scholarly journals Depletion of Alveolar Macrophages Does Not Prevent Hantavirus Disease Pathogenesis in Golden Syrian Hamsters

2016 ◽  
Vol 90 (14) ◽  
pp. 6200-6215 ◽  
Author(s):  
Christopher D. Hammerbeck ◽  
Rebecca L. Brocato ◽  
Todd M. Bell ◽  
Christopher W. Schellhase ◽  
Steven R. Mraz ◽  
...  
Keyword(s):  
Alveolar Macrophages ◽  
Immune Cell ◽  
Cell Types ◽  
Protective Role ◽  
Hantavirus Infection ◽  
Specific Cell ◽  
Disease Pathogenesis ◽  
Hamster Model ◽  
Syrian Hamsters ◽  
Antiviral Responses

ABSTRACTAndes virus (ANDV) is associated with a lethal vascular leak syndrome in humans termed hantavirus pulmonary syndrome (HPS). The mechanism for the massive vascular leakage associated with HPS is poorly understood; however, dysregulation of components of the immune response is often suggested as a possible cause. Alveolar macrophages are found in the alveoli of the lung and represent the first line of defense to many airborne pathogens. To determine whether alveolar macrophages play a role in HPS pathogenesis, alveolar macrophages were depleted in an adult rodent model of HPS that closely resembles human HPS. Syrian hamsters were treated, intratracheally, with clodronate-encapsulated liposomes or control liposomes and were then challenged with ANDV. Treatment with clodronate-encapsulated liposomes resulted in significant reduction in alveolar macrophages, but depletion did not prevent pathogenesis or prolong disease. Depletion also did not significantly reduce the amount of virus in the lung of ANDV-infected hamsters but altered neutrophil recruitment, MIP-1α and MIP-2 chemokine expression, and vascular endothelial growth factor (VEGF) levels in hamster bronchoalveolar lavage (BAL) fluid early after intranasal challenge. These data demonstrate that alveolar macrophages may play a limited protective role early after exposure to aerosolized ANDV but do not directly contribute to hantavirus disease pathogenesis in the hamster model of HPS.IMPORTANCEHantaviruses continue to cause disease worldwide for which there are no FDA-licensed vaccines, effective postexposure prophylactics, or therapeutics. Much of this can be attributed to a poor understanding of the mechanism of hantavirus disease pathogenesis. Hantavirus disease has long been considered an immune-mediated disease; however, by directly manipulating the Syrian hamster model, we continue to eliminate individual immune cell types. As the most numerous immune cells present in the respiratory tract, alveolar macrophages are poised to defend against hantavirus infection, but those antiviral responses may also contribute to hantavirus disease. Here, we demonstrate that, like in our prior T and B cell studies, alveolar macrophages neither prevent hantavirus infection nor cause hantavirus disease. While these studies reflect pathogenesis in the hamster model, they should help us rule out specific cell types and prompt us to consider other potential mechanisms of disease in an effort to improve the outcome of human HPS.

Differential susceptibilities of isolated hamster lung cell types to amiodarone toxicity

1998 ◽  
Vol 76 (7-8) ◽  
pp. 721-727 ◽  
Author(s):  
M W Bolt ◽  
W J Racz ◽  
J F Brien ◽  
T M Bray ◽  
T E Massey
Keyword(s):  
Alveolar Macrophages ◽  
Gradient Centrifugation ◽  
Cell Types ◽  
Clara Cell ◽  
Blue Dye ◽  
Alveolar Type ◽  
Specific Cell ◽  
Type Ii ◽  
Clara Cells

Treatment of cardiac dysrhythmias with the iodinated benzofuran derivative amiodarone (AM) is limited by pulmonary toxicity. The susceptibilities of different lung cell types of male Golden Syrian hamsters to AM-induced cytotoxicity were investigated in vitro. Bronchoalveolar lavage and protease digestion to release cells, followed by centrifugal elutriation and density gradient centrifugation, resulted in preparations enriched with alveolar macrophages (98%), alveolar type II cells (75-85%), and nonciliated bronchiolar epithelial (Clara) cells (35-50%). Alveolar type II cell and Clara cell preparations demonstrated decreased viability (by 0.5% trypan blue dye exclusion) when incubated with 50 µM AM for 36 h, and all AM-treated cell preparations demonstrated decreased viability when incubated with 100 or 200 µM AM. Based on a viability index ((viability of AM-treated cells ÷ viability of controls) × 100%), the Clara cell fraction was significantly (p < 0.05) more susceptible than all of the other cell types to 50 µM AM. However, AM cytotoxicity was greatest (p < 0.05) in alveolar macrophages following incubation with 100 or 200 µM AM. There was no difference between any of the enriched cell preparations in the amount of drug accumulated following 24 h of incubation with 50 µM AM, whereas alveolar macrophages accumulated the most drug during incubation with 100 µM AM. Thus, the most susceptible cell type was dependent on AM concentration. AM-induced cytotoxicity in specific cell types may initiate processes leading to inflammation and pulmonary fibrosis.Key words: amiodarone, susceptibility, alveolar macrophage, accumulation.

scholarly journals Single cell analysis reveals immune cell–adipocyte crosstalk regulating the transcription of thermogenic adipocytes

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Prashant Rajbhandari ◽  
Douglas Arneson ◽  
Sydney K Hart ◽  
In Sook Ahn ◽  
Graciel Diamante ◽  
...  
Keyword(s):  
Single Cell ◽  
Immune Cells ◽  
Immune Cell ◽  
Single Cell Analysis ◽  
Metabolic Response ◽  
Cell Types ◽  
Specific Cell ◽  
Beneficial Effects ◽  
Thermogenic Adipocytes ◽  
And Function

Immune cells are vital constituents of the adipose microenvironment that influence both local and systemic lipid metabolism. Mice lacking IL10 have enhanced thermogenesis, but the roles of specific cell types in the metabolic response to IL10 remain to be defined. We demonstrate here that selective loss of IL10 receptor α in adipocytes recapitulates the beneficial effects of global IL10 deletion, and that local crosstalk between IL10-producing immune cells and adipocytes is a determinant of thermogenesis and systemic energy balance. Single Nuclei Adipocyte RNA-sequencing (SNAP-seq) of subcutaneous adipose tissue defined a metabolically-active mature adipocyte subtype characterized by robust expression of genes involved in thermogenesis whose transcriptome was selectively responsive to IL10Rα deletion. Furthermore, single-cell transcriptomic analysis of adipose stromal populations identified lymphocytes as a key source of IL10 production in response to thermogenic stimuli. These findings implicate adaptive immune cell-adipocyte communication in the maintenance of adipose subtype identity and function.

Cell-specific and targeted delivery of RNA moieties

2020 ◽  
Author(s):  
Aditi Bhargava ◽  
Peter Ohara ◽  
Luc Jasmin
Keyword(s):  
Nucleic Acids ◽  
Targeted Delivery ◽  
Immune Cell ◽  
Neuronal Cell ◽  
Cell Types ◽  
Specific Cell ◽  
Chemically Modified ◽  
Covalently Linked

AbstractDelivery of therapeutic moieties to specific cell types, such as neurons remains a challenge. Genes present in neurons are also expressed in non-neuronal cell types such as glia where they mediate non-targeted related functions. Thus, non-specific targeting of these proteins/channels has numerous unwanted side effects, as is the case with current small molecules or drug therapies. Current methodologies that use nanoparticles, lipid-mediated uptake, or mannitol in conjunction with lipids to deliver double-stranded RNA (dsRNA) have yielded mixed and unreliable results. We used a neuroanatomical tracer (B subunit of Cholera Toxin (CTB)) that binds to the ganglioside receptors (GM1) expressed on cells, including primary sensory neurons to deliver encapsulated dsRNA. This approach greatly improved delivery of dsRNA to the desired cells by enhancing uptake, reducing vehicle-mediated toxicity and protecting nucleotides from degradation by endonucleases. The delivery complex is internalized, and once inside the cell, the dsRNA naturally dissociates itself from the carrier complex and is very effective in knocking down cognate targets, both in vivo and in vitro. Past methods have used CTB-fusion proteins or chemically modified oligos or DNA moieties that have been covalently conjugated to CTB. Furthermore, CTB conjugated to an antigen, protein, or chemically modified nucleic acid is a potent activator of immune cell (T and B cells, macrophages) response, whereas CTB admixed with antigens or unmodified nucleic acids does not evoke this immune response. Importantly, in our method, the nucleic acids are not covalently linked to the carrier molecules. Thus, our method holds strong potential for targeted delivery of therapeutic moieties for cell types expressing GM1 receptors, including neuronal cell types.

scholarly journals Effects of Decreased Calmodulin Protein on the Survival Mechanisms of Alveolar Macrophages during Pneumocystis Pneumonia

2009 ◽  
Vol 77 (8) ◽  
pp. 3344-3354 ◽  
Author(s):  
Mark E. Lasbury ◽  
Pamela J. Durant ◽  
Chung-Ping Liao ◽  
Chao-Hung Lee
Keyword(s):  
Bronchoalveolar Lavage ◽  
Alveolar Macrophages ◽  
Immune Cell ◽  
Cell Types ◽  
Pneumocystis Pneumonia ◽  
Mrna Levels ◽  
Gm Csf ◽  
Survival Signaling ◽  
Macrophage Colony ◽  
Phosphoinositide 3 Kinase

ABSTRACT Pneumocystis infection causes increased intracellular levels of reactive oxygen species (ROS) and the subsequent apoptosis of alveolar macrophages (Amø). Assessments of key prosurvival molecules in Amø and bronchoalveolar lavage fluids from infected rats and mice showed low levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) and reduced activation of phosphoinositide-3 kinase (PI-3K). Ubiquitous calcium-sensing protein calmodulin protein and mRNA levels were also reduced in Amø during Pneumocystis pneumonia (Pcp). Calmodulin has been implicated in control of GM-CSF production and PI-3K activation in other immune cell types. Experiments to determine the control of GM-CSF and PI-3K by calmodulin in Amø showed that GM-CSF expression and PI-3K activation could not be induced when calmodulin was inhibited. Calmodulin inhibition also led to increased levels of ROS and apoptosis in cells exposed to bronchoalveolar lavage fluids from infected animals. Supplementation of Amø with exogenous calmodulin increased survival signaling via GM-CSF and PI-3K and reduced ROS and apoptosis. These data support the hypotheses that calmodulin levels at least partially control survival signaling in Amø and that restoration of GM-CSF or PI-3K signaling will improve host response to the organism.

scholarly journals Differential pathogenesis between Andes virus strains CHI-7913 and Chile-9717869in Syrian Hamsters

2021 ◽  
Author(s):  
Bryce M. Warner ◽  
Angela Sloan ◽  
Yvon Deschambault ◽  
Sebastian Dowhanik ◽  
Kevin Tierney ◽  
...  
Keyword(s):  
Animal Model ◽  
South America ◽  
Syrian Hamster ◽  
Sequence Similarity ◽  
Experimental Studies ◽  
Hantavirus Infection ◽  
High Sequence Similarity ◽  
Hamster Model ◽  
Syrian Hamsters

Hantavirus cardiopulmonary syndrome (HCPS) is a severe respiratory disease caused by orthohantaviruses in the Americas with a fatality rate as high as 35%. In South America, Andes orthohantavirus (Hantaviridae, Orthohantavirus, ANDV) is a major cause of HCPS, particularly in Chile and Argentina, where thousands of cases have been reported since the virus was discovered. Two strains of ANDV that are classically used for experimental studies of the virus are Chile-9717869, isolated from the natural reservoir, the long-tailed pygmy rice rat, and CHI-7913, an isolate from a lethal human case of HCPS. An important animal model for studying pathogenesis of HCPS is the lethal Syrian golden hamster model of ANDV infection. In this model, ANDV strain Chile-9717869 is uniformly lethal and has been used extensively for pathogenesis, vaccination, and therapeutic studies. Here we show that the CHI-7913 strain, despite having high sequence similarity with Chile-9717869, does not cause lethal disease in Syrian hamsters. CHI-7913, while being able to infect hamsters and replicate to moderate levels, showed a reduced ability to replicate within the tissues compared with Chile-9717869. Hamsters infected with CHI-7913 had reduced expression of cytokines IL-4, IL-6, and IFN-γ compared with Chile-9717869 infected animals, suggesting potentially limited immune-mediated pathology. These results demonstrate that certain ANDV strains may not be lethal in the classical Syrian hamster model of infection, and further exploration into the differences between lethal and non-lethal strains provide important insights into molecular determinants of pathogenic hantavirus infection. Importance: Andes orthohantavirus (ANDV) is a New World hantavirus that is a major cause of hantavirus cardiopulmonary syndrome (HCPS, also referred to as hantavirus pulmonary syndrome) in South America, particularly in Chile and Argentina. ANDV is one of the few hantaviruses for which there is a reliable animal model, the Syrian hamster model, which recapitulates important aspects of human disease. Here we infected hamsters with a human isolate of ANDV, CHI-7913, to assess its pathogenicity compared with the classical lethal Chile-9717869 strain. CHI-7913 had 22 amino acid differences compared with Chile-9717869, did not cause lethal disease in hamsters, and showed reduced ability to replicate in vivo. Our data indicate potentially important molecular signatures for pathogenesis of ANDV infection in hamsters and may lead to insights into what drives pathogenesis of certain hantaviruses in humans.

scholarly journals Variation in Stem Cell Driven Hierarchies Underlies Clinical Outcome and Drug Response in AML

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 27-28
Author(s):  
Andy G.X. Zeng ◽  
Amanda Mitchell ◽  
Oleksandr Galkin ◽  
Jean C.Y. Wang ◽  
James A. Kennedy ◽  
...  
Keyword(s):  
Stem Cell ◽  
Relative Abundance ◽  
Drug Response ◽  
Drug Sensitivity ◽  
Immune Cell ◽  
Cell Types ◽  
Chemotherapy Response ◽  
Specific Cell ◽  
Cell Type ◽  
Cellular Hierarchy

AML is a stem cell disease wherein the properties of the disease-driving leukemia stem cells (LSCs) are reflected in the cellular hierarchies that they generate. We sought to understand how these hierarchies vary across patients and whether their characteristics are clinically relevant. To evaluate cellular hierarchies in AML, we re-analyzed the scRNA-seq data of 13,653 cells from 12 AML patients at diagnosis (van Galen, Cell 2019) and in particular the stem and progenitor blast populations. We identified three novel leukemia stem populations differing in their depth of quiescence, inflammatory signaling, and myeloid priming. Using the signatures of 7 malignant populations as well as 7 immune cell populations from this scRNA-seq data, we applied CIBERSORTx deconvolution (Newman, Nat Biotechnol 2019) on bulk RNA-seq data from multiple patient cohorts. This enabled determination of the relative abundance of each cell type in each patient, thereby capturing the "shape" of the leukemic hierarchies of hundreds of AML patients. AML patients within these cohorts clustered into 4 groups defined by different proportions of stem, progenitor, and mature blasts - each of which differed in their underlying genomic alterations and overall survival. Differences in chemotherapy response were mediated by specific cell types, notably a GMP-like blast population and a quiescent stem-like population (qLSPC). Dominance of the GMP-like population was associated with longer survival (HR -3.1, p=0.002), and these blasts were enriched among younger patients (&lt;65 years) and those with favorable risk cytogenetics. In contrast, qLSPCs were associated with poor survival (HR 2.3, p=0.02; TCGA) and were more abundant in older patients (&gt; 65 years) and patients with adverse cytogenetic alterations. Critically, this qLSPC population was enriched at relapse as well as within a subset of pediatric AML patients that failed to respond to induction chemotherapy. We confirmed that qLSPCs were also enriched among functionally validated leukemia engrafting (LSC+) sorted AML fractions. Accordingly, a high LSC17 score was strongly correlated with qLSPC abundance and anti-correlated with GMP-like abundance, suggesting that the score may reflect the underlying cellular hierarchy of each AML patient. Next, we generated drug sensitivity profiles for each cell type by correlating ex vivo drug sensitivity data for each of 112 inhibitors screened in the BEAT-AML trial with the relative abundance of each cell type across individual patients. In particular, Venetoclax sensitivity correlated with the abundance of primitive cell types and anti-correlated with mature cell types, suggesting that the composition of the leukemic hierarchy in AML patients is associated with drug response. We previously demonstrated that a high LSC17 score identifies patients who do not benefit from standard chemotherapy (Ng, Nature 2016). To develop a diagnostic tool for therapy selection amongst these poor prognosis patients, we retrained the LSC17 genes against cell type abundance and derived a subscore (LSC-7) to map patients along an axis of primitive vs mature leukemic hierarchies. We show that AML samples with a high LSC-7 score (more stem-like blasts) were more sensitive to Venetoclax whereas AML patients with a low LSC-7 score (more mature blasts) benefited from treatment with Gemtuzumab-Ozogamicin (GO). Used together, the LSC17 and LSC-7 scores enable risk stratification as well as subsequent drug selection for high-risk patients, and can both be measured by a single rapid NanoString assay. To apply this approach more broadly, we identified several published studies with drug screening data from primary patient samples and accompanying RNAseq data. By correlating cell type abundance with drug response, we were able to map the critical cell types that mediate sensitivity and resistance to inhibitors of mitochondrial metabolism, histone demethylation, and the CD47-SIRPa axis, among others. Our data establish that scRNA-seq informed deconvolution of bulk expression data permits characterization of the cellular hierarchy of individual AML patients. This framework can enhance our understanding of many aspects of biological, genomic, and clinical heterogeneity in AML, and represents a powerful tool to enable personalized therapeutic decision-making in AML. Figure Disclosures Wang: Trilium Therapeutics: Patents & Royalties. Dick:Bristol-Myers Squibb/Celgene: Research Funding.

scholarly journals Cell Programmed Nutrient Partitioning in the Tumor Microenvironment

2020 ◽  
Author(s):  
BI Reinfeld ◽  
MZ Madden ◽  
MM Wolf ◽  
A Chytil ◽  
JE Bader ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Glucose Uptake ◽  
Cancer Cells ◽  
Immune Cells ◽  
Immune Cell ◽  
Cell Types ◽  
Specific Cell ◽  
Mtorc1 Signaling ◽  
Nutrient Partitioning ◽  
Glutamine Uptake

The tumor microenvironment (TME) includes transformed cancer and infiltrating immune cells1,2. Cancer cells can consume large quantities of glucose through Warburg metabolism3,4 that can be visualized with positron emission tomography (PET). While infiltrating immune cells also rely on glucose, disruptions to metabolism can contribute to tumor immunological evasion5–9. How immune cell metabolism is programmed or restrained by competition with cancer cells for nutrients, remains uncertain. Here we used PET tracers to measure the accessibility of glucose and glutamine to cell subsets in the TME. Surprisingly, myeloid cells including macrophages were the greatest consumers of intra-tumoral glucose, followed by T cells and cancer cells. Cancer cells, in contrast, had the highest glutamine uptake. This distinct nutrient partitioning was programmed through selective mTORC1 signaling and glucose or glutamine-related gene expression. Inhibition of glutamine uptake enhanced glucose uptake across tumor resident cell types and shifted macrophage phenotype, demonstrating glucose is not limiting in the TME. Thus, cancer cells are not the only cells in tumors which exhibit high glucose uptake in vivo and instead preferentially utilize glutamine over other cell types. We observe that intrinsic cellular programs can play a major role in the use of some nutrients. Together, these data argue cell selective partitioning of glucose and glutamine can be exploited to develop therapies and imaging strategies to alter the metabolic programs of specific cell populations in the TME.

scholarly journals Insights Into the Role of DNA Methylation in Immune Cell Development and Autoimmune Disease

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiaqi Li ◽  
Lifang Li ◽  
Yimeng Wang ◽  
Gan Huang ◽  
Xia Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Autoimmune Disease ◽  
Autoimmune Diseases ◽  
Immune Cell ◽  
Gene Expression Regulation ◽  
Cell Types ◽  
Basic Function ◽  
Detailed Knowledge ◽  
Disease Pathogenesis

To date, nearly 100 autoimmune diseases have been an area of focus, and these diseases bring health challenges to approximately 5% of the population worldwide. As a type of disease caused by tolerance breakdown, both environmental and genetic risk factors contribute to autoimmune disease development. However, in most cases, there are still gaps in our understanding of disease pathogenesis, diagnosis, and treatment. Therefore, more detailed knowledge of disease pathogenesis and potential therapies is indispensable. DNA methylation, which does not affect the DNA sequence, is one of the key epigenetic silencing mechanisms and has been indicated to play a key role in gene expression regulation and to participate in the development of certain autoimmune diseases. Potential epigenetic regulation via DNA methylation has garnered more attention as a disease biomarker in recent years. In this review, we clarify the basic function and distribution of DNA methylation, evaluate its effects on gene expression and discuss related key enzymes. In addition, we summarize recent aberrant DNA methylation modifications identified in the most important cell types related to several autoimmune diseases and then provide potential directions for better diagnosing and monitoring disease progression driven by epigenetic control, which may broaden our understanding and contribute to further epigenetic research in autoimmune diseases.

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