Disruption of LEDGF/p75-directed integration derepresses antisense transcription of the HIV-1 genome.

Disruption of HIV-1 Integrase (IN) interactions with the host-factor Lens Epithelium-Derived Growth Factor (LEDGF)/p75 leads to decreased, random integration, increased latent infection, and described here, accumulation of HIV-1 antisense RNA (asRNA). asRNA increase was observed following interruptions of IN-LEDGF/p75 interactions either through pharmacologic perturbations of IN-LEDGF/p75 by treatment with allosteric HIV-1 integrase inhibitors (ALLINIs) or in cell lines with LEDGF genetic knockout. Additionally, by impairing Tat-dependent HIV transcription, asRNA abundance markedly increases.

Human mRNA in saliva can correctly identify individuals harboring acute infection.

There are a variety of clinical and laboratory criteria available to clinicians in controlled healthcare settings to help them identify whether an infectious disease is present. However, in situations such as a new epidemic caused by an unknown infectious agent, in health screening contexts performed within communities and outside of healthcare facilities or in battlefield or potential biowarfare situations, this gets more difficult. Pathogen-agnostic methods for rapid screening and triage of large numbers of people for infection status are needed, in particular methods that might work on an easily accessible biospecimen like saliva.

The Feline Immunodeficiency Virus Envelope Signal Peptide Is a Tetherin Antagonizing Protein.

Signal peptides are N-terminal peptides, generally less than 30 amino acids in length, that direct translocation of proteins into the endoplasmic reticulum and secretory pathway. The envelope glycoprotein (Env) of the nonprimate lentivirus feline immunodeficiency virus (FIV) contains the longest signal peptide of all eukaryotic, prokaryotic, and viral proteins (175 amino acids), yet the reason is unknown. Tetherin is a dual membrane-anchored host protein that inhibits the release of enveloped viruses from cells.

Allosteric Integrase Inhibitor Influences on HIV-1 Integration and Roles of LEDGF/p75 and HDGFL2 Host Factors.

Allosteric integrase (IN) inhibitors (ALLINIs), which are promising preclinical compounds that engage the lens epithelium-derived growth factor (LEDGF)/p75 binding site on IN, can inhibit different aspects of human immunodeficiency virus 1 (HIV-1) replication. During the late phase of replication, ALLINIs induce aberrant IN hyper-multimerization, the consequences of which disrupt IN binding to genomic RNA and virus particle morphogenesis. During the early phase of infection, ALLINIs can suppress HIV-1 integration into host genes, which is also observed in LEDGF/p75-depelted cells.

Localization and functions of native and eGFP-tagged capsid proteins in HIV-1 particles.

In infectious HIV-1 particles, the capsid protein (CA) forms a cone-shaped shell called the capsid, which encases the viral ribonucleoprotein complex (vRNP). Following cellular entry, the capsid is disassembled through a poorly understood process referred to as uncoating, which is required to release the reverse transcribed HIV-1 genome for integration into host chromatin. Whereas single virus imaging using indirect CA labeling techniques suggested uncoating to occur in the cytoplasm or at the nuclear pore, a recent study using eGFP-tagged CA reported uncoating in the nucleus.

Interferon resistance of emerging SARS-CoV-2 variants.

The emergence of SARS-CoV-2 variants with enhanced transmissibility, pathogenesis, and resistance to vaccines presents urgent challenges for curbing the COVID-19 pandemic. While Spike mutations that enhance virus infectivity or neutralizing antibody evasion may drive the emergence of these novel variants, studies documenting a critical role for interferon responses in the early control of SARS-CoV-2 infection, combined with the presence of viral genes that limit these responses, suggest that interferons may also influence SARS-CoV-2 evolution. Here, we compared the potency of 17 different human interferons against multiple viral lineages sampled during the course of the global outbreak, including ancestral and five major variants of concern that include the B.

Multivalent interactions essential for lentiviral integrase function.

A multimer of retroviral integrase (IN) synapses viral DNA ends within a stable intasome nucleoprotein complex for integration into a host cell genome. Reconstitution of the intasome from the maedi-visna virus (MVV), an ovine lentivirus, revealed a large assembly containing sixteen IN subunits. Herein, we report cryo-EM structures of the lentiviral intasome prior to engagement of target DNA and following strand transfer, refined at 3.

Broad antiviral and anti-inflammatory efficacy of nafamostat against SARS-CoV-2 and seasonal coronaviruses in primary human bronchiolar epithelia.

Antiviral strategies that target host systems needed for SARS-CoV-2 replication and pathogenesis may have therapeutic potential and help mitigate resistance development. Here, we evaluate nafamostat mesylate, a potent broad-spectrum serine protease inhibitor that blocks host protease activation of the viral spike protein. SARS-CoV-2 is used to infect human polarized mucociliated primary bronchiolar epithelia reconstituted with cells derived from healthy donors, smokers and subjects with chronic obstructive pulmonary disease.

Interferon Resistance of Emerging SARS-CoV-2 Variants.

The emergence of SARS-CoV-2 variants with enhanced transmissibility, pathogenesis and resistance to vaccines presents urgent challenges for curbing the COVID-19 pandemic. While Spike mutations that enhance virus infectivity or neutralizing antibody evasion may drive the emergence of these novel variants, studies documenting a critical role for interferon responses in the early control of SARS-CoV-2 infection, combined with the presence of viral genes that limit these responses, suggest that interferons may also influence SARS-CoV-2 evolution. Here, we compared the potency of 17 different human interferons against multiple viral lineages sampled during the course of the global outbreak, including ancestral and four major variants of concern.

Mucormycosis in Hematopoietic Cell Transplant Recipients and in Patients With Hematological Malignancies in the Era of New Antifungal Agents.

Background: The survival benefit of combination antifungal therapy for invasive mucormycosis (IM) in patients with hematologic malignancy (HM) and hematopoietic cell transplant (HCT) is not well defined.

Methods: This multicenter, retrospective study included HM and HCT recipients with proven or probable IM between January 1, 2007 and December 31, 2017 from 10 transplant centers across North America.

Results: Sixty-four patients with proven (n = 47) or probable (n = 17) IM defined by 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) consensus definitions were included.

Neutralizing SARS-CoV-2.

Experiments with hybrid viruses are illuminating how SARS-CoV-2 can escape neutralizing antibodies.

Structural and mechanistic bases for a potent HIV-1 capsid inhibitor.

The potent HIV-1 capsid inhibitor GS-6207 is an investigational principal component of long-acting antiretroviral therapy. We found that GS-6207 inhibits HIV-1 by stabilizing and thereby preventing functional disassembly of the capsid shell in infected cells. X-ray crystallography, cryo-electron microscopy, and hydrogen-deuterium exchange experiments revealed that GS-6207 tightly binds two adjoining capsid subunits and promotes distal intra- and inter-hexamer interactions that stabilize the curved capsid lattice.

Decarceration and community re-entry in the COVID-19 era.

Jails and prisons are exceptionally susceptible to viral outbreaks, such as severe acute respiratory syndrome coronavirus 2. The USA has extremely high rates of incarceration and COVID-19 is causing an urgent health crisis in correctional facilities and detention centres. Epidemics happening in prisons are compounding the elevated risks that COVID-19 poses to people of colour, older people, and those with comorbidities.

CPSF6-Dependent Targeting of Speckle-Associated Domains Distinguishes Primate from Nonprimate Lentiviral Integration.

Lentiviral DNA integration favors transcriptionally active chromatin. We previously showed that the interaction of human immunodeficiency virus type 1 (HIV-1) capsid with cleavage and polyadenylation specificity factor 6 (CPSF6) localizes viral preintegration complexes (PICs) to nuclear speckles for integration into transcriptionally active speckle-associated domains (SPADs). In the absence of the capsid-CPSF6 interaction, PICs uncharacteristically accumulate at the nuclear periphery and target heterochromatic lamina-associated domains (LADs) for integration.

A Potent Postentry Restriction to Primate Lentiviruses in a Yinpterochiropteran Bat.

Bats are primary reservoirs for multiple lethal human viruses, such as Ebola, Nipah, Hendra, rabies, severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome-related coronavirus (MERS-CoV), and, most recently, SARS-CoV-2. The innate immune systems of these immensely abundant, anciently diverged mammals remain insufficiently characterized. While bat genomes contain many endogenous retroviral elements indicative of past exogenous infections, little is known about restrictions to extant retroviruses.

COVID-19 Serosurveillance May Facilitate Return-to-Work Decisions.

Public health measures are needed to resolve the novel coronavirus disease (COVID-19) pandemic, although a looming economic fallout merits close attention. Early safe reintroduction of immune individuals into the workforce may be essential to protecting the economic welfare of communities. Reverse transcriptase-polymerase chain reaction testing, our primary diagnostic tool to date, has sensitivity and timing concerns, owing to sampling/handling errors, as well as a complex virus-host interaction.

Development of IFN-Stimulated Gene Expression from Embryogenesis through Adulthood, with and without Constitutive MDA5 Pathway Activation.

Pathogen-associated molecular patterns (e.g., dsRNA) activate expression of IFN-stimulated genes (ISGs), which protect hosts from infection.

Advantages of Outpatient Treatment with Long-Acting Lipoglycopeptides for Serious Gram-Positive Infections: A Review.

Treatment of serious gram-positive infections presents multiple challenges. Treatment often results in prolonged hospitalization for administration of intravenous antimicrobials and presents an inefficient use of hospital resources. Prolonged hospitalization is typically also unfavorable to patient preferences and potentially subjects patients to additional health care-associated complications.

Systemic Expression of a Viral RdRP Protects against Retrovirus Infection and Disease.

The innate immune system is normally programmed for immediate but transient upregulation in response to invading pathogens, and interferon (IFN)-stimulated gene (ISG) activation is a central feature. In contrast, chronic innate immune system activation is typically associated with autoimmunity and a broad array of autoinflammatory diseases that include the interferonopathies. Here, we studied retroviral susceptibility in a transgenic mouse model with lifelong innate immune system hyperactivation.

Hantavirus Infection with Renal Failure and Proteinuria, Colorado, USA, 2019.

In North America, hantaviruses commonly cause hantavirus pulmonary syndrome (HPS). Clinical descriptions of hantavirus-associated renal disease in the Americas are scarce. Herein, we discuss the case of a 61-year-old man whose predominant manifestations were acute kidney injury and proteinuria.

Lupus-associated endogenous retroviral LTR polymorphism and epigenetic imprinting promote HRES-1/RAB4 expression and mTOR activation.

Overexpression and long terminal repeat (LTR) polymorphism of the HRES‑1/Rab4 human endogenous retrovirus locus have been associated with T cell activation and disease manifestations in systemic lupus erythematosus (SLE). Although genomic DNA methylation is diminished overall in SLE, its role in HRES-1/Rab4 expression is unknown. Therefore, we determined how lupus-associated polymorphic rs451401 alleles of the LTR regulate transcription from the HRES-1/Rab4 promoter and thus affect T cell activation.

dsRNA-Seq: Identification of Viral Infection by Purifying and Sequencing dsRNA.

RNA viruses are a major source of emerging and re-emerging infectious diseases around the world. We developed a method to identify RNA viruses that is based on the fact that RNA viruses produce double-stranded RNA (dsRNA) while replicating. Purifying and sequencing dsRNA from the total RNA isolated from infected tissue allowed us to recover dsRNA virus sequences and replicated sequences from single-stranded RNA (ssRNA) viruses.

Case Report: Hepatic Fascioliasis in a Young Afghani Woman with Severe Wheezing, High-Grade Peripheral Eosinophilia, and Liver Lesions: A Brief Literature Review.

A 23-year-old recent emigrant from Afghanistan presented in August 2017 with severe wheezing and dyspnea that required hospital admission. Her illness was associated with marked peripheral blood eosinophilia (9,900-15,600/µL; 45.2-68%), as well as mild nausea, epigastric pain, and decreased appetite.