620 results match your criteria: "Laboratory of Clinical Infectious Diseases.[Affiliation]"

() is the world's most deadly infectious pathogen and new drugs are urgently required to combat the emergence of multi- (MDR) and extensively- (XDR) drug resistant strains. The bacterium specifically upregulates sterol uptake pathways in infected macrophages and the metabolism of host-derived cholesterol is essential for long-term survival Here, we report the development of antitubercular small molecules that inhibit the cholesterol oxidases CYP125 and CYP142, which catalyze the initial step of cholesterol metabolism. An efficient biophysical fragment screen was used to characterize the structure-activity relationships of CYP125 and CYP142, and identify a non-azole small molecule that can bind to the heme cofactor of both enzymes.

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IL-10 suppresses T cell expansion while promoting tissue-resident memory cell formation during SARS-CoV-2 infection in rhesus macaques.

PLoS Pathog

July 2024

T lymphocyte Biology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland, United States of America.

Article Synopsis
  • The study investigates how inflammatory responses affect pulmonary disease during SARS-CoV-2 infection, specifically using the rhesus macaque model of mild COVID-19.
  • It highlights the contrasting roles of the cytokines IFNγ and IL-10, where IFNγ contributes to lung lesions but isn't necessary for viral replication suppression, while IL-10 reduces inflammation and aids in T cell memory without hindering viral clearance.
  • The research reveals that IL-10 plays a key role in fostering airway memory T cells, indicating its importance in the immune response during SARS-CoV-2 infection.
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IQGAP1 domesticates macrophages to favor mycobacteria survival via modulating NF-κB signal and augmenting VEGF secretion.

Int Immunopharmacol

September 2024

Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, PR China; Yichang Key Laboratory of Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, PR China. Electronic address:

Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), still ranks among the leading causes of annual human death by infectious disease. Mtb has developed several strategies to survive for years at a time within the host despite the presence of a robust immune response, including manipulating the progression of the inflammatory response and forming granulomatous lesions. Here we demonstrate that IQGAP1, a highly conserved scaffolding protein, compartmentalizes and coordinates multiple signaling pathways in macrophages infected with Mycobacterium marinum (Mm or M.

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Pathogenic mycobacterium upregulates cholesterol 25-hydroxylase to promote granuloma development via foam cell formation.

iScience

March 2024

Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University; Institute of Infection and Inflammation, China Three Gorges University; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, P.R. China.

Pathogenic mycobacteria orchestrate the complex cell populations known as granuloma that is the hallmark of tuberculosis. Foam cells, a lipid-rich cell-type, are considered critical for granuloma formation; however, the causative factor in foam cell formation remains unclear. Atherosclerosis is a chronic inflammatory disease characterized by the abundant accumulation of lipid-laden-macrophage-derived foam cells during which cholesterol 25-hydroxylase (CH25H) is crucial in foam cell formation.

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Introduction: Granulomas, the pathological hallmark of () infection, are formed by different cell populations. Across various stages of tuberculosis conditions, most granulomas are classical caseous granulomas. They are composed of a necrotic center surrounded by multilayers of histocytes, with the outermost layer encircled by fibrosis.

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Background: subspecies ( ) is increasingly recognized as an emerging bacterial pathogen, particularly in cystic fibrosis (CF) patients and CF centres' respiratory outbreaks. We characterized genomic and phenotypic changes in 15 serial isolates from two CF patients (1S and 2B) with chronic pulmonary M. massiliense infection leading to death, as well as four isolates from a CF centre outbreak in which patient 2B was the index case.

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Caseous necrosis is a hallmark of tuberculosis (TB) pathology and creates a niche for drug-tolerant persisters within the host. Cavitary TB and high bacterial burden in caseum require longer treatment duration. An model that recapitulates the major features of Mycobacterium tuberculosis (Mtb) in caseum would accelerate the identification of compounds with treatment-shortening potential.

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Mild SARS-CoV-2 infection in rhesus macaques is associated with viral control prior to antigen-specific T cell responses in tissues.

Sci Immunol

March 2022

T lymphocyte Biology Section, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD, USA.

Article Synopsis
  • SARS-CoV-2 primarily replicates in mucosal sites, and this study used rhesus macaques to investigate the immune responses during mild COVID-19.
  • Viral RNA levels peaked shortly after infection and decreased rapidly, while lung abnormalities and immune cell activation were observed a few days later.
  • T cell responses (CD8 and CD4 T cells) appeared later, indicating that innate immunity may effectively limit the virus's replication before these specific immune cells respond.
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Background: Healthcare-associated transmission of nontuberculous mycobacteria (NTM) among people with cystic fibrosis (pwCF) has been reported and is of increasing concern. No standardized epidemiologic investigation tool has been published for healthcare-associated NTM outbreak investigations. This report describes the design of an ongoing observational study to standardize the approach to NTM outbreak investigation among pwCF.

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Loss of GdpP Function in Staphylococcus aureus Leads to β-Lactam Tolerance and Enhanced Evolution of β-Lactam Resistance.

Antimicrob Agents Chemother

February 2022

Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimoregrid.411024.2, Maryland, USA.

Infections caused by Staphylococcus aureus are a leading cause of mortality. Treating infections caused by S. aureus is difficult due to resistance against most traditional antibiotics, including β-lactams.

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The expansion of human T-betCD21 B cells is T cell dependent.

Sci Immunol

October 2021

Department of Rheumatology and Clinical Immunology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.

Accumulation of human CD21 B cells in peripheral blood is a hallmark of chronic activation of the adaptive immune system in certain infections and autoimmune disorders. The molecular pathways underpinning the development, function, and fate of these CD21 B cells remain incompletely characterized. Here, combined transcriptomic and chromatin accessibility analyses supported a prominent role for the transcription factor T-bet in the transcriptional regulation of these T-betCD21 B cells.

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Patients with GATA2 deficiencyharbor de novo or inherited germline mutations in the GATA2 transcription factor gene, predisposing them to myeloid malignancies. There is considerable variation in disease progression, even among family members with the same mutation in GATA2. We investigated somatic mutations in 106 patients with GATA2 deficiency to identify acquired mutations that are associated with myeloid malignancies.

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Phenotypic whole cell high-throughput screening of a ∼150,000 diverse set of compounds against (Mtb) in cholesterol-containing media identified 1,3-diarylpyrazolyl-acylsulfonamide as a moderately active hit. Structure-activity relationship (SAR) studies demonstrated a clear scope to improve whole cell potency to MIC values of <0.5 μM, and a plausible pharmacophore model was developed to describe the chemical space of active compounds.

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Purpose: Deficiency of adenosine deaminase 2 (DADA2) is an inherited inborn error of immunity, characterized by autoinflammation (recurrent fever), vasculopathy (livedo racemosa, polyarteritis nodosa, lacunar ischemic strokes, and intracranial hemorrhages), immunodeficiency, lymphoproliferation, immune cytopenias, and bone marrow failure (BMF). Tumor necrosis factor (TNF-α) blockade is the treatment of choice for the vasculopathy, but often fails to reverse refractory cytopenia. We aimed to study the outcome of hematopoietic cell transplantation (HCT) in patients with DADA2.

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GATA2 is a transcription factor critical for hematopoiesis. Germline mutations in GATA binding protein 2 (GATA2) led to haploinsufficiency, severe cytopenias of multiple cell lineages, susceptibility to infections and strong propensity to develop myelodysplastic syndrome, and acute myeloid leukemia. Mechanisms of progressive cytopenias remain unclear.

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Impaired respiratory burst contributes to infections in PKCδ-deficient patients.

J Exp Med

September 2021

Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale UMR 1163, Paris, France.

Patients with autosomal recessive protein kinase C δ (PKCδ) deficiency suffer from childhood-onset autoimmunity, including systemic lupus erythematosus. They also suffer from recurrent infections that overlap with those seen in patients with chronic granulomatous disease (CGD), a disease caused by defects of the phagocyte NADPH oxidase and a lack of reactive oxygen species (ROS) production. We studied an international cohort of 17 PKCδ-deficient patients and found that their EBV-B cells and monocyte-derived phagocytes produced only small amounts of ROS and did not phosphorylate p40phox normally after PMA or opsonized Staphylococcus aureus stimulation.

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T-cell activation and expansion in the tumor microenvironment (TME) are critical for antitumor immunity. Neutrophils in the TME acquire a complement-dependent T-cell suppressor phenotype that is characterized by inhibition of T-cell proliferation and activation through mechanisms distinct from those of myeloid-derived suppressor cells. In this study, we used ascites fluid supernatants (ASC) from patients with ovarian cancer as an authentic component of the TME to evaluate the effects of ASC on neutrophil function and mechanisms for neutrophil-driven immune suppression.

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Background: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency which can lead to gastrointestinal (GI) complications including inflammatory bowel disease. Radiographic findings in this cohort have not been well described.

Aims: To describe the frequency and spectrum of gastrointestinal abnormalities seen on computed tomography (CT) in patients with CGD and determine whether radiography was predictive of endoscopic or histopathologic inflammatory findings.

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Safety and Efficacy of Ustekinumab in the Inflammatory Bowel Disease of Chronic Granulomatous Disease.

Clin Gastroenterol Hepatol

February 2022

Translational Hepatology Section, Liver Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland. Electronic address:

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by mutations encoding the NADPH oxidase complex. Those affected are at increased risk of bacterial and fungal infections and require antimicrobial prophylaxis. Dysregulated inflammation may cause inflammatory bowel disease (IBD), termed CGD-associated IBD or CGD colitis, a distinct entity from Crohn's disease (CD) or ulcerative colitis (UC).

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PD-1 blockade exacerbates infection in rhesus macaques.

Sci Immunol

January 2021

T Lymphocyte Biology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.

Boosting immune cell function by targeting the coinhibitory receptor PD-1 may have applications in the treatment of chronic infections. Here, we examine the role of PD-1 during (Mtb) infection of rhesus macaques. Animals treated with anti-PD-1 monoclonal antibody developed worse disease and higher granuloma bacterial loads compared with isotype control-treated monkeys.

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Phenotypic screening of a Medicines for Malaria Venture compound library against () identified a cluster of pan-active 2-pyrazolylpyrimidinones. The biology triage of these actives using various tool strains of suggested a novel mechanism of action. The compounds were bactericidal against replicating and retained potency against clinical isolates of .

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