Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 16.487
Filtrar
1.
Viruses ; 14(10)2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36298843

RESUMO

Immune cell state alterations rewire HIV-1 gene expression, thereby influencing viral latency and reactivation, but the mechanisms are still unfolding. Here, using a screen approach on CD4+ T cell models of HIV-1 latency, we revealed Small Molecule Reactivators (SMOREs) with unique chemistries altering the CD4+ T cell state and consequently promoting latent HIV-1 transcription and reactivation through an unprecedented mechanism of action. SMOREs triggered rapid oxidative stress and activated a redox-responsive program composed of cell-signaling kinases (MEK-ERK axis) and atypical transcription factor (AP-1 and HIF-1α) cooperativity. SMOREs induced an unusual AP-1 phosphorylation signature to promote AP-1/HIF-1α binding to the latent HIV-1 proviral genome for its activation. Consistently, latent HIV-1 reactivation was compromised with pharmacologic inhibition of oxidative stress sensing or of cell-signaling kinases, and transcription factor's loss of expression, thus functionally linking the host redox-responsive program to viral transcriptional rewiring. Notably, SMOREs induced the redox program in primary CD4+ T cells and reactivated latent HIV-1 in aviremic patient samples alone and in combination with known latency-reversing agents, thus providing physiological relevance. Our findings suggest that manipulation of redox-sensitive pathways could be exploited to alter the course of HIV-1 latency, thus rendering host cells responsive to help achieve a sterilizing cure.


Assuntos
Infecções por HIV , HIV-1 , Fator de Transcrição AP-1 , Ativação Viral , Latência Viral , Humanos , Linfócitos T CD4-Positivos , Infecções por HIV/genética , Infecções por HIV/imunologia , Soropositividade para HIV/genética , Soropositividade para HIV/imunologia , HIV-1/genética , HIV-1/imunologia , Células Jurkat , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/imunologia , Oxirredução , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/imunologia , Ativação Viral/genética , Ativação Viral/imunologia , Latência Viral/genética , Latência Viral/imunologia
2.
Nature ; 609(7929): 998-1004, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36131022

RESUMO

Germinal centres are the engines of antibody evolution. Here, using human immunodeficiency virus (HIV) Env protein immunogen priming in rhesus monkeys followed by a long period without further immunization, we demonstrate germinal centre B (BGC) cells that last for at least 6 months. A 186-fold increase in BGC cells was present by week 10 compared with conventional immunization. Single-cell transcriptional profiling showed that both light- and dark-zone germinal centre states were sustained. Antibody somatic hypermutation of BGC cells continued to accumulate throughout the 29-week priming period, with evidence of selective pressure. Env-binding BGC cells were still 49-fold above baseline at 29 weeks, which suggests that they could remain active for even longer periods of time. High titres of HIV-neutralizing antibodies were generated after a single booster immunization. Fully glycosylated HIV trimer protein is a complex antigen, posing considerable immunodominance challenges for B cells1,2. Memory B cells generated under these long priming conditions had higher levels of antibody somatic hypermutation, and both memory B cells and antibodies were more likely to recognize non-immunodominant epitopes. Numerous BGC cell lineage phylogenies spanning more than the 6-month germinal centre period were identified, demonstrating continuous germinal centre activity and selection for at least 191 days with no further antigen exposure. A long-prime, slow-delivery (12 days) immunization approach holds promise for difficult vaccine targets and suggests that patience can have great value for tuning of germinal centres to maximize antibody responses.


Assuntos
Afinidade de Anticorpos , Linfócitos B , Movimento Celular , Células Clonais , Centro Germinativo , Anticorpos Anti-HIV , Imunização , Animais , Anticorpos Neutralizantes/genética , Anticorpos Neutralizantes/imunologia , Afinidade de Anticorpos/genética , Afinidade de Anticorpos/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Células Clonais/citologia , Células Clonais/imunologia , Epitopos de Linfócito B/imunologia , Perfilação da Expressão Gênica , Centro Germinativo/citologia , Centro Germinativo/imunologia , Anticorpos Anti-HIV/genética , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , Imunização Secundária , Macaca mulatta/imunologia , Macaca mulatta/virologia , Células B de Memória/citologia , Células B de Memória/imunologia , Análise de Célula Única , Hipermutação Somática de Imunoglobulina/genética , Hipermutação Somática de Imunoglobulina/imunologia , Fatores de Tempo , Produtos do Gene env do Vírus da Imunodeficiência Humana/administração & dosagem , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
3.
J Virol ; 96(17): e0119122, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-36000845

RESUMO

Epitopes with evidence of HLA-II-associated adaptation induce poorly immunogenic CD4+ T-cell responses in HIV-positive (HIV+) individuals. Many such escaped CD4+ T-cell epitopes are encoded by HIV-1 vaccines being evaluated in clinical trials. Here, we assessed whether this viral adaptation adversely impacts CD4+ T-cell responses following HIV-1 vaccination, thereby representing escaped epitopes. When evaluated in separate peptide pools, vaccine-encoded adapted epitopes (AE) induced CD4+ T-cell responses less frequently than nonadapted epitopes (NAE). We also demonstrated that in a polyvalent vaccine, where both forms of the same epitope were encoded, AE were less immunogenic. NAE-specific CD4+ T cells had increased, albeit low, levels of interferon gamma (IFN-γ) cytokine production. Single-cell transcriptomic analyses showed that NAE-specific CD4+ T cells expressed interferon-related genes, while AE-specific CD4+ T cells resembled a Th2 phenotype. Importantly, the magnitude of NAE-specific CD4+ T-cell responses, but not that of AE-specific responses, was found to positively correlate with Env-specific antibodies in a vaccine efficacy trial. Together, these findings show that HLA-II-associated viral adaptation reduces CD4+ T-cell responses in HIV-1 vaccine recipients and suggest that vaccines encoding a significant number of AE may not provide optimal B-cell help for HIV-specific antibody production. IMPORTANCE Despite decades of research, an effective HIV-1 vaccine remains elusive. Vaccine strategies leading to the generation of broadly neutralizing antibodies are likely needed to provide the best opportunity of generating a protective immune response against HIV-1. Numerous studies have demonstrated that T-cell help is necessary for effective antibody generation. However, immunogen sequences from recent HIV-1 vaccine efficacy trials include CD4+ T-cell epitopes that have evidence of immune escape. Our study shows that these epitopes, termed adapted epitopes, elicit lower frequencies of CD4+ T-cell responses in recipients from multiple HIV-1 vaccine trials. Additionally, the counterparts to these epitopes, termed nonadapted epitopes, elicited CD4+ T-cell responses that correlated with Env-specific antibodies in one efficacy trial. These results suggest that vaccine-encoded adapted epitopes dampen CD4+ T-cell responses, potentially impacting both HIV-specific antibody production and efficacious vaccine efforts.


Assuntos
Vacinas contra a AIDS , Formação de Anticorpos , Linfócitos T CD4-Positivos , Epitopos de Linfócito T , Infecções por HIV , HIV-1 , Antígenos HLA-D , Evasão da Resposta Imune , Vacinas contra a AIDS/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Linfócitos T CD4-Positivos/imunologia , Ensaios Clínicos como Assunto , Epitopos de Linfócito T/imunologia , Anticorpos Anti-HIV/biossíntese , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , HIV-1/imunologia , Antígenos HLA-D/imunologia , Humanos
4.
J Virol ; 96(15): e0037222, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35867565

RESUMO

Elimination of human immunodeficiency virus (HIV) reservoirs is a critical endpoint to eradicate HIV. One therapeutic intervention against latent HIV is "shock and kill." This strategy is based on the transcriptional activation of latent HIV with a latency-reversing agent (LRA) with the consequent killing of the reactivated cell by either the cytopathic effect of HIV or the immune system. We have previously found that the small molecule 3-hydroxy-1,2,3-benzotriazin-4(3H)-one (HODHBt) acts as an LRA by increasing signal transducer and activator of transcription (STAT) factor activation mediated by interleukin-15 (IL-15) in cells isolated from aviremic participants. The IL-15 superagonist N-803 is currently under clinical investigation to eliminate latent reservoirs. IL-15 and N-803 share similar mechanisms of action by promoting the activation of STATs and have shown some promise in preclinical models directed toward HIV eradication. In this work, we evaluated the ability of HODHBt to enhance IL-15 signaling in natural killer (NK) cells and the biological consequences associated with increased STAT activation in NK cell effector and memory-like functions. We showed that HODHBt increased IL-15-mediated STAT phosphorylation in NK cells, resulting in increases in the secretion of CXCL-10 and interferon gamma (IFN-γ) and the expression of cytotoxic proteins, including granzyme B, granzyme A, perforin, granulysin, FASL, and TRAIL. This increased cytotoxic profile results in increased cytotoxicity against HIV-infected cells and different tumor cell lines. HODHBt also improved the generation of cytokine-induced memory-like NK cells. Overall, our data demonstrate that enhancing the magnitude of IL-15 signaling with HODHBt favors NK cell cytotoxicity and memory-like generation, and thus, targeting this pathway could be further explored for HIV cure interventions. IMPORTANCE Several clinical trials targeting the HIV latent reservoir with LRAs have been completed. In spite of a lack of clinical benefit, they have been crucial to elucidate hurdles that "shock and kill" strategies have to overcome to promote an effective reduction of the latent reservoir to lead to a cure. These hurdles include low reactivation potential mediated by LRAs, the negative influence of some LRAs on the activity of natural killer and effector CD8 T cells, an increased resistance to apoptosis of latently infected cells, and an exhausted immune system due to chronic inflammation. To that end, finding therapeutic strategies that can overcome some of these challenges could improve the outcome of shock and kill strategies aimed at HIV eradication. Here, we show that the LRA HODHBt also improves IL-15-mediated NK cell effector and memory-like functions. As such, pharmacological enhancement of IL-15-mediated STAT activation can open new therapeutic avenues toward an HIV cure.


Assuntos
HIV-1 , Memória Imunológica , Interleucina-15 , Células Matadoras Naturais , Fatores de Transcrição STAT , Triazinas , Latência Viral , Linhagem Celular Tumoral , Quimiocina CXCL10 , Testes Imunológicos de Citotoxicidade , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/crescimento & desenvolvimento , HIV-1/imunologia , Humanos , Memória Imunológica/efeitos dos fármacos , Interferon gama , Interleucina-15/imunologia , Interleucina-15/metabolismo , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Fatores de Transcrição STAT/metabolismo , Ativação Transcricional/efeitos dos fármacos , Triazinas/farmacologia , Ativação Viral/efeitos dos fármacos , Latência Viral/efeitos dos fármacos
6.
Sci Rep ; 12(1): 11425, 2022 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-35794176

RESUMO

CCR5 is the main HIV co-receptor. We aimed to (1) compare CCR5 expression on immune cells between people living with HIV (PLHIV) using combination antiretroviral therapy (cART) and HIV-uninfected controls, (2) relate CCR5 expression to viral reservoir size and (3) assess determinants of CCR5 expression. This cross-sectional study included 209 PLHIV and 323 controls. Percentages of CCR5+ cells (%) and CCR5 mean fluorescence intensity assessed by flow cytometry in monocytes and lymphocyte subsets were correlated to host factors, HIV-1 cell-associated (CA)-RNA and CA-DNA, plasma inflammation markers and metabolites. Metabolic pathways were identified. PLHIV displayed higher percentages of CCR5+ monocytes and several CD8+ T cell subsets, but lower percentages of CCR5+ naive CD4+ T cells and regulatory T cells (Tregs). HIV-1 CA-DNA and CA-RNA correlated positively with percentages of CCR5+ lymphocytes. Metabolome analysis revealed three pathways involved in energy metabolism associated with percentage of CCR5+ CD8+ T cells in PLHIV. Our results indicate that CCR5 is differently expressed on various circulating immune cells in PLHIV. Hence, cell-trafficking of CD8+ T cells and Tregs may be altered in PLHIV. Associations between energy pathways and percentage of CCR5+ CD8+ T cells in PLHIV suggest higher energy demand of these cells in PLHIV.


Assuntos
Linfócitos T CD8-Positivos , Infecções por HIV , HIV-1 , Receptores CCR5 , Linfócitos T Reguladores , Linfócitos T CD8-Positivos/imunologia , Estudos Transversais , Infecções por HIV/sangue , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , RNA/metabolismo , Receptores CCR5/imunologia , Receptores de HIV , Linfócitos T Reguladores/imunologia
7.
J Virol ; 96(15): e0088522, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35856674

RESUMO

Anti-retroviral therapy (ART) generally suppresses HIV replication to undetectable levels in peripheral blood, but immune activation associated with increased morbidity and mortality is sustained during ART, and infection rebounds when treatment is interrupted. To identify drivers of immune activation and potential sources of viral rebound, we modified RNAscope in situ hybridization to visualize HIV-producing cells as a standard against which to compare the following assays of potential sources of immune activation and virus rebound following treatment interruption: (i) envelope detection by induced transcription-based sequencing (EDITS) assay; (ii) HIV-Flow; (iii) Flow-FISH assays that can scan tissues and cell suspensions to detect rare cells expressing env mRNA, gag mRNA/Gag protein and p24; and (iv) an ultrasensitive immunoassay that detects p24 in cell/tissue lysates at subfemtomolar levels. We show that the sensitivities of these assays are sufficient to detect one rare HIV-producing/env mRNA+/p24+ cell in one million uninfected cells. These high-throughput technologies provide contemporary tools to detect and characterize rare cells producing virus and viral antigens as potential sources of immune activation and viral rebound. IMPORTANCE Anti-retroviral therapy (ART) has greatly improved the quality and length of life for people living with HIV, but immune activation does not normalize during ART, and persistent immune activation has been linked to increased morbidity and mortality. We report a comparison of assays of two potential sources of immune activation during ART: rare cells producing HIV and the virus' major viral protein, p24, benchmarked on a cell model of active and latent infections and a method to visualize HIV-producing cells. We show that assays of HIV envelope mRNA (EDITS assay), gag mRNA, and p24 (Flow-FISH, HIV-Flow. and ultrasensitive p24 immunoassay) detect HIV-producing cells and p24 at sensitivities of one infected cell in a million uninfected cells, thereby providing validated tools to explore sources of immune activation during ART in the lymphoid and other tissue reservoirs.


Assuntos
Infecções por HIV , HIV-1 , RNA Viral , Tropismo Viral , Ativação Viral , Fármacos Anti-HIV/administração & dosagem , Fármacos Anti-HIV/uso terapêutico , Antígenos Virais/análise , Antígenos Virais/genética , Antígenos Virais/metabolismo , Linfócitos T CD4-Positivos , Proteína do Núcleo p24 do HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/genética , HIV-1/crescimento & desenvolvimento , HIV-1/imunologia , Humanos , Imunoensaio , Hibridização in Situ Fluorescente , RNA Mensageiro/análise , RNA Viral/análise , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética
8.
Nature ; 606(7913): 375-381, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35650437

RESUMO

Antiretroviral therapy is highly effective in suppressing human immunodeficiency virus (HIV)1. However, eradication of the virus in individuals with HIV has not been possible to date2. Given that HIV suppression requires life-long antiretroviral therapy, predominantly on a daily basis, there is a need to develop clinically effective alternatives that use long-acting antiviral agents to inhibit viral replication3. Here we report the results of a two-component clinical trial involving the passive transfer of two HIV-specific broadly neutralizing monoclonal antibodies, 3BNC117 and 10-1074. The first component was a randomized, double-blind, placebo-controlled trial that enrolled participants who initiated antiretroviral therapy during the acute/early phase of HIV infection. The second component was an open-label single-arm trial that enrolled individuals with viraemic control who were naive to antiretroviral therapy. Up to 8 infusions of 3BNC117 and 10-1074, administered over a period of 24 weeks, were well tolerated without any serious adverse events related to the infusions. Compared with the placebo, the combination broadly neutralizing monoclonal antibodies maintained complete suppression of plasma viraemia (for up to 43 weeks) after analytical treatment interruption, provided that no antibody-resistant HIV was detected at the baseline in the study participants. Similarly, potent HIV suppression was seen in the antiretroviral-therapy-naive study participants with viraemia carrying sensitive virus at the baseline. Our data demonstrate that combination therapy with broadly neutralizing monoclonal antibodies can provide long-term virological suppression without antiretroviral therapy in individuals with HIV, and our experience offers guidance for future clinical trials involving next-generation antibodies with long half-lives.


Assuntos
Fármacos Anti-HIV , Anticorpos Neutralizantes , Anticorpos Anti-HIV , Infecções por HIV , HIV-1 , Fármacos Anti-HIV/administração & dosagem , Fármacos Anti-HIV/efeitos adversos , Fármacos Anti-HIV/imunologia , Fármacos Anti-HIV/uso terapêutico , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/efeitos adversos , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Amplamente Neutralizantes/administração & dosagem , Anticorpos Amplamente Neutralizantes/efeitos adversos , Anticorpos Amplamente Neutralizantes/imunologia , Anticorpos Amplamente Neutralizantes/uso terapêutico , Método Duplo-Cego , Anticorpos Anti-HIV/administração & dosagem , Anticorpos Anti-HIV/efeitos adversos , Anticorpos Anti-HIV/imunologia , Anticorpos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/imunologia , HIV-1/isolamento & purificação , Humanos , Carga Viral/efeitos dos fármacos , Viremia/tratamento farmacológico , Viremia/imunologia , Viremia/virologia
9.
J Virol ; 96(13): e0040622, 2022 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-35658529

RESUMO

The antibody response against the HIV-1 envelope glycoproteins (Envs) guides evolution of this protein within each host. Whether antibodies with similar target specificities are elicited in different individuals and affect the population-level evolution of Env is poorly understood. To address this question, we analyzed properties of emerging variants in the gp41 fusion peptide-proximal region (FPPR) that exhibit distinct evolutionary patterns in HIV-1 clade B. For positions 534, 536, and 539 in the FPPR, alanine was the major emerging variant. However, 534A and 536A show a constant frequency in the population between 1979 and 2016, whereas 539A is gradually increasing. To understand the basis for these differences, we introduced alanine substitutions in the FPPR of primary HIV-1 strains and examined their functional and antigenic properties. Evolutionary patterns could not be explained by fusion competence or structural stability of the emerging variants. Instead, 534A and 536A exhibited modest but significant increases in sensitivity to antibodies against the membrane-proximal external region (MPER) and gp120-gp41 interface. These Envs were also more sensitive to poorly neutralizing sera from HIV-1-infected individuals than the clade ancestral form or 539A variant. Competition binding assays confirmed for all sera tested the presence of antibodies against the base of the Env trimer that compete with monoclonal antibodies targeting the MPER and gp120-gp41 interface. Our findings suggest that weakly neutralizing antibodies against the trimer base are commonly elicited; they do not exert catastrophic population size reduction effects on emerging variants but, instead, determine their set point frequencies in the population and historical patterns of change. IMPORTANCE Infection by HIV-1 elicits formation of antibodies that target the viral Env proteins and can inactivate the virus. The specific targets of these antibodies vary among infected individuals. It is unclear whether some target specificities are shared among the antibody responses of different individuals. We observed that antibodies against the base of the Env protein are commonly elicited during infection. The selective pressure applied by such antibodies is weak. As a result, they do not completely eliminate the sensitive forms of the virus from the population, but maintain their frequency at a low level that has not increased since the beginning of the AIDS pandemic. Interestingly, the changes in Env do not occur at the sites targeted by the antibodies, but at a distinct region of Env, the fusion peptide-proximal region, which regulates their exposure.


Assuntos
Proteína gp41 do Envelope de HIV , HIV-1 , Alanina/genética , Anticorpos Monoclonais , Anticorpos Neutralizantes , Anticorpos Anti-HIV , Proteína gp120 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/imunologia , HIV-1/imunologia , Humanos
10.
J Virol ; 96(14): e0032422, 2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-35758668

RESUMO

Induction of broadly neutralizing antibodies (bNAbs) to HIV and other diverse pathogens will likely require the use of multiple immunogens. An understanding of the dynamics of antibody development to multiple diverse but related antigens would facilitate the rational design of immunization strategies. Here, we characterize, in detail, the development of neutralizing antibodies in three individuals coinfected with several divergent HIV variants. Two of these coinfected individuals developed additive or cross-neutralizing antibody responses. However, interference was observed in the third case, with neutralizing antibody responses to one viral variant arising to the near exclusion of neutralizing responses to the other. Longitudinal characterization of the diversity in the Envelope glycoprotein trimer (Env) structure showed that in the individual who developed the broadest neutralizing antibodies, circulating viruses shared a conserved epitope on the trimer apex that was targeted by cross-neutralizing antibodies. In contrast, in the other two individuals, diversity was distributed across Env. Taken together, these data highlight that multiple related immunogens can result in immune interference. However, they also suggest that immunogen cocktails presenting shared, conserved neutralizing epitopes in a variable background may focus broadly neutralizing antibody responses to these targets. IMPORTANCE Despite being the focus of extensive research, we still do not know how to reproducibly elicit cross-neutralizing antibodies against variable pathogens by vaccination. Here, we characterize the antibody responses in people coinfected with more than one HIV variant, providing insights into how the use of antigen "cocktails" might affect the breadth of the elicited neutralizing antibody response and how the relatedness of the antigens may shape this.


Assuntos
Vacinas contra a AIDS , Anticorpos Amplamente Neutralizantes , Infecções por HIV , HIV-1 , Vacinas contra a AIDS/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Epitopos , Anticorpos Anti-HIV , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/imunologia , Humanos
11.
J Virol ; 96(8): e0166821, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35343783

RESUMO

Binding to the receptor, CD4, drives the pretriggered, "closed" (state-1) conformation of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer into more "open" conformations (states 2 and 3). Broadly neutralizing antibodies, which are elicited inefficiently, mostly recognize the state-1 Env conformation, whereas the more commonly elicited poorly neutralizing antibodies recognize states 2/3. HIV-1 Env metastability has created challenges for defining the state-1 structure and developing immunogens mimicking this labile conformation. The availability of functional state-1 Envs that can be efficiently cross-linked at lysine and/or acidic amino acid residues might assist these endeavors. To that end, we modified HIV-1AD8 Env, which exhibits an intermediate level of triggerability by CD4. We introduced lysine/acidic residues at positions that exhibit such polymorphisms in natural HIV-1 strains. Env changes that were tolerated with respect to gp120-gp41 processing, subunit association, and virus entry were further combined. Two common polymorphisms, Q114E and Q567K, as well as a known variant, A582T, additively rendered pseudoviruses resistant to cold, soluble CD4, and a CD4-mimetic compound, phenotypes indicative of stabilization of the pretriggered state-1 Env conformation. Combining these changes resulted in two lysine-rich HIV-1AD8 Env variants (E.2 and AE.2) with neutralization- and cold-resistant phenotypes comparable to those of natural, less triggerable tier 2/3 HIV-1 isolates. Compared with these and the parental Envs, the E.2 and AE.2 Envs were cleaved more efficiently and exhibited stronger gp120-trimer association in detergent lysates. These highly cross-linkable Envs enriched in a pretriggered conformation should assist characterization of the structure and immunogenicity of this labile state. IMPORTANCE The development of an efficient vaccine is critical for combating HIV-1 infection worldwide. However, the instability of the pretriggered shape (state 1) of the viral envelope glycoprotein (Env) makes it difficult to raise neutralizing antibodies against HIV-1. Here, by introducing multiple changes in Env, we derived two HIV-1 Env variants that are enriched in state 1 and can be efficiently cross-linked to maintain this shape. These Env complexes are more stable in detergent, assisting their purification. Thus, our study provides a path to a better characterization of the native pretriggered Env, which should assist vaccine development.


Assuntos
Vacinas contra a AIDS , Infecções por HIV , HIV-1 , Produtos do Gene env do Vírus da Imunodeficiência Humana , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Detergentes , Glicoproteínas/química , Glicoproteínas/imunologia , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/metabolismo , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/prevenção & controle , HIV-1/química , HIV-1/genética , HIV-1/imunologia , Humanos , Lisina , Conformação Proteica , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
12.
J Virol ; 96(7): e0187821, 2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35289647

RESUMO

Binding to the receptor, CD4, drives the pretriggered, "closed" (State-1) conformation of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer ([gp120/gp41]3) into more "open" conformations. HIV-1 Env on the viral membrane is maintained in a State-1 conformation that resists binding and neutralization by commonly elicited antibodies. Premature triggering of Env before the virus engages a target cell typically leads to increased susceptibility to spontaneous inactivation or ligand-induced neutralization. Here, we showed that single amino acid substitutions in the gp41 membrane-proximal external region (MPER) of a primary HIV-1 strain resulted in viral phenotypes indicative of premature triggering of Env to downstream conformations. Specifically, the MPER changes reduced viral infectivity and globally increased virus sensitivity to poorly neutralizing antibodies, soluble CD4, a CD4-mimetic compound, and exposure to cold. In contrast, the MPER mutants exhibited decreased sensitivity to the State 1-preferring inhibitor, BMS-806, and to the PGT151 broadly neutralizing antibody. Depletion of cholesterol from virus particles did not produce the same State 1-destabilizing phenotypes as MPER alterations. Notably, State 1-stabilizing changes in Env distant from the MPER could minimize the phenotypic effects of MPER alteration but did not affect virus sensitivity to cholesterol depletion. Thus, membrane-proximal gp41 elements contribute to the maintenance of the pretriggered Env conformation. The conformationally disruptive effects of MPER changes can be minimized by distant State 1-stabilizing Env modifications, a strategy that may be useful in preserving the native pretriggered state of Env. IMPORTANCE The pretriggered shape of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) is a major target for antibodies that can neutralize many strains of the virus. An effective HIV-1 vaccine may need to raise these types of antibodies, but this goal has proven difficult. One reason is that the pretriggered shape of Env is unstable and dependent on interactions near the viral membrane. Here, we showed that the membrane-proximal external region (MPER) of Env plays an important role in maintaining Env in a pretriggered shape. Alterations in the MPER resulted in global changes in Env conformation that disrupted its pretriggered shape. We also found that these disruptive effects of MPER changes could be minimized by distant Env modifications that stabilized the pretriggered shape. These modifications may be useful for preserving the native shape of Env for structural and vaccine studies.


Assuntos
Infecções por HIV , HIV-1 , Anticorpos Neutralizantes , Produtos do Gene env/química , Produtos do Gene env/imunologia , Glicoproteínas/química , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/química , HIV-1/imunologia , Humanos
13.
Front Immunol ; 13: 780922, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35211115

RESUMO

The natural process of human immunodeficiency virus type 1(HIV-1) infection is characterized by high viral load, immune cell exhaustion, and immunodeficiency, which eventually leads to the stage of acquired immunodeficiency syndrome (AIDS) and opportunistic infections. Rapidly progressing HIV-1 individuals often die of AIDS several years after infection without treatment. The promotion of ART greatly prolongs the survival time of HIV-infected persons. However, some patients have incomplete immune function reconstruction after ART due to latent storage of HIV-infected cells. Therefore, how to achieve a functional cure has always been the focus and hot spot of global AIDS research. Fortunately, the emergence of ECs/LTNPs who can control virus replication naturally has ignited new hope for realizing a functional cure for AIDS. Recently, a special category of infected individuals has attracted attention that can delay the progression of the disease more rigorously than the natural progression of HIV-1 infection described above. These patients are characterized by years of HIV-1 infection, long-term asymptomatic status, and normal CD4+T cell count without ART, classified as HIV-infected long-term nonprogressors (LTNPs) and elite controllers (ECs). Numerous studies have shown that the host and virus jointly determine the progression of HIV-1 infection, in which the level of innate immunity activation plays an important role. As the first line of defense against pathogen invasion, innate immunity is also a bridge to induce adaptive immunity. Compared with natural progressors, innate immunity plays an antiviral role in HIV-1 infection by inducing or activating many innate immune-related factors in the natural ECs. Learning the regulation of ECs immunity, especially the innate immunity in different characteristics, and thus studying the mechanism of the control of disease progression naturally, will contribute to the realization of the functional cure of AIDS. Therefore, this review will explore the relationship between innate immunity and disease progression in ECs of HIV-1 infection from the aspects of innate immune cells, signaling pathways, cytokines, which is helpful to provide new targets and theoretical references for the functional cure, prevention and control of AIDS, and development of a vaccine.


Assuntos
Infecções por HIV/imunologia , Imunidade Inata , Citocinas , Infecções por HIV/virologia , HIV-1/imunologia , Humanos , Transdução de Sinais
14.
Int J Mol Sci ; 23(4)2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35216318

RESUMO

A significant proportion of people living with HIV (PLHIV) who successfully achieve virological suppression fail to recover CD4+ T-cell counts. Since adipose tissue has been discovered as a key immune organ, this study aimed to assess the role of adipokines in the HIV immunodiscordant response. This is a multicenter prospective study including 221 PLHIV starting the first antiretroviral therapy (ART) and classified according to baseline CD4+ T-cell counts/µL (controls > 200 cells/µL and cases ≤ 200 cells/µL). Immune failure recovery was considered when cases did not reach more than 250 CD4+ T cells/µL at 144 weeks (immunological nonresponders, INR). Circulating adipokine concentrations were longitudinally measured using enzyme-linked immunosorbent assays. At baseline, apelin receptor (APLNR) and zinc-alpha-2-glycoprotein (ZAG) concentrations were significantly lower in INRs than in immunological responders (p = 0.043 and p = 0.034), and they remained lower during all ART follow-up visits (p = 0.044 and p = 0.028 for APLNR, p = 0.038 and p = 0.010 for ZAG, at 48 and 144 weeks, respectively). ZAG levels positively correlated with retinol-binding protein 4 (RBP4) levels (p < 0.01), and low circulating RBP4 concentrations were related to a low CD4+ T-cell gain (p = 0.018 and p = 0.039 at 48 and 144 weeks, respectively). Multiple regression adjusted for clinical variables and adipokine concentrations confirmed both low APLNR and RBP4 as independent predictors for CD4+ T cells at 144 weeks (p < 0.001). In conclusion, low APLNR and RBP4 concentrations were associated with poor immune recovery in treated PLHIV and could be considered predictive biomarkers of a discordant immunological response.


Assuntos
Adipocinas/metabolismo , Receptores de Apelina/metabolismo , Biomarcadores/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Infecções por HIV/metabolismo , Proteínas Plasmáticas de Ligação ao Retinol/metabolismo , Adipocinas/imunologia , Adulto , Terapia Antirretroviral de Alta Atividade/métodos , Receptores de Apelina/imunologia , Contagem de Linfócito CD4/métodos , Linfócitos T CD4-Positivos/imunologia , Feminino , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Proteínas Plasmáticas de Ligação ao Retinol/imunologia , Carga Viral/fisiologia
15.
Viruses ; 14(2)2022 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-35215997

RESUMO

HIV mainly targets CD4+ T cells, from which Th17 cells represent a major cell type, permissive, and are capable of supporting intracellular replication at mucosal sites. Th17 cells possess well-described dual roles, while being central to maintaining gut integrity, these may induce inflammation and contribute to autoimmune disorders; however, Th17 cells' antiviral function in HIV infection is not completely understood. Th17 cells are star players to HIV-1 pathogenesis and a potential target to prevent or decrease HIV transmission. HIV-1 can be spread among permissive cells via direct cell-to-cell and/or cell-free infection. The debate on which mode of transmission is more efficient is still ongoing without a concrete conclusion yet. Most assessments of virus transmission analyzing either cell-to-cell or cell-free modes use in vitro systems; however, the actual interactions and conditions in vivo are not fully understood. The fact that infected breast milk, semen, and vaginal secretions contain a mix of both cell-free viral particles and infected cells presents an argument for the probability of HIV taking advantage of both modes of transmission to spread. Here, we review important insights and recent findings about the role of Th17 cells during HIV pathogenesis in mucosal surfaces, and the mechanisms of HIV-1 infection spread among T cells in tissues.


Assuntos
Infecções por HIV/transmissão , Infecções por HIV/virologia , HIV-1/patogenicidade , Células Th17/virologia , Animais , Modelos Animais de Doenças , Infecções por HIV/imunologia , HIV-1/genética , HIV-1/imunologia , Humanos , Membrana Mucosa/patologia , Células Th17/imunologia , Replicação Viral
16.
Front Immunol ; 13: 803417, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35154118

RESUMO

T and natural killer (NK) cells are effector cells with key roles in anti-HIV immunity, including in lymphoid tissues, the major site of HIV persistence. However, little is known about the features of these effector cells from people living with HIV (PLWH), particularly from those who initiated antiretroviral therapy (ART) during acute infection. Our study design was to use 42-parameter CyTOF to conduct deep phenotyping of paired blood- and lymph node (LN)-derived T and NK cells from three groups of HIV+ aviremic individuals: elite controllers (N = 5), and ART-suppressed individuals who had started therapy during chronic (N = 6) vs. acute infection (N = 8), the latter of which is associated with better outcomes. We found that acute-treated individuals are enriched for specific subsets of T and NK cells, including blood-derived CD56-CD16+ NK cells previously associated with HIV control, and LN-derived CD4+ T follicular helper cells with heightened expansion potential. An in-depth comparison of the features of the cells from blood vs. LNs of individuals from our cohort revealed that T cells from blood were more activated than those from LNs. By contrast, LNs were enriched for follicle-homing CXCR5+ CD8+ T cells, which expressed increased levels of inhibitory receptors and markers of survival and proliferation as compared to their CXCR5- counterparts. In addition, a subset of memory-like CD56brightTCF1+ NK cells was enriched in LNs relative to blood. These results together suggest unique T and NK cell features in acute-treated individuals, and highlight the importance of examining effector cells not only in blood but also the lymphoid tissue compartment, where the reservoir mostly persists, and where these cells take on distinct phenotypic features.


Assuntos
Infecções por HIV/imunologia , Leucócitos/classificação , Linfócitos/imunologia , Fenótipo , Resposta Viral Sustentada , Adulto , Idoso , Antirretrovirais/uso terapêutico , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Feminino , Infecções por HIV/tratamento farmacológico , HIV-1/imunologia , Humanos , Células Matadoras Naturais/imunologia , Leucócitos/imunologia , Linfócitos/classificação , Masculino , Pessoa de Meia-Idade
17.
Nat Commun ; 13(1): 695, 2022 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-35121758

RESUMO

HIV Envelope (Env) is the main vaccine target for induction of neutralizing antibodies. Stabilizing Env into native-like trimer (NLT) conformations is required for recombinant protein immunogens to induce autologous neutralizing antibodies(nAbs) against difficult to neutralize HIV strains (tier-2) in rabbits and non-human primates. Immunizations of mice with NLTs have generally failed to induce tier-2 nAbs. Here, we show that DNA-encoded NLTs fold properly in vivo and induce autologous tier-2 nAbs in mice. DNA-encoded NLTs also uniquely induce both CD4 + and CD8 + T-cell responses as compared to corresponding protein immunizations. Murine neutralizing antibodies are identified with an advanced sequencing technology. The structure of an Env-Ab (C05) complex, as determined by cryo-EM, identifies a previously undescribed neutralizing Env C3/V5 epitope. Beyond potential functional immunity gains, DNA vaccines permit in vivo folding of structured antigens and provide significant cost and speed advantages for enabling rapid evaluation of new HIV vaccines.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Vacinas de DNA/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Vacinas contra a AIDS/administração & dosagem , Animais , Anticorpos Neutralizantes/ultraestrutura , Antígenos Virais/imunologia , Linhagem Celular Tumoral , Microscopia Crioeletrônica , ELISPOT , Epitopos/imunologia , Células HEK293 , Anticorpos Anti-HIV/ultraestrutura , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , HIV-1/fisiologia , Humanos , Interferon gama/imunologia , Interferon gama/metabolismo , Camundongos Endogâmicos BALB C , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/virologia , Vacinação/métodos , Vacinas de DNA/administração & dosagem , Produtos do Gene env do Vírus da Imunodeficiência Humana/química
18.
Nat Commun ; 13(1): 630, 2022 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-35110562

RESUMO

Broadly neutralizing antibodies (bNAbs) targeting the HIV-1 envelope glycoprotein (Env) are promising molecules for therapeutic or prophylactic interventions. Beyond neutralization, bNAbs exert Fc-dependent functions including antibody-dependent cellular cytotoxicity and activation of the complement. Here, we show that a subset of bNAbs targeting the CD4 binding site and the V1/V2 or V3 loops inhibit viral release from infected cells. We combined immunofluorescence, scanning electron microscopy, transmission electron microscopy and immunogold staining to reveal that some bNAbs form large aggregates of virions at the surface of infected cells. This activity correlates with the capacity of bNAbs to bind to Env at the cell surface and to neutralize cell-free viral particles. We further show that antibody bivalency is required for viral retention, and that aggregated virions are neutralized. We have thus identified an additional antiviral activity of bNAbs, which block HIV-1 release by tethering viral particles at the surface of infected cells.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Vírion/imunologia , Citotoxicidade Celular Dependente de Anticorpos , Anticorpos Amplamente Neutralizantes , Linhagem Celular , Epitopos , Infecções por HIV/imunologia , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Linfócitos T , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
19.
Nat Commun ; 13(1): 662, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35115533

RESUMO

Increasingly, antibodies are being used to treat and prevent viral infections. In the context of HIV, efficacy is primarily attributed to dose-dependent neutralization potency and to a lesser extent Fc-mediated effector functions. It remains unclear whether augmenting effector functions of broadly neutralizing antibodies (bNAbs) may improve their clinical potential. Here, we use bNAb 10E8v4 targeting the membrane external proximal region (MPER) to examine the role of antibody-mediated effector and complement (C') activity when administered prophylactically against SHIV challenge in rhesus macaques. With sub-protective dosing, we find a 78-88% reduction in post-acute viremia that is associated with 10E8v4-mediated phagocytosis acting at the time of challenge. Neither plasma nor tissue viremic outcomes in vivo is improved with an Fc-modified variant of 10E8v4 enhanced for C' functions as determined in vitro. These results suggest that effector functions inherent to unmodified 10E8v4 contribute to efficacy against SHIVSF162P3 in the absence of plasma neutralizing titers, while C' functions are dispensable in this setting, informing design of bNAb modifications for improving protective efficacy.


Assuntos
Anticorpos Amplamente Neutralizantes/imunologia , Proteínas do Sistema Complemento/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Fagocitose/imunologia , Viremia/imunologia , Animais , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Anticorpos Amplamente Neutralizantes/metabolismo , Anticorpos Amplamente Neutralizantes/farmacologia , Linhagem Celular Tumoral , Proteínas do Sistema Complemento/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Feminino , Anticorpos Anti-HIV/metabolismo , Anticorpos Anti-HIV/farmacologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Macaca mulatta , Masculino , Fagocitose/efeitos dos fármacos , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Vírus da Imunodeficiência Símia/imunologia , Vírus da Imunodeficiência Símia/fisiologia , Viremia/sangue , Viremia/prevenção & controle
20.
Nat Commun ; 13(1): 732, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35136084

RESUMO

Broadly-neutralizing antibodies (bNAbs) against HIV-1 Env can protect from infection. We characterize Ab1303 and Ab1573, heterologously-neutralizing CD4-binding site (CD4bs) antibodies, isolated from sequentially-immunized macaques. Ab1303/Ab1573 binding is observed only when Env trimers are not constrained in the closed, prefusion conformation. Fab-Env cryo-EM structures show that both antibodies recognize the CD4bs on Env trimer with an 'occluded-open' conformation between closed, as targeted by bNAbs, and fully-open, as recognized by CD4. The occluded-open Env trimer conformation includes outwardly-rotated gp120 subunits, but unlike CD4-bound Envs, does not exhibit V1V2 displacement, 4-stranded gp120 bridging sheet, or co-receptor binding site exposure. Inter-protomer distances within trimers measured by double electron-electron resonance spectroscopy suggest an equilibrium between occluded-open and closed Env conformations, consistent with Ab1303/Ab1573 binding stabilizing an existing conformation. Studies of Ab1303/Ab1573 demonstrate that CD4bs neutralizing antibodies that bind open Env trimers can be raised by immunization, thereby informing immunogen design and antibody therapeutic efforts.


Assuntos
Anticorpos Neutralizantes/farmacologia , Anticorpos Anti-HIV/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/imunologia , Animais , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Neutralizantes/ultraestrutura , Sítios de Ligação , Antígenos CD4/imunologia , Antígenos CD4/metabolismo , Microscopia Crioeletrônica , Cristalografia por Raios X , Desenho de Fármacos , Anticorpos Anti-HIV/isolamento & purificação , Anticorpos Anti-HIV/uso terapêutico , Anticorpos Anti-HIV/ultraestrutura , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Macaca , Simulação de Acoplamento Molecular , Ligação Proteica , Domínios Proteicos , Multimerização Proteica , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...