Host protein incorporation is conserved among diverse HIV-1 subtypes

The incorporation of biologically active host proteins into HIV-1 is a well-established phenomenon, particularly due to the budding mechanism of viral egress in which viruses acquire their external lipid membrane directly from the host cell. While this mechanism might seemingly imply that host protein incorporation is a passive uptake of all cellular antigens associated with the plasma membrane at the site of budding, this is not the case. Herein, we review the evidence indicating that host protein incorporation can be a selective and conserved process. We discuss how HIV-1 virions displaying host proteins on their surface can exhibit a myriad of altered phenotypes, with notable impacts on infectivity, homing, neutralization, and pathogenesis. This review describes the canonical and emerging methods to detect host protein incorporation, highlights the well-established host proteins that have been identified on HIV-1 virions, and reflects on the role of these incorporated proteins in viral pathogenesis and therapeutic targeting. Despite many advances in HIV treatment and prevention, there remains a global effort to develop increasingly effective anti-HIV therapies. Given the broad range of biologically active host proteins acquired on the surface of HIV-1, additional studies on the mechanisms and impacts of these incorporated host proteins may inform the development of novel treatments and vaccine designs.

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In Silico Insights into HIV-1 Vpu-Tetherin Interactions and Its Mutational Counterparts

Medical Sciences ◽

10.3390/medsci7060074 ◽

2019 ◽

Vol 7 (6) ◽

pp. 74

Author(s):

Patil Sneha ◽

Urmi Shah ◽

Seetharaman Balaji

Keyword(s):

Cell Surface ◽

Binding Affinity ◽

Hydrophobic Interactions ◽

Single Point ◽

Resistance Mechanism ◽

Point Mutations ◽

Protein Docking ◽

Host Protein ◽

Single Point Mutations ◽

Hiv 1

Tetherin, an interferon-induced host protein encoded by the bone marrow stromal antigen 2 (BST2/CD317/HM1.24) gene, is involved in obstructing the release of many retroviruses and other enveloped viruses by cross-linking the budding virus particles to the cell surface. This activity is antagonized in the case of human immunodeficiency virus (HIV)-1 wherein its accessory protein Viral Protein U (Vpu) interacts with tetherin, causing its downregulation from the cell surface. Vpu and tetherin connect through their transmembrane (TM) domains, culminating into events leading to tetherin degradation by recruitment of β-TrCP2. However, mutations in the TM domains of both proteins are reported to act as a resistance mechanism to Vpu countermeasure impacting tetherin’s sensitivity towards Vpu but retaining its antiviral activity. Our study illustrates the binding aspects of blood-derived, brain-derived, and consensus HIV-1 Vpu with tetherin through protein–protein docking. The analysis of the bound complexes confirms the blood-derived Vpu–tetherin complex to have the best binding affinity as compared to other two. The mutations in tetherin and Vpu are devised computationally and are subjected to protein–protein interactions. The complexes are tested for their binding affinities, residue connections, hydrophobic forces, and, finally, the effect of mutation on their interactions. The single point mutations in tetherin at positions L23Y, L24T, and P40T, and triple mutations at {L22S, F44Y, L37I} and {L23T, L37T, T45I}, while single point mutations in Vpu at positions A19H and W23Y and triplet of mutations at {V10K, A11L, A19T}, {V14T, I18T, I26S}, and {A11T, V14L, A15T} have revealed no polar contacts with minimal hydrophobic interactions between Vpu and tetherin, resulting in reduced binding affinity. Additionally, we have explored the aggregation potential of tetherin and its association with the brain-derived Vpu protein. This work is a possible step toward an understanding of Vpu–tetherin interactions.

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Identifying potential survival strategies of HIV-1 through virus-host protein interaction networks

BMC Systems Biology ◽

10.1186/1752-0509-4-96 ◽

2010 ◽

Vol 4 (1) ◽

Cited By ~ 23

Author(s):

David van Dijk ◽

Gokhan Ertaylan ◽

Charles AB Boucher ◽

Peter MA Sloot

Keyword(s):

Protein Interaction ◽

Protein Interaction Networks ◽

Interaction Networks ◽

Host Protein ◽

Survival Strategies ◽

Hiv 1

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Deaminase-independent inhibition of HIV-1 reverse transcription by APOBEC3G

Nucleic Acids Research ◽

10.1093/nar/gkm750 ◽

2007 ◽

Vol 35 (21) ◽

pp. 7096-7108 ◽

Cited By ~ 227

Author(s):

Yasumasa Iwatani ◽

Denise S.B. Chan ◽

F. Wang ◽

Kristen Stewart-Maynard ◽

Wataru Sugiura ◽

...

Keyword(s):

Nucleic Acid ◽

Single Molecule ◽

Reverse Transcription ◽

Cytidine Deaminase ◽

Rnase H ◽

Host Protein ◽

Nucleic Acid Binding ◽

Nucleic Acid Chaperone ◽

Kinetics Of ◽

Hiv 1

Abstract APOBEC3G (A3G), a host protein that inhibits HIV-1 reverse transcription and replication in the absence of Vif, displays cytidine deaminase and single-stranded (ss) nucleic acid binding activities. HIV-1 nucleocapsid protein (NC) also binds nucleic acids and has a unique property, nucleic acid chaperone activity, which is crucial for efficient reverse transcription. Here we report the interplay between A3G, NC and reverse transcriptase (RT) and the effect of highly purified A3G on individual reactions that occur during reverse transcription. We find that A3G did not affect the kinetics of NC-mediated annealing reactions, nor did it inhibit RNase H cleavage. In sharp contrast, A3G significantly inhibited all RT-catalyzed DNA elongation reactions with or without NC. In the case of ( − ) strong-stop DNA synthesis, the inhibition was independent of A3G's catalytic activity. Fluorescence anisotropy and single molecule DNA stretching analyses indicated that NC has a higher nucleic acid binding affinity than A3G, but more importantly, displays faster association/disassociation kinetics. RT binds to ssDNA with a much lower affinity than either NC or A3G. These data support a novel mechanism for deaminase-independent inhibition of reverse transcription that is determined by critical differences in the nucleic acid binding properties of A3G, NC and RT.

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Virus-producing cells determine the host protein profiles of HIV-1 virion cores

Retrovirology ◽

10.1186/1742-4690-9-65 ◽

2012 ◽

Vol 9 (1) ◽

pp. 65 ◽

Cited By ~ 47

Author(s):

Steven Santos ◽

Yuri Obukhov ◽

Sergei Nekhai ◽

Michael Bukrinsky ◽

Sergey Iordanskiy

Keyword(s):

Host Protein ◽

Protein Profiles ◽

Hiv 1

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Identification of a Novel Human Immunodeficiency Virus Type 1 Integrase Interactor, Gemin2, That Facilitates Efficient Viral cDNA Synthesis In Vivo

Journal of Virology ◽

10.1128/jvi.02471-05 ◽

2006 ◽

Vol 80 (12) ◽

pp. 5670-5677 ◽

Cited By ~ 42

Author(s):

Seiji Hamamoto ◽

Hironori Nishitsuji ◽

Teruo Amagasa ◽

Mari Kannagi ◽

Takao Masuda

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Host Protein ◽

Cdna Synthesis ◽

Immunodeficiency Virus ◽

Viral Cdna ◽

Hiv 1

ABSTRACT Retroviral integrase (IN) catalyzes the integration of viral cDNA into a host chromosome. Additional roles have been suggested for IN, including uncoating, reverse transcription, and nuclear import of the human immunodeficiency virus type 1 (HIV-1) genome. However, the underlying mechanism is largely unknown. Here, using a yeast two-hybrid system, we identified a survival motor neuron (SMN)-interacting protein 1 (Gemin2) that binds to HIV-1 IN. Reduction of Gemin2 with small interfering RNA duplexes (siGemin2) dramatically reduced HIV-1 infection in human primary monocyte-derived macrophages and also reduced viral cDNA synthesis. In contrast, siGemin2 did not affect HIV-1 expression from the integrated proviral DNA. Although Gemin2 was undetectable in cell-free viral particles, coimmunoprecipitation experiments using FLAG-tagged Gemin2 strongly suggested that Gemin2 interacts with the incoming viral genome through IN. Further experiments reducing SMN or other SMN-interacting proteins suggested that Gemin2 might act on HIV-1 either alone or with unknown proteins to facilitate efficient viral cDNA synthesis soon after infection. Thus, we provide the evidence for a novel host protein that binds to HIV-1 IN and facilitates viral cDNA synthesis and subsequent steps that precede integration in vivo.

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Efficient Incorporation of HLA Class II onto Human Immunodeficiency Virus Type 1 Requires Envelope Glycoprotein Packaging

Journal of Virology ◽

10.1128/jvi.74.8.3918-3923.2000 ◽

2000 ◽

Vol 74 (8) ◽

pp. 3918-3923 ◽

Cited By ~ 19

Author(s):

Dexter T. K. Poon ◽

Lori V. Coren ◽

David E. Ott

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Class Ii ◽

Hla Class Ii ◽

Class I ◽

Immunodeficiency Virus ◽

Protein Incorporation ◽

Hiv 1

ABSTRACT HLA class II DR is one of the most abundant cell surface proteins incorporated onto human immunodeficiency virus type 1 (HIV-1) during budding. The mechanism for HLA class II protein incorporation is not known and may involve a viral protein. To determine whether Env affects HLA class II protein incorporation, HIV-1 virions, either with or without Env on their surface, were produced from HLA class II-expressing cells and analyzed by whole-virus immunoprecipitation with antisera against HLA class II proteins. HLA class II proteins were detected on virions only when wild-type Env was incorporated, while similar experiments showed that HLA class I proteins were incorporated independent of Env packaging. Therefore, the packaging of HIV-1 Env protein is required for the efficient incorporation of HLA class II but not class I proteins into the virion. Analysis of two Env mutants revealed that the presence of a 43-amino-acid sequence between amino acids 708 and 750 in the gp41TM cytoplasmic tail was required for efficient incorporation of HLA class II proteins. These data show that HIV-1 actively incorporates HLA class II proteins in a process that, either directly or indirectly, requires Env.

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Nef enhances HIV-1 replication and infectivity independently of SERINC3 and SERINC5 in CEM T cells

10.1101/2020.07.15.205757 ◽

2020 ◽

Author(s):

Peter W. Ramirez ◽

Aaron A. Angerstein ◽

Marissa Suarez ◽

Thomas Vollbrecht ◽

Jared Wallace ◽

...

Keyword(s):

Growth Rate ◽

T Cells ◽

T Cell ◽

Viral Replication ◽

Cell Line ◽

Host Protein ◽

Target Cells ◽

Viral Fusion ◽

Viral Growth ◽

Hiv 1

AbstractThe lentiviral nef gene encodes several discrete activities aimed at co-opting or antagonizing cellular proteins and pathways to defeat host defenses and maintain persistent infection. Primary functions of Nef include downregulation of CD4 and MHC class-I from the cell surface, disruption or mimicry of T-cell receptor signaling, and enhancement of viral infectivity by counteraction of the host antiretroviral proteins SERINC3 and SERINC5. In the absence of Nef, SERINC3 and SERINC5 incorporate into virions and inhibit viral fusion with target cells, decreasing infectivity. However, whether Nef’s counteraction of SERINC3 and SERINC5 is the cause of its positive influence on viral growth-rate in CD4-positive T cells is unclear. Here, we utilized CRISPR/Cas9 to knockout SERINC3 and SERINC5 in a leukemic CD4-positive T cell line (CEM) that displays robust nef-related infectivity and growth-rate phenotypes. As previously reported, viral replication was severely attenuated in CEM cells infected with HIV-1 lacking Nef (HIV-1ΔNef). This attenuated growth-rate phenotype was observed regardless of whether or not the coding regions of the serinc3 and serinc5 genes were intact. Moreover, knockout of serinc3 and serinc5 failed to restore the infectivity of HIV-1ΔNef virions produced from infected CEM cells in single-cycle replication experiments using CD4-positive HeLa cells as targets. Taken together, our results corroborate a recent study using another T-lymphoid cell line (MOLT-3) and suggest that Nef modulates a still unidentified host protein(s) to enhance viral growth rate and infectivity in CD4-positive T cells.ImportanceHIV-1 Nef is a major pathogenicity factor in vivo. A well-described activity of Nef is the enhancement of virion-infectivity and viral propagation in vitro. The infectivity-effect has been attributed to Nef’s ability to prevent the cellular, antiretroviral proteins SERINC3 and SERINC5 from incorporating into viral particles. While the activity of the SERINCs as inhibitors of retroviral infectivity has been well-documented, the role these proteins play in controlling HIV-1 replication is less clear. We report here that genetic disruption of SERINC3 and SERINC5 rescues neither viral replication-rate nor the infectivity of cell-free virions produced from CD4-positive T cells of the CEM lymphoblastoid line infected with viruses lacking Nef. This indicates that failure to modulate SERINC3 and SERINC5 is not the cause of the virologic attenuation of nef-negative HIV-1 observed using this system.

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Elucidation of the Molecular Consequences of Two Unique p6Gag Mutations Derived from HIV-1 CRF07_BC-infected Patients

10.21203/rs.2.21304/v1 ◽

2020 ◽

Author(s):

Zetao Cheng ◽

Sherimay D. Ablan ◽

Eric O. Freed ◽

Haiying Wang ◽

Shixing Tang

Keyword(s):

Amino Acid ◽

Disease Progression ◽

Binding Domain ◽

Host Protein ◽

Virus Infectivity ◽

Virus Release ◽

Amino Acid Deletion ◽

Gag Protein ◽

Subtype B ◽

Hiv 1

Abstract Background We previously observed that individuals infected with HIV-1 CRF07_BC showed slower disease progression than those infected with HIV-1 subtype B or CRF01_AE. CRF07_BC viruses carry two unique mutations in the p6 Gag protein: insertion of PTAPPE sequences downstream of the original Tsg101 binding domain, and deletion of a seven-amino-acid sequence ( 30 PIDKELY 36 ) that partially overlaps with the Alix binding domain. To further define the role of these mutations in virus release and replication, we introduced them into the HIV-1 proviral clone pNL4-3 for functional characterization. Results We found that the seven-amino-acid deletion, but not the PTAPPE insertion, significantly decreased virus release, Gag processing, and virus infectivity. The seven-amino-acid deletion also resulted in a virus replication defect in both T-cell lines and peripheral blood mononuclear cells. We found that these defects were caused by the seven-amino-acid deletion in p6 Gag , especially deletion of Tyr-36 of p6 Gag , not the deletion of the overlapping p6* sequence in the HIV-1 GagPol protein. The p6 Gag deletion mutant was resistant to a dominant-negative Alix fragment, suggesting a loss of binding between p6 Gag and Alix. Conclusions Our results indicate that the patient-derived seven-amino-acid deletion in p6 Gag of HIV-1 CRF07_BC virus affects virus release, infectivity and replication capacity by disrupting the interaction between HIV-1 p6 Gag and host protein Alix. These results may explain the slower disease progression observed in the subjects infected with HIV-1 CRF07_BC bearing this unique mutation.

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Influence of GlycoGag on the Incorporation of Host Membrane Proteins Into the Envelope of the Moloney Murine Leukemia Virus

Frontiers in Virology ◽

10.3389/fviro.2021.747253 ◽

2021 ◽

Vol 1 ◽

Author(s):

Mariam Maltseva ◽

Marc-André Langlois

Keyword(s):

Murine Leukemia Virus ◽

Viral Particle ◽

Leukemia Virus ◽

Viral Envelope ◽

Host Protein ◽

Viral Population ◽

Phenotypic Characterization ◽

Particle Level ◽

Protein Incorporation ◽

Murine Leukemia

Analysis of viral particle heterogeneity produced from infected cells has been limited by the inefficiency of traditional analytical methods to characterize large populations of viruses at an individual particle level. Flow virometry (FVM) is an emerging technique based on flow cytometry principles that enables a high throughput, multiparametric, and phenotypic characterization of viruses at a single particle resolution. Here, we performed FVM to analyze surface markers found on Murine Leukemia Virus (MLV) and glycosylated Gag-deficient (glycoGag) MLV. The glycoGag viral accessory protein has several roles in the MLV viral infection cycle including directing retroviral assembly and particle release at lipid rafts. Based on previous studies, we hypothesize that glycoGag modulates host protein incorporation into the viral envelope during viral assembly and budding. Here, by using FVM, we reveal that glycoGag is associated with an increased incorporation of the host-derived tetraspanins CD81 and CD63 along with the lipid raft marker and immune antigen Thy1.2 during the assembly and release of viral particles from infected NIH 3T3, EL4, and primary CD4+ T cells. Moreover, we show differences in the uptake of host proteins by viruses that are released from the two cell lines and primary T lymphocytes. Additionally, at the individual viral particle level, we observed a degree of expression heterogeneity of host-derived antigens within the viral population. Finally, certain cellular antigens can show either enrichment or exclusion from the viral envelope depending on whether glycoGag is expressed by the virus. This suggests that glycoGag is involved in a mechanism of selective host protein incorporation into the viral envelope.

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