RESUMO
PURPOSE OF REVIEW: Advancements in antiretroviral therapy (ART) have positively impacted the life expectancy and possibility of living a normal life for people with HIV-1. However, lifelong daily medication is necessary to prevent disease progression. To this end, immunotherapeutic strategies are being tested with the aim of developing a functional cure in which the immune system effectively controls HIV-1 in the absence of ART. RECENT FINDINGS: The most promising advances in achieving sustained HIV-1 remission or cure include broadly neutralizing antibodies (bNAbs) that are administered alone or in combination with other agents. Newer and more innovative approaches redirecting T cells or natural killer cells to kill HIV-1 infected cells have also shown promising results. Finally, multiple ongoing trials focus on combining bNAbs with other immune-directed therapies to enhance both innate and adaptive immunity. SUMMARY: While immunotherapies as an alternative to conventional ART have generally proven to be well tolerated, these therapeutic approaches have largely been unsuccessful in inducing ART-free control of HIV-1. However, promising results from recent trials involving bNAbs that have reported durable HIV-1 control among a subset of participants, provide reason for cautious optimism that we with further optimization of these treatment strategies may be able to achieve functional cure for HIV-1.
Assuntos
Infecções por HIV , HIV-1 , Imunoterapia , Humanos , Infecções por HIV/imunologia , Infecções por HIV/terapia , HIV-1/imunologia , Imunoterapia/métodos , Anticorpos Anti-HIV/imunologia , Anticorpos Anti-HIV/uso terapêutico , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/uso terapêuticoRESUMO
Background: Our previous work has demonstrated the benefits of transcutaneous immunization in targeting Langerhans cells and preferentially inducing CD8 T-cell responses. Methods: In this randomized phase Ib clinical trial including 20 HIV uninfected volunteers, we compared the safety and immunogenicity of the MVA recombinant vaccine expressing HIV-B antigen (MVA-B) by transcutaneous and intramuscular routes. We hypothesized that the quality of innate and adaptive immunity differs according to the route of immunization and explored the quality of the vector vaccine-induced immune responses. We also investigated the early blood transcriptome and serum cytokine levels to identify innate events correlated with the strength and quality of adaptive immunity. Results: We demonstrate that MVA-B vaccine is safe by both routes, but that the quality and intensity of both innate and adaptive immunity differ significantly. Transcutaneous vaccination promoted CD8 responses in the absence of antibodies and slightly affected gene expression, involving mainly genes associated with metabolic pathways. Intramuscular vaccination, on the other hand, drove robust changes in the expression of genes involved in IL-6 and interferon signalling pathways, mainly those associated with humoral responses, and also some levels of CD8 response. Conclusion: Thus, vaccine delivery route perturbs early innate responses that shape the quality of adaptive immunity. Clinical Trial Registration: http://ClinicalTrials.gov, identifier PER-073-13.
Assuntos
Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/imunologia , Vacinas contra a AIDS/efeitos adversos , Administração Cutânea , Anticorpos Antivirais/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1 , Humanos , Imunidade Celular/imunologia , Injeções Intramusculares , Vacinação/métodos , Vacinas de DNA , Vacinas Sintéticas/imunologia , Vacinas Virais/efeitos adversosRESUMO
The envelope glycoprotein (Env) of the human immunodeficiency virus (HIV), has been the primary target for the development of a protective vaccine against infection. The extensive N-linked glycosylation on Env is an important consideration as it may affect efficacy, stability, and expression yields. The expression host has been shown to influence the extent and type of glycosylation that decorates the protein target. Here, we report the glycosylation profile of the candidate subtype C immunogen CO6980v0c22 gp145, which is currently in Phase I clinical trials, produced in two different host cells: CHO-K1 and Expi293F. The amino acid sequence for both glycoproteins was confirmed to be identical by peptide mass fingerprinting. However, the isoelectric point of the proteins differed; 4.5-5.5 and 6.0-7.0 for gp145 produced in CHO-K1 and Expi293F, respectively. These differences in pI were eliminated by enzymatic treatment with sialidase, indicating a large difference in the incorporation of sialic acid between hosts. This dramatic difference in the number of sialylated glycans between hosts was confirmed by analysis of PNGase F-released glycans using MALDI-ToF MS. These differences in glycosylation, however, did not greatly translate into differences in antibody recognition. Biosensor assays showed that gp145 produced in CHO-K1 had similar affinity toward the broadly neutralizing antibodies, 2G12 and PG16, as the gp145 produced in Expi293F. Additionally, both immunogens showed the same reactivity against plasma of HIV-infected patients. Taken together, these results support the notion that there are sizeable differences in the glycosylation of Env depending on the expression host. How these differences translate to vaccine efficacy remains unknown.
Assuntos
Glicopeptídeos/análise , Anticorpos Anti-HIV/imunologia , HIV-1/metabolismo , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Adulto , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Reações Antígeno-Anticorpo , Células CHO , Cricetinae , Cricetulus , Feminino , Glicosilação , Células HEK293 , Humanos , Pessoa de Meia-Idade , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Adulto Jovem , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismoRESUMO
Antibodies against the HIV-1 2F5 epitope are known as one of the most powerful and broadly protective anti-HIV antibodies. Therefore, vaccine strategies that include the 2F5 epitope in their formulation require a robust method to detect specific anti-2F5 antibody production by B cells. Towards this goal, we have biotinylated a previously reported computer-designed protein carrying the HIV-1 2F5 epitope aiming the further development of a platform to detect human B-cells expressing anti-2F5 antibodies through flow cytometry. Biophysical and immunological properties of our devised protein were characterized by computer simulation and experimental methods. Biotinylation did not affect folding and improved protein stability and solubility. The biotinylated protein exhibited similar binding affinity trends compared to its unbiotinylated counterpart and was recognized by anti-HIV-1 2F5 antibodies expressed on the surface of patient-derived peripheral blood mononuclear cells. Moreover, we present a high affinity marker for the identification of epitope-specific B cells that can be used to measure the efficacy of vaccine strategies based on the HIV-1 envelope protein.
Assuntos
Vacinas contra a AIDS/imunologia , Linfócitos B/metabolismo , Biotinilação , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Leucócitos Mononucleares/metabolismo , Simulação de Dinâmica Molecular , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Simulação por Computador , Epitopos/imunologia , HumanosRESUMO
As the HIV/AIDS pandemic still progresses, understanding the mechanisms governing viral transmission as well as protection from HIV acquisition is fundamental. In this context, cohorts of HIV serodiscordant heterosexual couples (SDC) represent a unique tool. The present study was aimed to evaluate specific parameters of innate, cellular and humoral immune responses in SDC. Specifically, plasma levels of cytokines and chemokines, HIV-specific T-cell responses, gp120-specific IgG and IgA antibodies, and HIV-specific antibody-dependent cellular cytotoxicity (ADCC) activity were assessed in nine HIV-exposed seronegative individuals (ESN) and their corresponding HIV seropositive partners (HIV+-P), in eighteen chronically infected HIV subjects (C), nine chronically infected subjects known to be HIV transmitters (CT) and ten healthy HIV- donors (HD). Very low magnitude HIV-specific cellular responses were found in two out of six ESN. Interestingly, HIV+-P had the highest ADCC magnitude, the lowest IgA levels and the highest IgG/IgA ratio, all compared to CT. Positive correlations between CD4+ T-cell counts and both IgG/IgA ratios and %ADCC killing uniquely distinguished HIV+-P. Additionally, evidence of IgA interference with ADCC responses from HIV+-P and CT is provided. These data suggest for the first time a potential role of ADCC and/or gp120-specific IgG/IgA balance in modulating heterosexual transmission. In sum, this study provides key information to understand the host factors that influence viral transmission, which should be considered in both the development of prophylactic vaccines and novel immunotherapies for HIV-1 infection.
Assuntos
Proteína gp120 do Envelope de HIV/sangue , Infecções por HIV/imunologia , HIV/imunologia , Imunidade Celular , Imunidade Humoral , Adulto , Idoso , Feminino , HIV/patogenicidade , Anticorpos Anti-HIV/sangue , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/transmissão , Infecções por HIV/virologia , Heterossexualidade , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Parceiros Sexuais , Linfócitos T/imunologiaRESUMO
BACKGROUND: Dual point-of-care tests for antibodies to human immunodeficiency virus (HIV) and Treponema pallidum allow for same-day testing and treatment and have been demonstrated to be cost-effective in preventing the adverse outcomes of HIV infection and syphilis. By recording and transmitting data as they are collected, electronic readers address challenges related to the decentralization of point-of-care testing. METHODS: We evaluated a smartphone-based electronic reader using 201 sera tested with 2 dual rapid tests for detection of antibodies to HIV and T. pallidum in Los Angeles, USA, and Lima, Peru. Tests were read both visually and with the electronic reader. Enzyme immunoassay followed by Western blot and T. pallidum particle agglutination were the reference tests for HIV and T. pallidum, respectively. RESULTS: The sensitivities of the 2 rapid tests for detection of HIV were 94.1% and 97.0% for electronic readings. Both tests had a specificity of 100% for detection of HIV by electronic reading. The sensitivities of the 2 rapid tests for detection of T. pallidum were 86.5% and 92.4% for electronic readings. The specificities for detection of T. pallidum were 99.1% and 99.0% by electronic reading. There were no significant differences between the accuracies of visual and electronic readings, and the performance did not differ between the 2 study sites. CONCLUSIONS: Our results show the electronic reader to be a promising option for increasing the use of point-of-care testing programs.
Assuntos
Anticorpos Anti-HIV/análise , Infecções por HIV/imunologia , Técnicas Imunoenzimáticas/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito , Smartphone , Sífilis/imunologia , Treponema pallidum/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/diagnóstico , Infecções por HIV/economia , Infecções por HIV/virologia , Humanos , Técnicas Imunoenzimáticas/economia , Técnicas Imunoenzimáticas/normas , Los Angeles/epidemiologia , Peru/epidemiologia , Sistemas Automatizados de Assistência Junto ao Leito/economia , Sistemas Automatizados de Assistência Junto ao Leito/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Smartphone/instrumentação , Sífilis/diagnóstico , Sífilis/economia , Sífilis/microbiologiaRESUMO
Various HIV-1 env genetic and biochemical features impact the elicitation of cross-reactive neutralizing antibodies in natural infections. Thus, we aimed to investigate cross-neutralizing antibodies in individuals infected with HIV-1 env subtypes B, F1, C or the B/Bbr variant as well as env characteristics. Therefore, plasma samples from Brazilian chronically HIV-1 infected individuals were submitted to the TZM-bl neutralization assay. We also analyzed putative N-glycosylation sites (PNGLs) and the size of gp120 variable domains in the context of HIV-1 subtypes prevalent in Brazil. We observed a greater breadth and potency of the anti-Env neutralizing response in individuals infected with the F1 or B HIV-1 subtypes compared with the C subtype and the variant B/Bbr. We observed greater V1 B/Bbr and smaller V4 F1 than those of other subtypes (p<0.005), however neither was there a correlation verified between the variable region length and neutralization potency, nor between PNLG and HIV-1 subtypes. The enrichment of W at top of V3 loop in weak neutralizing response viruses and the P in viruses with higher neutralization susceptibility was statistically significant (p = 0.013). Some other signatures sites were associated to HIV-1 subtype-specific F1 and B/Bbr samples might influence in the distinct neutralizing response. These results indicate that a single amino acid substitution may lead to a distinct conformational exposure or load in the association domain of the trimer of gp120 and interfere with the induction power of the neutralizing response, which affects the sensitivity of the neutralizing antibody and has significant implications for vaccine design.
Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/genética , HIV-1/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Brasil/epidemiologia , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , Humanos , FilogeniaRESUMO
Computational methods have traditionally struggled to predict the effect of mutations in antibody-antigen complexes on binding affinity. This has limited their usefulness during antibody engineering and development, and their ability to predict biologically relevant escape mutations. Here we present mCSM-AB, a user-friendly web server for accurately predicting antibody-antigen affinity changes upon mutation which relies on graph-based signatures. We show that mCSM-AB performs better than comparable methods that have been previously used for antibody engineering. mCSM-AB web server is available at http://structure.bioc.cam.ac.uk/mcsm_ab.
Assuntos
Anticorpos/genética , Anticorpos/imunologia , Afinidade de Anticorpos/genética , Antígenos/imunologia , Internet , Mutação , Software , Anticorpos/química , Afinidade de Anticorpos/imunologia , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/genética , Complexo Antígeno-Anticorpo/imunologia , Antígenos/química , Antígenos/genética , Benchmarking , Conjuntos de Dados como Assunto , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/genética , Anticorpos Anti-HIV/imunologia , Engenharia de Proteínas , Vacinas/química , Vacinas/genética , Vacinas/imunologiaRESUMO
UNLABELLED: Elucidating the factors that modulate HIV-specific antibody-dependent cellular cytotoxicity (ADCC) will help in understanding its role in HIV immunity. The aim of this study was to determine whether IgA could modify the magnitude of ADCC in HIV infection, abrogating its protective role. Plasma samples from 20 HIV-positive (HIV(+)) subjects enrolled during primary HIV infection (PHI), 10 chronically infected subjects (chronic), and 7 elite controllers (EC) were used. ADCC was determined by using a fluorometric ADCC assay, before and after removal of plasma IgA. Data were analyzed by using nonparametric statistics. ADCC was documented in 80% of PHI enrollment samples and in 100% of PHI 12-month, chronic, and EC samples; it peaked after acute infection, reached a plateau in chronic infection, and decreased after initiation of antiretroviral treatment (ART). Significant associations between ADCC and disease progression were found only after removal of plasma IgA from 12-month PHI samples: the magnitude of ADCC not only increased after IgA removal but also correlated with CD4(+) T-cell preservation. This work provides evidence that gp120-specific IgA was capable of modifying ADCC responses during natural HIV infection for the first time and adds to similar evidence provided in other settings. Furthermore, it underscores the complexity of the ADCC phenomenon and will help in an understanding of its underlying mechanisms. IMPORTANCE: Although the induction of ADCC-mediating antibodies in HIV-infected subjects has been extensively documented, the association of these antibodies with protection from disease progression is poorly understood. Here, we demonstrate that plasma IgA is a factor capable of modifying the magnitude of IgG-mediated ADCC in HIV infection, mitigating its beneficial effect. These results help in understanding why previous studies failed to demonstrate correlations between ADCC and disease progression, and they also contribute to the notion that an HIV vaccine should stimulate the production of ADCC-mediating IgG antibodies but not IgA.
Assuntos
Citotoxicidade Celular Dependente de Anticorpos , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Imunoglobulina A/imunologia , Viremia/imunologia , Adulto , Idoso , Fluorometria , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
We assessed the laboratory performance of the Chembio dual-path platform HIV-syphilis rapid immunodiagnostic test and electronic reader for detection of HIV and Treponema pallidum antibodies in 450 previously characterized serum specimens. For visual or electronic reader HIV antibody detection, the sensitivity was 100% and the specificity was 98.7%. For visual T. pallidum antibody detection, the test sensitivity was 94.7% and the specificity was 100.0%; with the electronic reader, the sensitivity was 94.7% and the specificity was 99.7%.