Abstract P139: The Relationship Between Tissue Sodium Storage, Immune Cell Activation And Salt-sensitive Hypertension

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Melis Sahinoz ◽  
Fernando Elijovich ◽  
Cheryl L Laffer ◽  
Ashley Pitzer ◽  
Thomas G Stewart ◽  
...  
Keyword(s):  
Cell Activation ◽  
Immune Cell ◽  
Small Sample Size ◽  
Salt Sensitivity ◽  
Small Sample ◽  
Sensitivity Index ◽  
Salt Loading ◽  
Immune Cell Activation ◽  
Salt Depletion

Introduction: Salt Sensitivity (SS) of blood pressure (BP) is an independent predictor of death due to cardiovascular disease, but its pathogenesis is poorly understood. Sodium (Na + ) is stored in the skin and muscle interstitium. This hyperosmolar Na + activates monocytes in vitro via oxidative stress with generation of isolevuglandin (isoLG) protein adducts that are immunogenic and activate the adaptive immune system. Methods: Five subjects with essential hypertension discontinued all anti-hypertensive therapy for two weeks before the study. SS was assessed by an inpatient protocol of salt loading (460 mmoL/24h) and salt depletion (10 mmoL/24h, plus furosemide 40 mg x 3). Muscle and skin Na + contents were measured at baseline (BA) by 23 Sodium magnetic resonance imaging ( 23 NaMRI). Urine and serum electrolytes, glomerular filtration rate and the % CD14 + monocytes containing isoLG adducts using flow cytometry were obtained at BA, after salt-loading (HI) and after salt-depletion (LO). All continuous data are displayed as median (interquartile range). Spearman’s correlation was used to test associations. Results: Median age was 54 years (44-55), 60% of subjects were female, screening systolic BP (SBP) was 140 mmHg (134-148), diastolic BP was 88 mmHg (84-99) and BMI was 35 kg/m 2 (30-39). SBP response to salt-depletion (salt-sensitivity index, SSI) varied from -13.8 to +1.8 mmHg. %isoLG + CD14 + cells were 48 (27-65) at BA, 55 (31-56) at HI, and 70 (33-72) at LO (p=0.594, by the Kruskal-Wallis test). The correlation between SSI and delta (Δ) %isoLG LO minus HI, was 0.86, [95% confidence interval (CI), -0.07-0.99] which may suggest conclusively as we gather more data that the greater the SSI, the larger the decrease in isoLGs by salt depletion. Muscle Na + content correlated with 24h urine Na + (BA) (r=0.90, 95% CI, 0.11-0.99), however, the correlation with BP, SSI or isoLGs was inconclusive, potentially due to the small sample size. Skin Na + content correlated with baseline %CD14IsoLG + (r=0.91; 95% CI, 0.12-0.99). Conclusions: Na + intake is a component of the determinants of muscle Na + . Skin Na + is associated with increased isoLGs in monocytes, a marker of immune cell activation. Variability in ΔCD14isoLG may serve as a biomarker for SS of BP in humans.

scholarly journals Neuraminidase inhibition contributes to influenza A virus neutralization by anti-hemagglutinin stem antibodies

2019 ◽  
Vol 216 (2) ◽  
pp. 304-316 ◽  
Author(s):  
Ivan Kosik ◽  
Davide Angeletti ◽  
James S. Gibbs ◽  
Matthew Angel ◽  
Kazuyo Takeda ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Influenza A ◽  
Cell Activation ◽  
Immune Cell ◽  
Broadly Neutralizing Antibodies ◽  
Neutralization Activity ◽  
Immune Cell Activation ◽  
Influenza Virus Hemagglutinin ◽  
Infected Cells

Broadly neutralizing antibodies (Abs) that bind the influenza virus hemagglutinin (HA) stem may enable universal influenza vaccination. Here, we show that anti-stem Abs sterically inhibit viral neuraminidase (NA) activity against large substrates, with activity inversely proportional to the length of the fibrous NA stalk that supports the enzymatic domain. By modulating NA stalk length in recombinant IAVs, we show that anti-stem Abs inhibit virus release from infected cells by blocking NA, accounting for their in vitro neutralization activity. NA inhibition contributes to anti-stem Ab protection in influenza-infected mice, likely due at least in part to NA-mediated inhibition of FcγR-dependent activation of innate immune cells by Ab bound to virions. Food and Drug Administration–approved NA inhibitors enhance anti-stem–based Fc-dependent immune cell activation, raising the possibility of therapeutic synergy between NA inhibitors and anti-stem mAb treatment in humans.

Abstract 11: Single Cell Eccite-seq Analysis Reveal An Important Role Of Monocyte-specific Nlrp3 Inflammasome For Salt-sensitivity Of Hypertension In Humans

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Ashley L Pitzer ◽  
Melis Sahinoz ◽  
Michael Raddatz ◽  
Celestine Wanjalla ◽  
Suman Pakala ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Flow Cytometry ◽  
Nlrp3 Inflammasome ◽  
Immune Cell ◽  
Cell Types ◽  
Salt Sensitivity ◽  
Dietary Salt ◽  
Salt Loading ◽  
Salt Diet ◽  
Salt Depletion

Salt sensitivity of blood pressure is an independent predictor of death due to cardiovascular events. Diagnosis of salt-sensitivity is not feasible in the clinic, making it difficult to investigate therapeutic strategies. We hypothesized that NLRP3-inflammasome and IL-1β production in monocytes plays a role in salt-sensitive hypertension. We phenotyped salt-sensitivity of blood pressure using an acute inpatient Weinberger protocol of an isocaloric high salt diet and rapid intravenous salt-loading, followed by low salt diet and furosemide-induced salt-depletion. Ambulatory blood pressure was continuously monitored and averaged for the days of salt-loading and salt-depletion. Blood samples were obtained at baseline, salt-loading, and after salt-depletion. Median age was 54 years (44-55), 3 of the 5 subjects were female, screening systolic blood pressure was 140 mmHg (134-148), diastolic blood pressure was 88 mmHg (84-99), and BMI was 35 kg/m 2 (30-39). Using cell hashing and ECCITE-seq analysis, we profiled transcriptomes in multiple immune cell types using antibody-derived tags (ADTs). UMAP clustering of different cell types were identified by ADTs including monocyte markers CD14 and CD16. Interestingly, UMAP visualization of CD14+ and CD16+ clusters indicated a greater decrease in CD14+ clusters after salt-depletion in the salt-resistant subjects than the salt-sensitive; however the salt-sensitive subjects had a greater decrease in CD16+ clusters than the salt-resistant group after both salt-loading and salt-depletion. These data were confirmed using flow cytometry. Unlike in salt-resistant participants, we found that within monocyte clusters, salt-sensitivity was associated with down regulation of the inflammasome components NLRP3 (0.386 ± 1.18 vs. 0.197 ± 0.778) and IL-1β (0.858 ± 2.32 vs. 0.159 ± 0.925) following salt-depletion. Using flow cytometry, we found Δ% isoLG+ CD14+/CD16+ monocytes correlated with salt-sensitivity of blood pressure (r=0.88, 95% CI, p=0.05). These results suggest that the inflammasome and monocyte activation are dynamically regulated by dietary salt in vivo and can serve as a potential diagnostic biomarker for salt-sensitivity of blood pressure.

scholarly journals AHCC Activation and Selection of Human Lymphocytes via Genotypic and Phenotypic Changes to an Adherent Cell Type: A Possible Novel Mechanism of T Cell Activation

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Loretta Olamigoke ◽  
Elvedina Mansoor ◽  
Vivek Mann ◽  
Ivory Ellis ◽  
Elvis Okoro ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Immune Cell ◽  
Human Lymphocytes ◽  
Gene Array ◽  
Adherent Cell ◽  
Immune Cell Activation ◽  
Wide Range

Active Hexose Correlated Compound (AHCC) is a fermented mushroom extract and immune supplement that has been used to treat a wide range of health conditions. It helps in augmentation of the natural immune response and affects immune cell activation and outcomes. The goal of this project was to study and understand the role and mechanisms of AHCC supplementation in the prevention of immunosuppression through T cell activation. The method described here involves “in vitro” culturing of lymphocytes, exposing them to different concentrations of AHCC (0 μg/mL, 50 μg/mL, 100 μg/mL, 250 μg/mL, and 500 μg/mL) at 0 hours. Interestingly, clumping and aggregation of the cells were seen between 24 and 72 hours of incubation. The cells lay down extracellular matrix, which become adherent, and phenotypical changes from small rounded lymphocytes to large macrophage-like, spindle shaped, elongated, fibroblast-like cells even beyond 360 hours were observed. These are probably translated from genotypic changes in the cells since the cells propagate for at least 3 to 6 generations (present observations). RNA isolated was subjected to gene array analysis. We hypothesize that cell adhesion is an activation and survival pathway in lymphocytes and this could be the mechanism of AHCC activation in human lymphocytes.

scholarly journals Collagens are functional, high affinity ligands for the inhibitory immune receptor LAIR-1

2006 ◽  
Vol 203 (6) ◽  
pp. 1419-1425 ◽  
Author(s):  
Robert Jan Lebbink ◽  
Talitha de Ruiter ◽  
Jelle Adelmeijer ◽  
Arjan B. Brenkman ◽  
Joop M. van Helvoort ◽  
...  
Keyword(s):  
Immune Regulation ◽  
Cell Activation ◽  
Cell Function ◽  
Immune Cell ◽  
Cell Interaction ◽  
Immune Cell Function ◽  
Affinity Ligands ◽  
Immune Cell Activation ◽  
High Affinity

Collagens are the most abundant proteins in the human body, important in maintenance of tissue structure and hemostasis. Here we report that collagens are high affinity ligands for the broadly expressed inhibitory leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1). The interaction is dependent on the conserved Gly-Pro-Hyp collagen repeats. Antibody cross-linking of LAIR-1 is known to inhibit immune cell function in vitro. We now show that collagens are functional ligands for LAIR-1 and directly inhibit immune cell activation in vitro. Thus far, all documented ligands for immune inhibitory receptors are membrane molecules, implying a regulatory role in cell–cell interaction. Our data reveal a novel mechanism of peripheral immune regulation by inhibitory immune receptors binding to extracellular matrix collagens.

scholarly journals Neuraminidase Inhibition Contributes to Influenza A Virus Neutralization by Anti-Hemagglutinin Stem Antibodies

2018 ◽  
Author(s):  
Ivan Kosik ◽  
Davide Angeletti ◽  
James S. Gibbs ◽  
Matthew Angel ◽  
Kazuyo Takeda ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Influenza A ◽  
Cell Activation ◽  
Immune Cell ◽  
Broadly Neutralizing Antibodies ◽  
Neutralization Activity ◽  
Immune Cell Activation ◽  
Influenza Virus Hemagglutinin ◽  
Infected Cells

SummaryBroadly neutralizing antibodies (Abs) that bind the influenza virus hemagglutinin (HA) stem may enable universal influenza vaccination. Here, we show that anti-stem Abs sterically inhibit viral neuraminidase activity against large substrates, with activity inversely proportional to the length of the fibrous NA stalk that supports the enzymatic domain. By modulating NA stalk length in recombinant IAVs, we show that anti-stem Abs inhibit virus release from infected cells by blocking NA, accounting for theirin vitroneutralization activity. NA inhibition contributes to anti-stem Ab protection in influenza infected mice, likely due at least in part to NA-mediated inhibition of FcγR dependent activation of innate immune cells by antibody bound to virions. FDA approved NA inhibitors enhance anti-stem based Fcγdependent immune cell activation, raising the possibility of therapeutic synergy between NA inhibitors and anti-stem mAb treatment in humans.

scholarly journals Deoxyribonuclease 1-Mediated Clearance of Circulating Chromatin Prevents From Immune Cell Activation and Pro-inflammatory Cytokine Production, a Phenomenon Amplified by Low Trap1 Activity: Consequences for Systemic Lupus Erythematosus

2021 ◽  
Vol 12 ◽  
Author(s):  
Jasmin Felux ◽  
Annika Erbacher ◽  
Magali Breckler ◽  
Roxane Hervé ◽  
Delphine Lemeiter ◽  
...  
Keyword(s):  
Immune Cells ◽  
Lupus Erythematosus ◽  
Cell Activation ◽  
Immune Cell ◽  
Wild Type ◽  
Systemic Lupus ◽  
Immune Cell Activation ◽  
Deficient Mice

Increased concentrations of circulating chromatin, especially oligo-nucleosomes, are observed in sepsis, cancer and some inflammatory autoimmune diseases like systemic lupus erythematosus (SLE). In SLE, circulating nucleosomes mainly result from increased apoptosis and decreased clearance of apoptotic cells. Once released, nucleosomes behave both as an autoantigen and as a damage-associated molecular pattern (DAMP) by activating several immune cells, especially pro-inflammatory cells. Deoxyribonuclease 1 (DNase1) is a major serum nuclease whose activity is decreased in mouse and human lupus. Likewise, the mitochondrial chaperone tumor necrosis factor (TNF) receptor-associated protein-1 (Trap1) protects against oxidative stress, which is increased in SLE. Here, using wild type, DNase1-deficient and DNase1/Trap1-deficient mice, we demonstrate that DNase1 is a major serum nuclease involved in chromatin degradation, especially when the plasminogen system is activated. In vitro degradation assays show that chromatin digestion is strongly impaired in serum from DNase1/Trap1-deficient mice as compared to wild type mice. In vivo, after injection of purified chromatin, clearance of circulating chromatin is delayed in DNase1/Trap1-deficient mice in comparison to wild type mice. Since defective chromatin clearance may lead to chromatin deposition in tissues and subsequent immune cell activation, spleen cells were stimulated in vitro with chromatin. Splenocytes were activated by chromatin, as shown by interleukin (IL)-12 secretion and CD69 up-regulation. Moreover, cell activation was exacerbated when Trap1 is deficient. Importantly, we also show that cytokines involved in lupus pathogenesis down-regulate Trap1 expression in splenocytes. Therefore, combined low activities of both DNase1 and Trap1 lead to an impaired degradation of chromatin in vitro, delayed chromatin clearance in vivo and enhanced activation of immune cells. This situation may be encountered especially, but not exclusively, in SLE by the negative action of cytokines on Trap1 expression.

scholarly journals The Flavonoid Fisetin Attenuates Postischemic Immune Cell Infiltration, Activation and Infarct Size after Transient Cerebral Middle Artery Occlusion in Mice

2012 ◽  
Vol 32 (5) ◽  
pp. 835-843 ◽  
Author(s):  
Mathias Gelderblom ◽  
Frank Leypoldt ◽  
Jan Lewerenz ◽  
Gabriel Birkenmayer ◽  
Denise Orozco ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Infarct Size ◽  
Brain Tissue ◽  
Tissue Damage ◽  
Cell Activation ◽  
Immune Cell ◽  
Biological Effects ◽  
Artery Occlusion ◽  
Immune Cell Activation

The development of the brain tissue damage in ischemic stroke is composed of an immediate component followed by an inflammatory response with secondary tissue damage after reperfusion. Fisetin, a flavonoid, has multiple biological effects, including neuroprotective and antiinflammatory properties. We analyzed the effects of fisetin on infarct size and the inflammatory response in a mouse model of stroke, temporary middle cerebral artery occlusion, and on the activation of immune cells, murine primary and N9 microglial and Raw264.7 macrophage cells and human macrophages, in an in vitro model of inflammatory immune cell activation by lipopolysaccharide (LPS). Fisetin not only protected brain tissue against ischemic reperfusion injury when given before ischemia but also when applied 3 hours after ischemia. Fisetin also prominently inhibited the infiltration of macrophages and dendritic cells into the ischemic hemisphere and suppressed the intracerebral immune cell activation as measured by intracellular tumor necrosis factor α (TNFα) production. Fisetin also inhibited LPS-induced TNFα production and neurotoxicity of macrophages and microglia in vitro by suppressing nuclear factor κB activation and JNK/Jun phosphorylation. Our findings strongly suggest that the fisetin-mediated inhibition of the inflammatory response after stroke is part of the mechanism through which fisetin is neuroprotective in cerebral ischemia.

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