FcγR-mediated SARS-CoV-2 infection of monocytes activates inflammation.

SARS-CoV-2 can cause acute respiratory distress and death in some patients. Although severe COVID-19 is linked to substantial inflammation, how SARS-CoV-2 triggers inflammation is not clear. Monocytes and macrophages are sentinel cells that sense invasive infection to form inflammasomes that activate caspase-1 and gasdermin D, leading to inflammatory death (pyroptosis) and the release of potent inflammatory mediators.

The oral drug nitazoxanide restricts SARS-CoV-2 infection and attenuates disease pathogenesis in Syrian hamsters.

A well-tolerated and cost-effective oral drug that blocks SARS-CoV-2 growth and dissemination would be a major advance in the global effort to reduce COVID-19 morbidity and mortality. Here, we show that the oral FDA-approved drug nitazoxanide (NTZ) significantly inhibits SARS-CoV-2 viral replication and infection in different primate and human cell models including stem cell-derived human alveolar epithelial type 2 cells. Furthermore, NTZ synergizes with remdesivir, and it broadly inhibits growth of SARS-CoV-2 variants B.

SARS-CoV-2 infects blood monocytes to activate NLRP3 and AIM2 inflammasomes, pyroptosis and cytokine release.

SARS-CoV-2 causes acute respiratory distress that can progress to multiorgan failure and death in a minority of patients. Although severe COVID-19 disease is linked to exuberant inflammation, how SARS-CoV-2 triggers inflammation is not understood. Monocytes and macrophages are sentinel immune cells in the blood and tissue, respectively, that sense invasive infection to form inflammasomes that activate caspase-1 and gasdermin D (GSDMD) pores, leading to inflammatory death (pyroptosis) and processing and release of IL-1 family cytokines, potent inflammatory mediators.

SARS-CoV-2 infects blood monocytes to activate NLRP3 and AIM2 inflammasomes, pyroptosis and cytokine release.

Unlabelled: SARS-CoV-2 causes acute respiratory distress that can progress to multiorgan failure and death in some patients. Although severe COVID-19 disease is linked to exuberant inflammation, how SARS-CoV-2 triggers inflammation is not understood. Monocytes are sentinel blood cells that sense invasive infection to form inflammasomes that activate caspase-1 and gasdermin D (GSDMD) pores, leading to inflammatory death (pyroptosis) and processing and release of IL-1 family cytokines, potent inflammatory mediators.

Identification of a Distal Locus Enhancer Element That Controls Cell Type-Specific and Gene Expression in Human T Cells.

The human locus genes , , and are expressed in a cell type-specific manner. In this study, we show that a highly conserved NFAT binding site within the distal noncoding element hHS-8 coordinately controls and gene expression in human T cells. Upon activation of primary human CD4 T cells, hHS-8 and the and promoters display increased H3K27 acetylation and nuclease sensitivity and coordinate induction of , , and hHS-8 enhancer RNA transcription occurs.

Cytoplasmic RNA Sensor Pathways and Nitazoxanide Broadly Inhibit Intracellular Mycobacterium tuberculosis Growth.

To establish stable infection, Mycobacterium tuberculosis (MTb) must overcome host innate immune mechanisms, including those that sense pathogen-derived nucleic acids. Here, we show that the host cytosolic RNA sensing molecules RIG-I-like receptor (RLR) signaling proteins RIG-I and MDA5, their common adaptor protein MAVS, and the RNA-dependent kinase PKR each independently inhibit MTb growth in human cells. Furthermore, we show that MTb broadly stimulates RIG-I, MDA5, MAVS, and PKR gene expression and their biological activities.

The FDA-Approved Oral Drug Nitazoxanide Amplifies Host Antiviral Responses and Inhibits Ebola Virus.

Here, we show that the US Food and Drug Administration-approved oral drug nitazoxanide (NTZ) broadly amplifies the host innate immune response to viruses and inhibits Ebola virus (EBOV) replication. We find that NTZ enhances retinoic-acid-inducible protein I (RIG-I)-like-receptor, mitochondrial antiviral signaling protein, interferon regulatory factor 3, and interferon activities and induces transcription of the antiviral phosphatase GADD34. NTZ significantly inhibits EBOV replication in human cells through its effects on RIG-I and protein kinase R (PKR), suggesting that it counteracts EBOV VP35 protein's ability to block RIG-I and PKR sensing of EBOV.

Treatment of drug-resistant tuberculosis among people living with HIV.

Purpose Of Review: This review aims to describe the key principles in treatment of drug-resistant tuberculosis (TB) in people living with HIV, including early access to timely diagnostics, linkage into care, TB treatment strategies including the use of new and repurposed drugs, co-management of HIV disease, and treatment complications and programmatic support to optimize treatment outcomes. These are necessary strategies to decrease the likelihood of poor treatment outcomes including lower treatment completion rates and higher mortality.

Recent Findings: Diagnosis of drug-resistant TB is the gateway into care; yet understanding the utility and the limitations of genotypic methods in this population is necessary.

Initiation, scale-up and outcomes of the Cambodian National MDR-TB programme 2006-2016: hospital and community-based treatment through an NGO-NTP partnership.

Introduction: Prolonged inpatient multidrug-resistant tuberculosis (MDR-TB) treatment for all patients is not sustainable for high-burden settings, but there is limited information on community-based treatment programme outcomes for MDR-TB.

Methods: The Cambodian Health Committee, a non-governmental organisation (NGO), launched the Cambodian MDR-TB programme in 2006 in cooperation with the National Tuberculosis Program (NTP) including a community-based treatment option as a key programme component. The programme was transferred to NTP oversight in 2011 with NGO clinical management continuing.

Diagnostic Potential of Imaging Flow Cytometry.

Imaging flow cytometry (IFC) captures multichannel images of hundreds of thousands of single cells within minutes. IFC is seeing a paradigm shift from low- to high-information-content analysis, driven partly by deep learning algorithms. We predict a wealth of applications with potential translation into clinical practice.

Imaging flow cytometry analysis of intracellular pathogens.

Imaging flow cytometry has been applied to address questions in infection biology, in particular, infections induced by intracellular pathogens. This methodology, which utilizes specialized analytic software makes it possible to analyze hundreds of quantified features for hundreds of thousands of individual cellular or subcellular events in a single experiment. Imaging flow cytometry analysis of host cell-pathogen interaction can thus quantitatively addresses a variety of biological questions related to intracellular infection, including cell counting, internalization score, and subcellular patterns of co-localization.

A Role for IFITM Proteins in Restriction of Mycobacterium tuberculosis Infection.

The interferon (IFN)-induced transmembrane (IFITM) proteins are critical mediators of the host antiviral response. Here, we expand the role of IFITM proteins to host defense against intracellular bacterial infection by demonstrating that they restrict Mycobacterium tuberculosis (MTb) intracellular growth. Simultaneous knockdown of IFITM1, IFITM2, and IFITM3 by RNAi significantly enhances MTb growth in human monocytic and alveolar/epithelial cells, whereas individual overexpression of each IFITM impairs MTb growth in these cell types.

Achieving high treatment success for multidrug-resistant TB in Africa: initiation and scale-up of MDR TB care in Ethiopia--an observational cohort study.

Background: In Africa, fewer than half of patients receiving therapy for multidrug-resistant TB (MDR TB) are successfully treated, with poor outcomes reported for HIV-coinfected patients.

Methods: A standardised second-line drug (SLD) regimen was used in a non-governmental organisation-Ministry of Health (NGO-MOH) collaborative community and hospital-based programme in Ethiopia that included intensive side effect monitoring, adherence strategies and nutritional supplementation. Clinical outcomes for patients with at least 24 months of follow-up were reviewed and predictors of treatment failure or death were evaluated by Cox proportional hazards models.

T cells and adaptive immunity to Mycobacterium tuberculosis in humans.

The adaptive immune response mediated by T cells is critical for control of Mycobacterium tuberculosis (M. tuberculosis) infection in humans. However, the M.

TB-IRIS, T-cell activation, and remodeling of the T-cell compartment in highly immunosuppressed HIV-infected patients with TB.

Objective: To investigate the impact of tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) upon immunological recovery and the T-cell compartment after initiation of TB and antiretroviral therapy (ART).

Design And Methods: We prospectively evaluated T-cell immunophenotypes by flow cytometry and cytokines by Luminex assays in a subset (n = 154) of highly immunosuppressed HIV-infected patients with TB from the Cambodian Early versus Late Introduction of Antiretrovirals randomized clinical trial. We compared findings from patients who developed TB-IRIS with findings from patients who did not develop TB-IRIS.

A distal locus element mediates IFN-γ priming of lipopolysaccharide-stimulated TNF gene expression.

Interferon γ (IFN-γ) priming sensitizes monocytes and macrophages to lipopolysaccharide (LPS) stimulation, resulting in augmented expression of a set of genes including TNF. Here, we demonstrate that IFN-γ priming of LPS-stimulated TNF transcription requires a distal TNF/LT locus element 8 kb upstream of the TNF transcription start site (hHS-8). IFN-γ stimulation leads to increased DNase I accessibility of hHS-8 and its recruitment of interferon regulatory factor 1 (IRF1), and subsequent LPS stimulation enhances H3K27 acetylation and induces enhancer RNA synthesis at hHS-8.

Causes and determinants of mortality in HIV-infected adults with tuberculosis: an analysis from the CAMELIA ANRS 1295-CIPRA KH001 randomized trial.

Background: Shortening the interval between antituberculosis treatment onset and initiation of antiretroviral therapy (ART) reduces mortality in severely immunocompromised human immunodeficiency virus (HIV)-infected patients with tuberculosis. A better understanding of causes and determinants of death may lead to new strategies to further enhance survival.

Methods: We assessed mortality rates, causes of death, and factors of mortality in Cambodian HIV-infected adults with CD4 count ≤200 cells/µL and tuberculosis, randomized to initiate ART either 2 weeks (early ART) or 8 weeks (late ART) after tuberculosis treatment onset in the CAMELIA clinical trial.

Plasma concentrations, efficacy and safety of efavirenz in HIV-infected adults treated for tuberculosis in Cambodia (ANRS 1295-CIPRA KH001 CAMELIA trial).

Objective: To assess efavirenz plasma concentrations and their association with treatment efficacy and tolerance of efavirenz 600 mg daily in HIV-tuberculosis co-infected patients.

Methods: HIV-infected adults with CD4+ T cell count ≤ 200/mm(3) received standard 6-month tuberculosis treatment and antiretroviral therapy including a daily-dose of 600 mg of efavirenz, irrespective of their body weight. Mid-dose blood samples were drawn both on tuberculosis treatment (week +2 and week +6 after antiretroviral therapy initiation, and week 22 of follow-up) and off tuberculosis treatment (week 50 of follow-up).

Epigenetic control of cytokine gene expression: regulation of the TNF/LT locus and T helper cell differentiation.

Epigenetics encompasses transient and heritable modifications to DNA and nucleosomes in the native chromatin context. For example, enzymatic addition of chemical moieties to the N-terminal "tails" of histones, particularly acetylation and methylation of lysine residues in the histone tails of H3 and H4, plays a key role in regulation of gene transcription. The modified histones, which are physically associated with gene regulatory regions that typically occur within conserved noncoding sequences, play a functional role in active, poised, or repressed gene transcription.

Plasma concentrations of efavirenz with a 600 mg standard dose in Cambodian HIV-infected adults treated for tuberculosis with a body weight above 50 kg.

Background: The optimal dose of efavirenz for HIV-infected patients receiving a tuberculosis regimen including rifampicin remains debated, especially for subjects weighing over 50 kg. To address this issue, we measured plasma efavirenz concentrations from Cambodian adults with tuberculosis enrolled in the CAMELIA randomized trial (ClinicalTrials.gov number, NCT01300481) 6 weeks after the onset of antiretroviral therapy.

The transcription factor NFATp plays a key role in susceptibility to TB in mice.

In T cells, the transcription factor nuclear factor of activated T cells p (NFATp) is a key regulator of the cytokine genes tumor necrosis factor (TNF) and interferon-γ (IFN-γ). Here, we show that NFATp-deficient (NFATp(-/-)) mice have a dramatic and highly significant increase in mortality after Mycobacterium tuberculosis (MTb) infection as compared to mortality of control animals after MTb infection. Animals deficient in NFATp have significantly impaired levels of TNF and IFN-γ transcription and protein expression in naïve or total CD4(+) T cells, but display wild-type levels of TNF mRNA or protein from MTb-stimulated dendritic cells (DC).

Regulation of Mycobacterium tuberculosis-dependent HIV-1 transcription reveals a new role for NFAT5 in the toll-like receptor pathway.

Tuberculosis (TB) disease in HIV co-infected patients contributes to increased mortality by activating innate and adaptive immune signaling cascades that stimulate HIV-1 replication, leading to an increase in viral load. Here, we demonstrate that silencing of the expression of the transcription factor nuclear factor of activated T cells 5 (NFAT5) by RNA interference (RNAi) inhibits Mycobacterium tuberculosis (MTb)-stimulated HIV-1 replication in co-infected macrophages. We show that NFAT5 gene and protein expression are strongly induced by MTb, which is a Toll-like receptor (TLR) ligand, and that an intact NFAT5 binding site in the viral promoter of R5-tropic HIV-1 subtype B and subtype C molecular clones is required for efficent induction of HIV-1 replication by MTb.

Monocyte-specific accessibility of a matrix attachment region in the tumor necrosis factor locus.

Regulation of TNF gene expression is cell type- and stimulus-specific. We have previously identified highly conserved noncoding regulatory elements within DNase I-hypersensitive sites (HSS) located 9 kb upstream (HSS-9) and 3 kb downstream (HSS+3) of the TNF gene, which play an important role in the transcriptional regulation of TNF in T cells. They act as enhancers and interact with the TNF promoter and with each other, generating a higher order chromatin structure.