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1.
Immunity ; 51(4): 724-734.e4, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31586542

RESUMO

HIV- and SIV-envelope (Env) trimers are both extensively glycosylated, and antibodies identified to date have been unable to fully neutralize SIVmac239. Here, we report the isolation, structure, and glycan interactions of antibody ITS90.03, a monoclonal antibody that completely neutralized the highly neutralization-resistant isolate, SIVmac239. The co-crystal structure of a fully glycosylated SIVmac239-gp120 core in complex with rhesus CD4 and the antigen-binding fragment of ITS90.03 at 2.5-Å resolution revealed that ITS90 recognized an epitope comprised of 45% glycan. SIV-gp120 core, rhesus CD4, and their complex could each be aligned structurally to their human counterparts. The structure revealed that glycans masked most of the SIV Env protein surface, with ITS90 targeting a glycan hole, which is occupied in ∼83% of SIV strains by glycan N238. Overall, the SIV glycan shield appears to functionally resemble its HIV counterpart in coverage of spike, shielding from antibody, and modulation of receptor accessibility.


Assuntos
Anticorpos Monoclonais/química , Anticorpos Neutralizantes/química , Infecções por HIV/imunologia , HIV/fisiologia , Polissacarídeos/química , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/fisiologia , Animais , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Neutralizantes/metabolismo , Antígenos CD4/metabolismo , Células Cultivadas , Cristalização , Cristalografia por Raios X , Modelos Animais de Doenças , Glicosilação , Anticorpos Anti-HIV/imunologia , Anticorpos Anti-HIV/metabolismo , Proteína gp120 do Envelope de HIV/metabolismo , Humanos , Macaca mulatta , Glicoproteínas de Membrana/metabolismo , Polissacarídeos/metabolismo , Ligação Proteica , Relação Estrutura-Atividade , Proteínas do Envelope Viral/metabolismo
2.
Immunity ; 46(6): 1005-1017.e5, 2017 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-28636951

RESUMO

CCR5 is the primary chemokine receptor utilized by HIV to infect leukocytes, whereas CCR5 ligands inhibit infection by blocking CCR5 engagement with HIV gp120. To guide the design of improved therapeutics, we solved the structure of CCR5 in complex with chemokine antagonist [5P7]CCL5. Several structural features appeared to contribute to the anti-HIV potency of [5P7]CCL5, including the distinct chemokine orientation relative to the receptor, the near-complete occupancy of the receptor binding pocket, the dense network of intermolecular hydrogen bonds, and the similarity of binding determinants with the FDA-approved HIV inhibitor Maraviroc. Molecular modeling indicated that HIV gp120 mimicked the chemokine interaction with CCR5, providing an explanation for the ability of CCR5 to recognize diverse ligands and gp120 variants. Our findings reveal that structural plasticity facilitates receptor-chemokine specificity and enables exploitation by HIV, and provide insight into the design of small molecule and protein inhibitors for HIV and other CCR5-mediated diseases.


Assuntos
Quimiocina CCL5/química , Proteína gp120 do Envelope de HIV/química , Infecções por HIV/imunologia , HIV-1/fisiologia , Modelos Moleculares , Mimetismo Molecular , Receptores CCR5/química , Animais , Antagonistas dos Receptores CCR5/química , Antagonistas dos Receptores CCR5/farmacologia , Quimiocina CCL5/metabolismo , Clonagem Molecular , Cristalografia por Raios X , Cicloexanos/química , Cicloexanos/farmacologia , Proteína gp120 do Envelope de HIV/metabolismo , Inibidores da Fusão de HIV/química , Infecções por HIV/tratamento farmacológico , Humanos , Maraviroc , Ligação Proteica , Conformação Proteica , Receptores CCR5/metabolismo , Células Sf9 , Spodoptera , Relação Estrutura-Atividade , Triazóis/química , Triazóis/farmacologia , Internalização do Vírus/efeitos dos fármacos
3.
Proc Natl Acad Sci U S A ; 120(13): e2222073120, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36961924

RESUMO

Binding to the host cell receptors, CD4 and CCR5/CXCR4, triggers large-scale conformational changes in the HIV-1 envelope glycoprotein (Env) trimer [(gp120/gp41)3] that promote virus entry into the cell. CD4-mimetic compounds (CD4mcs) comprise small organic molecules that bind in the highly conserved CD4-binding site of gp120 and prematurely induce inactivating Env conformational changes, including shedding of gp120 from the Env trimer. By inducing more "open," antibody-susceptible Env conformations, CD4mcs also sensitize HIV-1 virions to neutralization by antibodies and infected cells to antibody-dependent cellular cytotoxicity (ADCC). Here, we report the design, synthesis, and evaluation of novel CD4mcs based on an indoline scaffold. Compared with our current lead indane scaffold CD4mc, BNM-III-170, several indoline CD4mcs exhibit increased potency and breadth against HIV-1 variants from different geographic clades. Viruses that were selected for resistance to the lead indane CD4mc, BNM-III-170, are susceptible to inhibition by the indoline CD4mcs. The indoline CD4mcs also potently sensitize HIV-1-infected cells to ADCC mediated by plasma from HIV-1-infected individuals. Crystal structures indicate that the indoline CD4mcs gain potency compared to the indane CD4mcs through more favorable π-π overlap from the indoline pose and by making favorable contacts with the vestibule of the CD4-binding pocket on gp120. The rational design of indoline CD4mcs thus holds promise for further improvements in antiviral activity, potentially contributing to efforts to treat and prevent HIV-1 infection.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Humanos , Citotoxicidade Celular Dependente de Anticorpos , Proteína gp120 do Envelope de HIV , Antígenos CD4/metabolismo , Anticorpos Anti-HIV/farmacologia
4.
Immunity ; 44(4): 939-50, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-27067056

RESUMO

VRC01-class antibodies neutralize diverse HIV-1 strains by targeting the conserved CD4-binding site. Despite extensive investigations, crucial events in the early stage of VRC01 development remain elusive. We demonstrated how VRC01-class antibodies emerged in a Chinese donor by antigen-specific single B cell sorting, structural and functional studies, and longitudinal antibody and virus repertoire analyses. A monoclonal antibody DRVIA7 with modest neutralizing breadth was isolated that displayed a subset of VRC01 signatures. X-ray and EM structures revealed a VRC01-like angle of approach, but less favorable interactions between the DRVIA7 light-chain CDR1 and the N terminus with N276 and V5 glycans of gp120. Although the DRVIA7 lineage was unable to acquire broad neutralization, longitudinal analysis revealed a repertoire-encoded VRC01 light-chain CDR3 signature and VRC01-like neutralizing heavy-chain precursors that rapidly matured within 2 years. Thus, light chain accommodation of the glycan shield should be taken into account in vaccine design targeting this conserved site of vulnerability.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Sítios de Ligação de Anticorpos/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Sequência de Aminoácidos , Anticorpos Amplamente Neutralizantes , Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , Dados de Sequência Molecular
5.
J Infect Dis ; 229(3): 763-774, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38035854

RESUMO

BACKGROUND: Chronic inflammation persists in some people living with human immunodeficiency virus (HIV) during antiretroviral therapy and is associated with premature aging. The glycoprotein 120 (gp120) subunit of HIV-1 envelope sheds and can be detected in plasma, showing immunomodulatory properties even in the absence of detectable viremia. We evaluated whether plasma soluble gp120 (sgp120) and a family of gp120-specific anti-cluster A antibodies, linked to CD4 depletion in vitro, contribute to chronic inflammation, immune dysfunction, and subclinical cardiovascular disease in participants of the Canadian HIV and Aging Cohort Study with undetectable viremia. METHODS: Cross-sectional assessment of sgp120 and anti-cluster A antibodies was performed in 386 individuals from the cohort. Their association with proinflammatory cytokines and subclinical coronary artery disease was assessed using linear regression models. RESULTS: High levels of sgp120 and anti-cluster A antibodies were inversely correlated with CD4+ T cell count and CD4/CD8 ratio. The presence of sgp120 was associated with increased levels of interleukin 6. In participants with detectable atherosclerotic plaque and detectable sgp120, anti-cluster A antibodies and their combination with sgp120 levels correlated positively with the total volume of atherosclerotic plaques. CONCLUSIONS: This study showed that sgp120 may act as a pan toxin causing immune dysfunction and sustained inflammation in a subset of people living with HIV, contributing to the development of premature comorbid conditions.


Assuntos
Infecções por HIV , HIV-1 , Humanos , Viremia , Estudos de Coortes , Estudos Transversais , Canadá , Infecções por HIV/tratamento farmacológico , Anticorpos Anti-HIV , Glicoproteínas , Proteína gp120 do Envelope de HIV
6.
Curr Issues Mol Biol ; 46(4): 3729-3740, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38666962

RESUMO

Despite present antiviral agents that can effectively work against HIV-1 replication, side effects and drug resistance have pushed researchers toward novel approaches. In this context, there is a continued focus on discovering new and more effective antiviral compounds, particularly those that have a natural origin. Polysaccharides are known for their numerous bioactivities, including inhibiting HIV-1 infection and replication. In the present study, phosphorylated chitosan oligosaccharides (PCOSs) were evaluated for their anti-HIV-1 potential in vitro. Treatment with PCOSs effectively protected cells from HIV-1-induced lytic effects and suppressed the production of HIV-1 p24 protein. In addition, results show that PCOSs lost their protective effect upon post-infection treatment. According to the results of ELISA, PCOSs notably disrupted the binding of HIV-1 gp120 protein to T cell surface receptor CD4, which is required for HIV-1 entry. Overall, the results point out that PCOSs might prevent HIV-1 infection at the entry stage, possibly via blocking the viral entry through disruption of virus-cell fusion. Nevertheless, the current results only present the potential of PCOSs, and further studies to elucidate its action mechanism in detail are needed to employ phosphorylation of COSs as a method to develop novel antiviral agents.

7.
Biochem Biophys Res Commun ; 727: 150310, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38941793

RESUMO

Targeting the hydrophobic Phe43 pocket of HIV's envelope glycoprotein gp120 is a critical strategy for antiviral interventions due to its role in interacting with the host cell's CD4. Previous inhibitors, including small molecules and CD4 mimetic peptides based on scyllatoxin, have demonstrated significant binding and neutralization capabilities but were often chemically synthesized or contained non-canonical amino acids. Microbial expression using natural amino acids offers advantages such as cost-effectiveness, scalability, and efficient production of fusion proteins. In this study, we enhanced the previous scyllatoxin-based synthetic peptide by substituting natural amino acids and successfully expressed it in E. coli. The peptide was optimized by mutating the C-terminal amidated valine to valine and glutamine, and by reducing the disulfide bonds from three to two. Circular dichroism confirmed proper secondary structure formation, and fluorescence polarization analysis revealed specific, concentration-dependent binding to HIV gp120, supported by molecular dynamics simulations. These findings indicate the potential for scalable microbial production of effective antiviral peptides, with significant applications in pharmaceutical development for HIV treatment.


Assuntos
Escherichia coli , Proteína gp120 do Envelope de HIV , Peptídeos , Ligação Proteica , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/genética , Escherichia coli/metabolismo , Escherichia coli/genética , Peptídeos/química , Peptídeos/metabolismo , Peptídeos/farmacologia , Simulação de Dinâmica Molecular , Humanos , Sequência de Aminoácidos , Desenho de Fármacos
8.
Biochem Biophys Res Commun ; 709: 149830, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38547606

RESUMO

HIV envelope protein gp120 is considered a primary molecular determinant of viral neutralization phenotype due to its critical role in viral entry and immune evasion. The intrinsically disordered regions (IDRs) in gp120 are responsible for their extensive sequence variations and significant structural rearrangements. Despite HIV neutralization phenotype and sequence/structural information of gp120 have been experimentally characterized, there remains a gap in our understanding of the correlation between the viral phenotype and IDRs in gp120. Here, we combined machine learning (ML) techniques and molecular dynamics (MD) simulations to gain data-driven and molecule-mechanism insights into relationships between viral sequence, structure, and phenotypes from the perspective of IDRs in gp120. ML models, trained only on the length and disorder score of IDRs, achieved equivalent performance to the best baseline model using amino acid sequences to discriminate HIV neutralization phenotype, indicating that the lengths or disorder of specific IDRs are strongly related to HIV neutralization phenotypes. Comparative MD analysis reveals that gp120 with extreme neutralization phenotypes in multiple conformational states, especially some IDRs, exhibit significantly distinct structural dynamics, conformational flexibility, and thermodynamic distributions. Taken together, our study provided insights into the role of IDRs in gp120 responding to HIV neutralization phenotypes, which will advance the understanding of molecular mechanisms underlying viral function associated with HIV neutralization phenotype and help develop antiviral vaccines or drugs.


Assuntos
Proteína gp120 do Envelope de HIV , Infecções por HIV , Humanos , Proteína gp120 do Envelope de HIV/genética , Conformação Proteica , Sequência de Aminoácidos , Fenótipo , Testes de Neutralização
9.
J Virol ; 97(10): e0075223, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37712704

RESUMO

IMPORTANCE: The phenomenon of reversible clustering is expected to further nuance HIV immune stealth because virus surfaces can escape interaction with antibodies (Abs) by hiding temporarily within clusters. It is well known that mucin reduces HIV virulence, and the current perspective is that mucin aggregates HIV-1 to reduce infections. Our findings, however, suggest that mucin is dispersing HIV clusters. The study proposes a new paradigm for how HIV-1 may broadly evade Ab recognition with reversible clustering and why mucin effectively neutralizes HIV-1.


Assuntos
HIV-1 , Mucinas , Humanos , Anticorpos Neutralizantes , Glicosilação , Anticorpos Anti-HIV , Proteína gp120 do Envelope de HIV , Infecções por HIV/imunologia , Infecções por HIV/virologia , Soropositividade para HIV , HIV-1/fisiologia , Mucinas/metabolismo
10.
J Virol ; 97(11): e0117123, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37888980

RESUMO

IMPORTANCE: CD4-mimetic compounds (CD4mcs) are small-molecule inhibitors of human immunodeficiency virus (HIV-1) entry into host cells. CD4mcs target a pocket on the viral envelope glycoprotein (Env) spike that is used for binding to the receptor, CD4, and is highly conserved among HIV-1 strains. Nonetheless, naturally occurring HIV-1 strains exhibit a wide range of sensitivities to CD4mcs. Our study identifies changes distant from the binding pocket that can influence the susceptibility of natural HIV-1 strains to the antiviral effects of multiple CD4mcs. We relate the antiviral potency of the CD4mc against this panel of HIV-1 variants to the ability of the CD4mc to activate entry-related changes in Env conformation prematurely. These findings will guide efforts to improve the potency and breadth of CD4mcs against natural HIV-1 variants.


Assuntos
Fármacos Anti-HIV , Antígenos CD4 , Proteína gp120 do Envelope de HIV , HIV-1 , Mimetismo Molecular , Receptores de HIV , Humanos , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Sítios de Ligação/efeitos dos fármacos , Antígenos CD4/química , Antígenos CD4/metabolismo , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/química , HIV-1/classificação , HIV-1/efeitos dos fármacos , HIV-1/metabolismo , Ligação Proteica/efeitos dos fármacos , Receptores de HIV/metabolismo , Internalização do Vírus/efeitos dos fármacos
11.
J Virol ; 97(10): e0115423, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37772823

RESUMO

IMPORTANCE: HIV infection can be effectively treated to prevent the development of AIDS, but it cannot be cured. We have attached poisons to anti-HIV antibodies to kill the infected cells that persist even after years of effective antiviral therapy. Here we show that the killing of infected cells can be markedly enhanced by the addition of soluble forms of the HIV receptor CD4 or by mimics of CD4.


Assuntos
Antígenos CD4 , Citotoxinas , Anticorpos Anti-HIV , Infecções por HIV , HIV-1 , Imunoconjugados , Humanos , Antígenos CD4/química , Antígenos CD4/imunologia , Antígenos CD4/uso terapêutico , Linhagem Celular , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/patologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/imunologia , Imunoconjugados/química , Imunoconjugados/imunologia , Imunoconjugados/uso terapêutico , Peso Molecular , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/imunologia , Anticorpos Anti-HIV/uso terapêutico , Citotoxinas/química , Citotoxinas/uso terapêutico
12.
Int J Mol Sci ; 25(2)2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38256260

RESUMO

The human immunodeficiency virus (HIV) epidemic is a global issue. The estimated number of people with HIV is 39,000,000 to date. Antiviral therapy is the primary approach to treat the infection. However, it does not allow for a complete elimination of the pathogen. The advances in modern gene therapy methods open up new possibilities of effective therapy. One of these areas of possibility is the development of technologies to prevent virus penetration into the cell. Currently, a number of technologies aimed at either the prevention of virus binding to the CCR5 coreceptor or its knockout are undergoing various stages of clinical trials. Since HIV can also utilize the CXCR4 coreceptor, technologies to modify this receptor are also required. Standard knockout of CXCR4 is impossible due to its physiological significance. This review presents an analysis of interactions between individual amino acids in CXCR4 and physiological ligands and HIV gp120. It also discusses potential targets for gene therapy approaches aimed at modifying the coreceptor.


Assuntos
Antifibrinolíticos , Epidemias , Infecções por HIV , Humanos , Aminoácidos , Terapia Genética , Infecções por HIV/genética , Infecções por HIV/terapia , Receptores CXCR4/genética
13.
Int J Mol Sci ; 25(4)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38397105

RESUMO

Acquired Immunodeficiency Syndrome is caused by the Human Immunodeficiency Virus (HIV), and a significant number of fatalities occur annually. There is a dire need to develop an effective vaccine against HIV-1. Understanding the structural proteins of viruses helps in designing a vaccine based on immunogenic peptides. In the current experiment, we identified gp120 epitopes using bioinformatic epitope prediction tools, molecular docking, and MD simulations. The Gb-1 peptide was considered an adjuvant. Consecutive sequences of GTG, GSG, GGTGG, and GGGGS linkers were used to bind the B cell, Cytotoxic T Lymphocytes (CTL), and Helper T Lymphocytes (HTL) epitopes. The final vaccine construct consisted of 315 amino acids and is expected to be a recombinant protein of approximately 35.49 kDa. Based on docking experiments, molecular dynamics simulations, and tertiary structure validation, the analysis of the modeled protein indicates that it possesses a stable structure and can interact with Toll-like receptors. The analysis demonstrates that the proposed vaccine can provoke an immunological response by activating T and B cells, as well as stimulating the release of IgA and IgG antibodies. This vaccine shows potential for HIV-1 prophylaxis. The in-silico design suggests that multiple-epitope constructs can be used as potentially effective immunogens for HIV-1 vaccine development.


Assuntos
Epitopos , Infecções por HIV , HIV-1 , Vacinas , Humanos , Sequência de Aminoácidos , Biologia Computacional , Imunidade , Imunoinformática , Simulação de Acoplamento Molecular , Peptídeos , Vacinas de Subunidades Antigênicas
14.
Int J Mol Sci ; 25(8)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38673879

RESUMO

Reactive astrocytes are key players in HIV-associated neurocognitive disorders (HAND), and different types of reactive astrocytes play opposing roles in the neuropathologic progression of HAND. A recent study by our group found that gp120 mediates A1 astrocytes (neurotoxicity), which secrete proinflammatory factors and promote HAND disease progression. Here, by comparing the expression of A2 astrocyte (neuroprotective) markers in the brains of gp120 tgm mice and gp120+/α7nAChR-/- mice, we found that inhibition of alpha 7 nicotinic acetylcholine receptor (α7nAChR) promotes A2 astrocyte generation. Notably, kynurenine acid (KYNA) is an antagonist of α7nAChR, and is able to promote the formation of A2 astrocytes, the secretion of neurotrophic factors, and the enhancement of glutamate uptake through blocking the activation of α7nAChR/NF-κB signaling. In addition, learning, memory and mood disorders were significantly improved in gp120 tgm mice by intraperitoneal injection of kynurenine (KYN) and probenecid (PROB). Meanwhile, the number of A2 astrocytes in the mouse brain was significantly increased and glutamate toxicity was reduced. Taken together, KYNA was able to promote A2 astrocyte production and neurotrophic factor secretion, reduce glutamate toxicity, and ameliorate gp120-induced neuropathological deficits. These findings contribute to our understanding of the role that reactive astrocytes play in the development of HAND pathology and provide new evidence for the treatment of HAND via the tryptophan pathway.


Assuntos
Astrócitos , Ácido Glutâmico , Cinurenina , Animais , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Ácido Glutâmico/toxicidade , Camundongos , Cinurenina/metabolismo , Ácido Cinurênico/metabolismo , Ácido Cinurênico/farmacologia , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp120 do Envelope de HIV/toxicidade , Transdução de Sinais/efeitos dos fármacos , Camundongos Knockout , Probenecid/farmacologia , Camundongos Endogâmicos C57BL , Masculino , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/efeitos dos fármacos , NF-kappa B/metabolismo
15.
Int J Mol Sci ; 25(7)2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38612400

RESUMO

Human Immunodeficiency Virus type 1 (HIV-1)-associated neurocognitive disorders (HANDs) remain prevalent in HIV-1-infected individuals despite the evident success of combined antiretroviral therapy (cART). The mechanisms underlying HAND prevalence in the cART era remain perplexing. Ample evidence indicates that HIV-1 envelope glycoprotein protein 120 (gp120), a potent neurotoxin, plays a pivotal role in HAND pathogenesis. Methamphetamine (Meth) abuse exacerbates HANDs, but how this occurs is not fully understood. We hypothesize that Meth exacerbates HANDs by enhancing gp120-mediated neuroinflammation. To test this hypothesis, we studied the effect of Meth on gp120-induced microglial activation and the resultant production of proinflammatory cytokines in primary rat microglial cultures. Our results show that Meth enhanced gp120-induced microglial activation, as revealed by immunostaining and Iba-1 expression, and potentiated gp120-mediated NLRP3 expression and IL-1ß processing and release, as assayed by immunoblotting and ELISA. Meth also augmented the co-localization of NLRP3 and caspase-1, increased the numbers of NLRP3 puncta and ROS production, increased the levels of iNOS expression and NO production, and increased the levels of cleaved gasderminD (GSDMD-N; an executor of pyroptosis) in gp120-primed microglia. The Meth-associated effects were attenuated or blocked by MCC950, an NLRP3 inhibitor, or Mito-TEMPO, a mitochondrial superoxide scavenger. These results suggest that Meth enhances gp120-associated microglial NLRP3 activation and the resultant proinflammatory responses via mitochondria-dependent signaling.


Assuntos
Transtornos Relacionados ao Uso de Anfetaminas , HIV-1 , Animais , Ratos , Glicoproteínas , Inflamassomos , Microglia , Proteína 3 que Contém Domínio de Pirina da Família NLR
16.
J Neuroinflammation ; 20(1): 87, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36997969

RESUMO

Despite extensive astrocyte activation in patients suffering from HIV-associated neurocognitive disorders (HAND), little is known about the contribution of astrocytes to HAND neuropathology. Here, we report that the robust activation of neurotoxic astrocytes (A1 astrocytes) in the CNS promotes neuron damage and cognitive deficits in HIV-1 gp120 transgenic mice. Notably, knockout of α7 nicotinic acetylcholine receptors (α7nAChR) blunted A1 astrocyte responses, ultimately facilitating neuronal and cognitive improvement in the gp120tg mice. Furthermore, we provide evidence that Kynurenic acid (KYNA), a tryptophan metabolite with α7nAChR inhibitory properties, attenuates gp120-induced A1 astrocyte formation through the blockade of α7nAChR/JAK2/STAT3 signaling activation. Meanwhile, compared with gp120tg mice, mice fed with tryptophan showed dramatic improvement in cognitive performance, which was related to the inhibition of A1 astrocyte responses. These initial and determinant findings mark a turning point in our understanding of the role of α7nAChR in gp120-mediated A1 astrocyte activation, opening up new opportunities to control neurotoxic astrocyte generation through KYNA and tryptophan administration.


Assuntos
Infecções por HIV , Ácido Cinurênico , Camundongos , Animais , Ácido Cinurênico/farmacologia , Ácido Cinurênico/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Astrócitos/metabolismo , Triptofano/metabolismo , HIV/metabolismo , Camundongos Transgênicos , Transtornos Neurocognitivos/metabolismo , Infecções por HIV/complicações , Infecções por HIV/metabolismo
17.
J Virol ; 96(2): e0134821, 2022 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-34705555

RESUMO

The surface envelope glycoproteins of nonprimate lentiviruses and betaretroviruses share sequence similarity with the inner proximal domain ß-sandwich of the human immunodeficiency virus type 1 (HIV-1) gp120 glycoprotein that faces the transmembrane glycoprotein as well as patterns of cysteine and glycosylation site distribution that points to a similar two-domain organization in at least some lentiviruses. Here, high-reliability models of the surface glycoproteins obtained with the AlphaFold algorithm are presented for the gp135 glycoprotein of the small ruminant caprine arthritis-encephalitis (CAEV) and visna lentiviruses and the betaretroviruses Jaagsiekte sheep retrovirus (JSRV), mouse mammary tumor virus (MMTV), and consensus human endogenous retrovirus type K (HERV-K). The models confirm and extend the inner domain structural conservation in these viruses and identify two outer domains with a putative receptor binding site in the CAEV and visna virus gp135. The location of that site is consistent with patterns of sequence conservation and glycosylation site distribution in gp135. In contrast, a single domain is modeled for the JSRV, MMTV, and HERV-K betaretrovirus envelope proteins that is highly conserved structurally in the proximal region and structurally diverse in apical regions likely to interact with cell receptors. The models presented here identify sites in small ruminant lentivirus and betaretrovirus envelope glycoproteins likely to be critical for virus entry and virus neutralization by antibodies and will facilitate their functional and structural characterization. IMPORTANCE Structural information on the surface envelope proteins of lentiviruses and related betaretroviruses is critical to understand mechanisms of virus-host interactions. However, experimental determination of these structures has been challenging, and only the structure of the human immunodeficiency virus type 1 gp120 has been determined. The advent of the AlphaFold artificial intelligence method for structure prediction allows high-quality modeling of the structures of small ruminant lentiviral and betaretroviral surface envelope proteins. The models are consistent with much of the previously described experimental data, show regions likely to interact with receptors, and identify domains that may be involved in mechanisms of antibody neutralization resistance in the small ruminant lentiviruses. The models will allow more precise design of mutants to further determine mechanisms of viral entry and immune evasion in this group of viruses and constructs for structural determination of these surface envelope proteins.


Assuntos
Algoritmos , Betaretrovirus/química , Produtos do Gene env/química , Lentivirus/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Sequência Conservada , Retrovirus Endógenos/química , Produtos do Gene env/metabolismo , Humanos , Modelos Moleculares , Ligação Proteica , Domínios Proteicos , Receptores Virais/metabolismo , Ruminantes
18.
J Virol ; 96(7): e0006322, 2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35319227

RESUMO

The retroviral surface envelope protein subunit (SU) mediates receptor binding and triggers membrane fusion by the transmembrane (TM) subunit. SU evolves rapidly under strong selective conditions, resulting in seemingly unrelated SU structures in highly divergent retroviruses. Structural modeling of the SUs of several retroviruses and related endogenous retroviral elements with AlphaFold 2 identifies a TM-proximal SU ß-sandwich structure that has been conserved in the orthoretroviruses for at least 110 million years. The SU of orthoretroviruses diversified by the differential expansion of the ß-sandwich core to form domains involved in virus-host interactions. The ß-sandwich domain is also conserved in the SU equivalent GP1 of Ebola virus although with a significantly different orientation in the trimeric envelope protein structure relative to the ß-sandwich of human immunodeficiency virus type 1 gp120, with significant evidence for divergent rather than convergent evolution. The unified structural view of orthoretroviral SU and filoviral GP1 identifies an ancient, structurally conserved, and evolvable domain underlying the structural diversity of orthoretroviral SU and filoviral GP1. IMPORTANCE The structural relationships of SUs of retroviral groups are obscured by the high rate of sequence change of SU and the deep-time divergence of retroviral lineages. Previous data showed no structural or functional relationships between the SUs of type C gammaretroviruses and lentiviruses. A deeper understanding of structural relationships between the SUs of different retroviral lineages would allow the generalization of critical processes mediated by these proteins in host cell infection. Modeling of SUs with AlphaFold 2 reveals a conserved core domain underlying the structural diversity of orthoretroviral SUs. Definition of the conserved SU structural core allowed the identification of a homologue structure in the SU equivalent GP1 of filoviruses that most likely shares an origin, unifying the SU of orthoretroviruses and GP1 of filoviruses into a single protein family. These findings will allow an understanding of the structural basis for receptor-mediated membrane fusion mechanisms in a broad range of biomedically important retroviruses.


Assuntos
Ebolavirus , Retrovirus Endógenos , Proteínas do Envelope Viral , Ebolavirus/metabolismo , Retrovirus Endógenos/metabolismo , Produtos do Gene env/química , Produtos do Gene env/metabolismo , Humanos , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/metabolismo
19.
J Neurovirol ; 29(5): 564-576, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37801175

RESUMO

Central nervous system (CNS) dysfunction remains prevalent in people with HIV (PWH) despite effective antiretroviral therapy (ART). There is evidence that low-level HIV infection and ART drugs may contribute to CNS damage in the brain of PWH with suppressed viral loads. As cannabis is used at a higher rate in PWH compared to the general population, there is interest in understanding how HIV proteins and ART drugs interact with the endocannabinoid system (ECS) and inflammation in the CNS. Therefore, we investigated the effects of the HIV envelope protein gp120 and tenofovir alafenamide (TAF) on cannabinoid receptor 1 (CB1R), glial fibrillary acidic protein (GFAP), and IBA1 in the brain and on locomotor activity in mice. The gp120 transgenic (tg) mouse model was administered TAF daily for 30 days and then analyzed using the open field test before being euthanized, and their brains were analyzed for CB1R, GFAP, and IBA1 expression using immunohistochemical approaches. CB1R expression levels were significantly increased in CA1, CA2/3, and dentate gyrus of gp120tg mice compared to wt littermates; TAF reversed these effects. As expected, TAF showed a medium effect of enhancing GFAP in the frontal cortex of gp120tg mice in the frontal cortex. TAF had minimal effect on IBA1 signal. TAF showed medium to large effects on fine movements, rearing, total activity, total distance, and lateral activity in the open-field test. These findings suggest that TAF may reverse gp120-induced effects on CB1R expression and, unlike tenofovir disoproxil fumarate (TDF), may not affect gliosis in the brain.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Humanos , Camundongos , Animais , Infecções por HIV/tratamento farmacológico , Infecções por HIV/genética , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Proteína gp120 do Envelope de HIV/genética , Adenina/farmacologia , Camundongos Transgênicos , Hipocampo , Receptores de Canabinoides/uso terapêutico
20.
Cell Mol Neurobiol ; 43(7): 3343-3373, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37470889

RESUMO

HIV-related neuropathic pain (HRNP) is a neurodegeneration that gradually develops during the long-term course of acquired immune deficiency syndrome (AIDS) and manifests as abnormal sock/sleeve-like symmetrical pain and nociceptive hyperalgesia in the extremities, which seriously reduces patient quality of life. To date, the pathogenesis of HRNP is not completely clear. There is a lack of effective clinical treatment for HRNP and it is becoming a challenge and hot spot for medical research. In this study, we conducted a systematic review of the progress of HRNP research in recent years including (1) the etiology, classification and clinical symptoms of HRNP, (2) the establishment of HRNP pathological models, (3) the pathological mechanisms underlying HRNP from three aspects: molecules, signaling pathways and cells, (4) the therapeutic strategies for HRNP, and (5) the limitations of recent HRNP research and the future research directions and prospects of HRNP. This detailed review provides new and systematic insight into the pathological mechanism of HRNP, which establishes a theoretical basis for the future exploitation of novel target drugs. HIV infection, antiretroviral therapy and opioid abuse contribute to the etiology of HRNP with symmetrical pain in both hands and feet, allodynia and hyperalgesia. The pathogenesis involves changes in cytokine expression, activation of signaling pathways and neuronal cell states. The therapy for HRNP should be patient-centered, integrating pharmacologic and nonpharmacologic treatments into multimodal intervention.


Assuntos
Infecções por HIV , Neuralgia , Humanos , Animais , Hiperalgesia/metabolismo , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , HIV , Experimentação Humana Terapêutica , Qualidade de Vida , Neuralgia/tratamento farmacológico , Neuralgia/metabolismo , Modelos Animais de Doenças
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