RESUMEN
Tunneling nanotubes (TNTs) are cellular connections, which represent a novel route for cell-to-cell communication. Strong evidence points to a role for TNTs in the intercellular transfer of signals, molecules, organelles, and pathogens, involving them in many cellular functions. In myeloid cells (e.g., monocytes/macrophages, dendritic cells, and osteoclasts), intercellular communication via TNT contributes to their differentiation and immune functions, by favoring material and pathogen transfer, as well as cell fusion. This chapter addresses the complexity of the definition and characterization of TNTs in myeloid cells, the different processes involved in their formation, their existence in vivo, and finally their function(s) in health and infectious diseases, with the example of HIV-1 infection.
Asunto(s)
Comunicación Celular , Células Mieloides , Humanos , Comunicación Celular/fisiología , Animales , Infecciones por VIH/inmunología , VIH-1/fisiología , Estructuras de la Membrana Celular , NanotubosRESUMEN
Pathogenic changes in gut microbial composition precede the onset of HIV-1 infection in men who have sex with men (MSM). This process is associated with increased levels of systemic inflammatory biomarkers and risk for AIDS development. Using mediation analysis framework, in this report we link the effects of unprotected receptive intercourse among MSM prior to primary HIV-1 infection to higher levels of proinflammatory cytokines sCD14 and sCD163 in plasma and a significant decrease in the abundance of A. muciniphila, B. caccae, B. fragilis, B. uniformis, Bacteroides spp., Butyricimonas spp., and Odoribacter spp., and a potential increase in the abundance of Dehalobacterium spp. and Methanobrevibacter spp. in stools of MSM with the highest number of sexual partners. These differences in microbiota, together with a reduction in the pairwise correlations among commensal and short-chain fatty acid-producing bacteria with a number of sexual partners, support an increase in gut dysbiosis with the number of sexual partners. These results demonstrate the interconnectedness of sexual behavior, immune response, and microbiota composition, notably among MSM participating in high-risk sexual behaviors.
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Microbioma Gastrointestinal , Infecciones por VIH , VIH-1 , Homosexualidad Masculina , Inflamación , Conducta Sexual , Masculino , Humanos , Infecciones por VIH/microbiología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Adulto , Inflamación/microbiología , VIH-1/fisiología , Disbiosis/microbiología , Persona de Mediana EdadRESUMEN
The HIV-1 capsid is composed of capsid (CA) protein hexamers and pentamers (capsomers) that contain a central pore hypothesised to regulate capsid assembly and facilitate nucleotide import early during post-infection. These pore functions are mediated by two positively charged rings created by CA Arg-18 (R18) and Lys-25 (K25). Here we describe the forced evolution of viruses containing mutations in R18 and K25. Whilst R18 mutants fail to replicate, K25A viruses acquire compensating mutations that restore nearly wild-type replication fitness. These compensating mutations, which rescue reverse transcription and infection without reintroducing lost pore charges, map to three adaptation hot-spots located within and between capsomers. The second-site suppressor mutations act by restoring the formation of pentamers lost upon K25 mutation, enabling closed conical capsid assembly both in vitro and inside virions. These results indicate that there is no intrinsic requirement for K25 in either nucleotide import or capsid assembly. We propose that whilst HIV-1 must maintain a precise hexamer:pentamer equilibrium for proper capsid assembly, compensatory mutations can tune this equilibrium to restore fitness lost by mutation of the central pore.
Asunto(s)
Proteínas de la Cápside , Cápside , VIH-1 , Mutación , Ensamble de Virus , Replicación Viral , VIH-1/genética , VIH-1/fisiología , Ensamble de Virus/genética , Proteínas de la Cápside/genética , Proteínas de la Cápside/metabolismo , Proteínas de la Cápside/química , Cápside/metabolismo , Humanos , Replicación Viral/genética , Virión/metabolismo , Virión/genética , Células HEK293 , Infecciones por VIH/virología , Infecciones por VIH/genéticaRESUMEN
The viral capsid performs critical functions during HIV-1 infection and is a validated target for antiviral therapy. Previous studies have established that the proper structure and stability of the capsid are required for efficient HIV-1 reverse transcription in target cells. Moreover, it has recently been demonstrated that permeabilized virions and purified HIV-1 cores undergo efficient reverse transcription in vitro when the capsid is stabilized by addition of the host cell metabolite inositol hexakisphosphate (IP6). However, the molecular mechanism by which the capsid promotes reverse transcription is undefined. Here we show that wild type HIV-1 virions can undergo efficient reverse transcription in vitro in the absence of a membrane-permeabilizing agent. This activity, originally termed "natural endogenous reverse transcription" (NERT), depends on expression of the viral envelope glycoprotein during virus assembly and its incorporation into virions. Truncation of the gp41 cytoplasmic tail markedly reduced NERT activity, suggesting that gp41 licenses the entry of nucleotides into virions. By contrast to reverse transcription in permeabilized virions, NERT required neither the addition of IP6 nor a mature capsid, indicating that an intact viral membrane can substitute for the function of the viral capsid during reverse transcription in vitro. Collectively, these results demonstrate that the viral capsid functions as a nanoscale container for reverse transcription during HIV-1 infection.
Asunto(s)
Cápside , VIH-1 , Transcripción Reversa , VIH-1/fisiología , VIH-1/metabolismo , Cápside/metabolismo , Humanos , Virión/metabolismo , Proteína gp41 de Envoltorio del VIH/metabolismo , Proteína gp41 de Envoltorio del VIH/genética , Ensamble de Virus/fisiología , Infecciones por VIH/virología , Infecciones por VIH/metabolismo , Ácido Fítico/metabolismoRESUMEN
BACKGROUND: Coinfection with two phylogenetically distinct Human Immunodeficiency Virus-1 (HIV-1) variants might provide an opportunity for rapid viral expansion and the emergence of fit variants that drive disease progression. However, autologous neutralising immune responses are known to drive Envelope (Env) diversity which can either enhance replicative capacity, have no effect, or reduce viral fitness. This study investigated whether in vivo outgrowth of coinfecting variants was linked to pseudovirus and infectious molecular clones' infectivity to determine whether diversification resulted in more fit virus with the potential to increase disease progression. RESULTS: For most participants, emergent recombinants displaced the co-transmitted variants and comprised the major population at 52 weeks postinfection with significantly higher entry efficiency than other co-circulating viruses. Our findings suggest that recombination within gp41 might have enhanced Env fusogenicity which contributed to the increase in pseudovirus entry efficiency. Finally, there was a significant correlation between pseudovirus entry efficiency and CD4 + T cell count, suggesting that the enhanced replicative capacity of recombinant variants could result in more virulent viruses. CONCLUSION: Coinfection provides variants with the opportunity to undergo rapid recombination that results in more infectious virus. This highlights the importance of monitoring the replicative fitness of emergent viruses.
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Coinfección , Infecciones por VIH , VIH-1 , Filogenia , Humanos , Infecciones por VIH/virología , Infecciones por VIH/complicaciones , VIH-1/genética , VIH-1/fisiología , Coinfección/virología , Evolución Molecular , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Proteína gp41 de Envoltorio del VIH/genética , Masculino , Femenino , Recombinación Genética , Internalización del Virus , Adulto , Recuento de Linfocito CD4 , Replicación ViralRESUMEN
HIV-1 polymerase, commonly known as HIV reverse transcriptase (RT), catalyzes the critical reaction of reverse transcription by synthesizing a double-stranded DNA copy of the viral genomic RNA. During the replication cycle, this synthesized DNA is integrated into the host genome. This entire process is essential for viral replication and is targeted by several antiviral drugs. Numerous studies in biochemistry and structural biology have led to a good understanding of HIV-1 RT functions. However, the discovery of epitranscriptomic marks, such as 2'-O-methylations, on the HIV-1 RNA genome raise the questions about RT's ability to copy RNAs decorated with these biochemical modifications. This review focuses on the importance of RT in the viral cycle, its structure and function and the impact of 2'-O-methylations on its activity and replication regulation, particularly in quiescent cells.
Asunto(s)
Transcriptasa Inversa del VIH , VIH-1 , Replicación Viral , Transcriptasa Inversa del VIH/metabolismo , Transcriptasa Inversa del VIH/genética , Transcriptasa Inversa del VIH/química , VIH-1/fisiología , VIH-1/genética , Humanos , Metilación , ARN Viral/metabolismo , ARN Viral/genética , Transcripción Reversa , Infecciones por VIH/virología , Infecciones por VIH/tratamiento farmacológicoRESUMEN
While antiretroviral therapy (ART) has revolutionized the management of human immunodeficiency virus (HIV) and has enabled people living with HIV (PLWH) to achieve near-normal life expectancies, an HIV cure remains elusive due to the presence of HIV reservoirs. Furthermore, compared with individuals in the general population, PLWH support a higher burden of multimorbidity, including pulmonary diseases of both an infectious and non-infection nature, which may be a consequence of the formation of HIV reservoirs. Their gut, lymph nodes, brain, testes and lungs constitute important anatomic sites for the reservoirs. While CD4+ T cells, and particularly memory CD4+ T cells, are the best characterized cellular HIV reservoirs, tissue resident macrophages (TRM) and alveolar macrophages (AM) also harbor HIV infection. AM are the most abundant cells in bronchoalveolar (BAL) fluid in healthy conditions, and act as sentinels in the alveolar space by patrolling and clearing debris, microbes and surfactant recycling. Long-lived tissue-resident AM of embryonic origin have the capacity of self-renewal without replenishment from peripheral monocytes. As in other tissues, close cell-cell contacts in lungs also provide a milieu conducive for cell-to-cell spread of HIV infection and establishment of reservoirs. As lungs are in constant exposure to antigens from the external environment, this situation contributes to pro-inflammatory phenotype rendering pulmonary immune cells exhausted and senescent-an environment facilitating HIV persistence. Factors such as tobacco and e-cigarette smoking, lung microbiome dysbiosis and respiratory coinfections further drive antigenic stimulation and HIV replication. HIV replication, in turn, contributes to ongoing inflammation and clonal expansion. Herein, the potential role of AM in HIV persistence is discussed. Furthermore, their contribution towards pulmonary inflammation and immune dysregulation, which may in turn render PLWH susceptible to chronic lung disease, despite ART, is explored. Finally, strategies to eliminate HIV-infected AM are discussed.
Asunto(s)
Infecciones por VIH , Enfermedades Pulmonares , Macrófagos Alveolares , Humanos , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Infecciones por VIH/complicaciones , Macrófagos Alveolares/virología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/fisiología , Enfermedades Pulmonares/virología , Enfermedades Pulmonares/inmunología , Pulmón/virología , Pulmón/inmunología , VIH-1/fisiología , Reservorios de Enfermedades/virología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/virologíaRESUMEN
While antiretroviral therapy (ART) has revolutionized the management of human immunodeficiency virus (HIV) and has enabled people living with HIV (PLWH) to achieve near-normal life expectancies, an HIV cure remains elusive due to the presence of HIV reservoirs. Furthermore, compared with individuals in the general population, PLWH support a higher burden of multimorbidity, including pulmonary diseases of both an infectious and non-infection nature, which may be a consequence of the formation of HIV reservoirs. Their gut, lymph nodes, brain, testes and lungs constitute important anatomic sites for the reservoirs. While CD4+ T-cells, and particularly memory CD4+ T-cells, are the best characterized cellular HIV reservoirs, tissue resident macrophages (TRM) and alveolar macrophages (AM) also harbor HIV infection. AM are the most abundant cells in bronchoalveolar (BAL) fluid in healthy conditions, and act as sentinels in the alveolar space by patrolling and clearing debris, microbes and surfactant recycling. Long-lived tissue-resident AM of embryonic origin have the capacity of self-renewal without replenishment from peripheral monocytes. As in other tissues, close cell-cell contacts in lungs also provide a milieu conducive for cell-to-cell spread of HIV infection and establishment of reservoirs. As lungs are in constant exposure to antigens from the external environment, this situation contributes to pro-inflammatory phenotype rendering pulmonary immune cells exhausted and senescent-an environment facilitating HIV persistence. Factors such as tobacco and e-cigarette smoking, lung microbiome dysbiosis and respiratory co-infections further drive antigenic stimulation and HIV replication. HIV replication, in turn, contributes to ongoing inflammation and clonal expansion. Herein, the potential role of AM in HIV persistence is discussed. Furthermore, their contribution towards pulmonary inflammation and immune dysregulation, which may in turn render PLWH susceptible to chronic lung disease, despite ART, is explored. Finally, strategies to eliminate HIV-infected AM are discussed.
Asunto(s)
Infecciones por VIH , Enfermedades Pulmonares , Macrófagos Alveolares , Humanos , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Macrófagos Alveolares/virología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/fisiología , Enfermedades Pulmonares/virología , Enfermedades Pulmonares/inmunología , VIH-1/fisiología , Pulmón/virología , Pulmón/inmunología , Reservorios de Enfermedades/virologíaRESUMEN
Different host proteins target different HIV proteins and antagonize their functions, depending on the stage of the HIV life cycle and the stage of infection. Concurrently, HIV proteins also target and antagonize various different host proteins to facilitate HIV replication within host cells. The preceding quite specific area of knowledge in HIV pathogenesis, however, remains insufficiently understood. We therefore propose, in this review article, to examine and discuss the HIV proteins that counteract those host restriction proteins which results directly in increased infectivity of HIV. We elaborate on HIV proteins that antagonize host cellular proteins to promote HIV replication, and thus HIV infection. We examine the functions and mechanisms via which Nef, Vif, Vpu, Env, Vpr, and Vpx counteract host proteins such as Ser5, PSGL-1, IFITMS, A3G, tetherin, GBP5, SAMHD1, STING, HUSH, REAF, and TET2 to increase HIV infectivity. Nef antagonizes three host proteins, viz., Ser5, PSGL1, and IFITIMs, while Vpx also antagonizes three host restriction factors, viz., SAMHD1, STING, and HUSH complex; therefore, these proteins may be potential candidates for therapeutic intervention in HIV infection. Tetherin is targeted by Vpu and Env, PSGL1 is targeted by Nef and Vpu, while Ser5 is targeted by Nef and Env proteins. Finally, conclusive remarks and future perspectives are also presented.
Asunto(s)
Infecciones por VIH , VIH-1 , Interacciones Huésped-Patógeno , Proteínas del Virus de la Inmunodeficiencia Humana , Humanos , Infecciones por VIH/metabolismo , Infecciones por VIH/virología , Infecciones por VIH/inmunología , Proteínas del Virus de la Inmunodeficiencia Humana/metabolismo , VIH-1/fisiología , Replicación Viral , Animales , Factores de Restricción AntiviralesRESUMEN
The different susceptibility to HIV-1 infection in U937 cells-permissive (Plus) or nonpermissive (Minus)-is linked to the expression in Minus cells of interferon (IFN)-γ inducible antiviral factors such as tripartite motif-containing protein 22 (TRIM22) and class II transactivator (CIITA). CIITA interacts with Cyclin T1, a key component of the Positive-Transcription Elongation Factor b (P-TEFb) complex needed for the efficient transcription of HIV-1 upon interaction with the viral transactivator Tat. TRIM22 interacts with CIITA, recruiting it into nuclear bodies together with Cyclin T1. A 50 kDa Cyclin T1 was found only in Minus cells, alongside the canonical 80 kDa protein. The expression of this truncated form remained unaffected by proteasome inhibitors but was reduced by IFNγ treatment. Unlike the nuclear full-length protein, truncated Cyclin T1 was also present in the cytoplasm, and this subcellular localization correlated with its capacity to inhibit Tat-mediated HIV-1 transcription. The 50 kDa Cyclin T1 in Minus cells likely contributes to their non-permissive phenotype by acting as a dominant negative factor, disrupting P-TEFb complex formation and function. Its reduction upon IFNγ treatment suggests a regulatory loop by which its inhibitory role on HIV-1 replication is then exerted by the IFNγ-induced CIITA, which binds to the canonical Cyclin T1, displacing it from the P-TEFb complex.
Asunto(s)
Ciclina T , VIH-1 , Humanos , Ciclina T/metabolismo , VIH-1/fisiología , Células U937 , Infecciones por VIH/virología , Infecciones por VIH/metabolismo , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/genética , Replicación Viral , Fenotipo , Interferón gamma/farmacología , Interferón gamma/metabolismo , Proteínas de Motivos Tripartitos/metabolismo , Proteínas de Motivos Tripartitos/genética , Proteínas Represoras/metabolismo , Proteínas Represoras/genética , Antígenos de Histocompatibilidad MenorRESUMEN
The chemokine co-receptors CXCR4 and CCR5 mediate HIV entry and signal transduction necessary for viral infection. However, to date only the CCR5 antagonist maraviroc is approved for treating HIV-1 infection. Given that approximately 50% of late-stage HIV patients also develop CXCR4-tropic virus, clinical anti-HIV CXCR4 antagonists are needed. Here, we describe a novel allosteric CXCR4 antagonist TIQ-15 which inhibits CXCR4-tropic HIV-1 infection of primary and transformed CD4 T cells. TIQ-15 blocks HIV entry with an IC50 of 13 nM. TIQ-15 also inhibits SDF-1α/CXCR4-mediated cAMP production, cofilin activation, and chemotactic signaling. In addition, TIQ-15 induces CXCR4 receptor internalization without affecting the levels of the CD4 receptor, suggesting that TIQ-15 may act through a novel allosteric site on CXCR4 for blocking HIV entry. Furthermore, TIQ-15 did not inhibit VSV-G pseudotyped HIV-1 infection, demonstrating its specificity in blocking CXCR4-tropic virus entry, but not CXCR4-independent endocytosis or post-entry steps. When tested against a panel of clinical isolates, TIQ-15 showed potent inhibition against CXCR4-tropic and dual-tropic viruses, and moderate inhibition against CCR5-tropic isolates. This observation was followed by a co-dosing study with maraviroc, and TIQ-15 demonstrated synergistic activity. In summary, here we describe a novel HIV-1 entry inhibitor, TIQ-15, which potently inhibits CXCR4-tropic viruses while possessing low-level synergistic activities against CCR5-tropic viruses. TIQ-15 could potentially be co-dosed with the CCR5 inhibitor maraviroc to block viruses of mixed tropisms.
Asunto(s)
Infecciones por VIH , VIH-1 , Receptores CXCR4 , Internalización del Virus , Humanos , Receptores CXCR4/antagonistas & inhibidores , Receptores CXCR4/metabolismo , VIH-1/efectos de los fármacos , VIH-1/fisiología , Internalización del Virus/efectos de los fármacos , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Linfocitos T CD4-Positivos/virología , Linfocitos T CD4-Positivos/efectos de los fármacos , Inhibidores de Fusión de VIH/farmacología , Maraviroc/farmacología , Triazoles/farmacología , Fármacos Anti-VIH/farmacología , Células HEK293RESUMEN
Human immunodeficiency virus 1 (HIV-1) infection is characterized by a dynamic and persistent state of viral replication that overwhelms the host immune system in the absence of antiretroviral therapy (ART). The impact of prolonged treatment on the antiviral efficacy of HIV-1-specific CD8+ T cells has nonetheless remained unknown. Here, we used single-cell technologies to address this issue in a cohort of aging individuals infected early during the pandemic and subsequently treated with continuous ART. Our data showed that long-term ART was associated with a process of clonal succession, which effectively rejuvenated HIV-1-specific CD8+ T cell populations in the face of immune senescence. Tracking individual transcriptomes further revealed that initially dominant CD8+ T cell clonotypes displayed signatures of exhaustion and terminal differentiation, whereas newly dominant CD8+ T cell clonotypes displayed signatures of early differentiation and stemness associated with natural control of viral replication. These findings reveal a degree of immune resilience that could inform adjunctive treatments for HIV-1.
Asunto(s)
Linfocitos T CD8-positivos , Infecciones por VIH , VIH-1 , Replicación Viral , Linfocitos T CD8-positivos/inmunología , VIH-1/inmunología , VIH-1/fisiología , Humanos , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Replicación Viral/efectos de los fármacos , Masculino , Persona de Mediana Edad , Femenino , Terapia Antirretroviral Altamente Activa , Antirretrovirales/uso terapéutico , Análisis de la Célula Individual , Diferenciación Celular/inmunologíaRESUMEN
Cystatin F (CstF) is a protease inhibitor of cysteine cathepsins, including those involved in activating the perforin/granzyme cytotoxic pathways. It is targeted at the endolysosomal pathway but can also be secreted to the extracellular milieu or endocytosed by bystander cells. CstF was shown to be significantly increased in tuberculous pleurisy, and during HIV coinfection, pleural fluids display high viral loads. In human macrophages, our previous results revealed a strong upregulation of CstF in phagocytes activated by interferon γ or after infection with Mycobacterium tuberculosis (Mtb). CstF manipulation using RNA silencing led to increased proteolytic activity of lysosomal cathepsins, improving Mtb intracellular killing. In the present work, we investigate the impact of CstF depletion in macrophages during the coinfection of Mtb-infected phagocytes with lymphocytes infected with HIV. The results indicate that decreasing the CstF released by phagocytes increases the major pro-granzyme convertase cathepsin C of cytotoxic immune cells from peripheral blood-derived lymphocytes. Consequently, an observed augmentation of the granzyme B cytolytic activity leads to a significant reduction in viral replication in HIV-infected CD4+ T-lymphocytes. Ultimately, this knowledge can be crucial for developing new therapeutic approaches to control both pathogens based on manipulating CstF.
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Catepsina C , Coinfección , Granzimas , Infecciones por VIH , Macrófagos , Mycobacterium tuberculosis , Humanos , Granzimas/metabolismo , Granzimas/genética , Infecciones por VIH/metabolismo , Infecciones por VIH/inmunología , Macrófagos/metabolismo , Macrófagos/inmunología , Macrófagos/microbiología , Macrófagos/virología , Coinfección/microbiología , Catepsina C/metabolismo , Catepsina C/genética , Cistatinas/metabolismo , Cistatinas/genética , Tuberculosis/metabolismo , Tuberculosis/inmunología , Tuberculosis/microbiología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , VIH-1/fisiología , Biomarcadores de TumorRESUMEN
Remarkable advances are being made in developing interventions for eliciting long-term remission of HIV-1 infection. The success of these interventions will obviate the need for lifelong antiretroviral therapy, the current standard-of-care, and benefit the millions living today with HIV-1. Mathematical modelling has made significant contributions to these efforts. It has helped elucidate the possible mechanistic origins of natural and post-treatment control, deduced potential pathways of the loss of such control, quantified the effects of interventions, and developed frameworks for their rational optimization. Yet, several important questions remain, posing challenges to the translation of these promising interventions. Here, we survey the recent advances in the mathematical modelling of HIV-1 control and remission, highlight their contributions, and discuss potential avenues for future developments.
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Infecciones por VIH , VIH-1 , Humanos , Infecciones por VIH/tratamiento farmacológico , VIH-1/fisiología , Modelos Teóricos , Modelos Biológicos , Fármacos Anti-VIH/uso terapéuticoRESUMEN
Antiviral therapies with reduced frequencies of administration and high barriers to resistance remain a major goal. For HIV, theories have proposed that viral-deletion variants, which conditionally replicate with a basic reproductive ratio [R0] > 1 (termed "therapeutic interfering particles" or "TIPs"), could parasitize wild-type virus to constitute single-administration, escape-resistant antiviral therapies. We report the engineering of a TIP that, in rhesus macaques, reduces viremia of a highly pathogenic model of HIV by >3log10 following a single intravenous injection. Animal lifespan was significantly extended, TIPs conditionally replicated and were continually detected for >6 months, and sequencing data showed no evidence of viral escape. A single TIP injection also suppressed virus replication in humanized mice and cells from persons living with HIV. These data provide proof of concept for a potential new class of single-administration antiviral therapies.
Asunto(s)
Partículas Similares a Virus Artificiales , Eliminación de Gen , Infecciones por VIH , VIH-1 , Interferencia Viral , Replicación Viral , Animales , Humanos , Ratones , Número Básico de Reproducción , Modelos Animales de Enfermedad , Ingeniería Genética , Infecciones por VIH/terapia , Infecciones por VIH/virología , VIH-1/genética , VIH-1/fisiología , Macaca mulatta , Prueba de Estudio Conceptual , Virus de la Inmunodeficiencia de los Simios/genética , Virus de la Inmunodeficiencia de los Simios/fisiología , Viremia/terapia , Viremia/virologíaRESUMEN
A stripped-down HIV genome can interfere with normal virus replication.
Asunto(s)
Partículas Similares a Virus Artificiales , Infecciones por VIH , Interferencia Viral , Replicación Viral , Animales , Humanos , Fármacos Anti-VIH/uso terapéutico , Genoma Viral , Infecciones por VIH/terapia , Infecciones por VIH/virología , VIH-1/genética , VIH-1/fisiología , Macaca mulatta , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/genéticaRESUMEN
The HIV reservoir is more dynamic than previously thought with around 70% of the latent reservoir originating from viruses circulating within 1 year of the initiation of antiretroviral therapy (ART). In an ex vivo model system of HIV latency, it was reported that early exposure to class I histone deacetylase (HDAC) inhibitors might prevent these more recently infected cells from entering a state of stable viral latency. This finding raises the possibility that co-administration of HDAC inhibitors at the time of ART initiation may prevent the establishment of much of the HIV reservoir. Here, we tested the effects of the HDAC inhibitors suberoylanilide hydroxamic acid (SAHA) and panobinostat co-administered at the time of ART initiation on the formation of the viral reservoir in HIV-infected humanized mice. As previously shown, SAHA and panobinostat were well tolerated in humanized mice. Unexpectedly, co-administration of SAHA resulted in an increase in the frequency of CD4+ cells carrying HIV DNA but did not alter the frequency of cell-associated HIV RNA in HIV-infected, ART-treated humanized mice. Co-administration of panobinostat did not alter levels of cell-associated HIV DNA or RNA. Our in vivo findings indicate that co-administration of HDAC inhibitors initiated at the same time of ART treatment does not prevent recently infected cells from entering latency.IMPORTANCECurrent antiretroviral therapy (ART) does not eradicate cells harboring replication-competent HIV reservoir. Withdrawal of ART inevitably results in a rapid viremia rebound. The HIV reservoir is more dynamic than previously thought. Early exposure to class I histone deacetylase (HDAC) inhibitors inhibit these more recently infected cells from entering a state of stable viral latency in an ex vivo model of latency, raising the possibility that co-administration of HDAC inhibitors at the time of ART initiation may reduce much of the HIV reservoir. Here, we tested the effects of the HDAC inhibitors suberoylanilide hydroxamic acid or panobinostat during ART initiation on the formation of the viral reservoir in HIV-infected humanized mice. Our in vivo study indicates that in contrast to in vitro observations, the co-administration of HDAC inhibitors at the same time of ART initiation does not prevent recently infected cells from entering latency.
Asunto(s)
Linfocitos T CD4-Positivos , Infecciones por VIH , VIH-1 , Inhibidores de Histona Desacetilasas , Panobinostat , Latencia del Virus , Vorinostat , Inhibidores de Histona Desacetilasas/farmacología , Animales , Latencia del Virus/efectos de los fármacos , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Ratones , Panobinostat/farmacología , Humanos , Vorinostat/farmacología , VIH-1/efectos de los fármacos , VIH-1/fisiología , VIH-1/genética , Linfocitos T CD4-Positivos/virología , Linfocitos T CD4-Positivos/efectos de los fármacos , Ácidos Hidroxámicos/farmacología , Modelos Animales de Enfermedad , Carga Viral/efectos de los fármacos , ARN Viral , ADN ViralRESUMEN
In vitro studies have shown that deletion of nef and deleterious mutation in the Nef dimerization interface attenuates HIV replication and associated pathogenesis. Humanized rodents with human immune cells and lymphoid tissues are robust in vivo models for investigating the interactions between HIV and the human immune system. Here, we demonstrate that nef deletion impairs HIV replication and HIV-induced immune dysregulation in the blood and human secondary lymphoid tissue (human spleen) in bone marrow-liver-thymus-spleen (BLTS) humanized mice. Furthermore, we also show that nef defects (via deleterious mutations in the dimerization interface) impair HIV replication and HIV-induced immune dysregulation in the blood and human spleen in BLTS-humanized mice. We demonstrate that the reduced replication of nef-deleted and nef-defective HIV is associated with robust antiviral innate immune response, and T helper 1 response. Our results support the proposition that Nef may be a therapeutic target for adjuvants in HIV cure strategies.
Asunto(s)
Modelos Animales de Enfermedad , Infecciones por VIH , VIH-1 , Hígado , Bazo , Viremia , Replicación Viral , Productos del Gen nef del Virus de la Inmunodeficiencia Humana , Animales , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Ratones , Humanos , Viremia/inmunología , Bazo/inmunología , Bazo/virología , VIH-1/inmunología , VIH-1/genética , VIH-1/fisiología , Hígado/virología , Hígado/inmunología , Hígado/patología , Médula Ósea/virología , Médula Ósea/inmunología , Timo/inmunología , Timo/virología , Inmunidad InnataRESUMEN
In humans, sterile alpha motif (SAM) domain- and histidine-aspartic acid (HD) domain-containing protein 1 (SAMHD1) is a dNTPase enzyme that prevents HIV-1 infection in non-cycling cells, such as differentiated THP-1 cells and human primary macrophages. Although phosphorylation of threonine 592 (T592) in SAMHD1 is recognized as the primary regulator of the ability to prevent HIV-1 infection, the contributions of SAMHD1 acetylation to this ability remain unknown. Mass spectrometry analysis of SAMHD1 proteins derived from cycling and non-cycling THP-1 cells, primary cycling B cells, and primary macrophages revealed that SAMHD1 is preferentially acetylated at lysine residues 354, 494, and 580 (K354, K494, and K580). In non-cycling cells, SAMHD1 is preferentially acetylated at K580, suggesting that this post-translational modification may contribute to the ability of SAMHD1 to block HIV-1 infection. Consistent with this finding, we found that mutations in K580 disrupted the ability of SAMHD1 to block HIV-1 infection without affecting the ability of SAMHD1 to deplete cellular dNTP levels. Gene editing of SAMHD1 in macrophage-like cells revealed that an intact K580 is required for HIV-1 restriction. This finding suggests that K580 acetylation in SAMHD1 is essential for blocking HIV-1 infection. More importantly, we found that a larger proportion of SAMHD1 featuring K580 acetylation could be detected in human primary macrophages when compared to human primary monocytes. In agreement, we found that SAMHD1 is acetylated during the monocyte-to-macrophage differentiation process. This finding agrees with the idea that the blockade of HIV-1 infection in macrophages requires SAMHD1 acetylation.IMPORTANCEThe natural inhibitor of HIV-1, sterile alpha motif (SAM) domain- and histidine-aspartic acid (HD) domain-containing protein 1 (SAMHD1), plays a pivotal role in preventing HIV-1 infection of macrophages and dendritic cells, which are vital components of the immune system. This study unveils that SAMHD1 undergoes post-translational modifications, specifically acetylation at lysines 354, 494, and 580. Our research underscores the significance of these modifications, demonstrating that acetylation at residue K580 is indispensable for SAMHD1's efficacy in blocking HIV-1 infection. Notably, K580 is found in a critical regulatory domain of SAMHD1, highlighting acetylation as a novel layer of SAMHD1 regulation for HIV-1 restriction in humans. A comprehensive understanding of the regulation mechanisms governing this anti-HIV-1 protein is crucial for leveraging nature's defense mechanisms against HIV-1 and could pave the way for innovative therapeutic strategies.