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1.
Proc Natl Acad Sci U S A ; 121(4): e2308942121, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38241441

RESUMO

In the Antibody Mediated Prevention (AMP) trials (HVTN 704/HPTN 085 and HVTN 703/HPTN 081), prevention efficacy (PE) of the monoclonal broadly neutralizing antibody (bnAb) VRC01 (vs. placebo) against HIV-1 acquisition diagnosis varied according to the HIV-1 Envelope (Env) neutralization sensitivity to VRC01, as measured by 80% inhibitory concentration (IC80). Here, we performed a genotypic sieve analysis, a complementary approach to gaining insight into correlates of protection that assesses how PE varies with HIV-1 sequence features. We analyzed HIV-1 Env amino acid (AA) sequences from the earliest available HIV-1 RNA-positive plasma samples from AMP participants diagnosed with HIV-1 and identified Env sequence features that associated with PE. The strongest Env AA sequence correlate in both trials was VRC01 epitope distance that quantifies the divergence of the VRC01 epitope in an acquired HIV-1 isolate from the VRC01 epitope of reference HIV-1 strains that were most sensitive to VRC01-mediated neutralization. In HVTN 704/HPTN 085, the Env sequence-based predicted probability that VRC01 IC80 against the acquired isolate exceeded 1 µg/mL also significantly associated with PE. In HVTN 703/HPTN 081, a physicochemical-weighted Hamming distance across 50 VRC01 binding-associated Env AA positions of the acquired isolate from the most VRC01-sensitive HIV-1 strain significantly associated with PE. These results suggest that incorporating mutation scoring by BLOSUM62 and weighting by the strength of interactions at AA positions in the epitope:VRC01 interface can optimize performance of an Env sequence-based biomarker of VRC01 prevention efficacy. Future work could determine whether these results extend to other bnAbs and bnAb combinations.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Humanos , Anticorpos Amplamente Neutralizantes , Anticorpos Neutralizantes , Anticorpos Anti-HIV , Epitopos/genética
2.
PLoS Pathog ; 20(8): e1012496, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39173097

RESUMO

Persistence of the rebound-competent viral reservoir (RCVR) within the CD4+ T cell compartment of people living with HIV remains a major barrier to HIV cure. Here, we determined the effects of the pan-lymphocyte-depleting monoclonal antibody (mAb) alemtuzumab on the RCVR in SIVmac239-infected rhesus macaques (RM) receiving antiretroviral therapy (ART). Alemtuzumab administered during chronic ART or at the time of ART initiation induced >95% depletion of circulating CD4+ T cells in peripheral blood and substantial CD4+ T cell depletion in lymph nodes. However, treatment was followed by proliferation and reconstitution of CD4+ T cells in blood, and despite ongoing ART, levels of cell-associated SIV DNA in blood and lymphoid tissues were not substantially different between alemtuzumab-treated and control RM after immune cell reconstitution, irrespective of the time of alemtuzumab treatment. Upon ART cessation, 19 of 22 alemtuzumab-treated RM and 13 of 13 controls rebounded with no difference in the time to rebound between treatment groups. Time to rebound and reactivation rate was associated with plasma viral loads (pVLs) at time of ART initiation, suggesting lymphocyte depletion had no durable impact on the RCVR. However, 3 alemtuzumab-treated RM that had lowest levels of pre-ART viremia, failed to rebound after ART withdrawal, in contrast to controls with similar levels of SIV replication. These observations suggest that alemtuzumab therapy has little to no ability to reduce well-established RCVRs but may facilitate RCVR destabilization when pre-ART virus levels are particularly low.


Assuntos
Alemtuzumab , Depleção Linfocítica , Macaca mulatta , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Carga Viral , Animais , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Vírus da Imunodeficiência Símia/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/tratamento farmacológico , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Alemtuzumab/farmacologia , Depleção Linfocítica/métodos , Carga Viral/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD4-Positivos/efeitos dos fármacos
3.
PLoS Pathog ; 19(11): e1011825, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38011264

RESUMO

Despite widespread immunization with Bacille-Calmette-Guérin (BCG), the only currently licensed tuberculosis (TB) vaccine, TB remains a leading cause of mortality globally. There are many TB vaccine candidates in the developmental pipeline, but the lack of a robust animal model to assess vaccine efficacy has hindered our ability to prioritize candidates for human clinical trials. Here we use a murine ultra-low dose (ULD) Mycobacterium tuberculosis (Mtb) challenge model to assess protection conferred by BCG vaccination. We show that BCG confers a reduction in lung bacterial burdens that is more durable than that observed after conventional dose challenge, curbs Mtb dissemination to the contralateral lung, and, in a small percentage of mice, prevents detectable infection. These findings are consistent with the ability of human BCG vaccination to mediate protection, particularly against disseminated disease, in specific human populations and clinical settings. Overall, our findings demonstrate that the ultra-low dose Mtb infection model can measure distinct parameters of immune protection that cannot be assessed in conventional dose murine infection models and could provide an improved platform for TB vaccine testing.


Assuntos
Mycobacterium bovis , Mycobacterium tuberculosis , Vacinas contra a Tuberculose , Animais , Camundongos , Humanos , Vacina BCG , Modelos Animais de Doenças , Vacinação
4.
PLoS Pathog ; 19(4): e1011298, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37075079

RESUMO

The global SARS-CoV-2 pandemic prompted rapid development of COVID-19 vaccines. Although several vaccines have received emergency approval through various public health agencies, the SARS-CoV-2 pandemic continues. Emergent variants of concern, waning immunity in the vaccinated, evidence that vaccines may not prevent transmission and inequity in vaccine distribution have driven continued development of vaccines against SARS-CoV-2 to address these public health needs. In this report, we evaluated a novel self-amplifying replicon RNA vaccine against SARS-CoV-2 in a pigtail macaque model of COVID-19 disease. We found that this vaccine elicited strong binding and neutralizing antibody responses against homologous virus. We also observed broad binding antibody against heterologous contemporary and ancestral strains, but neutralizing antibody responses were primarily targeted to the vaccine-homologous strain. While binding antibody responses were sustained, neutralizing antibody waned to undetectable levels in some animals after six months but were rapidly recalled and conferred protection from disease when the animals were challenged 7 months after vaccination as evident by reduced viral replication and pathology in the lower respiratory tract, reduced viral shedding in the nasal cavity and lower concentrations of pro-inflammatory cytokines in the lung. Cumulatively, our data demonstrate in pigtail macaques that a self-amplifying replicon RNA vaccine can elicit durable and protective immunity to SARS-CoV-2 infection. Furthermore, these data provide evidence that this vaccine can provide durable protective efficacy and reduce viral shedding even after neutralizing antibody responses have waned to undetectable levels.


Assuntos
Vacinas contra COVID-19 , Vacinas de mRNA , Vacinas contra COVID-19/imunologia , Macaca nemestrina , Pulmão/imunologia , Pulmão/virologia , SARS-CoV-2/fisiologia , Animais , Anticorpos Neutralizantes/imunologia , COVID-19/transmissão
5.
Clin Infect Dis ; 77(8): 1133-1136, 2023 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-37293702

RESUMO

Infants who are human immunodeficiency virus (HIV)-exposed uninfected (iHEU) experience higher risk of infectious morbidity than infants HIV-unexposed uninfected (iHUU). We compared tuberculosis (TB) infection prevalence in 418 Bacillus Calmette-Guérin vaccinated sub-Saharan African iHEU and iHUU aged 9-18 months using T-SPOT.TB. Prevalence of TB infection was low and did not differ by HIV exposure status.


Assuntos
Infecções por HIV , Tuberculose Latente , Tuberculose , Lactente , Humanos , Criança , HIV , Infecções por HIV/epidemiologia , Tuberculose/prevenção & controle , Prevalência
6.
J Virol ; 96(23): e0142422, 2022 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-36377872

RESUMO

Vaccine strategies aimed at eliciting human immunodeficiency virus (HIV)-specific CD8+ T cells are one major target of interest in HIV functional cure strategies. We hypothesized that CD8+ T cells elicited by therapeutic vaccination during antiretroviral therapy (ART) would be recalled and boosted by treatment with the interleukin 15 (IL-15) superagonist N-803 after ART discontinuation. We intravenously immunized four simian immunodeficiency virus-positive (SIV+) Mauritian cynomolgus macaques receiving ART with vesicular stomatitis virus (VSV), modified vaccinia virus Ankara strain (MVA), and recombinant adenovirus serotype 5 (rAd-5) vectors all expressing SIVmac239 Gag. Immediately after ART cessation, these animals received three doses of N-803. Four control animals received no vaccines or N-803. The vaccine regimen generated a high-magnitude response involving Gag-specific CD8+ T cells that were proliferative and biased toward an effector memory phenotype. We then compared cells elicited by vaccination (Gag specific) to cells elicited by SIV infection and unaffected by vaccination (Nef specific). We found that N-803 treatment enhanced the frequencies of both bulk and proliferating antigen-specific CD8+ T cells elicited by vaccination and the antigen-specific CD8+ T cells elicited by SIV infection. In sum, we demonstrate that a therapeutic heterologous prime-boost-boost (HPBB) vaccine can elicit antigen-specific effector memory CD8+ T cells that are boosted by N-803. IMPORTANCE While antiretroviral therapy (ART) can suppress HIV replication, it is not a cure. It is therefore essential to develop therapeutic strategies to enhance the immune system to better become activated and recognize virus-infected cells. Here, we evaluated a novel therapeutic vaccination strategy delivered to SIV+ Mauritian cynomolgus macaques receiving ART. ART was then discontinued and we delivered an immunotherapeutic agent (N-803) after ART withdrawal with the goal of eliciting and boosting anti-SIV cellular immunity. Immunologic and virologic analysis of peripheral blood and lymph nodes collected from these animals revealed transient boosts in the frequency, activation, proliferation, and memory phenotype of CD4+ and CD8+ T cells following each intervention. Overall, these results are important in educating the field of the transient nature of the immunological responses to this particular therapeutic regimen and the similar effects of N-803 on boosting T cells elicited by vaccination or elicited naturally by infection.


Assuntos
Linfócitos T CD8-Positivos , Vacinas contra a SAIDS , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Proliferação de Células , Macaca mulatta/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vacinação , Vaccinia virus
8.
PLoS Pathog ; 17(7): e1009278, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34228762

RESUMO

Simian immunodeficiency virus (SIV) challenge of rhesus macaques (RMs) vaccinated with strain 68-1 Rhesus Cytomegalovirus (RhCMV) vectors expressing SIV proteins (RhCMV/SIV) results in a binary outcome: stringent control and subsequent clearance of highly pathogenic SIV in ~55% of vaccinated RMs with no protection in the remaining 45%. Although previous work indicates that unconventionally restricted, SIV-specific, effector-memory (EM)-biased CD8+ T cell responses are necessary for efficacy, the magnitude of these responses does not predict efficacy, and the basis of protection vs. non-protection in 68-1 RhCMV/SIV vector-vaccinated RMs has not been elucidated. Here, we report that 68-1 RhCMV/SIV vector administration strikingly alters the whole blood transcriptome of vaccinated RMs, with the sustained induction of specific immune-related pathways, including immune cell, toll-like receptor (TLR), inflammasome/cell death, and interleukin-15 (IL-15) signaling, significantly correlating with subsequent vaccine efficacy. Treatment of a separate RM cohort with IL-15 confirmed the central involvement of this cytokine in the protection signature, linking the major innate and adaptive immune gene expression networks that correlate with RhCMV/SIV vaccine efficacy. This change-from-baseline IL-15 response signature was also demonstrated to significantly correlate with vaccine efficacy in an independent validation cohort of vaccinated and challenged RMs. The differential IL-15 gene set response to vaccination strongly correlated with the pre-vaccination activity of this pathway, with reduced baseline expression of IL-15 response genes significantly correlating with higher vaccine-induced induction of IL-15 signaling and subsequent vaccine protection, suggesting that a robust de novo vaccine-induced IL-15 signaling response is needed to program vaccine efficacy. Thus, the RhCMV/SIV vaccine imparts a coordinated and persistent induction of innate and adaptive immune pathways featuring IL-15, a known regulator of CD8+ T cell function, that support the ability of vaccine-elicited unconventionally restricted CD8+ T cells to mediate protection against SIV challenge.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Interleucina-15/imunologia , Vacinas contra a SAIDS/imunologia , Vírus da Imunodeficiência Símia/imunologia , Animais , Citomegalovirus , Feminino , Vetores Genéticos , Macaca mulatta , Masculino , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle
10.
PLoS Pathog ; 16(12): e1009101, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33290394

RESUMO

The RV144 vaccine efficacy clinical trial showed a reduction in HIV-1 infections by 31%. Vaccine efficacy was associated with stronger binding antibody responses to the HIV Envelope (Env) V1V2 region, with decreased efficacy as responses wane. High levels of Ab-dependent cellular cytotoxicity (ADCC) together with low plasma levels of Env-specific IgA also correlated with decreased infection risk. We investigated whether B cell priming from RV144 vaccination impacted functional antibody responses to HIV-1 following infection. Antibody responses were assessed in 37 vaccine and 63 placebo recipients at 6, 12, and 36 months following HIV diagnosis. The magnitude, specificity, dynamics, subclass recognition and distribution of the binding antibody response following infection were different in RV144 vaccine recipients compared to placebo recipients. Vaccine recipients demonstrated increased IgG1 binding specifically to V1V2, as well as increased IgG2 and IgG4 but decreased IgG3 to HIV-1 Env. No difference in IgA binding to HIV-1 Env was detected between the vaccine and placebo recipients following infection. RV144 vaccination limited the development of broadly neutralizing antibodies post-infection, but enhanced Fc-mediated effector functions indicating B cell priming by RV144 vaccination impacted downstream antibody function. However, these functional responses were not associated with clinical markers of disease progression. These data reveal that RV144 vaccination primed B cells towards specific binding and functional antibody responses following HIV-1 infection.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , Adulto , Formação de Anticorpos/imunologia , Linfócitos B/imunologia , Feminino , Anticorpos Anti-HIV/sangue , HIV-1 , Humanos , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
11.
PLoS Pathog ; 16(11): e1008666, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33232376

RESUMO

Cytomegaloviruses (CMVs) are highly adapted to their host species resulting in strict species specificity. Hence, in vivo examination of all aspects of CMV biology employs animal models using host-specific CMVs. Infection of rhesus macaques (RM) with rhesus CMV (RhCMV) has been established as a representative model for infection of humans with HCMV due to the close evolutionary relationships of both host and virus. However, the only available RhCMV clone that permits genetic modifications is based on the 68-1 strain which has been passaged in fibroblasts for decades resulting in multiple genomic changes due to tissue culture adaptations. As a result, 68-1 displays reduced viremia in RhCMV-naïve animals and limited shedding compared to non-clonal, low passage isolates. To overcome this limitation, we used sequence information from primary RhCMV isolates to construct a full-length (FL) RhCMV by repairing all mutations affecting open reading frames (ORFs) in the 68-1 bacterial artificial chromosome (BAC). Inoculation of adult, immunocompetent, RhCMV-naïve RM with the reconstituted virus resulted in significant viremia in the blood similar to primary isolates of RhCMV and furthermore led to high viral genome copy numbers in many tissues at day 14 post infection. In contrast, viral dissemination was greatly reduced upon deletion of genes also lacking in 68-1. Transcriptome analysis of infected tissues further revealed that chemokine-like genes deleted in 68-1 are among the most highly expressed viral transcripts both in vitro and in vivo consistent with an important immunomodulatory function of the respective proteins. We conclude that FL-RhCMV displays in vitro and in vivo characteristics of a wildtype virus while being amenable to genetic modifications through BAC recombineering techniques.


Assuntos
Infecções por Citomegalovirus/virologia , Citomegalovirus/genética , Genoma Viral/genética , Viremia , Animais , Linhagem Celular , Cromossomos Artificiais Bacterianos , Citomegalovirus/patogenicidade , DNA Recombinante , Modelos Animais de Doenças , Feminino , Fibroblastos/virologia , Humanos , Macaca mulatta , Masculino , Mutação , Fases de Leitura Aberta/genética , Filogenia , Especificidade da Espécie
12.
PLoS Pathog ; 16(2): e1008179, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32027734

RESUMO

Most HIV-1 infected individuals do not know their infection dates. Precise infection timing is crucial information for studies that document transmission networks or drug levels at infection. To improve infection timing, we used the prospective RV217 cohort where the window when plasma viremia becomes detectable is narrow: the last negative visit occurred a median of four days before the first detectable HIV-1 viremia with an RNA test, referred below as diagnosis. We sequenced 1,280 HIV-1 genomes from 39 participants at a median of 4, 32 and 170 days post-diagnosis. HIV-1 infections were dated by using sequence-based methods and a viral load regression method. Bayesian coalescent and viral load regression estimated that infections occurred a median of 6 days prior to diagnosis (IQR: 9-3 and 11-4 days prior, respectively). Poisson-Fitter, which analyzes the distribution of hamming distances among sequences, estimated a median of 7 days prior to diagnosis (IQR: 15-4 days) based on sequences sampled 4 days post-diagnosis, but it did not yield plausible results using sequences sampled at 32 days. Fourteen participants reported a high-risk exposure event at a median of 8 days prior to diagnosis (IQR: 12 to 6 days prior). These different methods concurred that HIV-1 infection occurred about a week before detectable viremia, corresponding to 20 days (IQR: 34-15 days) before peak viral load. Together, our methods comparison helps define a framework for future dating studies in early HIV-1 infection.


Assuntos
Genoma Viral , Infecções por HIV/diagnóstico , HIV-1/metabolismo , Técnicas de Diagnóstico Molecular , Carga Viral , Viremia/diagnóstico , Adulto , África Oriental , Feminino , Infecções por HIV/genética , HIV-1/genética , Humanos , Masculino , Estudos Prospectivos , Tailândia , Fatores de Tempo , Viremia/genética
13.
Proc Natl Acad Sci U S A ; 115(36): E8378-E8387, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30127007

RESUMO

Two phase 3 placebo-controlled trials of the CYD-TDV vaccine, evaluated in children aged 2-14 y (CYD14) and 9-16 y (CYD15), demonstrated vaccine efficacy (VE) of 56.5% and 60.8%, respectively, against symptomatic virologically confirmed dengue (VCD). Sieve analyses were conducted to evaluate whether and how VE varied with amino acid sequence features of dengue viruses (DENVs). DENV premembrane/envelope amino acid sequences from VCD endpoint cases were aligned with the vaccine insert sequences, and extensions of the proportional hazards model were applied to assess variation in VE with amino acid mismatch proportion distances from vaccine strains, individual amino acid residues, and phylogenetic genotypes. In CYD14, VE against VCD of any serotype (DENV-Any) decreased significantly with increasing amino acid distance from the vaccine, whereas in CYD15, VE against DENV-Any was distance-invariant. Restricting to the common age range and amino acid distance range between the trials and accounting for differential VE by serotype, however, showed no evidence of VE variation with distance in either trial. In serotype-specific analyses, VE against DENV4 decreased significantly with increasing amino acid distance from the DENV4 vaccine insert and was significantly greater against residue-matched DENV4 at eight signature positions. These effects were restricted to 2- to 8-y-olds, potentially because greater seropositivity of older children at baseline might facilitate a broader protective immune response. The relevance of an antigenic match between vaccine strains and circulating DENVs was also supported by greater estimated VE against serotypes and genotypes for which the circulating DENVs had shorter amino acid sequence distances from the vaccine.


Assuntos
Vacinas contra Dengue/administração & dosagem , Vírus da Dengue/genética , Dengue/prevenção & controle , Variação Genética , Genótipo , Fatores Etários , Criança , Pré-Escolar , Dengue/genética , Dengue/imunologia , Vacinas contra Dengue/genética , Vacinas contra Dengue/imunologia , Vírus da Dengue/imunologia , Feminino , Humanos , Masculino
14.
PLoS Comput Biol ; 15(4): e1006952, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30933973

RESUMO

The broadly neutralizing antibody (bnAb) VRC01 is being evaluated for its efficacy to prevent HIV-1 infection in the Antibody Mediated Prevention (AMP) trials. A secondary objective of AMP utilizes sieve analysis to investigate how VRC01 prevention efficacy (PE) varies with HIV-1 envelope (Env) amino acid (AA) sequence features. An exhaustive analysis that tests how PE depends on every AA feature with sufficient variation would have low statistical power. To design an adequately powered primary sieve analysis for AMP, we modeled VRC01 neutralization as a function of Env AA sequence features of 611 HIV-1 gp160 pseudoviruses from the CATNAP database, with objectives: (1) to develop models that best predict the neutralization readouts; and (2) to rank AA features by their predictive importance with classification and regression methods. The dataset was split in half, and machine learning algorithms were applied to each half, each analyzed separately using cross-validation and hold-out validation. We selected Super Learner, a nonparametric ensemble-based cross-validated learning method, for advancement to the primary sieve analysis. This method predicted the dichotomous resistance outcome of whether the IC50 neutralization titer of VRC01 for a given Env pseudovirus is right-censored (indicating resistance) with an average validated AUC of 0.868 across the two hold-out datasets. Quantitative log IC50 was predicted with an average validated R2 of 0.355. Features predicting neutralization sensitivity or resistance included 26 surface-accessible residues in the VRC01 and CD4 binding footprints, the length of gp120, the length of Env, the number of cysteines in gp120, the number of cysteines in Env, and 4 potential N-linked glycosylation sites; the top features will be advanced to the primary sieve analysis. This modeling framework may also inform the study of VRC01 in the treatment of HIV-infected persons.


Assuntos
Anticorpos Monoclonais/farmacologia , Proteína gp160 do Envelope de HIV/genética , Proteína gp160 do Envelope de HIV/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Sítios de Ligação , Anticorpos Amplamente Neutralizantes , Antígenos CD4 , Simulação por Computador , Previsões/métodos , Glicosilação , Anticorpos Anti-HIV/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , Humanos , Ligação Proteica
15.
Nature ; 502(7469): 100-4, 2013 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-24025770

RESUMO

Established infections with the human and simian immunodeficiency viruses (HIV and SIV, respectively) are thought to be permanent with even the most effective immune responses and antiretroviral therapies only able to control, but not clear, these infections. Whether the residual virus that maintains these infections is vulnerable to clearance is a question of central importance to the future management of millions of HIV-infected individuals. We recently reported that approximately 50% of rhesus macaques (RM; Macaca mulatta) vaccinated with SIV protein-expressing rhesus cytomegalovirus (RhCMV/SIV) vectors manifest durable, aviraemic control of infection with the highly pathogenic strain SIVmac239 (ref. 5). Here we show that regardless of the route of challenge, RhCMV/SIV vector-elicited immune responses control SIVmac239 after demonstrable lymphatic and haematogenous viral dissemination, and that replication-competent SIV persists in several sites for weeks to months. Over time, however, protected RM lost signs of SIV infection, showing a consistent lack of measurable plasma- or tissue-associated virus using ultrasensitive assays, and a loss of T-cell reactivity to SIV determinants not in the vaccine. Extensive ultrasensitive quantitative PCR and quantitative PCR with reverse transcription analyses of tissues from RhCMV/SIV vector-protected RM necropsied 69-172 weeks after challenge did not detect SIV RNA or DNA sequences above background levels, and replication-competent SIV was not detected in these RM by extensive co-culture analysis of tissues or by adoptive transfer of 60 million haematolymphoid cells to naive RM. These data provide compelling evidence for progressive clearance of a pathogenic lentiviral infection, and suggest that some lentiviral reservoirs may be susceptible to the continuous effector memory T-cell-mediated immune surveillance elicited and maintained by cytomegalovirus vectors.


Assuntos
Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Animais , Citomegalovirus/genética , Citomegalovirus/imunologia , Feminino , Macaca mulatta , Masculino , Dados de Sequência Molecular , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Fatores de Tempo , Vacinas Atenuadas/imunologia , Carga Viral , Replicação Viral/fisiologia
16.
Clin Infect Dis ; 67(8): 1237-1246, 2018 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-29659737

RESUMO

Background: Exclusive breastfeeding reduces the rate of postnatal human immunodeficiency virus (HIV) transmission compared to nonexclusive breastfeeding; however, the mechanisms of this protection are unknown. Our study aimed to interrogate the mechanisms underlying the protective effect of exclusive breastfeeding. Methods: We performed a prospective, longitudinal study of infants from a high-HIV-prevalence, low-income setting in South Africa. We evaluated the role of any non-breast milk feeds, excluding prescribed medicines on stool microbial communities via 16S rRNA gene sequencing, peripheral T-cell activation via flow cytometry, and buccal mucosal gene expression via quantitative polymerase chain reaction assay. Results: A total of 155 infants were recruited at birth with mean gestational age of 38.9 weeks and mean birth weight of 3.2 kg. All infants were exclusively breastfed (EBF) at birth, but only 43.5% and 20% remained EBF at 6 or 14 weeks of age, respectively. We observed lower stool microbial diversity and distinct microbial composition in exclusively breastfed infants. These microbial communities, and the relative abundance of key taxa, were correlated with peripheral CD4+ T-cell activation, which was lower in EBF infants. In the oral mucosa, gene expression of chemokine and chemokine receptors involved in recruitment of HIV target cells to tissues, as well as epithelial cytoskeletal proteins, was lower in EBF infants. Conclusions: These data suggest that nonexclusive breastfeeding alters the gut microbiota, increasing T-cell activation and, potentially, mucosal recruitment of HIV target cells. Study findings highlight a biologically plausible mechanistic explanation for the reduced postnatal HIV transmission observed in EBF infants.


Assuntos
Aleitamento Materno , Linfócitos T CD4-Positivos/imunologia , Microbioma Gastrointestinal , Infecções por HIV/prevenção & controle , Ativação Linfocitária , Mucosa Bucal/imunologia , Quimiocinas/genética , Quimiocinas/imunologia , Fezes/microbiologia , Expressão Gênica , Infecções por HIV/transmissão , Humanos , Lactente , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Estudos Longitudinais , Estudos Prospectivos , RNA Ribossômico 16S/genética , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/imunologia , África do Sul/epidemiologia
17.
Bioinformatics ; 33(15): 2386-2388, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28379332

RESUMO

SUMMARY: Analysis of HIV-1 virions from participants infected in a randomized controlled preventive HIV-1 vaccine efficacy trial can help elucidate mechanisms of partial protection. By comparing the genetic sequence of viruses from vaccine and placebo recipients to the sequence of the vaccine itself, a technique called 'sieve analysis', one can identify functional specificities of vaccine-induced immune responses. We have created an interactive web-based visualization and data access tool for exploring the results of sieve analyses performed on four major preventive HIV-1 vaccine efficacy trials: (i) the HIV Vaccine Trial Network (HVTN) 502/Step trial, (ii) the RV144/Thai trial, (iii) the HVTN 503/Phambili trial and (iv) the HVTN 505 trial. The tool acts simultaneously as a platform for rapid reinterpretation of sieve effects and as a portal for organizing and sharing the viral sequence data. Access to these valuable datasets also enables the development of novel methodology for future sieve analyses. AVAILABILITY AND IMPLEMENTATION: Visualization: http://sieve.fredhutch.org/viz . Source code: https://github.com/nkullman/SIEVE . Data API: http://sieve.fredhutch.org/data . CONTACT: agartlan@fredhutch.org.


Assuntos
Biologia Computacional/métodos , Infecções por HIV/imunologia , HIV-1/imunologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Software , Vacinas contra a AIDS/imunologia , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , Humanos , Internet
18.
Nature ; 490(7420): 417-20, 2012 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-22960785

RESUMO

The RV144 trial demonstrated 31% vaccine efficacy at preventing human immunodeficiency virus (HIV)-1 infection. Antibodies against the HIV-1 envelope variable loops 1 and 2 (Env V1 and V2) correlated inversely with infection risk. We proposed that vaccine-induced immune responses against V1/V2 would have a selective effect against, or sieve, HIV-1 breakthrough viruses. A total of 936 HIV-1 genome sequences from 44 vaccine and 66 placebo recipients were examined. We show that vaccine-induced immune responses were associated with two signatures in V2 at amino acid positions 169 and 181. Vaccine efficacy against viruses matching the vaccine at position 169 was 48% (confidence interval 18% to 66%; P = 0.0036), whereas vaccine efficacy against viruses mismatching the vaccine at position 181 was 78% (confidence interval 35% to 93%; P = 0.0028). Residue 169 is in a cationic glycosylated region recognized by broadly neutralizing and RV144-derived antibodies. The predicted distance between the two signature sites (21 ± 7 Å) and their match/mismatch dichotomy indicate that multiple factors may be involved in the protection observed in RV144. Genetic signatures of RV144 vaccination in V2 complement the finding of an association between high V1/V2-binding antibodies and reduced risk of HIV-1 acquisition, and provide evidence that vaccine-induced V2 responses plausibly had a role in the partial protection conferred by the RV144 regimen.


Assuntos
Vacinas contra a AIDS/imunologia , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , 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 , Vacinas contra a AIDS/efeitos adversos , Predisposição Genética para Doença , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Humanos , Dados de Sequência Molecular , Filogenia , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise de Sequência de DNA
19.
J Infect Dis ; 214(2): 258-64, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27056950

RESUMO

BACKGROUND: Pritelivir is a novel helicase-primase inhibitor in clinical development for treatment of herpes simplex virus type 2 (HSV-2) infections. In preclinical work, resistance-mediating mutations were identified in the HSV-2 genome at 3 loci in the UL5 gene and 1 locus in UL52. METHODS: To evaluate whether daily pritelivir treatment results in emergence of resistance-mediating mutations, we analyzed HSV-2 strains detected in genital swab specimens from trial participants who were randomly assigned to receive different dosages of pritelivir. We sequenced resistance regions from 87 participants' samples, the UL5 gene in 73 samples from 44 participants, and the UL52 gene in 71 samples from 43 participants. RESULTS: We found no evidence that pritelivir induced known resistance-mediating mutations or for amino acid variation at other loci. In one participant's HSV-2 isolate, we found a previously unidentified mutation close to the putative resistance-mediating region in UL5 and subsequently determined in vitro susceptibility to pritelivir. We characterized mutations from 32 cultivated HSV-2 isolates previously found to be susceptible to pritelivir in vitro and identified several novel mutations that most likely reflect preexisting variation in circulating HSV-2. CONCLUSIONS: This study demonstrates evidence of retained susceptibility of HSV-2 to pritelivir in immunocompetent persons following daily therapy for up to 28 days.


Assuntos
Antivirais/administração & dosagem , Farmacorresistência Viral , Herpes Genital/tratamento farmacológico , Herpesvirus Humano 2/efeitos dos fármacos , Piridinas/administração & dosagem , Tiazóis/administração & dosagem , Antivirais/farmacologia , Feminino , Herpesvirus Humano 2/isolamento & purificação , Humanos , Masculino , Mutação , Piridinas/farmacologia , Análise de Sequência de DNA , Sulfonamidas , Tiazóis/farmacologia , Proteínas Virais/genética
20.
PLoS Comput Biol ; 11(2): e1003973, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25646817

RESUMO

The RV144 clinical trial showed the partial efficacy of a vaccine regimen with an estimated vaccine efficacy (VE) of 31% for protecting low-risk Thai volunteers against acquisition of HIV-1. The impact of vaccine-induced immune responses can be investigated through sieve analysis of HIV-1 breakthrough infections (infected vaccine and placebo recipients). A V1/V2-targeted comparison of the genomes of HIV-1 breakthrough viruses identified two V2 amino acid sites that differed between the vaccine and placebo groups. Here we extended the V1/V2 analysis to the entire HIV-1 genome using an array of methods based on individual sites, k-mers and genes/proteins. We identified 56 amino acid sites or "signatures" and 119 k-mers that differed between the vaccine and placebo groups. Of those, 19 sites and 38 k-mers were located in the regions comprising the RV144 vaccine (Env-gp120, Gag, and Pro). The nine signature sites in Env-gp120 were significantly enriched for known antibody-associated sites (p = 0.0021). In particular, site 317 in the third variable loop (V3) overlapped with a hotspot of antibody recognition, and sites 369 and 424 were linked to CD4 binding site neutralization. The identified signature sites significantly covaried with other sites across the genome (mean = 32.1) more than did non-signature sites (mean = 0.9) (p < 0.0001), suggesting functional and/or structural relevance of the signature sites. Since signature sites were not preferentially restricted to the vaccine immunogens and because most of the associations were insignificant following correction for multiple testing, we predict that few of the genetic differences are strongly linked to the RV144 vaccine-induced immune pressure. In addition to presenting results of the first complete-genome analysis of the breakthrough infections in the RV144 trial, this work describes a set of statistical methods and tools applicable to analysis of breakthrough infection genomes in general vaccine efficacy trials for diverse pathogens.


Assuntos
Vacinas contra a AIDS/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/genética , HIV-1/imunologia , Proteínas do Vírus da Imunodeficiência Humana/química , Vacinas contra a AIDS/genética , Sítios de Ligação/genética , Genoma Viral/genética , Infecções por HIV/prevenção & controle , Proteínas do Vírus da Imunodeficiência Humana/genética , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de Proteína
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