scholarly journals Bicaudal D2 facilitates the cytoplasmic trafficking and nuclear import of HIV-1 genomes during infection

2017 ◽  
Vol 114 (50) ◽  
pp. E10707-E10716 ◽  
Author(s):  
Adarsh Dharan ◽  
Silvana Opp ◽  
Omar Abdel-Rahim ◽  
Sevnur Komurlu Keceli ◽  
Sabrina Imam ◽  
...  
Keyword(s):  
Viral Genome ◽  
Target Cells ◽  
Adapter Protein ◽  
Nuclear Entry ◽  
Microtubule Network ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Microtubule Motor ◽  
Hiv 1

Numerous viruses, including HIV-1, exploit the microtubule network to traffic toward the nucleus during infection. Although numerous studies have observed a role for the minus-end microtubule motor dynein in HIV-1 infection, the mechanism by which the viral core containing the viral genome associates with dynein and induces its perinuclear trafficking has remained unclear. Here, we report that the dynein adapter protein bicaudal D2 (BICD2) is able to interact with HIV-1 viral cores in target cells. We also observe that BICD2 can bind in vitro-assembled capsid tubes through its CC3 domain. We observe that BICD2 facilitates infection by promoting the trafficking of viral cores to the nucleus, thereby promoting nuclear entry of the viral genome and infection. Finally, we observe that depletion of BICD2 in the monocytic cell line THP-1 results in an induction of IFN-stimulated genes in these cells. Collectively, these results identify a microtubule adapter protein critical for trafficking of HIV-1 in the cytoplasm of target cells and evasion of innate sensing mechanisms in macrophages.

scholarly journals HIV-1 uncoating occurs via a series of rapid biomechanical changes in the core related to individual stages of reverse transcription

2021 ◽  
Author(s):  
Sanela Rankovic ◽  
Akshay Deshpande ◽  
Shimon Harel ◽  
Christopher Aiken ◽  
Itay Rousso
Keyword(s):  
Reverse Transcription ◽  
Viral Genome ◽  
Morphological Changes ◽  
Viral Capsid ◽  
Target Cells ◽  
Viral Core ◽  
Successful Infection ◽  
Capsid Shell ◽  
Hiv 1

AbstractThe HIV core consists of the viral genome and associated proteins encased by a cone-shaped protein shell termed the capsid. Successful infection requires reverse transcription of the viral genome and disassembly of the capsid shell within a cell in a process known as uncoating. The integrity of the viral capsid is critical for reverse transcription, yet the viral capsid must be breached to release the nascent viral DNA prior to integration. We employed atomic force microscopy to study the stiffness changes in HIV-1 cores during reverse transcription in vitro in reactions containing the capsid-stabilizing host metabolite IP6. Cores exhibited a series of stiffness spikes, with up to three spikes typically occurring between 10-30, 40-80, and 120-160 minutes after initiation of reverse transcription. Addition of the reverse transcriptase (RT) inhibitor efavirenz eliminated the appearance of these spikes and the subsequent disassembly of the capsid, thus establishing that both result from reverse transcription. Using timed addition of efavirenz, and analysis of an RNAseH-defective RT mutant, we established that the first stiffness spike requires minus-strand strong stop DNA synthesis, with subsequent spikes requiring later stages of reverse transcription. Additional rapid AFM imaging experiments revealed repeated morphological changes in cores that were temporally correlated with the observed stiffness spikes. Our study reveals discrete mechanical changes in the viral core that are likely related to specific stages of reverse transcription. Our results suggest that reverse-transcription-induced changes in the capsid progressively remodel the viral core to prime it for temporally accurate uncoating in target cells.

scholarly journals Upregulation of human immunodeficiency virus-1 in chronically infected monocytic cell line by both contact with endothelial cells and cytokines

Blood ◽  
1994 ◽  
Vol 84 (5) ◽  
pp. 1567-1572 ◽  
Author(s):  
ST Fan ◽  
K Hsia ◽  
TS Edgington
Keyword(s):  
Human Immunodeficiency Virus ◽  
Endothelial Cells ◽  
Viral Gene ◽  
Target Cells ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Immunodeficiency Virus ◽  
The Impact ◽  
Hiv 1

Abstract Cells of monocytic lineage (Mo) persistently infected with human immunodeficiency virus (HIV) have been suspected to be a major reservoir for in vivo transmission of virus to susceptible target cells. Cellular events and mechanisms that upregulate viral gene expression in such cells are important issues. Because the traffic of such cells is central to biodistribution of HIV, we have explored the impact of interaction of endothelium with HIV-1-infected U1 promonocytic cells. Coculturing of U1 with human umbilical endothelial cells (HUVEC) for 24 to 72 hours in the absence of stimulation induced HIV-1 p24 biosynthesis significantly. Antibody-blocking experiments indicated that CD11/CD18 integrins play a role in upregulation of HIV expression elicited by interaction with HUVEC. Engagement of CD11b/CD18 by adherence of U1 to surfaces coated with either the cognate ligand fibrinogen or monoclonal antibody specific for CD11b/CD18 also enhanced p24 biosynthesis. Furthermore, endothelial cells were found to constitutively synthesize and secrete soluble factors that enhanced HIV- 1 synthesis. The enhancing factors, of estimated size 10 to 45 kD, were induced in HUVEC to high levels by monokines or by lipopolysaccharide, resulting in markedly enhanced HIV-1 expression by U1. These endothelial cell-derived HIV-1-enhancing factors consist of, among others, interleukin-6 (IL-6), IL-1 beta, and granulocyte-macrophage CSF (GM-CSF). Our results suggest that activation of HIV biosynthesis in infected Mo via interaction with endothelium may impact significantly on the tissue distribution and pathogenesis of HIV infections.

scholarly journals HIV-1 Engages a Dynein-Dynactin-BICD2 Complex for Infection and Transport to the Nucleus

2018 ◽  
Vol 92 (20) ◽  
Author(s):  
Stephanie K. Carnes ◽  
Jing Zhou ◽  
Christopher Aiken
Keyword(s):  
Heavy Chain ◽  
Intracellular Transport ◽  
Adaptor Proteins ◽  
Target Cells ◽  
Dynein Heavy Chain ◽  
Cell Extracts ◽  
Microtubule Motor ◽  
Dynactin Complex ◽  
Hiv 1

ABSTRACTHuman immunodeficiency virus type 1 (HIV-1) infection depends on efficient intracytoplasmic transport of the incoming viral core to the target cell nucleus. Evidence suggests that this movement is facilitated by the microtubule motor dynein, a large multiprotein complex that interacts with dynactin and cargo-specific adaptor proteins for retrograde movement via microtubules. Dynein adaptor proteins are necessary for activating dynein movement and for linking specific cargoes to dynein. We hypothesized that HIV-1 engages the dynein motor complex via an adaptor for intracellular transport. Here, we show that small interfering RNA depletion of the dynein heavy chain, components of the dynactin complex, and the dynein adaptor BICD2 reduced cell permissiveness to HIV-1 infection. Cell depletion of dynein heavy chain and BICD2 resulted in impaired HIV-1 DNA accumulation in the nucleus and decreased retrograde movement of the virus. Biochemical studies revealed that dynein components and BICD2 associate with capsid-like assemblies of the HIV-1 CA protein in cell extracts and that purified recombinant BICD2 binds to CA assembliesin vitro. Association of dynein with CA assemblies was reduced upon immunodepletion of BICD2 from cell extracts. We conclude that BICD2 is a capsid-associated dynein adaptor utilized by HIV-1 for transport to the nucleus.IMPORTANCEDuring HIV-1 infection, the virus must travel across the cytoplasm to enter the nucleus. The host cell motor protein complex dynein has been implicated in HIV-1 intracellular transport. We show that expression of the dynein heavy chain, components of the dynein-associated dynactin complex, and the dynein adaptor BICD2 in target cells are important for HIV-1 infection and nuclear entry. BICD2 interacts with the HIV-1 capsidin vitro, suggesting that it functions as a capsid-specific adaptor for HIV-1 intracellular transport. Our work identifies specific host proteins involved in microtubule-dependent HIV-1 intracellular transport and highlights the BICD2-capsid interaction as a potential target for antiviral therapy.

scholarly journals Capsid lattice destabilization leads to premature loss of the viral genome and integrase enzyme during HIV-1 infection

2020 ◽  
Author(s):  
Jenna E. Eschbach ◽  
Jennifer L. Elliott ◽  
Wen Li ◽  
Kaneil K. Zadrozny ◽  
Keanu Davis ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Reverse Transcription ◽  
Viral Genome ◽  
Target Cells ◽  
Viral Core ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACTThe human immunodeficiency virus type 1 (HIV-1) capsid (CA) protein forms a conical lattice around the viral ribonucleoprotein complex (vRNP) consisting of a dimeric viral genome and associated proteins, together constituting the viral core. Upon entry into target cells, the viral core undergoes a process termed uncoating, during which CA molecules are shed from the lattice. Although the timing and degree of uncoating are important for reverse transcription and integration, the molecular basis of this phenomenon remains unclear. Using complementary approaches, we assessed the impact of core destabilization on the intrinsic stability of the CA lattice in vitro and fates of viral core components in infected cells. We found that substitutions in CA can impact the intrinsic stability of the CA lattice in vitro in the absence of vRNPs, which mirrored findings from assessment of CA stability in virions. Altering CA stability tended to increase the propensity to form morphologically aberrant particles, in which the vRNPs were mislocalized between the CA lattice and the viral lipid envelope. Importantly, destabilization of the CA lattice led to premature dissociation of CA from vRNPs in target cells, which was accompanied by proteasomal-independent losses of the viral genome and integrase enzyme. Overall, our studies show that the CA lattice protects the vRNP from untimely degradation in target cells and provide the mechanistic basis of how CA stability influences reverse transcription.AUTHOR SUMMARYThe human immunodeficiency virus type 1 (HIV-1) capsid (CA) protein forms a conical lattice around the viral RNA genome and the associated viral enzymes and proteins, together constituting the viral core. Upon infection of a new cell, viral cores are released into the cytoplasm where they undergo a process termed “uncoating”, i.e. shedding of CA molecules from the conical lattice. Although proper and timely uncoating has been shown to be important for reverse transcription, the molecular mechanisms that link these two events remain poorly understood. In this study, we show that destabilization of the CA lattice leads to premature dissociation of CA from viral cores, which exposes the viral genome and the integrase enzyme for degradation in target cells. Thus, our studies demonstrate that the CA lattice protects the viral ribonucleoprotein complexes from untimely degradation in target cells and provide the first causal link between how CA stability affects reverse transcription.

scholarly journals HIV-1-derived exosomal microRNAs miR88 and miR99 promote the release of cytokines from human alveolar macrophages by binding to TLR8

2019 ◽  
Vol 17 ◽  
pp. 205873921987043
Author(s):  
Hui Zhao ◽  
Zhenming Sun ◽  
Lifang Li ◽  
Shuyin Zhi ◽  
Yiru Zhao ◽  
...  
Keyword(s):  
Alveolar Macrophages ◽  
Quantitative Polymerase Chain Reaction ◽  
The Body ◽  
Inflammatory Factors ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Necrosis Factor Alpha ◽  
Human Alveolar Macrophages ◽  
Hiv 1

The human monocytic cell line U937 and human alveolar macrophages were used as in vitro models to explore the role of miR88 and miR99 in the chronic abnormal activation of the body caused by human immunodeficiency virus (HIV). The functions and underlying mechanisms of miR88 and miR99 were studied by real-time quantitative polymerase chain reaction, transwell, and chromatin immunoprecipitation (ChIP) assays. HIV-1-infected cells released miR88 and miR99 into the extracellular space through exosomes, and miR88 and miR99 promoted the release of tumor necrosis factor alpha (TNFα), interleukin (IL)-6, and IL-12 by activating inflammatory factors, such as TLR8, on the surface of macrophages. HIV-derived microRNAs miR88 and miR99 performed these functions by binding to TLR8 and stimulating the release of pro-inflammatory factors from macrophages, such as TNFα, IL-6, and IL-12; these factors may be involved in chronic abnormal immune activation induced by HIV infection.

scholarly journals Human herpesvirus-6 dysregulates monocyte-mediated anticryptococcal defences

2006 ◽  
Vol 55 (6) ◽  
pp. 695-702 ◽  
Author(s):  
Claudio Cermelli ◽  
Valeria Cenacchi ◽  
Francesca Beretti ◽  
Francesco Pezzini ◽  
Dario Di Luca ◽  
...  
Keyword(s):  
Human Herpesvirus ◽  
Cell Types ◽  
Cell Contact ◽  
Target Cells ◽  
Human Herpesvirus 6 ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Herpesvirus 6 ◽  
Set Up

In order to investigate the interplay occurring between pathogens in the course of double infections, an in vitro model was set up in which the monocytic cell line THP-1 was exposed to Cryptococcus neoformans (Cn) and human herpesvirus 6 (HHV-6). Cn and HHV-6, both highly neurotropic, can cause serious diseases of the central nervous system and have monocytes, among other cell types, as target cells, causing alteration of their secretion pattern. Here, it was shown that unlike THP-1 cells exposed to cell-free virus inocula, THP-1 exposed to HHV-6-producing lymphocytes exhibited augmented phagocytosis against Cn. The phenomenon occurred after 24 h of monocyte/lymphocyte co-culture and was independent of direct cell-to-cell contact. Moreover, in the presence of HHV-6, THP-1 cells expressed enhanced secretory responses but reduced capability to counteract fungal infection: the enhanced ingestion by monocytes was followed by facilitated fungal survival and replication. These data provide initial in vitro evidence that HHV-6 may dysregulate monocyte-mediated anticryptococcal defences with an overall pro-cryptococcus result.

scholarly journals Upregulation of human immunodeficiency virus-1 in chronically infected monocytic cell line by both contact with endothelial cells and cytokines

Blood ◽  
1994 ◽  
Vol 84 (5) ◽  
pp. 1567-1572
Author(s):  
ST Fan ◽  
K Hsia ◽  
TS Edgington
Keyword(s):  
Human Immunodeficiency Virus ◽  
Endothelial Cells ◽  
Viral Gene ◽  
Target Cells ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Immunodeficiency Virus ◽  
The Impact ◽  
Hiv 1

Cells of monocytic lineage (Mo) persistently infected with human immunodeficiency virus (HIV) have been suspected to be a major reservoir for in vivo transmission of virus to susceptible target cells. Cellular events and mechanisms that upregulate viral gene expression in such cells are important issues. Because the traffic of such cells is central to biodistribution of HIV, we have explored the impact of interaction of endothelium with HIV-1-infected U1 promonocytic cells. Coculturing of U1 with human umbilical endothelial cells (HUVEC) for 24 to 72 hours in the absence of stimulation induced HIV-1 p24 biosynthesis significantly. Antibody-blocking experiments indicated that CD11/CD18 integrins play a role in upregulation of HIV expression elicited by interaction with HUVEC. Engagement of CD11b/CD18 by adherence of U1 to surfaces coated with either the cognate ligand fibrinogen or monoclonal antibody specific for CD11b/CD18 also enhanced p24 biosynthesis. Furthermore, endothelial cells were found to constitutively synthesize and secrete soluble factors that enhanced HIV- 1 synthesis. The enhancing factors, of estimated size 10 to 45 kD, were induced in HUVEC to high levels by monokines or by lipopolysaccharide, resulting in markedly enhanced HIV-1 expression by U1. These endothelial cell-derived HIV-1-enhancing factors consist of, among others, interleukin-6 (IL-6), IL-1 beta, and granulocyte-macrophage CSF (GM-CSF). Our results suggest that activation of HIV biosynthesis in infected Mo via interaction with endothelium may impact significantly on the tissue distribution and pathogenesis of HIV infections.

scholarly journals HIV-1 CA inhibitors are antagonized by inositol phosphate stabilization of the viral capsid in cells

2021 ◽  
Author(s):  
Gregory A Sowd ◽  
Jiong Shi ◽  
Christopher Aiken
Keyword(s):  
Antiretroviral Therapy ◽  
Antiviral Activity ◽  
Binding Site ◽  
Target Cells ◽  
Nuclear Entry ◽  
Inositol Hexakisphosphate ◽  
Capsid Stability ◽  
Hiv 1 ◽  
In Cells

The HIV-1 capsid, composed of the CA protein, is the target of the novel antiretroviral drug lenacapavir (LCV). CA inhibitors block host factor binding and alter capsid stability to prevent nuclear entry and reverse transcription (RTN), respectively. Capsid stability is mediated in vitro by binding to the host cell metabolite inositol hexakisphosphate (IP6). IP6 depletion in target cells has little effect on HIV-1 infection. We hypothesized that capsid-altering concentrations of CA inhibitors might reveal an effect of IP6 depletion on HIV-1 infection in target cells. To test this, we studied the effects of IP6 depletion on inhibition of infection by the CA inhibitors PF74 and LCV. At low doses of either compound that affect HIV-1 nuclear entry, no effect of IP6 depletion on antiviral activity was observed. Increased antiviral activity was observed in IP6-depleted cells at inhibitor concentrations that affect capsid stability, correlating with increased RTN inhibition. Assays of uncoating and endogenous RTN of purified cores in vitro provided additional support. Our results show that inositol phosphates stabilize the HIV-1 capsid in target cells, thereby dampening the antiviral effects of capsid-targeting antiviral compounds. We propose that targeting of the IP6-binding site in conjunction with CA inhibitors will lead to robust antiretroviral therapy. Importance HIV-1 infection and subsequent depletion of CD4 + T cells results in AIDS. Antiretroviral therapy (ART) treatment of infected individuals prevents progression to AIDS. The HIV-1 capsid has recently become an ART target. Capsid inhibitors block HIV-1 infection at multiple steps, offering advantages over current ART. The cellular metabolite inositol hexakisphosphate (IP6) binds the HIV-1 capsid, stabilizing it in vitro . However, the function of this interaction in target cells is unclear. Our results imply that IP6 stabilizes the incoming HIV-1 capsid in cells, thus limiting the antiviral efficiency of capsid-destabilizing antivirals. We present a model of capsid inhibitor function and propose that targeting of the IP6-binding site in conjunction with capsid inhibitors currently in development will lead to more robust ART.

scholarly journals Capsid Lattice Destabilization Leads to Premature Loss of the Viral Genome and Integrase Enzyme during HIV-1 Infection

2020 ◽  
Vol 95 (2) ◽  
pp. e00984-20
Author(s):  
Jenna E. Eschbach ◽  
Jennifer L. Elliott ◽  
Wen Li ◽  
Kaneil K. Zadrozny ◽  
Keanu Davis ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Reverse Transcription ◽  
Viral Genome ◽  
Target Cells ◽  
Viral Core ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACTThe human immunodeficiency virus type 1 (HIV-1) capsid (CA) protein forms a conical lattice around the viral ribonucleoprotein complex (vRNP) consisting of a dimeric viral genome and associated proteins, together constituting the viral core. Upon entry into target cells, the viral core undergoes a process termed uncoating, during which CA molecules are shed from the lattice. Although the timing and degree of uncoating are important for reverse transcription and integration, the molecular basis of this phenomenon remains unclear. Using complementary approaches, we assessed the impact of core destabilization on the intrinsic stability of the CA lattice in vitro and fates of viral core components in infected cells. We found that substitutions in CA can impact the intrinsic stability of the CA lattice in vitro in the absence of vRNPs, which mirrored findings from an assessment of CA stability in virions. Altering CA stability tended to increase the propensity to form morphologically aberrant particles, in which the vRNPs were mislocalized between the CA lattice and the viral lipid envelope. Importantly, destabilization of the CA lattice led to premature dissociation of CA from vRNPs in target cells, which was accompanied by proteasomal-independent losses of the viral genome and integrase enzyme. Overall, our studies show that the CA lattice protects the vRNP from untimely degradation in target cells and provide the mechanistic basis of how CA stability influences reverse transcription.IMPORTANCE The human immunodeficiency virus type 1 (HIV-1) capsid (CA) protein forms a conical lattice around the viral RNA genome and the associated viral enzymes and proteins, together constituting the viral core. Upon infection of a new cell, viral cores are released into the cytoplasm where they undergo a process termed “uncoating,” i.e., shedding of CA molecules from the conical lattice. Although proper and timely uncoating has been shown to be important for reverse transcription, the molecular mechanisms that link these two events remain poorly understood. In this study, we show that destabilization of the CA lattice leads to premature dissociation of CA from viral cores, which exposes the viral genome and the integrase enzyme for degradation in target cells. Thus, our studies demonstrate that the CA lattice protects the viral ribonucleoprotein complexes from untimely degradation in target cells and provide the first causal link between how CA stability affects reverse transcription.

scholarly journals HIV-1 subverts the complement system in semen to enhance viral transmission

2021 ◽  
Author(s):  
Bernadien M. Nijmeijer ◽  
Marta Bermejo-Jambrina ◽  
Tanja M. Kaptein ◽  
Carla M. S. Ribeiro ◽  
Doris Wilflingseder ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Virus Transmission ◽  
Sexual Contact ◽  
Target Cells ◽  
People Living With Hiv ◽  
Lectin Receptor ◽  
Pre Treatment ◽  
Living With Hiv ◽  
Hiv 1

AbstractSemen is important in determining HIV-1 susceptibility but it is unclear how it affects virus transmission during sexual contact. Mucosal Langerhans cells (LCs) are the first immune cells to encounter HIV-1 during sexual contact and have a barrier function as LCs are restrictive to HIV-1. As semen from people living with HIV-1 contains complement-opsonized HIV-1, we investigated the effect of complement on HIV-1 dissemination by human LCs in vitro and ex vivo. Notably, pre-treatment of HIV-1 with semen enhanced LC infection compared to untreated HIV-1 in the ex vivo explant model. Infection of LCs and transmission to target cells by opsonized HIV-1 was efficiently inhibited by blocking complement receptors CR3 and CR4. Complement opsonization of HIV-1 enhanced uptake, fusion, and integration by LCs leading to an increased transmission of HIV-1 to target cells. However, in the absence of both CR3 and CR4, C-type lectin receptor langerin was able to restrict infection of complement-opsonized HIV-1. These data suggest that complement enhances HIV-1 infection of LCs by binding CR3 and CR4, thereby bypassing langerin and changing the restrictive nature of LCs into virus-disseminating cells. Targeting complement factors might be effective in preventing HIV-1 transmission.

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