The innate immune roles of host factors TRIM5α and Cyclophilin A on HIV-1 replication

2015 ◽  
Vol 204 (5) ◽  
pp. 557-565 ◽  
Author(s):  
Yi-Qun Kuang ◽  
Hong-Liang Liu ◽  
Yong-Tang Zheng
Keyword(s):  
Cyclophilin A ◽  
Innate Immune ◽  
Host Factors ◽  
Hiv 1

scholarly journals Roles of Capsid-Interacting Host Factors in Multimodal Inhibition of HIV-1 by PF74

2016 ◽  
Vol 90 (12) ◽  
pp. 5808-5823 ◽  
Author(s):  
Akatsuki Saito ◽  
Damien Ferhadian ◽  
Gregory A. Sowd ◽  
Erik Serrao ◽  
Jiong Shi ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Dose Response ◽  
Response Curve ◽  
Cyclophilin A ◽  
Dose Response Curve ◽  
Host Factors ◽  
Viral Capsid ◽  
Antiviral Compound ◽  
Drug Concentrations ◽  
Hiv 1

ABSTRACTThe viral capsid of HIV-1 interacts with a number of host factors to orchestrate uncoating and regulate downstream events, such as reverse transcription, nuclear entry, and integration site targeting. PF-3450074 (PF74), an HIV-1 capsid-targeting low-molecular-weight antiviral compound, directly binds to the capsid (CA) protein at a site also utilized by host cell proteins CPSF6 and NUP153. Here, we found that the dose-response curve of PF74 is triphasic, consisting of a plateau and two inhibitory phases of different slope values, consistent with a bimodal mechanism of drug action. High PF74 concentrations yielded a steep curve with the highest slope value among different classes of known antiretrovirals, suggesting a dose-dependent, cooperative mechanism of action. CA interactions with both CPSF6 and cyclophilin A (CypA) were essential for the unique dose-response curve. A shift of the steep curve at lower drug concentrations upon blocking the CA-CypA interaction suggests a protective role for CypA against high concentrations of PF74. These findings, highlighting the unique characteristics of PF74, provide a model in which its multimodal mechanism of action of both noncooperative and cooperative inhibition by PF74 is regulated by interactions of cellular proteins with incoming viral capsids.IMPORTANCEPF74, a novel capsid-targeting antiviral against HIV-1, shares its binding site in the viral capsid protein (CA) with the host factors CPSF6 and NUP153. This work reveals that the dose-response curve of PF74 consists of two distinct inhibitory phases that are differentially regulated by CA-interacting host proteins. PF74's potency depended on these CA-binding factors at low doses. In contrast, the antiviral activity of high PF74 concentrations was attenuated by cyclophilin A. These observations provide novel insights into both the mechanism of action of PF74 and the roles of host factors during the early steps of HIV-1 infection.

scholarly journals Human TRIM5α: Autophagy Connects Cell-Intrinsic HIV-1 Restriction and Innate Immune Sensor Functioning

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 320 ◽  
Author(s):  
Alexandra P. M. Cloherty ◽  
Anusca G. Rader ◽  
Brandon Compeer ◽  
Carla M. S. Ribeiro
Keyword(s):  
Therapeutic Potential ◽  
Innate Immune ◽  
Health Concern ◽  
Restriction Factor ◽  
Viral Reservoirs ◽  
Minimal Restriction ◽  
Immunodeficiency Virus ◽  
A Cell ◽  
Species Specific ◽  
Hiv 1

Human immunodeficiency virus-1 (HIV-1) persists as a global health concern, with an incidence rate of approximately 2 million, and estimated global prevalence of over 35 million. Combination antiretroviral treatment is highly effective, but HIV-1 patients that have been treated still suffer from chronic inflammation and residual viral replication. It is therefore paramount to identify therapeutically efficacious strategies to eradicate viral reservoirs and ultimately develop a cure for HIV-1. It has been long accepted that the restriction factor tripartite motif protein 5 isoform alpha (TRIM5α) restricts HIV-1 infection in a species-specific manner, with rhesus macaque TRIM5α strongly restricting HIV-1, and human TRIM5α having a minimal restriction capacity. However, several recent studies underscore human TRIM5α as a cell-dependent HIV-1 restriction factor. Here, we present an overview of the latest research on human TRIM5α and propose a novel conceptualization of TRIM5α as a restriction factor with a varied portfolio of antiviral functions, including mediating HIV-1 degradation through autophagy- and proteasome-mediated mechanisms, and acting as a viral sensor and effector of antiviral signaling. We have also expanded on the protective antiviral roles of autophagy and outline the therapeutic potential of autophagy modulation to intervene in chronic HIV-1 infection.

scholarly journals From Capsids to Complexes: Expanding the Role of TRIM5α in the Restriction of Divergent RNA Viruses and Elements

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 446
Author(s):  
Kevin M. Rose ◽  
Stephanie J. Spada ◽  
Rebecca Broeckel ◽  
Kristin L. McNally ◽  
Vanessa M. Hirsch ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Molecular Basis ◽  
Human Population ◽  
Rna Viruses ◽  
Arms Race ◽  
Innate Immune ◽  
Immunodeficiency Virus ◽  
Underlying Mechanisms ◽  
Hiv 1

An evolutionary arms race has been ongoing between retroviruses and their primate hosts for millions of years. Within the last century, a zoonotic transmission introduced the Human Immunodeficiency Virus (HIV-1), a retrovirus, to the human population that has claimed the lives of millions of individuals and is still infecting over a million people every year. To counteract retroviruses such as this, primates including humans have evolved an innate immune sensor for the retroviral capsid lattice known as TRIM5α. Although the molecular basis for its ability to restrict retroviruses is debated, it is currently accepted that TRIM5α forms higher-order assemblies around the incoming retroviral capsid that are not only disruptive for the virus lifecycle, but also trigger the activation of an antiviral state. More recently, it was discovered that TRIM5α restriction is broader than previously thought because it restricts not only the human retroelement LINE-1, but also the tick-borne flaviviruses, an emergent group of RNA viruses that have vastly different strategies for replication compared to retroviruses. This review focuses on the underlying mechanisms of TRIM5α-mediated restriction of retroelements and flaviviruses and how they differ from the more widely known ability of TRIM5α to restrict retroviruses.

scholarly journals Innate Immune DNA Sensing of Flaviviruses

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 979
Author(s):  
Tongtong Zhu ◽  
Ana Fernandez-Sesma
Keyword(s):  
Innate Immune System ◽  
Rna Viruses ◽  
Innate Immune ◽  
Host Factors ◽  
Dna Sensing ◽  
Antiviral Responses ◽  
Sensory Pathways ◽  
Sensing System ◽  
Positive Sense ◽  
Successful Replication

Flaviviruses are arthropod-borne RNA viruses that have been used extensively to study host antiviral responses. Often selected just to represent standard single-stranded positive-sense RNA viruses in early studies, the Flavivirus genus over time has taught us how truly unique it is in its remarkable ability to target not just the RNA sensory pathways but also the cytosolic DNA sensing system for its successful replication inside the host cell. This review summarizes the main developments on the unexpected antagonistic strategies utilized by different flaviviruses, with RNA genomes, against the host cyclic GAMP synthase (cGAS)/stimulator of interferon genes (STING) cytosolic DNA sensing pathway in mammalian systems. On the basis of the recent advancements on this topic, we hypothesize that the mechanisms of viral sensing and innate immunity are much more fluid than what we had anticipated, and both viral and host factors will continue to be found as important factors contributing to the host innate immune system in the future.

scholarly journals The Cysteine Residues of HIV-1 Capsid Regulate Oligomerization and Cyclophilin A-Induced Changes

2005 ◽  
Vol 88 (3) ◽  
pp. 2078-2088 ◽  
Author(s):  
Marjorie Bon Homme ◽  
Carol Carter ◽  
Suzanne Scarlata
Keyword(s):  
Cyclophilin A ◽  
Cysteine Residues ◽  
Induced Changes ◽  
Hiv 1

The balance between p53 isoforms modulates the efficiency of HIV-1 infection in macrophages

2021 ◽  
Author(s):  
Yann Breton ◽  
Corinne Barat ◽  
Michel J. Tremblay
Keyword(s):  
Virus Replication ◽  
Potential Role ◽  
Host Factors ◽  
Fine Tuning ◽  
Mrna Levels ◽  
Cellular Environment ◽  
P53 Isoforms ◽  
Antiviral Role ◽  
Hiv 1

Several host factors influence HIV-1 infection and replication. The p53-mediated antiviral role in monocytes-derived macrophages (MDMs) was previously highlighted. Indeed, an increase in p53 level results in a stronger restriction against HIV-1 early replication steps through SAMHD1 activity. In this study, we investigated the potential role of some p53 isoforms in HIV-1 infection. Transfection of isoform-specific siRNA induces distinctive effects on the virus life cycle. For example, in contrast to a siRNA targeting all isoforms, a knockdown of Δ133p53 transcripts reduces virus replication in MDMs that is correlated with a decrease in phosphorylated inactive SAMHD1. Combination of Δ133p53 knockdown and Nutlin-3, a pharmacological inhibitor of MDM2 that stabilizes p53, further reduces susceptibility of MDMs to HIV-1 infection, thus suggesting an inhibitory role of Δ133p53 towards p53 antiviral activity. In contrast, p53β knockdown in MDMs increases the viral production independently of SAMHD1. Moreover, experiments with a Nef-deficient virus show that this viral protein plays a protective role against the antiviral environment mediated by p53. Finally, HIV-1 infection affects the expression pattern of p53 isoforms by increasing p53β and p53γ mRNA levels while stabilizing the protein level of p53α and some isoforms from the p53β subclass. The balance between the various p53 isoforms is therefore an important factor in the overall susceptibility of macrophages to HIV-1 infection, fine-tuning the p53 response against HIV-1. This study brings a new understanding of the complex role of p53 in virus replication processes in myeloid cells. Importance As of today, HIV-1 is still considered as a global pandemic without a functional cure, partly because of the presence of stable viral reservoirs. Macrophages constitute one of these cell reservoirs, contributing to the viral persistence. Studies investigating the host factors involved in cell susceptibility to HIV-1 infection might lead to a better understanding of the reservoir formation and will eventually allow the development of an efficient cure. Our team previously showed the antiviral role of p53 in macrophages, which acts by compromising the early steps of HIV-1 replication. In this study, we demonstrate the involvement of p53 isoforms, which regulates p53 activity and define the cellular environment influencing viral replication. In addition, the results concerning the potential role of p53 in antiviral innate immunity could be transposed to other fields of virology and suggest that knowledge in oncology can be applied to HIV-1 research.

scholarly journals Whole Exome Sequencing of HIV-1 long-term non-progressors identifies rare variants in genes encoding innate immune sensors and signaling molecules

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Sara Konstantin Nissen ◽  
Mette Christiansen ◽  
Marie Helleberg ◽  
Kathrine Kjær ◽  
Sofie Eg Jørgensen ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Rare Variants ◽  
Signaling Molecules ◽  
Innate Immune ◽  
Whole Exome ◽  
Genes Encoding ◽  
Hiv 1

scholarly journals siRNA and shRNA screens advance key understanding of host factors required for HIV-1 replication

Retrovirology ◽  
2009 ◽  
Vol 6 (1) ◽  
pp. 78 ◽  
Author(s):  
Kin-Hang Kok ◽  
Ting Lei ◽  
Dong-Yan Jin
Keyword(s):  
Host Factors ◽  
Hiv 1

scholarly journals MxB sensitivity of HIV-1 is determined by a highly variable and dynamic capsid surface

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Richard J Miles ◽  
Claire Kerridge ◽  
Laura Hilditch ◽  
Christopher Monit ◽  
David A Jacques ◽  
...  
Keyword(s):  
Nuclear Import ◽  
Cytotoxic T Lymphocyte ◽  
Cyclophilin A ◽  
Conformational Flexibility ◽  
Restriction Factors ◽  
Nuclear Entry ◽  
Linear Forms ◽  
Cofactor Binding ◽  
Cofactor Recruitment ◽  
Hiv 1

The type one interferon induced restriction factor Myxovirus resistance B (MxB) restricts HIV-1 nuclear entry evidenced by inhibition of 2-LTR but not linear forms of viral DNA. The HIV-1 capsid is the key determinant of MxB sensitivity and cofactor binding defective HIV-1 capsid mutants P90A (defective for cyclophilin A and Nup358 recruitment) and N74D (defective for CPSF6 recruitment) have reduced dependency on nuclear transport associated cofactors, altered integration targeting preferences and are not restricted by MxB expression. This has suggested that nuclear import mechanism may determine MxB sensitivity. Here we have use genetics to separate HIV-1 nuclear import cofactor dependence from MxB sensitivity. We provide evidence that MxB sensitivity depends on HIV-1 capsid conformation, rather than cofactor recruitment. We show that depleting CPSF6 to change nuclear import pathway does not impact MxB sensitivity, but mutants that recapitulate the effect of Cyclophilin A binding on capsid conformation and dynamics strongly impact MxB sensitivity. We demonstrate that HIV-1 primary isolates have different MxB sensitivities due to cytotoxic T lymphocyte (CTL) selected differences in Gag sequence but similar cofactor dependencies. Overall our work demonstrates a complex relationship between cyclophilin dependence and MxB sensitivity likely driven by CTL escape. We propose that cyclophilin binding provides conformational flexibility to HIV-1 capsid facilitating simultaneous evasion of capsid-targeting restriction factors including TRIM5 as well as MxB.

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