Recruitment of monocytes primed to express heme oxygenase-1 ameliorates pathological lung inflammation in cystic fibrosis.

Overwhelming neutrophilic inflammation is a leading cause of lung damage in many pulmonary diseases, including cystic fibrosis (CF). The heme oxygenase-1 (HO-1)/carbon monoxide (CO) pathway mediates the resolution of inflammation and is defective in CF-affected macrophages (MΦs). Here, we provide evidence that systemic administration of PP-007, a CO releasing/O transfer agent, induces the expression of HO-1 in a myeloid differentiation factor 88 (MyD88) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)-dependent manner.

Methylation of dual-specificity phosphatase 4 controls cell differentiation.

Mitogen-activated protein kinases (MAPKs) are inactivated by dual-specificity phosphatases (DUSPs), the activities of which are tightly regulated during cell differentiation. Using knockdown screening and single-cell transcriptional analysis, we demonstrate that DUSP4 is the phosphatase that specifically inactivates p38 kinase to promote megakaryocyte (Mk) differentiation. Mechanistically, PRMT1-mediated methylation of DUSP4 triggers its ubiquitinylation by an E3 ligase HUWE1.

Bone Marrow-Derived VSELs Engraft as Lung Epithelial Progenitor Cells after Bleomycin-Induced Lung Injury.

Background: Alveolar type 2 (AT2) cells and bronchioalveolar stem cells (BASC) perform critical regenerative functions in response to lung damage. Published data show that nonhematopoietic, bone marrow-derived "very small embryonic-like stem cells" (VSELs) can differentiate in vivo into surfactant protein C (SPC)-producing AT2 cells in the lung. Here, we test directly whether VSEL-derived BASC and AT2 cells function to produce differentiated progeny.

MRTFA: A critical protein in normal and malignant hematopoiesis and beyond.

Myocardin-related transcription factor A (MRTFA) is a coactivator of serum response factor, a transcription factor that participates in several critical cellular functions including cell growth and apoptosis. MRTFA couples transcriptional regulation to actin cytoskeleton dynamics, and the transcriptional targets of the MRTFA-serum response factor complex include genes encoding cytoskeletal proteins as well as immediate early genes. Previous work has shown that MRTFA promotes the differentiation of many cell types, including various types of muscle cells and hematopoietic cells, and MRTFA's interactions with other protein partners broaden its cellular roles.

Combined liver-cytokine humanization comes to the rescue of circulating human red blood cells.

In vivo models that recapitulate human erythropoiesis with persistence of circulating red blood cells (RBCs) have remained elusive. We report an immunodeficient murine model in which combined human liver and cytokine humanization confer enhanced human erythropoiesis and RBC survival in the circulation. We deleted the fumarylacetoacetate hydrolase () gene in MISTRG mice expressing several human cytokines in place of their murine counterparts.

Single cell epigenetic visualization assay.

Characterization of the epigenetic status of individual cells remains a challenge. Current sequencing approaches have limited coverage, and it is difficult to assign an epigenetic status to the transcription state of individual gene alleles in the same cell. To address these limitations, a targeted microscopy-based epigenetic visualization assay (EVA) was developed for detection and quantification of epigenetic marks at genes of interest in single cells.

Thrombocytopathy and endotheliopathy: crucial contributors to COVID-19 thromboinflammation.

The core pathology of coronavirus disease 2019 (COVID-19) is infection of airway cells by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that results in excessive inflammation and respiratory disease, with cytokine storm and acute respiratory distress syndrome implicated in the most severe cases. Thrombotic complications are a major cause of morbidity and mortality in patients with COVID-19. Patients with pre-existing cardiovascular disease and/or traditional cardiovascular risk factors, including obesity, diabetes mellitus, hypertension and advanced age, are at the highest risk of death from COVID-19.

Current understanding of human megakaryocytic-erythroid progenitors and their fate determinants.

Purpose Of Review: This review focuses on our current understanding of fate decisions in bipotent megakaryocyte-erythroid progenitors (MEPs). Although extensive research has been carried out over decades, our understanding of how MEP commit to the erythroid versus megakaryocyte fate remains unclear.

Recent Findings: We discuss the isolation of primary human MEP, and focus on gene expression patterns, epigenetics, transcription factors and extrinsic factors that have been implicated in MEP fate determination.

CDC's Flu on Call Simulation: Testing a National Helpline for Use During an Influenza Pandemic.

During an influenza pandemic, healthcare facilities are likely to be filled to capacity, leading to delays in seeing a provider and obtaining treatment. Flu on Call is a collaborative effort between the US Centers for Disease Control and Prevention and partners to develop a toll-free telephone helpline to reduce the burden on healthcare facilities and improve access to antivirals for people who are ill during an influenza pandemic. This study tested the feasibility of Flu on Call during a 1-day simulation using a severe pandemic scenario.

Differentiation of PTH-Expressing Cells From Human Pluripotent Stem Cells.

Differentiation of pluripotent stem cells into functional parathyroid-like cells would accelerate development of important therapeutic options for subjects with parathyroid-related disorders, from the design and screening of novel pharmaceutical agents to the development of durable cellular therapies. We have established a highly reproducible directed differentiation approach leading to PTH-expressing cells from human embryonic stem cells and induced pluripotent stem cells. We accomplished this through the comparison of multiple different basal media, the inclusion of the CDK inhibitor PD0332991 in both definitive endoderm and anterior foregut endoderm stages, and a 2-stage pharyngeal endoderm series.

A versatile flow-based assay for immunocyte-mediated cytotoxicity.

Cell-mediated cytotoxicity is a critical function of the immune system in mounting defense against pathogens and cancers. Current methods that allow direct evaluation of cell-mediated cytotoxicity suffer from a wide-range of drawbacks. Here, we present a novel strategy to measure cytotoxicity that is direct, sensitive, rapid, and highly adaptable.