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1.
PLoS One ; 14(8): e0219142, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31393868

RESUMO

BACKGROUND: Additional forms of pre-exposure prophylaxis are needed to prevent HIV-1 infection. 3BNC117 and 10-1074 are broadly neutralizing anti-HIV-1 antibodies that target non-overlapping epitopes on the HIV-1 envelope. We investigated the safety, tolerability, pharmacokinetics, and immunogenicity of the intravenous administration of the combination of 3BNC117 and 10-1074 in healthy adults. METHODS: This randomized, double-blind, placebo-controlled, single center, phase 1 study enrolled healthy adults aged 18-65 years to receive one infusion of 3BNC117 immediately followed by 10-1074 at 10 mg/kg, three infusions of 3BNC117 followed by 10-1074 at 3 mg/kg or 10 mg/kg every 8 weeks, or placebo infusions. The primary outcomes were safety and pharmacokinetics. This trial is registered with ClinicalTrials.gov, number NCT02824536. FINDINGS: Twenty-four participants were enrolled in a 3:1 ratio to receive the study products or placebo. The combination of 3BNC117 and 10-1074 was safe and generally well tolerated. There were no serious adverse events considered related to the infusions. The mean elimination half-lives of 3BNC117 and 10-1074 were 16.4 ± 4.6 days and 23.0 ± 5.4 days, respectively, similar to what was observed in previous studies in which each antibody was administered alone. Anti-drug antibody responses were rare and without evidence of related adverse events or impact on elimination kinetics. INTERPRETATION: Single and repeated doses of the combination of 3BNC117 and 10-1074 were well tolerated in healthy adults. These data support the further development of the combination of 3BNC117 and 10-1074 as a long-acting injectable form of pre-exposure prophylaxis for the prevention of HIV-1 infection.

2.
J Pharm Sci ; 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31348937

RESUMO

The broadly neutralizing anti-HIV antibody, 10-1074, is a highly somatically hypermutated IgG1 being developed for prophylaxis in sub-Saharan Africa. A series of algorithms were applied to identify potentially destabilizing residues in the framework of the Fv region. Of 17 residues defined, a variant was identified encompassing 1 light and 3 heavy chain residues, with significantly increased conformational stability while maintaining full neutralization activity. Central to the stabilization was the replacement of the heavy chain residue T108 with R108 at the base of the CDR3 loop which allowed for the formation of a nascent salt bridge with heavy chain residue D137. Three additional mutations were necessary to confer increased conformational stability as evidenced by differential scanning fluorimetry and isothermal chemical unfolding. In addition, we observed increased stability during low pH incubation in which 40% of the parental monomer aggregated while the combinatorial variant showed no increase in aggregation. Incubation of the variant at 100 mg/mL for 6 weeks at 40°C showed a 9-fold decrease in subvisible particles ≥2 µm relative to the parental molecule. Stability-based designs have also translated to improved pharmacokinetics. Together, these data show that increasing conformational stability of the Fab can have profound effects on the manufacturability and long-term stability of a monoclonal antibody.

3.
J Virol ; 93(7)2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30700599

RESUMO

The humoral response to invading mucosal pathogens comprises multiple antibody isotypes derived from systemic and mucosal compartments. To understand the contribution of each antibody isotype/source to the mucosal humoral response, parallel investigation of the specificities and functions of antibodies within and across isotypes and compartments is required. The role of IgA against HIV-1 is complex, with studies supporting a protective role as well as a role for serum IgA in blocking effector functions. Thus, we explored the fine specificity and function of IgA in both plasma and mucosal secretions important to infant HIV-1 infection, i.e., breast milk. IgA and IgG were isolated from milk and plasma from 20 HIV-1-infected lactating Malawian women. HIV-1 binding specificities, neutralization potency, inhibition of virus-epithelial cell binding, and antibody-mediated phagocytosis were measured. Fine-specificity mapping showed IgA and IgG responses to multiple HIV-1 Env epitopes, including conformational V1/V2 and linear V2, V3, and constant region 5 (C5). Env IgA was heterogeneous between the milk and systemic compartments (Env IgA, τ = 0.00 to 0.63, P = 0.0046 to 1.00). Furthermore, IgA and IgG appeared compartmentalized as there was a lack of correlation between the specificities of Env-specific IgA and IgG (in milk, τ = -0.07 to 0.26, P = 0.35 to 0.83). IgA and IgG also differed in functions: while neutralization and phagocytosis were consistently mediated by milk and plasma IgG, they were rarely detected in IgA from both milk and plasma. Understanding the ontogeny of the divergent IgG and IgA antigen specificity repertoires and their effects on antibody function will inform vaccination approaches targeted toward mucosal pathogens.IMPORTANCE Antibodies within the mucosa are part of the first line of defense against mucosal pathogens. Evaluating mucosal antibody isotypes, specificities, and antiviral functions in relationship to the systemic antibody profile can provide insights into whether the antibody response is coordinated in response to mucosal pathogens. In a natural immunity cohort of HIV-infected lactating women, we mapped the fine specificity and function of IgA in breast milk and plasma and compared these with the autologous IgG responses. Antigen specificities and functions differed between IgG and IgA, with antiviral functions (neutralization and phagocytosis) predominantly mediated by the IgG fraction in both milk and plasma. Furthermore, the specificity of milk IgA differed from that of systemic IgA. Our data suggest that milk IgA and systemic IgA should be separately examined as potential correlates of risk. Preventive vaccines may need to employ different strategies to elicit functional antiviral immunity by both antibody isotypes in the mucosa.

4.
J Virol ; 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30429340

RESUMO

As part of the continuing effort to develop an effective HIV vaccine, we generated a poxviral vaccine vector (previously described) designed to improve on the results of the RV144 Phase III clinical trial. The construct, NYVAC-KC, is a replication-competent, attenuated recombinant of the vaccinia virus strain, NYVAC. NYVAC is a vector that has been used in many previous clinical studies but is replication deficient. Here we report a side-by-side comparison of replication-restricted NYVAC and replication-competent NYVAC-KC in a non-human primate study, which utilized a prime-boost regimen similar to that of RV144. NYVAC-C and NYVAC-C-KC express the HIV-1 antigens gp140 and Gag/Gag-Pol-Nef-derived VLPs from clade C and were used as the prime, with recombinant virus plus envelope protein as the boost. In nearly every T and B cell immune assay against HIV-1, including neutralization and antibody binding, NYVAC-C-KC induced a greater immune response than did NYVAC-C, indicating that replication competence in a poxvirus may improve upon the modestly successful regimen used in the RV144 clinical trial.ImportanceThough the RV144 Phase III clinical trial showed promise that an effective vaccine against HIV-1 is possible, a successful vaccine will require improvement over the vaccine candidate (ALVAC) used in the RV144 study. With that goal in mind, we have tested in non-human primates an attenuated, but replication-competent vector, NYVAC-KC, in direct comparison to its parental vector, NYVAC, which is replication-restricted in human cells, similar to the ALVAC vector used in RV144. We have utilized a prime-boost regimen for administration of the vaccine candidate that is similar to the one used in the RV144 study. The results of this study indicate that a replication-competent poxvirus vector may improve upon the effectiveness of the RV144 clinical trial vaccine candidate.

5.
J Virol ; 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30429343

RESUMO

The use of heterologous immunization regimens and improved vector systems has led to increases in immunogenicity of HIV-1 vaccine candidates in non-human primates. In order to resolve interrelations between different delivery modalities, three different poxvirus boost regimens were compared. Three groups of rhesus macaques were each primed with the same DNA vaccine encoding for Gag, PolNef, and gp140. The groups were then boosted either with the vaccinia virus strain NYVAC or a variant with improved replication competence in human cells termed NYVAC-KC. The latter was either administered by scarification or intramuscularly. Finally, macaques were boosted with adjuvanted gp120 protein to enhance humoral responses. The regimen elicited very potent CD4+ and CD8+ T cell responses in a well-balanced manner, peaking two weeks after the boost. T cells were broadly reactive and polyfunctional. All animals exhibited antigen-specific humoral responses already after the poxvirus boost that further increased following protein administration. Polyclonal reactivity of IgG antibodies was highest against HIV-1 clade C Env-proteins with considerable cross-reactivity to other clades. Substantial effector functional activities (ADCC and ADCVI) were observed in sera obtained after the last protein boost. Notably, major differences between the groups were absent, indicating that the potent priming induced by the DNA vaccine initially framed the immune responses in such a way that the subsequent boosts with NYVAC and protein only led to an increase in the response magnitudes without skewing the quality. This study highlights the importance of selecting the best combination of vector systems in heterologous prime-boost vaccination regimens.ImportanceThe evaluation of HIV vaccine efficacy trials indicates that protection would most likely correlate with a polyfunctional immune response involving several effector functions from all arms of the immune system. Heterologous prime-boost regimens have been shown to elicit vigorous T cell and antibody responses in non-human primates that, however, qualitatively and quantitatively differ depending on the respective vector systems used. The present study evaluated a DNA prime, poxvirus and protein boost regimen, and compared how two poxvirus vectors with varying degrees of replication capacity and two different delivery modalities - conventional intramuscular delivery and percutaneous delivery by scarification - impact several immune effectors. It was found that despite the different poxvirus boosts, the overall immune responses in the three groups were similar, suggesting the potent DNA priming as the major determining factor of immune responses. These findings emphasize the importance of selecting optimal priming agents in heterologous prime-boost vaccination settings.

6.
Nat Med ; 24(11): 1701-1707, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30258217

RESUMO

Monotherapy of HIV-1 infection with single antiretroviral agents is ineffective because error-prone HIV-1 replication leads to the production of drug-resistant viral variants1,2. Combinations of drugs can establish long-term control, however, antiretroviral therapy (ART) requires daily dosing, can cause side effects and does not eradicate the infection3,4. Although anti-HIV-1 antibodies constitute a potential alternative to ART5,6, treatment of viremic individuals with a single antibody also results in emergence of resistant viral variants7-9. Moreover, combinations of first-generation anti-HIV-1 broadly neutralizing antibodies (bNAbs) had little measurable effect on the infection10-12. Here we report on a phase 1b clinical trial ( NCT02825797 ) in which two potent bNAbs, 3BNC11713 and 10-107414, were administered in combination to seven HIV-1 viremic individuals. Infusions of 30 mg kg-1 of each of the antibodies were well-tolerated. In the four individuals with dual antibody-sensitive viruses, immunotherapy resulted in an average reduction in HIV-1 viral load of 2.05 log10 copies per ml that remained significantly reduced for three months following the first of up to three infusions. In addition, none of these individuals developed resistance to both antibodies. Larger studies will be necessary to confirm the efficacy of antibody combinations in reducing HIV-1 viremia and limiting the emergence of resistant viral variants.

7.
J Virol ; 92(8)2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29437967

RESUMO

A preventive human immunodeficiency virus type 1 (HIV-1) vaccine is an essential part of the strategy to eradicate AIDS. A critical question is whether antibodies that do not neutralize primary isolate (tier 2) HIV-1 strains can protect from infection. In this study, we investigated the ability of an attenuated poxvirus vector (NYVAC) prime-envelope gp120 boost to elicit potentially protective antibody responses in a rhesus macaque model of mucosal simian-human immunodeficiency virus (SHIV) infection. NYVAC vector delivery of a group M consensus envelope, trivalent mosaic envelopes, or a natural clade B isolate B.1059 envelope elicited antibodies that mediated neutralization of tier 1 viruses, cellular cytotoxicity, and phagocytosis. None of the macaques made neutralizing antibodies against the tier 2 SHIV SF162P3 used for mucosal challenge. Significant protection from infection was not observed for the three groups of vaccinated macaques compared to unvaccinated macaques, although binding antibody to HIV-1 Env correlated with decreased viremia after challenge. Thus, NYVAC Env prime-gp120 boost vaccination elicited polyfunctional, nonneutralizing antibody responses with minimal protective activity against tier 2 SHIV mucosal challenge.IMPORTANCE The antibody responses that confer protection against HIV-1 infection remain unknown. Polyfunctional antibody responses correlated with time to infection in previous macaque studies. Determining the ability of vaccines to induce these types of responses is critical for understanding how to improve upon the one efficacious human HIV-1 vaccine trial completed thus far. We characterized the antibody responses induced by a NYVAC-protein vaccine and determined the protective capacity of polyfunctional antibody responses in an R5, tier 2 mucosal SHIV infection model.


Assuntos
Vacinas contra a AIDS/imunologia , HIV-1/imunologia , Imunização Secundária , Imunogenicidade da Vacina , Vírus da Imunodeficiência Símia/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Animais , Humanos , Macaca mulatta
8.
J Virol ; 92(8)2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29386288

RESUMO

Induction of broadly cross-reactive antiviral humoral responses with the capacity to target globally diverse circulating strains is a key goal for HIV-1 immunogen design. A major gap in the field is the identification of diverse HIV-1 envelope antigens to evaluate vaccine regimens for binding antibody breadth. In this study, we define unique antigen panels to map HIV-1 vaccine-elicited antibody breadth and durability. Diverse HIV-1 envelope glycoproteins were selected based on genetic and geographic diversity to cover the global epidemic, with a focus on sexually acquired transmitted/founder viruses with a tier 2 neutralization phenotype. Unique antigenicity was determined by nonredundancy (Spearman correlation), and antigens were clustered using partitioning around medoids (PAM) to identify antigen diversity. Cross-validation demonstrated that the PAM method was better than selection by reactivity and random selection. Analysis of vaccine-elicited V1V2 binding antibody in longitudinal samples from the RV144 clinical trial revealed the striking heterogeneity among individual vaccinees in maintaining durable responses. These data support the idea that a major goal for vaccine development is to improve antibody levels, breadth, and durability at the population level. Elucidating the level and durability of vaccine-elicited binding antibody breadth needed for protection is critical for the development of a globally efficacious HIV vaccine.IMPORTANCE The path toward an efficacious HIV-1 vaccine will require characterization of vaccine-induced immunity that can recognize and target the highly genetically diverse virus envelope glycoproteins. Antibodies that target the envelope glycoproteins, including diverse sequences within the first and second hypervariable regions (V1V2) of gp120, were identified as correlates of risk for the one partially efficacious HIV-1 vaccine. To build upon this discovery, we experimentally and computationally evaluated humoral responses to define envelope glycoproteins representative of the antigenic diversity of HIV globally. These diverse envelope antigens distinguished binding antibody breadth and durability among vaccine candidates, thus providing insights for advancing the most promising HIV-1 vaccine candidates.


Assuntos
Vacinas contra a AIDS/imunologia , Variação Genética/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Vacinas contra a AIDS/genética , Animais , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/genética , HIV-1/genética , Humanos , Macaca mulatta
9.
JCI Insight ; 2(24)2017 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-29263306

RESUMO

Accurate HIV-1 incidence estimation is critical to the success of HIV-1 prevention strategies. Current assays are limited by high false recent rates (FRRs) in certain populations and a short mean duration of recent infection (MDRI). Dynamic early HIV-1 antibody response kinetics were harnessed to identify biomarkers for improved incidence assays. We conducted retrospective analyses on circulating antibodies from known recent and longstanding infections and evaluated binding and avidity measurements of Env and non-Env antigens and multiple antibody forms (i.e., IgG, IgA, IgG3, IgG4, dIgA, and IgM) in a diverse panel of 164 HIV-1-infected participants (clades A, B, C). Discriminant function analysis identified an optimal set of measurements that were subsequently evaluated in a 324-specimen blinded biomarker validation panel. These biomarkers included clade C gp140 IgG3, transmitted/founder clade C gp140 IgG4 avidity, clade B gp140 IgG4 avidity, and gp41 immunodominant region IgG avidity. MDRI was estimated at 215 day or alternatively, 267 days. FRRs in untreated and treated subjects were 5.0% and 3.6%, respectively. Thus, computational analysis of dynamic HIV-1 antibody isotype and antigen interactions during infection enabled design of a promising HIV-1 recency assay for improved cross-sectional incidence estimation.

10.
J Virol ; 91(24)2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29021394

RESUMO

An important goal of human immunodeficiency virus (HIV) vaccine design is identification of strategies that elicit effective antiviral humoral immunity. One novel approach comprises priming with DNA and boosting with modified vaccinia virus Ankara (MVA) expressing HIV-1 Env on virus-like particles. In this study, we evaluated whether the addition of a gp120 protein in alum or MVA-expressed secreted gp140 (MVAgp140) could improve immunogenicity of a DNA prime-MVA boost vaccine. Five rhesus macaques per group received two DNA primes at weeks 0 and 8 followed by three MVA boosts (with or without additional protein or MVAgp140) at weeks 18, 26, and 40. Both boost immunogens enhanced the breadth of HIV-1 gp120 and V1V2 responses, antibody-dependent cellular cytotoxicity (ADCC), and low-titer tier 1B and tier 2 neutralizing antibody responses. However, there were differences in antibody kinetics, linear epitope specificity, and CD4 T cell responses between the groups. The gp120 protein boost elicited earlier and higher peak responses, whereas the MVAgp140 boost resulted in improved antibody durability and comparable peak responses after the final immunization. Linear V3 specific IgG responses were particularly enhanced by the gp120 boost, whereas the MVAgp140 boost also enhanced responses to linear C5 and C2.2 epitopes. Interestingly, gp120, but not the MVAgp140 boost, increased peak CD4+ T cell responses. Thus, both gp120 and MVAgp140 can augment potential protection of a DNA/MVA vaccine by enhancing gp120 and V1/V2 antibody responses, whereas potential protection by gp120, but not MVAgp140 boosts, may be further impacted by increased CD4+ T cell responses.IMPORTANCE Prior immune correlate analyses with humans and nonhuman primates revealed the importance of antibody responses in preventing HIV-1 infection. A DNA prime-modified vaccinia virus Ankara (MVA) boost vaccine has proven to be potent in eliciting antibody responses. Here we explore the ability of boosts with recombinant gp120 protein or MVA-expressed gp140 to enhance antibody responses elicited by the GOVX-B11 DNA prime-MVA boost vaccine. We found that both types of immunogen boosts enhanced potentially protective antibody responses, whereas the gp120 protein boosts also increased CD4+ T cell responses. Our data provide important information for HIV vaccine designs that aim for effective and balanced humoral and T cell responses.


Assuntos
Vacinas contra a AIDS/imunologia , Glicoproteínas/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Imunização Secundária , Imunogenicidade da Vacina , Vacinas de DNA/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Citotoxicidade Celular Dependente de Anticorpos , Linfócitos T CD4-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Glicoproteínas/genética , Anticorpos Anti-HIV/sangue , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1/química , HIV-1/imunologia , Imunoglobulina G/sangue , Macaca mulatta , Vacinas de DNA/genética , Vírus Vaccinia/crescimento & desenvolvimento , Vírus Vaccinia/imunologia
11.
J Virol ; 91(19)2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28490585

RESUMO

Evaluation of the epitope specificities, locations (systemic or mucosal), and effector functions of antibodies elicited by novel HIV-1 immunogens engineered to improve exposure of specific epitopes is critical for HIV-1 vaccine development. Utilizing an array of humoral assays, we evaluated the magnitudes, epitope specificities, avidities, and functions of systemic and mucosal immune responses elicited by a vaccine regimen containing Env cross-linked to a CD4-mimetic miniprotein (gp140-M64U1) in rhesus macaques. Cross-linking of gp140 Env to M64U1 resulted in earlier increases of both the magnitude and avidity of the IgG binding response than those with Env protein alone. Notably, IgG binding responses at an early time point correlated with antibody-dependent cellular cytotoxicity (ADCC) function at the peak immunity time point, which was higher for the cross-linked Env group than for the Env group. In addition, the cross-linked Env group developed higher IgG responses against a linear epitope in the gp120 C1 region of the HIV-1 envelope glycoprotein. These data demonstrate that structural modification of the HIV-1 envelope immunogen by cross-linking of gp140 with the CD4-mimetic M64U1 elicited an earlier increase of binding antibody responses and altered the specificity of the IgG responses, correlating with the rise of subsequent antibody-mediated antiviral functions.IMPORTANCE The development of an efficacious HIV-1 vaccine remains a global priority to prevent new cases of HIV-1 infection. Of the six HIV-1 efficacy trials to date, only one has demonstrated partial efficacy, and immune correlate analysis of that trial revealed a role for binding antibodies and antibody Fc-mediated effector functions. New HIV-1 envelope immunogens are being engineered to selectively expose the most vulnerable and conserved sites on the HIV-1 envelope, with the goal of eliciting antiviral antibodies. Evaluation of the humoral responses elicited by these novel immunogen designs in nonhuman primates is critical for understanding how to improve upon immunogen design to inform further testing in human clinical trials. Our results demonstrate that structural modifications of Env that aim to mimic the CD4-bound conformation can result in earlier antibody elicitation, altered epitope specificity, and increased antiviral function postimmunization.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Antígenos CD4/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Macaca mulatta/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Animais , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antígenos CD4/genética , Linfócitos T CD4-Positivos/imunologia , Epitopos/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Vacinação , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética
12.
J Virol ; 91(9)2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28179536

RESUMO

The nonreplicating attenuated poxvirus vector NYVAC expressing clade C(CN54) HIV-1 Env(gp120) and Gag-Pol-Nef antigens (NYVAC-C) showed limited immunogenicity in phase I clinical trials. To enhance the capacity of the NYVAC vector to trigger broad humoral responses and a more balanced activation of CD4+ and CD8+ T cells, here we compared the HIV-1-specific immunogenicity elicited in nonhuman primates immunized with two replicating NYVAC vectors that have been modified by the insertion of the K1L and C7L vaccinia virus host range genes and express the clade C(ZM96) trimeric HIV-1 gp140 protein or a Gag(ZM96)-Pol-Nef(CN54) polyprotein as Gag-derived virus-like particles (termed NYVAC-C-KC). Additionally, one NYVAC-C-KC vector was generated by deleting the viral gene B19R, an inhibitor of the type I interferon response (NYVAC-C-KC-ΔB19R). An immunization protocol mimicking that of the RV144 phase III clinical trial was used. Two groups of macaques received two doses of the corresponding NYVAC-C-KC vectors (weeks 0 and 4) and booster doses with NYVAC-C-KC vectors plus the clade C HIV-1 gp120 protein (weeks 12 and 24). The two replicating NYVAC-C-KC vectors induced enhanced and similar HIV-1-specific CD4+ and CD8+ T cell responses, similar levels of binding IgG antibodies, low levels of IgA antibodies, and high levels of antibody-dependent cellular cytotoxicity responses and HIV-1-neutralizing antibodies. Small differences within the NYVAC-C-KC-ΔB19R group were seen in the magnitude of CD4+ and CD8+ T cells, the induction of some cytokines, and the neutralization of some HIV-1 isolates. Thus, replication-competent NYVAC-C-KC vectors acquired relevant immunological properties as vaccine candidates against HIV/AIDS, and the viral B19 molecule exerts some control of immune functions.IMPORTANCE It is of special importance to find a safe and effective HIV/AIDS vaccine that can induce strong and broad T cell and humoral immune responses correlating with HIV-1 protection. Here we developed novel replicating poxvirus NYVAC-based HIV/AIDS vaccine candidates expressing clade C HIV-1 antigens, with one of them lacking the vaccinia virus B19 protein, an inhibitor of the type I interferon response. Immunization of nonhuman primates with these novel NYVAC-C-KC vectors and the protein component gp120 elicited high levels of T cell and humoral immune responses, with the vector containing a deletion in B19R inducing a trend toward a higher magnitude of CD4+ and CD8+ T cell responses and neutralization of some HIV-1 strains. These poxvirus vectors could be considered HIV/AIDS vaccine candidates based on their activation of potential immune correlates of protection.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/sangue , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Anticorpos Anti-HIV/sangue , Proteína gp120 do Envelope de HIV/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo , Vacinas contra a AIDS/genética , Animais , Anticorpos Neutralizantes/imunologia , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Anticorpos Anti-HIV/imunologia , Antígenos HIV/imunologia , Infecções por HIV/prevenção & controle , Interferon Tipo I/genética , Macaca mulatta , Masculino , Receptores de Interferon/genética , Receptores de Interferon/imunologia , Vacinação , Vírus Vaccinia/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética
13.
J Virol ; 91(9)2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28202751

RESUMO

We compared the HIV-1-specific immune responses generated by targeting HIV-1 envelope protein (Env gp140) to either CD40 or LOX-1, two endocytic receptors on dendritic cells (DCs), in rhesus macaques primed with a poxvirus vector (NYVAC-KC) expressing Env gp140. The DC-targeting vaccines, humanized recombinant monoclonal antibodies fused to Env gp140, were administered as a boost with poly-ICLC adjuvant either alone or coadministered with the NYVAC-KC vector. All the DC-targeting vaccine administrations with poly-ICLC increased the low-level serum anti-Env IgG responses elicited by NYVAC-KC priming significantly more (up to a P value of 0.01) than in a group without poly-ICLC. The responses were robust and cross-reactive and contained antibodies specific to multiple epitopes within gp140, including the C1, C2, V1, V2, and V3, C4, C5, and gp41 immunodominant regions. The DC-targeting vaccines also elicited modest serum Env-specific IgA responses. All groups gave serum neutralization activity limited to tier 1 viruses and antibody-dependent cytotoxicity responses (ADCC) after DC-targeting boosts. Furthermore, CD4+ and CD8+ T cell responses specific to multiple Env epitopes were strongly boosted by the DC-targeting vaccines plus poly-ICLC. Together, these results indicate that prime-boost immunization via NYVAC-KC and either anti-CD40.Env gp140/poly-ICLC or anti-LOX-1.Env gp140/poly-ICLC induced balanced antibody and T cell responses against HIV-1 Env. Coadministration of NYVAC-KC with the DC-targeting vaccines increased T cell responses but had minimal effects on antibody responses except for suppressing serum IgA responses. Overall, targeting Env to CD40 gave more robust T cell and serum antibody responses with broader epitope representation and greater durability than with LOX-1.IMPORTANCE An effective vaccine to prevent HIV-1 infection does not yet exist. An approach to elicit strong protective antibody development is to direct virus protein antigens specifically to dendritic cells, which are now known to be the key cell type for controlling immunity. In this study, we have tested in nonhuman primates two prototype vaccines engineered to direct the HIV-1 coat protein Env to dendritic cells. These vaccines bind to either CD40 or LOX-1, two dendritic cell surface receptors with different functions and tissue distributions. We tested the vaccines described above in combination with attenuated virus vectors that express Env. Both vaccines, but especially that delivered via CD40, raised robust immunity against HIV-1 as measured by monitoring potentially protective antibody and T cell responses in the blood. The safety and efficacy of the CD40-targeted vaccine justify further development for future human clinical trials.


Assuntos
Vacinas contra a AIDS/imunologia , Linfócitos T CD4-Positivos/imunologia , Antígenos CD40/imunologia , Linfócitos T CD8-Positivos/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Receptores Depuradores Classe E/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Vacinas contra a AIDS/genética , Animais , Anticorpos Neutralizantes/imunologia , Células CHO , Carboximetilcelulose Sódica/análogos & derivados , Cricetulus , Células Dendríticas/imunologia , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Macaca mulatta , Masculino , Poli I-C/imunologia , Polilisina/análogos & derivados , Polilisina/imunologia , Vacinação
14.
Blood Adv ; 1(25): 2329-2342, 2017 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-29296883

RESUMO

Adjuvants have a critical role for improving vaccine efficacy against many pathogens, including HIV. Here, using transcriptional RNA profiling and systems serology, we assessed how distinct innate pathways altered HIV-specific antibody responses in nonhuman primates (NHPs) using 8 clinically based adjuvants. NHPs were immunized with a glycoprotein 140 HIV envelope protein (Env) and insoluble aluminum salts (alum), MF59, or adjuvant nanoemulsion (ANE) coformulated with or without Toll-like receptor 4 (TLR4) and 7 agonists. These were compared with Env administered with polyinosinic-polycytidylic acid:poly-L-lysine, carboxymethylcellulose (pIC:LC) or immune-stimulating complexes. Addition of the TLR4 agonist to alum enhanced upregulation of a set of inflammatory genes, whereas the TLR7 agonist suppressed expression of alum-responsive inflammatory genes and enhanced upregulation of antiviral and interferon (IFN) genes. Moreover, coformulation of the TLR4 or 7 agonists with alum boosted Env-binding titers approximately threefold to 10-fold compared with alum alone, but remarkably did not alter gene expression or enhance antibody titers when formulated with ANE. The hierarchy of adjuvant potency was established after the second of 4 immunizations. In terms of antibody durability, antibody titers decreased ∼10-fold after the final immunization and then remained stable after 65 weeks for all adjuvants. Last, Env-specific Fc-domain glycan structures and a series of antibody effector functions were assessed by systems serology. Antiviral/IFN gene signatures correlated with Fc-receptor binding across all adjuvant groups. This study defines the potency and durability of 8 different clinically based adjuvants in NHPs and shows how specific innate pathways can alter qualitative aspects of Env antibody function.

15.
EBioMedicine ; 14: 97-111, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27919754

RESUMO

HIV-1 infection occurs primarily through mucosal transmission. Application of biologically relevant mucosal models can advance understanding of the functional properties of antibodies that mediate HIV protection, thereby guiding antibody-based vaccine development. Here, we employed a human ex vivo vaginal HIV-1 infection model and a rhesus macaque in vivo intrarectal SHIV challenge model to probe the protective capacity of monoclonal broadly-neutralizing (bnAb) and non-neutralizing Abs (nnAbs) that were functionally modified by isotype switching. For human vaginal explants, we developed a replication-competent, secreted NanoLuc reporter virus system and showed that CD4 binding site bnAbs b12 IgG1 and CH31 IgG1 and IgA2 isoforms potently blocked HIV-1JR-CSF and HIV-1Bal26 infection. However, IgG1 and IgA nnAbs, either alone or together, did not inhibit infection despite the presence of FcR-expressing effector cells in the tissue. In macaques, the CH31 IgG1 and IgA2 isoforms infused before high-dose SHIV challenge were completely to partially protective, respectively, while nnAbs (CH54 IgG1 and CH38 mIgA2) were non-protective. Importantly, in both mucosal models IgG1 isotype bnAbs were more protective than the IgA2 isotypes, attributable in part to greater neutralization activity of the IgG1 variants. These findings underscore the importance of potent bnAb induction as a primary goal of HIV-1 vaccine development.


Assuntos
Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Membrana Mucosa/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Biomarcadores , Modelos Animais de Doenças , Feminino , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , HIV-1/genética , Humanos , Imunidade nas Mucosas , Imunofenotipagem , Leucócitos/imunologia , Leucócitos/metabolismo , Macaca mulatta , Membrana Mucosa/virologia , Testes de Neutralização , 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/imunologia , Vagina/imunologia , Vagina/virologia
16.
JCI Insight ; 1(20): e88522, 2016 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-27942585

RESUMO

The ALVAC prime/ALVAC + AIDSVAX B/E boost RV144 vaccine trial induced an estimated 31% efficacy in a low-risk cohort where HIV­1 exposures were likely at mucosal surfaces. An immune correlates study demonstrated that antibodies targeting the V2 region and in a secondary analysis antibody-dependent cellular cytotoxicity (ADCC), in the presence of low envelope-specific (Env-specific) IgA, correlated with decreased risk of infection. Thus, understanding the B cell repertoires induced by this vaccine in systemic and mucosal compartments are key to understanding the potential protective mechanisms of this vaccine regimen. We immunized rhesus macaques with the ALVAC/AIDSVAX B/E gp120 vaccine regimen given in RV144, and then gave a boost 6 months later, after which the animals were necropsied. We isolated systemic and intestinal vaccine Env-specific memory B cells. Whereas Env-specific B cell clonal lineages were shared between spleen, draining inguinal, anterior pelvic, posterior pelvic, and periaortic lymph nodes, members of Env­specific B cell clonal lineages were absent in the terminal ileum. Env­specific antibodies were detectable in rectal fluids, suggesting that IgG antibodies present at mucosal sites were likely systemically produced and transported to intestinal mucosal sites.


Assuntos
Vacinas contra a AIDS/imunologia , Linfócitos B/classificação , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/prevenção & controle , Imunidade nas Mucosas , Animais , Anticorpos Anti-HIV/análise , Proteína gp120 do Envelope de HIV/administração & dosagem , Imunização Secundária , Imunoglobulina G/análise , Macaca mulatta
17.
J Virol ; 90(19): 8644-60, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27440894

RESUMO

UNLABELLED: Poxvirus prime-protein boost used in the RV144 trial remains the only immunization strategy shown to elicit a modest level of protection against HIV-1 acquisition in humans. Although neutralizing antibodies (NAb) were generated, they were against sensitive viruses, not the more resistant "tier 2" isolates that dominate circulating strains. Instead, risk reduction correlated with antibodies recognizing epitopes in the V1/V2 region of HIV-1 envelope glycoprotein (Env). Here, we examined whether tier 2 virus NAb and V1/V2-specific non-NAb could be elicited by a poxvirus prime-gp120 boost strategy in a rabbit model. We studied two clade B Envs that differ in multiple parameters, including tissue origin, neutralization sensitivity, and presence of the N197 (N7) glycan that was previously shown to modulate the exposure of conserved epitopes on Env. We demonstrate that immunized rabbits generated cross-reactive neutralizing activities against >50% of the tier 2 global HIV-1 isolates tested. Some of these activities were directed against the CD4 binding site (CD4bs). These rabbits also generated antibodies that recognized protein scaffolds bearing V1/V2 sequences from diverse HIV-1 isolates and mediated antibody-dependent cellular cytotoxicity. However, there are subtle differences in the specificities and the response rates of V1/V2-specific antibodies between animals immunized with different Envs, with or without the N7 glycan. These findings demonstrate that antibody responses that have been correlated with protection against HIV-1 acquisition in humans can be elicited in a preclinical model by a poxvirus prime-gp120 boost strategy and that improvements may be achievable by optimizing the nature of the priming and boosting immunogens. IMPORTANCE: The only vaccine approach shown to elicit any protective efficacy against HIV-1 acquisition is based on a poxvirus prime-protein boost regimen (RV144 Thai trial). Reduction of risk was associated with nonneutralizing antibodies targeting the V1/V2 loops of the envelope protein gp120. However, the modest efficacy (31.2%) achieved in this trial highlights the need to examine approaches and factors that may improve vaccine-induced responses, including cross-reactive neutralizing activities. We show here that rabbits immunized with a novel recombinant vaccinia virus prime-gp120 protein boost regimen generated antibodies that recognize protein scaffolds bearing V1/V2 sequences from diverse HIV-1 isolates and mediated antibody-dependent cellular cytotoxicity. Importantly, immunized rabbits also showed neutralizing activities against heterologous tier 2 HIV-1 isolates. These findings may inform the design of prime-boost immunization approaches and help improve the protective efficacy of candidate HIV-1 vaccines.


Assuntos
Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Anti-HIV/sangue , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Imunização/métodos , Animais , Portadores de Fármacos , Proteína gp120 do Envelope de HIV/genética , HIV-1/genética , Coelhos , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Vírus Vaccinia/genética
18.
PLoS One ; 11(4): e0153484, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27077384

RESUMO

Improved antigenicity against HIV-1 envelope (Env) protein is needed to elicit vaccine-induced protective immunity in humans. Here we describe the first tests in non-human primates (NHPs) of Env gp140 protein fused to a humanized anti-LOX-1 recombinant antibody for delivering Env directly to LOX-1-bearing antigen presenting cells, especially dendritic cells (DC). LOX-1, or 1ectin-like oxidized low-density lipoprotein (LDL) receptor-1, is expressed on various antigen presenting cells and endothelial cells, and is involved in promoting humoral immune responses. The anti-LOX-1 Env gp140 fusion protein was tested for priming immune responses and boosting responses in animals primed with replication competent NYVAC-KC Env gp140 vaccinia virus. Anti-LOX-1 Env gp140 vaccination elicited robust cellular and humoral responses when used for either priming or boosting immunity. Co-administration with Poly ICLC, a TLR3 agonist, was superior to GLA, a TLR4 agonist. Both CD4+ and CD8+ Env-specific T cell responses were elicited by anti-LOX-1 Env gp140, but in particular the CD4+ T cells were multifunctional and directed to multiple epitopes. Serum IgG and IgA antibody responses induced by anti-LOX-1 Env gp140 against various gp140 domains were cross-reactive across HIV-1 clades; however, the sera neutralized only HIV-1 bearing sequences most similar to the clade C 96ZM651 Env gp140 carried by the anti-LOX-1 vehicle. These data, as well as the safety of this protein vaccine, justify further exploration of this DC-targeting vaccine approach for protective immunity against HIV-1.


Assuntos
HIV-1/imunologia , Receptores Depuradores Classe E/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Antivirais/imunologia , Especificidade de Anticorpos , Humanos , Macaca mulatta , Masculino , Camundongos , Proteínas Recombinantes de Fusão/imunologia , Linfócitos T/imunologia
19.
J Virol ; 90(8): 4133-4149, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26865719

RESUMO

UNLABELLED: In a follow-up to the modest efficacy observed in the RV144 trial, researchers in the HIV vaccine field seek to substantiate and extend the results by evaluating other poxvirus vectors and combinations with DNA and protein vaccines. Earlier clinical trials (EuroVacc trials 01 to 03) evaluated the immunogenicity of HIV-1 clade C GagPolNef and gp120 antigens delivered via the poxviral vector NYVAC. These showed that a vaccination regimen including DNA-C priming prior to a NYVAC-C boost considerably enhanced vaccine-elicited immune responses compared to those with NYVAC-C alone. Moreover, responses were improved by using three as opposed to two DNA-C primes. In the present study, we assessed in nonhuman primates whether such vaccination regimens can be streamlined further by using fewer and accelerated immunizations and employing a novel generation of improved DNA-C and NYVAC-C vaccine candidates designed for higher expression levels and more balanced immune responses. Three different DNA-C prime/NYVAC-C+ protein boost vaccination regimens were tested in rhesus macaques. All regimens elicited vigorous and well-balanced CD8(+)and CD4(+)T cell responses that were broad and polyfunctional. Very high IgG binding titers, substantial antibody-dependent cellular cytotoxicity (ADCC), and modest antibody-dependent cell-mediated virus inhibition (ADCVI), but very low neutralization activity, were measured after the final immunizations. Overall, immune responses elicited in all three groups were very similar and of greater magnitude, breadth, and quality than those of earlier EuroVacc vaccines. In conclusion, these findings indicate that vaccination schemes can be simplified by using improved antigens and regimens. This may offer a more practical and affordable means to elicit potentially protective immune responses upon vaccination, especially in resource-constrained settings. IMPORTANCE: Within the EuroVacc clinical trials, we previously assessed the immunogenicity of HIV clade C antigens delivered in a DNA prime/NYVAC boost regimen. The trials showed that the DNA prime crucially improved the responses, and three DNA primes with a NYVAC boost appeared to be optimal. Nevertheless, T cell responses were primarily directed toward Env, and humoral responses were modest. The aim of this study was to assess improved antigens for the capacity to elicit more potent and balanced responses in rhesus macaques, even with various simpler immunization regimens. Our results showed that the novel antigens in fact elicited larger numbers of T cells with a polyfunctional profile and a good Env-GagPolNef balance, as well as high-titer and Fc-functional antibody responses. Finally, comparison of the different schedules indicates that a simpler regimen of only two DNA primes and one NYVAC boost in combination with protein may be very efficient, thus showing that the novel antigens allow for easier immunization protocols.


Assuntos
Vacinas contra a AIDS/imunologia , Primers do DNA , HIV-1/imunologia , Vacinas de DNA/imunologia , Vacinas contra a AIDS/genética , Animais , Anticorpos Neutralizantes/imunologia , Citotoxicidade Celular Dependente de Anticorpos , Anticorpos Anti-HIV/imunologia , Antígenos HIV/imunologia , Interferon gama/biossíntese , Masculino , Linfócitos T/imunologia , Vacinação/métodos , Vacinas de DNA/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologia
20.
Sci Transl Med ; 7(296): 296ra112, 2015 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-26180102

RESUMO

In the RV144 vaccine trial, two antibody responses were found to correlate with HIV-1 acquisition. Because human leukocyte antigen (HLA) class II-restricted CD4(+) T cells are involved in antibody production, we tested whether HLA class II genotypes affected HIV-1-specific antibody levels and HIV-1 acquisition in 760 individuals. Indeed, antibody responses correlated with acquisition only in the presence of single host HLA alleles. Envelope (Env)-specific immunoglobulin A (IgA) antibodies were associated with increased risk of acquisition specifically in individuals with DQB1*06. IgG antibody responses to Env amino acid positions 120 to 204 were higher and were associated with decreased risk of acquisition and increased vaccine efficacy only in the presence of DPB1*13. Screening IgG responses to overlapping peptides spanning Env 120-204 and viral sequence analysis of infected individuals defined differences in vaccine response that were associated with the presence of DPB1*13 and could be responsible for the protection observed. Overall, the underlying genetic findings indicate that HLA class II modulated the quantity, quality, and efficacy of antibody responses in the RV144 trial.


Assuntos
Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/genética , Infecções por HIV/imunologia , Cadeias beta de HLA-DP/genética , Cadeias beta de HLA-DQ/genética , Antígenos de Histocompatibilidade Classe II , Vacinas contra a AIDS , Alelos , Formação de Anticorpos/imunologia , Epitopos/química , Genótipo , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/metabolismo , HIV-1 , Humanos , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Análise Multivariada , Estrutura Terciária de Proteína , Análise de Regressão
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