Publications by authors named "Tirouvanziam R"

Preexisting anti-interferon-α (anti-IFN-α) autoantibodies in blood are associated with susceptibility to life-threatening COVID-19. However, it is unclear whether anti-IFN-α autoantibodies in the airways, the initial site of infection, can also determine disease outcomes. In this study, we developed a multiparameter technology, FlowBEAT, to quantify and profile the isotypes of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and anti-IFN-α antibodies in longitudinal samples collected over 20 months from the airways and blood of 129 donors spanning mild to severe COVID-19.

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Dysregulated neutrophil recruitment drives many pulmonary diseases, but most preclinical screening methods are unsuited to evaluate pulmonary neutrophilia, limiting progress towards therapeutics. Namely, high throughput therapeutic screening systems typically exclude critical neutrophilic pathophysiology, including blood-to-lung recruitment, dysfunctional activation, and resulting impacts on the air-blood barrier. To meet the conflicting demands of physiological complexity and high throughput, we developed an assay of 96-well Leukocyte recruitment in an Air-Blood Barrier Array (L-ABBA-96) that enables -like neutrophil recruitment compatible with downstream phenotyping by automated flow cytometry.

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Triple-negative breast cancer (TNBC) is an aggressive and highly metastatic type of tumor. TNBC is often enriched in tumor-infiltrating neutrophils (TINs), which support cancer growth in part by counteracting tumor-infiltrating lymphocytes (TILs). Prior studies identified the enhancer of zeste homolog 2 (EZH2) as a pro-tumor methyltransferase in primary and metastatic TNBCs.

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Although tuberculosis (TB) remains a major killer among infectious diseases and the leading cause of death for people with HIV, drivers of immunopathology, particularly at the site of infection in the lungs remain incompletely understood. To fill this gap, we compared cytokine profiles in paired plasma and sputum samples collected from adults with pulmonary TB with and without HIV. We found that people with pulmonary TB with HIV had significantly higher markers of inflammation in both plasma and sputum than those without HIV; these differences were present despite a similar extent of radiographic involvement.

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Most repurposed drugs have proved ineffective for treating COVID-19. We evaluated median effective and toxic concentrations (EC, CC) of 49 drugs, mostly from previous clinical trials, in Vero cells. Ratios of reported unbound peak plasma concentrations, (C)/EC, were used to predict the potential in vivo efficacy.

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While breakthroughs with organoids have emerged as next-generation tools, standardization for drug discovery remains a challenge. This work introduces human airway organoids with reversed biopolarity (AORBs), cultured and analyzed in a high-throughput, single-organoid-per-well format, enabling milestones towards standardization. AORBs exhibit a spatio-temporally stable apical-out morphology, facilitating high-yield direct intact-organoid virus infection.

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Introduction: Inflammation appears early in cystic fibrosis (CF) pathogenesis, with specific elevated inflammatory markers in bronchoalveolar lavage fluid (BALF) correlating with structural lung disease. Our aim was to identify markers of airway inflammation able to predict bronchiectasis progression over two years with high sensitivity and specificity.

Methods: Children with CF with two chest computed tomography (CT) scans and bronchoscopies at a two-year interval were included (n= 10 at 1 and 3 years and n= 27 at 3 and 5 years).

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Article Synopsis
  • This multicolor immunofluorescence panel (OMIP) utilizes 14 colors and 13 antibodies to analyze neutrophil subsets in human samples, aiming to better understand their role in health and disease.
  • It features specific markers that help identify neutrophil characteristics related to development, movement, immune response, and functionality.
  • The panel is designed for flexibility, allowing easy substitution of markers to study new neutrophil functions while being tested on both clinical samples and lab-stimulated neutrophils.
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Background: Detecting airway inflammation non-invasively in infants with cystic fibrosis (CF) is difficult. We hypothesized that markers of inflammation in CF [IL-1β, IL-6, IL-8, IL-10, IL-17A, neutrophil elastase (NE) and tumor necrosis factor (TNF-α)] could be measured in infants with CF from nasal fluid and would be elevated during viral infections or clinician-defined pulmonary exacerbations (PEx).

Methods: We collected nasal fluid, nasal swabs, and hair samples from 34 infants with CF during monthly clinic visits, sick visits, and hospitalizations.

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Background: In chronic cystic fibrosis (CF) lung disease, neutrophilic inflammation and T-cell inhibition occur concomitantly, partly due to neutrophil-mediated release of the T-cell inhibitory enzyme Arg1. However, the onset of this tonic inhibition of T cells, and the impact of pulmonary exacerbations (PEs) on this process, remain unknown.

Methods: Children with CF aged 0-5 years were enrolled in a longitudinal, single-center cohort study.

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Background: Cystic fibrosis (CF) airway disease is characterized by chronic inflammation, featuring neutrophil influx to the lumen. Airway macrophages (AMs) can promote both inflammation and resolution, and are thus critical to maintaining and restoring homeostasis. CF AM functions, specifically scavenging activity and resolution of inflammation, have been shown to be impaired, yet underlying processes remain unknown.

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Myeloperoxidase (MPO) is released by neutrophils in inflamed tissues. MPO oxidizes chloride, bromide, and thiocyanate to produce hypochlorous acid (HOCl), hypobromous acid (HOBr), and hypothiocyanous acid (HOSCN), respectively. These oxidants are toxic to pathogens, but may also react with host cells to elicit biological activity and potential toxicity.

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Juvenile idiopathic arthritis (JIA) is an inflammatory rheumatic disorder. Polymorphonuclear neutrophils (PMNs) are present in JIA synovial fluid (SF), but with variable frequency. SF PMNs in JIA were previously shown to display high exocytic but low phagocytic and immunoregulatory activities.

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Plasmodium cynomolgi causes zoonotic malarial infections in Southeast Asia and this parasite species is important as a model for Plasmodium vivax and Plasmodium ovale. Each of these species produces hypnozoites in the liver, which can cause relapsing infections in the blood. Here we present methods and data generated from iterative longitudinal systems biology infection experiments designed and performed by the Malaria Host-Pathogen Interaction Center (MaHPIC) to delve deeper into the biology, pathogenesis, and immune responses of P.

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Article Synopsis
  • The study highlights that Black/African American patients made up nearly 70% of COVID-19 deaths in certain areas, yet targeted research on them is limited.
  • Using advanced single-cell analyses of immune responses from Black/AA patients, researchers found that a specific type of neutrophil plays a critical role in causing severe respiratory issues during COVID-19, even when viral loads are low.
  • Key findings reveal that these neutrophils produce high levels of inflammatory proteins, contributing to a harmful immune response that can lead to acute respiratory distress syndrome (ARDS) in this vulnerable population.
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poses a health threat throughout Southeast Asian communities and currently causes most cases of malaria in Malaysia. This zoonotic parasite species has been studied in (rhesus monkeys) as a model for severe malarial infections, chronicity, and antigenic variation. The phenomenon of antigenic variation was first recognized during rhesus monkey infections.

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In inflammatory diseases, polymorphonuclear neutrophils (PMNs) are known to produce elevated levels of pro-inflammatory cytokines and proteases. To limit ensuing exacerbated cell responses and tissue damage, novel therapeutic agents are sought. 4aa and 4ba, two pyridazinone-scaffold-based phosphodiesterase-IV inhibitors are compared in vitro to zardaverine for their ability to: (1) modulate production of pro-inflammatory mediators, reactive oxygen species (ROS), and phagocytosis; (2) modulate degranulation by PMNs after transepithelial lung migration.

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Background: Macrophages are the major resident immune cells in human airways coordinating responses to infection and injury. In cystic fibrosis (CF), neutrophils are recruited to the airways shortly after birth, and actively exocytose damaging enzymes prior to chronic infection, suggesting a potential defect in macrophage immunomodulatory function. Signaling through the exhaustion marker programmed death protein 1 (PD-1) controls macrophage function in cancer, sepsis, and airway infection.

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SARS-CoV-2-infected subjects are generally asymptomatic during initial viral replication but may suffer severe immunopathology after the virus has receded and monocytes have infiltrated the airways. In bronchoalveolar lavage fluid from severe COVID-19 patients, monocytes express mRNA encoding inflammatory mediators and contain SARS-CoV-2 transcripts. We leverage a human small airway model of infection and inflammation, whereby primary blood monocytes transmigrate across SARS-CoV-2-infected lung epithelium to characterize viral burden, gene expression, and inflammatory mediator secretion by epithelial cells and monocytes.

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Background: In this pilot study, we investigated whether induced sputum (IS) could serve as a viable alternative to bronchoalveolar lavage (BAL) and yield robust inflammatory biomarkers in toddlers with cystic fibrosis (CF) featuring minimal structural lung disease.

Methods: We collected IS, BAL (right middle lobe and lingula), and blood, and performed chest computed tomography (CT) scans from 2-year-olds with CF (N = 11), all within a single visit. Inflammatory biomarkers included 20 soluble immune mediators and neutrophil elastase (NE), as well as frequency and phenotype of T cells, monocytes/macrophages, and neutrophils.

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Background: Adiposity and mitochondrial dysfunction are related factors contributing to metabolic disease development. This pilot study examined whether in vivo and ex vivo indices of mitochondrial metabolism were differentially associated with body composition in males and females.

Methods: Thirty-four participants including 19 females (mean 27 yr) and 15 males (mean 29 yr) had body composition assessed by dual energy x-ray absorptiometry and magnetic resonance (MR) imaging.

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A population of neutrophils recruited into cystic fibrosis (CF) airways is associated with proteolytic lung damage, exhibiting high expression of primary granule exocytosis marker CD63 and reduced phagocytic receptor CD16. Causative factors for this population are unknown, limiting intervention. Here we present a laboratory model to characterize responses of differentiated airway epithelium and neutrophils following respiratory infection.

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Due to the severity of COVID-19 disease, the U.S. Centers for Disease Control and Prevention and World Health Organization recommend that manipulation of active viral cultures of SARS-CoV-2 and respiratory secretions from COVID-19 patients be performed in biosafety level (BSL)3 laboratories.

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Cystic fibrosis (CF) airways feature high extracellular levels of the IL-1 family of proinflammatory mediators. These mediators are cleavage products of caspase-1, the final protease in the inflammasome cascade. Due to the proven chronic presence of reprogrammed neutrophils in the CF airway lumen, understanding inflammasome signaling in these cells is of great importance to understand how disease is perpetuated in this milieu.

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