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1.
Front Immunol ; 12: 794638, 2021.
Article in English | MEDLINE | ID: covidwho-1731769

ABSTRACT

CCR5 plays a central role in infectious disease, host defense, and cancer progression, thereby making it an ideal target for therapeutic development. Notably, CCR5 is the major HIV entry co-receptor, where its surface density correlates with HIV plasma viremia. The level of CCR5 receptor occupancy (RO) achieved by a CCR5-targeting therapeutic is therefore a critical predictor of its efficacy. However, current methods to measure CCR5 RO lack sensitivity, resulting in high background and overcalculation. Here, we report on two independent, flow cytometric methods of calculating CCR5 RO using the anti-CCR5 antibody, Leronlimab. We show that both methods led to comparable CCR5 RO values, with low background on untreated CCR5+CD4+ T cells and sensitive measurements of occupancy on both blood and tissue-resident CD4+ T cells that correlated longitudinally with plasma concentrations in Leronlimab-treated macaques. Using these assays, we found that Leronlimab stabilized cell surface CCR5, leading to an increase in the levels of circulating and tissue-resident CCR5+CD4+ T cells in vivo in Leronlimab-treated macaques. Weekly Leronlimab treatment in a chronically SIV-infected macaque led to increased CCR5+CD4+ T cells levels and fully suppressed plasma viremia, both concomitant with full CCR5 RO on peripheral blood CD4+ T cells, demonstrating that CCR5+CD4+ T cells were protected from viral replication by Leronlimab binding. Finally, we extended these results to Leronlimab-treated humans and found that weekly 700 mg Leronlimab led to complete CCR5 RO on peripheral blood CD4+ T cells and a statistically significant increase in CCR5+CD4+ T cells in peripheral blood. Collectively, these results establish two RO calculation methods for longitudinal monitoring of anti-CCR5 therapeutic antibody blockade efficacy in both macaques and humans, demonstrate that CCR5+CD4+ T cell levels temporarily increase with Leronlimab treatment, and facilitate future detailed investigations into the immunological impacts of CCR5 inhibition in multiple pathophysiological processes.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , CD4-Positive T-Lymphocytes/immunology , COVID-19/drug therapy , Flow Cytometry/methods , HIV Antibodies/therapeutic use , HIV Infections/drug therapy , HIV-1/physiology , Receptors, CCR5/metabolism , SARS-CoV-2/physiology , Simian Acquired Immunodeficiency Syndrome/drug therapy , Simian Immunodeficiency Virus/physiology , Animals , CD4 Lymphocyte Count , Female , Humans , Primates , Protein Binding , Receptors, CCR5/immunology , Treatment Outcome
2.
Front Immunol ; 12: 820126, 2021.
Article in English | MEDLINE | ID: covidwho-1715000

ABSTRACT

This study aims to assess the immunological response and impact on virological control of the mRNA vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among people living with HIV (PLWH). In this single-center observational study, all PLWH were offered vaccination with mRNA1273 or BNT162b2. Both anti-N and anti-S1-receptor binding domain (RBD) antibodies were measured together with HIV-1 RNA levels after the first dose (M0) and then at 1 (M1), 2 (M2) and 6 (M6) months later. A total of 131 individuals (median age: 54 years [IQR: 47.0-60.5]; male: 70.2%; median baseline CD4 T-cell: 602/µl [IQR 445.0-825.5]; median nadir CD4 T-cells 223/µl [IQR 111.0-330.0]) were included. All participants were positive for anti-RBD antibodies at 30 days, 60 days and 6 months after the first dose, with no statistical difference between those with HIV-1 RNA below or >20 copies/ml. HIV-1 RNA data were collected for 128 patients at baseline and 30 days after the first dose; for 124 individuals, 30 days after the second dose; and for 83 patients, 6 months after the first dose. Nineteen (14.8%) of 128 had detectable HIV-1 RNA (>20 copies/ml) at M0, 13/128 (10.2%) at M1 (among which 5 were newly detectable), 15/124 (12.1%) at M2 (among which 5 were newly detectable), and 8/83 (9.6%) at M6. No serious adverse effects were reported. All participants elicited antibodies after two doses of mRNA vaccines, with only a minor impact on HIV-1 RNA levels over a 6-month period.


Subject(s)
/immunology , CD4-Positive T-Lymphocytes/immunology , COVID-19/immunology , HIV Infections/immunology , HIV-1/physiology , RNA, Viral/analysis , SARS-CoV-2/physiology , Adult , Aged , Antibodies, Viral/blood , Antibody Formation , Coronavirus Nucleocapsid Proteins/immunology , Female , Humans , Immunity, Heterologous , Male , Middle Aged , Phosphoproteins/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination
3.
Viruses ; 14(1)2021 12 30.
Article in English | MEDLINE | ID: covidwho-1580401

ABSTRACT

Medicinal chemistry optimization of a previously described stilbene inhibitor of HIV-1, 5350150 (2-(2-(5-nitro-2-thienyl)vinyl)quinoline), led to the identification of the thiazole-5-carboxamide derivative (GPS491), which retained potent anti-HIV-1 activity with reduced toxicity. In this report, we demonstrate that the block of HIV-1 replication by GPS491 is accompanied by a drastic inhibition of viral gene expression (IC50 ~ 0.25 µM), and alterations in the production of unspliced, singly spliced, and multiply spliced HIV-1 RNAs. GPS491 also inhibited the replication of adenovirus and multiple coronaviruses. Low µM doses of GPS491 reduced adenovirus infectious yield ~1000 fold, altered virus early gene expression/viral E1A RNA processing, blocked viral DNA amplification, and inhibited late (hexon) gene expression. Loss of replication of multiple coronaviruses (229E, OC43, SARS-CoV2) upon GPS491 addition was associated with the inhibition of viral structural protein expression and the formation of virus particles. Consistent with the observed changes in viral RNA processing, GPS491 treatment induced selective alterations in the accumulation/phosphorylation/function of splicing regulatory SR proteins. Our study establishes that a compound that impacts the activity of cellular factors involved in RNA processing can prevent the replication of several viruses with minimal effect on cell viability.


Subject(s)
Adenoviridae/drug effects , Antiviral Agents/pharmacology , Coronavirus/drug effects , HIV-1/drug effects , RNA Processing, Post-Transcriptional/drug effects , Thiazoles/pharmacology , Virus Replication/drug effects , Adenoviridae/physiology , Antiviral Agents/chemistry , Cell Line , Coronavirus/classification , Coronavirus/physiology , Gene Expression/drug effects , HIV-1/physiology , Humans , RNA Splicing Factors/metabolism , RNA, Viral/metabolism , Thiazoles/chemistry
5.
Viruses ; 13(11)2021 11 19.
Article in English | MEDLINE | ID: covidwho-1538549

ABSTRACT

A growing number of studies indicate that mRNAs and long ncRNAs can affect protein populations by assembling dynamic ribonucleoprotein (RNP) granules. These phase-separated molecular 'sponges', stabilized by quinary (transient and weak) interactions, control proteins involved in numerous biological functions. Retroviruses such as HIV-1 form by self-assembly when their genomic RNA (gRNA) traps Gag and GagPol polyprotein precursors. Infectivity requires extracellular budding of the particle followed by maturation, an ordered processing of ∼2400 Gag and ∼120 GagPol by the viral protease (PR). This leads to a condensed gRNA-NCp7 nucleocapsid and a CAp24-self-assembled capsid surrounding the RNP. The choreography by which all of these components dynamically interact during virus maturation is one of the missing milestones to fully depict the HIV life cycle. Here, we describe how HIV-1 has evolved a dynamic RNP granule with successive weak-strong-moderate quinary NC-gRNA networks during the sequential processing of the GagNC domain. We also reveal two palindromic RNA-binding triads on NC, KxxFxxQ and QxxFxxK, that provide quinary NC-gRNA interactions. Consequently, the nucleocapsid complex appears properly aggregated for capsid reassembly and reverse transcription, mandatory processes for viral infectivity. We show that PR is sequestered within this RNP and drives its maturation/condensation within minutes, this process being most effective at the end of budding. We anticipate such findings will stimulate further investigations of quinary interactions and emergent mechanisms in crowded environments throughout the wide and growing array of RNP granules.


Subject(s)
HIV Infections/virology , HIV-1 , Nucleocapsid Proteins/immunology , Viral Proteases/immunology , HIV-1/immunology , HIV-1/physiology , Humans , Virus Assembly
6.
PLoS Pathog ; 17(10): e1009726, 2021 10.
Article in English | MEDLINE | ID: covidwho-1484867

ABSTRACT

The zinc finger antiviral protein (ZAP) is a broad inhibitor of virus replication. Its best-characterized function is to bind CpG dinucleotides present in viral RNAs and, through the recruitment of TRIM25, KHNYN and other cofactors, target them for degradation or prevent their translation. The long and short isoforms of ZAP (ZAP-L and ZAP-S) have different intracellular localization and it is unclear how this regulates their antiviral activity against viruses with different sites of replication. Using ZAP-sensitive and ZAP-insensitive human immunodeficiency virus type I (HIV-1), which transcribe the viral RNA in the nucleus and assemble virions at the plasma membrane, we show that the catalytically inactive poly-ADP-ribose polymerase (PARP) domain in ZAP-L is essential for CpG-specific viral restriction. Mutation of a crucial cysteine in the C-terminal CaaX box that mediates S-farnesylation and, to a lesser extent, the residues in place of the catalytic site triad within the PARP domain, disrupted the activity of ZAP-L. Addition of the CaaX box to ZAP-S partly restored antiviral activity, explaining why ZAP-S lacks antiviral activity for CpG-enriched HIV-1 despite conservation of the RNA-binding domain. Confocal microscopy confirmed the CaaX motif mediated localization of ZAP-L to vesicular structures and enhanced physical association with intracellular membranes. Importantly, the PARP domain and CaaX box together jointly modulate the interaction between ZAP-L and its cofactors TRIM25 and KHNYN, implying that its proper subcellular localisation is required to establish an antiviral complex. The essential contribution of the PARP domain and CaaX box to ZAP-L antiviral activity was further confirmed by inhibition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication, which replicates in double-membrane vesicles derived from the endoplasmic reticulum. Thus, compartmentalization of ZAP-L on intracellular membranes provides an essential effector function in ZAP-L-mediated antiviral activity against divergent viruses with different subcellular replication sites.


Subject(s)
Prenylation/physiology , RNA Viruses/drug effects , RNA-Binding Proteins/pharmacology , Virus Replication/physiology , CpG Islands/physiology , HEK293 Cells , HIV-1/physiology , HeLa Cells , Humans , RNA Viruses/physiology , RNA, Viral/chemistry , RNA, Viral/metabolism , RNA-Binding Motifs/physiology , RNA-Binding Proteins/chemistry , RNA-Binding Proteins/metabolism , SARS-CoV-2/physiology , Transfection , Virus Replication/drug effects
7.
J Allergy Clin Immunol ; 148(5): 1176-1191, 2021 11.
Article in English | MEDLINE | ID: covidwho-1401557

ABSTRACT

BACKGROUND: The risk of severe coronavirus disease 2019 (COVID-19) varies significantly among persons of similar age and is higher in males. Age-independent, sex-biased differences in susceptibility to severe COVID-19 may be ascribable to deficits in a sexually dimorphic protective attribute that we termed immunologic resilience (IR). OBJECTIVE: We sought to examine whether deficits in IR that antedate or are induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection independently predict COVID-19 mortality. METHODS: IR levels were quantified with 2 novel metrics: immune health grades (IHG-I [best] to IHG-IV) to gauge CD8+ and CD4+ T-cell count equilibrium, and blood gene expression signatures. IR metrics were examined in a prospective COVID-19 cohort (n = 522); primary outcome was 30-day mortality. Associations of IR metrics with outcomes in non-COVID-19 cohorts (n = 13,461) provided the framework for linking pre-COVID-19 IR status to IR during COVID-19, as well as to COVID-19 outcomes. RESULTS: IHG-I, tracking high-grade equilibrium between CD8+ and CD4+ T-cell counts, was the most common grade (73%) among healthy adults, particularly in females. SARS-CoV-2 infection was associated with underrepresentation of IHG-I (21%) versus overrepresentation (77%) of IHG-II or IHG-IV, especially in males versus females (P < .01). Presentation with IHG-I was associated with 88% lower mortality, after controlling for age and sex; reduced risk of hospitalization and respiratory failure; lower plasma IL-6 levels; rapid clearance of nasopharyngeal SARS-CoV-2 burden; and gene expression signatures correlating with survival that signify immunocompetence and controlled inflammation. In non-COVID-19 cohorts, IR-preserving metrics were associated with resistance to progressive influenza or HIV infection, as well as lower 9-year mortality in the Framingham Heart Study, especially in females. CONCLUSIONS: Preservation of immunocompetence with controlled inflammation during antigenic challenges is a hallmark of IR and associates with longevity and AIDS resistance. Independent of age, a male-biased proclivity to degrade IR before and/or during SARS-CoV-2 infection predisposes to severe COVID-19.


Subject(s)
COVID-19/immunology , HIV Infections/epidemiology , HIV-1/physiology , Respiratory Insufficiency/epidemiology , SARS-CoV-2/physiology , Sex Factors , T-Lymphocytes/immunology , Adult , Aged , COVID-19/epidemiology , COVID-19/mortality , Cohort Studies , Disease Resistance , Female , Humans , Immunocompetence , Interleukin-6/blood , Longitudinal Studies , Male , Middle Aged , Prospective Studies , Severity of Illness Index , Survival Analysis , Transcriptome/immunology , United States/epidemiology , Viral Load
9.
Viruses ; 13(2)2021 02 10.
Article in English | MEDLINE | ID: covidwho-1395005

ABSTRACT

Since the discovery of HIV-1, the viral capsid has been recognized to have an important role as a structural protein that holds the viral genome, together with viral proteins essential for viral life cycle, such as the reverse transcriptase (RT) and the integrase (IN). The reverse transcription process takes place between the cytoplasm and the nucleus of the host cell, thus the Reverse Transcription Complexes (RTCs)/Pre-integration Complexes (PICs) are hosted in intact or partial cores. Early biochemical assays failed to identify the viral CA associated to the RTC/PIC, possibly due to the stringent detergent conditions used to fractionate the cells or to isolate the viral complexes. More recently, it has been observed that some host partners of capsid, such as Nup153 and CPSF6, can only bind multimeric CA proteins organized in hexamers. Those host factors are mainly located in the nuclear compartment, suggesting the entrance of the viral CA as multimeric structure inside the nucleus. Recent data show CA complexes within the nucleus having a different morphology from the cytoplasmic ones, clearly highlighting the remodeling of the viral cores during nuclear translocation. Thus, the multimeric CA complexes lead the viral genome into the host nuclear compartment, piloting the intranuclear journey of HIV-1 in order to successfully replicate. The aim of this review is to discuss and analyze the main discoveries to date that uncover the viral capsid as a key player in the reverse transcription and PIC maturation until the viral DNA integration into the host genome.


Subject(s)
Capsid/metabolism , Cell Nucleus/virology , HIV-1/physiology , Active Transport, Cell Nucleus , Capsid/chemistry , Capsid Proteins/chemistry , Capsid Proteins/metabolism , Cell Nucleus/metabolism , HIV-1/chemistry , HIV-1/metabolism , Models, Biological , Nuclear Pore Complex Proteins/metabolism , Reverse Transcription , Virus Integration , Virus Replication
12.
Dalton Trans ; 49(39): 13538-13543, 2020 Oct 12.
Article in English | MEDLINE | ID: covidwho-1305373

ABSTRACT

Lectins, which exhibit viral-interaction abilities, have garnered attention in the current pandemic era as potential neutralizing agents and vaccine candidates. Viral invasion through envelope proteins is modulated by N-linked glycosylation in the spike (S) protein. This study demonstrates the biophysical aspects between lectins and high-mannose and -galactose N-glycans to provide insights into binding events.


Subject(s)
Antiviral Agents/pharmacology , Concanavalin A/pharmacology , Polysaccharides/metabolism , Viral Envelope Proteins/metabolism , Coronavirus/drug effects , Coronavirus/physiology , Coronavirus Infections/drug therapy , HIV Infections/drug therapy , HIV-1/drug effects , HIV-1/physiology , Host-Pathogen Interactions/drug effects , Humans , Mannose/metabolism , Spike Glycoprotein, Coronavirus/metabolism
13.
J Mol Cell Biol ; 13(4): 259-268, 2021 08 04.
Article in English | MEDLINE | ID: covidwho-1147985

ABSTRACT

Viruses hijack host functions to invade their target cells and spread to new cells. Specifically, viruses learned to usurp liquid‒liquid phase separation (LLPS), a newly exploited mechanism, used by the cell to concentrate enzymes to accelerate and confine a wide variety of cellular processes. LLPS gives rise to actual membraneless organelles (MLOs), which do not only increase reaction rates but also act as a filter to select molecules to be retained or to be excluded from the liquid droplet. This is exactly what seems to happen with the condensation of SARS-CoV-2 nucleocapsid protein to favor the packaging of intact viral genomes, excluding viral subgenomic or host cellular RNAs. Another older pandemic virus, HIV-1, also takes advantage of LLPS in the host cell during the viral cycle. Recent discoveries highlighted that HIV-1 RNA genome condensates in nuclear MLOs accompanied by specific host and viral proteins, breaking the dogma of retroviruses that limited viral synthesis exclusively to the cytoplasmic compartment. Intriguing fundamental properties of viral/host LLPS remain still unclear. Future studies will contribute to deeply understanding the role of pathogen-induced MLOs in the epidemic invasion of pandemic viruses.


Subject(s)
HIV-1/physiology , Organelles/metabolism , SARS-CoV-2/physiology , COVID-19/pathology , COVID-19/virology , HIV Infections/pathology , HIV Infections/virology , HIV-1/genetics , HIV-1/isolation & purification , Host-Pathogen Interactions , Humans , Nucleocapsid Proteins/metabolism , RNA, Viral/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Virus Replication
14.
Int J Infect Dis ; 101: 243-246, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-796902

ABSTRACT

Despite measures put in place to curb the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) across South Africa, there has been a rapid spread which caused extensive morbidity and mortality. Whilst there is currently increased COVID-19 associated death, autopsies on COVID positive individuals are not routinely performed. An autopsy was performed on a 19 years old African patient who was recently diagnosed with human immunodeficiency virus (HIV). He presented with clinical features suggestive of SARS-CoV-2, which he subsequently tested positive for. Important histopathological findings included diffuse alveolar damage and fibrin thrombi. No superimposed infections were noted. The cause of death was attributed to COVID-19. We report the first autopsy case of an HIV-infected individual with COVID-19 as the cause of death.


Subject(s)
COVID-19/pathology , Adult , Autopsy , COVID-19/etiology , COVID-19/mortality , COVID-19/virology , Fatal Outcome , HIV Infections/pathology , HIV-1/physiology , Humans , Lung/pathology , Lung/virology , Male , Pandemics , SARS-CoV-2 , South Africa , Young Adult
15.
mBio ; 11(5)2020 09 15.
Article in English | MEDLINE | ID: covidwho-772275

ABSTRACT

Membrane-associated RING-CH-type 8 (MARCH8) strongly blocks human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) incorporation into virions by downregulating its cell surface expression, but the mechanism is still unclear. We now report that MARCH8 also blocks the Ebola virus (EBOV) glycoprotein (GP) incorporation via surface downregulation. To understand how these viral fusion proteins are downregulated, we investigated the effects of MARCH8 on EBOV GP maturation and externalization via the conventional secretion pathway. MARCH8 interacted with EBOV GP and furin when detected by immunoprecipitation and retained the GP/furin complex in the Golgi when their location was tracked by a bimolecular fluorescence complementation (BiFC) assay. MARCH8 did not reduce the GP expression or affect the GP modification by high-mannose N-glycans in the endoplasmic reticulum (ER), but it inhibited the formation of complex N-glycans on the GP in the Golgi. Additionally, the GP O-glycosylation and furin-mediated proteolytic cleavage were also inhibited. Moreover, we identified a novel furin cleavage site on EBOV GP and found that only those fully glycosylated GPs were processed by furin and incorporated into virions. Furthermore, the GP shedding and secretion were all blocked by MARCH8. MARCH8 also blocked the furin-mediated cleavage of HIV-1 Env (gp160) and the highly pathogenic avian influenza virus H5N1 hemagglutinin (HA). We conclude that MARCH8 has a very broad antiviral activity by prohibiting different viral fusion proteins from glycosylation and proteolytic cleavage in the Golgi, which inhibits their transport from the Golgi to the plasma membrane and incorporation into virions.IMPORTANCE Enveloped viruses express three classes of fusion proteins that are required for their entry into host cells via mediating virus and cell membrane fusion. Class I fusion proteins are produced from influenza viruses, retroviruses, Ebola viruses, and coronaviruses. They are first synthesized as a type I transmembrane polypeptide precursor that is subsequently glycosylated and oligomerized. Most of these precursors are cleaved en route to the plasma membrane by a cellular protease furin in the late secretory pathway, generating the trimeric N-terminal receptor-binding and C-terminal fusion subunits. Here, we show that a cellular protein, MARCH8, specifically inhibits the furin-mediated cleavage of EBOV GP, HIV-1 Env, and H5N1 HA. Further analyses uncovered that MARCH8 blocked the EBOV GP glycosylation in the Golgi and inhibited its transport from the Golgi to the plasma membrane. Thus, MARCH8 has a very broad antiviral activity by specifically inactivating different viral fusion proteins.


Subject(s)
Ebolavirus/chemistry , Glycoproteins/antagonists & inhibitors , HIV-1/chemistry , Hemagglutinins, Viral/metabolism , Influenza A Virus, H5N1 Subtype/chemistry , Ubiquitin-Protein Ligases/genetics , Viral Envelope Proteins/antagonists & inhibitors , Viral Envelope Proteins/physiology , Animals , Cell Line , Chlorocebus aethiops , Ebolavirus/physiology , Glycosylation , HEK293 Cells , HIV-1/physiology , HeLa Cells , Hep G2 Cells , Humans , Influenza A Virus, H5N1 Subtype/physiology , Protein Binding , THP-1 Cells , Ubiquitin-Protein Ligases/metabolism , Vero Cells , Viral Fusion Proteins/antagonists & inhibitors , Viral Fusion Proteins/metabolism
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