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1.
Phys Rev Lett ; 130(4): 043401, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36763437

RESUMO

We look into dark solitons in a quasi-1D dipolar Bose gas and in a quantum droplet. We derive the analytical solitonic solution of a Gross-Pitaevskii-like equation accounting for beyond mean-field effects. The results show there is a certain critical value of the dipolar interactions, for which the width of a motionless soliton diverges. Moreover, there is a peculiar solution of the motionless soliton with a nonzero density minimum. We also present the energy spectrum of these solitons with an additional excitation subbranch appearing. Finally, we perform a series of numerical experiments revealing the coexistence of a dark soliton inside a quantum droplet.

2.
Lancet ; 395(10227): 888-898, 2020 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-32085823

RESUMO

BACKGROUND: Antiretroviral therapy (ART) cannot cure HIV infection because of a persistent reservoir of latently infected cells. Approaches that force HIV transcription from these cells, making them susceptible to killing-termed kick and kill regimens-have been explored as a strategy towards an HIV cure. RIVER is the first randomised trial to determine the effect of ART-only versus ART plus kick and kill on markers of the HIV reservoir. METHODS: This phase 2, open-label, multicentre, randomised, controlled trial was undertaken at six clinical sites in the UK. Patients aged 18-60 years who were confirmed as HIV-positive within a maximum of the past 6 months and started ART within 1 month from confirmed diagnosis were randomly assigned by a computer generated randomisation list to receive ART-only (control) or ART plus the histone deacetylase inhibitor vorinostat (the kick) and replication-deficient viral vector T-cell inducing vaccines encoding conserved HIV sequences ChAdV63. HIVconsv-prime and MVA.HIVconsv-boost (the kill; ART + V + V; intervention). The primary endpoint was total HIV DNA isolated from peripheral blood CD4+ T-cells at weeks 16 and 18 after randomisation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT02336074. FINDINGS: Between June 14, 2015 and Jul 11, 2017, 60 men with HIV were randomly assigned to receive either an ART-only (n=30) or an ART + V + V (n=30) regimen; all 60 participants completed the study, with no loss-to-follow-up. Mean total HIV DNA at weeks 16 and 18 after randomisation was 3·02 log10 copies HIV DNA per 106 CD4+ T-cells in the ART-only group versus 3·06 log10 copies HIV DNA per 106 CD4+ T-cells in ART + V + V group, with no statistically significant difference between the two groups (mean difference of 0·04 log10 copies HIV DNA per 106 CD4+ T-cells [95% CI -0·03 to 0·11; p=0·26]). There were no intervention-related serious adverse events. INTERPRETATION: This kick and kill approach conferred no significant benefit compared with ART alone on measures of the HIV reservoir. Although this does not disprove the efficacy kick and kill strategy, for future trials enhancement of both kick and kill agents will be required. FUNDING: Medical Research Council (MR/L00528X/1).


Assuntos
Vacinas contra a AIDS/administração & dosagem , Antirretrovirais/uso terapêutico , Reservatórios de Doenças , Infecções por HIV , Inibidores de Histona Desacetilases/administração & dosagem , Vorinostat/administração & dosagem , Adulto , DNA Viral/análise , Infecções por HIV/tratamento farmacológico , Humanos , Masculino , Transcrição Gênica/efeitos dos fármacos , Resultado do Tratamento
3.
PLoS Pathog ; 15(8): e1007981, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31449552

RESUMO

Despite extensive research on the mechanisms of HLA-mediated immune control of HIV-1 pathogenesis, it is clear that much remains to be discovered, as exemplified by protective HLA alleles like HLA-B*81 which are associated with profound protection from CD4+ T cell decline without robust control of early plasma viremia. Here, we report on additional HLA class I (B*1401, B*57, B*5801, as well as B*81), and HLA class II (DQB1*02 and DRB1*15) alleles that display discordant virological and immunological phenotypes in a Zambian early infection cohort. HLA class I alleles of this nature were also associated with enhanced immune responses to conserved epitopes in Gag. Furthermore, these HLA class I alleles were associated with reduced levels of lipopolysaccharide (LPS) in the plasma during acute infection. Elevated LPS levels measured early in infection predicted accelerated CD4+ T cell decline, as well as immune activation and exhaustion. Taken together, these data suggest novel mechanisms for HLA-mediated immune control of HIV-1 pathogenesis that do not necessarily involve significant control of early viremia and point to microbial translocation as a direct driver of HIV-1 pathogenesis rather than simply a consequence.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Genes MHC Classe I/genética , Infecções por HIV/imunologia , HIV-1/imunologia , HIV-1/patogenicidade , Lipopolissacarídeos/deficiência , Replicação Viral/imunologia , Alelos , Estudos de Coortes , Feminino , Infecções por HIV/genética , Infecções por HIV/virologia , HIV-1/genética , Humanos , Masculino , Linfócitos T Citotóxicos/imunologia , Carga Viral , Replicação Viral/genética
4.
Proc Natl Acad Sci U S A ; 112(12): E1480-9, 2015 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-25730868

RESUMO

HIV-1 infection is characterized by varying degrees of chronic immune activation and disruption of T-cell homeostasis, which impact the rate of disease progression. A deeper understanding of the factors that influence HIV-1-induced immunopathology and subsequent CD4(+) T-cell decline is critical to strategies aimed at controlling or eliminating the virus. In an analysis of 127 acutely infected Zambians, we demonstrate a dramatic and early impact of viral replicative capacity (vRC) on HIV-1 immunopathogenesis that is independent of viral load (VL). Individuals infected with high-RC viruses exhibit a distinct inflammatory cytokine profile as well as significantly elevated T-cell activation, proliferation, and CD8(+) T-cell exhaustion, during the earliest months of infection. Moreover, the vRC of the transmitted virus is positively correlated with the magnitude of viral burden in naive and central memory CD4(+) T-cell populations, raising the possibility that transmitted viral phenotypes may influence the size of the initial latent viral reservoir. Taken together, these findings support an unprecedented role for the replicative fitness of the founder virus, independent of host protective genes and VL, in influencing multiple facets of HIV-1-related immunopathology, and that a greater focus on this parameter could provide novel approaches to clinical interventions.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Replicação Viral , Contagem de Linfócito CD4 , Linfócitos T CD8-Positivos/imunologia , Estudos de Coortes , Citocinas/sangue , Citocinas/metabolismo , Progressão da Doença , Feminino , Infecções por HIV/sangue , Homeostase , Humanos , Memória Imunológica , Inflamação , Estimativa de Kaplan-Meier , Ativação Linfocitária , Masculino , Dados de Sequência Molecular , Fatores de Tempo , Carga Viral
5.
J Infect Dis ; 215(1): 95-104, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28077588

RESUMO

BACKGROUND: We report the first-in-human safety and immunogenicity assessment of a prototype intranasally administered, replication-competent Sendai virus (SeV)-vectored, human immunodeficiency virus type 1 (HIV-1) vaccine. METHODS: Sixty-five HIV-1-uninfected adults in Kenya, Rwanda, and the United Kingdom were assigned to receive 1 of 4 prime-boost regimens (administered at 0 and 4 months, respectively; ratio of vaccine to placebo recipients, 12:4): priming with a lower-dose SeV-Gag given intranasally, followed by boosting with an adenovirus 35-vectored vaccine encoding HIV-1 Gag, reverse transcriptase, integrase, and Nef (Ad35-GRIN) given intramuscularly (SLA); priming with a higher-dose SeV-Gag given intranasally, followed by boosting with Ad35-GRIN given intramuscularly (SHA); priming with Ad35-GRIN given intramuscularly, followed by boosting with a higher-dose SeV-Gag given intranasally (ASH); and priming and boosting with a higher-dose SeV-Gag given intranasally (SHSH). RESULTS: All vaccine regimens were well tolerated. Gag-specific IFN-γ enzyme-linked immunospot-determined response rates and geometric mean responses were higher (96% and 248 spot-forming units, respectively) in groups primed with SeV-Gag and boosted with Ad35-GRIN (SLA and SHA) than those after a single dose of Ad35-GRIN (56% and 54 spot-forming units, respectively) or SeV-Gag (55% and 59 spot-forming units, respectively); responses persisted for ≥8 months after completion of the prime-boost regimen. Functional CD8+ T-cell responses with greater breadth, magnitude, and frequency in a viral inhibition assay were also seen in the SLA and SHA groups after Ad35-GRIN boost, compared with those who received either vaccine alone. SeV-Gag did not boost T-cell counts in the ASH group. In contrast, the highest Gag-specific antibody titers were seen in the ASH group. Mucosal antibody responses were sporadic. CONCLUSIONS: SeV-Gag primed functional, durable HIV-specific T-cell responses and boosted antibody responses. The prime-boost sequence appears to determine which arm of the immune response is stimulated. CLINICAL TRIALS REGISTRATION: NCT01705990.


Assuntos
Vacinas contra a AIDS/efeitos adversos , Vacinas contra a AIDS/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/prevenção & controle , HIV-1/imunologia , Vírus Sendai/genética , Vacinas de DNA/efeitos adversos , Vacinas de DNA/imunologia , Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/genética , Administração Intranasal , Adulto , Feminino , Genes Virais/imunologia , Vetores Genéticos , Anticorpos Anti-HIV/sangue , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/genética , Humanos , Imunidade Celular , Imunidade Humoral , Imunização Secundária , Imunogenicidade da Vacina , Quênia , Masculino , Pessoa de Meia-Idade , Ruanda , Vírus Sendai/imunologia , Vírus Sendai/fisiologia , Reino Unido , Vacinas de DNA/administração & dosagem , Replicação Viral
6.
Vaccines (Basel) ; 12(6)2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38932373

RESUMO

There are varying data concerning the effect of prior anti-vector immunity on the T-cell response induced by immunisation with an identical vectored vaccine containing a heterologous antigen insert. To determine whether prior exposure to ChAdOx1-SARS-CoV2 immunisation (Vaxzevria®) impacts magnitudes of antigen-specific T-cell responses elicited by subsequent administration of the same viral vector (encoding HBV antigens, ChAdOx1-HBV), healthy volunteers that had received Vaxzevria® (n = 15) or the Pfizer or Moderna mRNA COVID-19 vaccine (n = 11) between 10 and 18 weeks prior were recruited to receive a single intramuscular injection of ChAdOx1-HBV. Anti-ChAdOx1-neutralising antibody titers were determined, and vector or insert-specific T-cell responses were measured by a gamma-interferon ELISpot and intracellular cytokine staining (ICS) assay using multiparameter flow cytometry. Participants were followed for three months after the ChAdOx1-HBV injection, which was well-tolerated, and no dropouts occurred. The baseline ChAdOx1 neutralisation titers were higher in the Vaxzevria® cohort (median of 848) than in the mRNA cohort (median of 25). T-cell responses to HBV antigens, measured by ELISpot, were higher on day 28 in the mRNA group (p = 0.013) but were similar between groups on day 84 (p = 0.441). By ICS, these differences persisted at the last time point. There was no clear correlation between the baseline responses to the adenoviral hexon and the subsequent ELISpot responses. As vaccination within 3 months using the same viral vector backbone affected the insert-specific T-cell responses, a greater interval after prior adenoviral immunisation using heterologous antigens may be warranted in settings in which these cells play critical roles.

7.
Sci Rep ; 13(1): 17155, 2023 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-37821472

RESUMO

'Kick and kill' cure strategies aim to induce HIV protein expression in latently infected cells (kick), and thus trigger their elimination by cytolytic T cells (kill). In the Research in Viral Eradication of HIV Reservoirs trial (NCT02336074), people diagnosed with primary HIV infection received immediate antiretroviral therapy (ART) and were randomised 24 weeks later to either a latency-reversing agent, vorinostat, together with ChAdV63.HIVconsv and MVA.HIVconsv vaccines, or ART alone. This intervention conferred no reduction in HIV-1 reservoir size over ART alone, despite boosting virus-specific CD4+ and CD8+ T cells. The effects of the intervention were examined at the cellular level in the two trial arms using unbiased computational analysis of polyfunctional scores. This showed that the frequency and polyfunctionality of virus-specific CD4+ and CD8+ T cell populations were significantly increased over 12 weeks post-vaccination, compared to the ART-only arm. HIV-specific IL-2-secreting CD8+ T cells also expanded significantly in the intervention arm and were correlated with antiviral activity against heterologous HIV in vitro. Therapeutic vaccination during ART commenced in primary infection can induce functional T cell responses that are phenotypically similar to those of HIV controllers. Analytical therapy interruption may help determine their ability to control HIV in vivo.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Humanos , HIV-1/fisiologia , Antirretrovirais/farmacologia , Antirretrovirais/uso terapêutico , Soropositividade para HIV/tratamento farmacológico , Linfócitos T CD8-Positivos , Vacinação , Linfócitos T CD4-Positivos , Latência Viral
8.
iScience ; 26(1): 105862, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36590902

RESUMO

We assessed a cohort of people living with human immunodeficiency virus (PLWH) (n = 110) and HIV negative controls (n = 64) after 1, 2 or 3 SARS-CoV-2 vaccine doses. At all timepoints, PLWH had significantly lower neutralizing antibody (nAb) titers than HIV-negative controls. We also observed a delayed development of neutralization in PLWH that was underpinned by a reduced frequency of spike-specific memory B cells (MBCs). Improved neutralization breadth was seen against the Omicron variant (BA.1) after the third vaccine dose in PLWH but lower nAb responses persisted and were associated with global MBC dysfunction. In contrast, SARS-CoV-2 vaccination induced robust T cell responses that cross-recognized variants in PLWH. Strikingly, individuals with low or absent neutralization had detectable functional T cell responses. These PLWH had reduced numbers of circulating T follicular helper cells and an enriched population of CXCR3+CD127+CD8+T cells after two doses of SARS-CoV-2 vaccination.

9.
J Virol ; 85(7): 3367-74, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21248048

RESUMO

Previous studies have found an association between a single-nucleotide polymorphism 35 kb upstream of the HLA-C locus (-35 SNP), HLA-C expression, and HIV-1 set point viral loads. We show that the difference in HLA-C expression across -35 SNP genotypes can be attributed primarily to the very low expression of a single allelic product, HLA-Cw7, which is a common HLA type. We suggest that association of the -35 SNP and HIV-1 load manifests as a result of linkage disequilibrium of this polymorphism with both favorable and unfavorable HLA-C and -B alleles.


Assuntos
Expressão Gênica , HIV-1/imunologia , Antígenos HLA-C/biossíntese , Polimorfismo de Nucleotídeo Único , Elementos Reguladores de Transcrição , Humanos , Desequilíbrio de Ligação , Carga Viral
10.
J Virol ; 85(7): 3507-16, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21270166

RESUMO

HIV-1-specific T lymphocyte responses in individuals exposed to HIV-1 but who remain persistently seronegative (HESNs) have been reported in some but not all previous studies. This study was designed to resolve unequivocally the question of whether HESNs make HIV-1-specific T cell responses. We performed a blind investigation to measure HIV-1-specific T cell responses in both HIV-1-serodiscordant couples and HIV-1-unexposed seronegative controls (HUSNs). We found low-frequency HIV-1-specific T cells in both HESNs and HUSNs but show that the response rates were higher over time in the former (P = 0.01). Furthermore, the magnitudes of the HIV-1-specific T cell responses were significantly higher among responding HESNs than among HUSNs over time (P = 0.002). In both groups, responses were mediated by CD4 T cells. The responses were mapped to single peptides, which often corresponded to epitopes restricted by multiple HLA-DR types that have previously been detected in HIV-1-infected patients. HIV-1-specific T cell responses in HUSNs and some HESNs likely represent cross-reactivity to self or foreign non-HIV-1 antigens. The significantly greater T cell responses in HESNs, including in two who were homozygous for CCR5Δ32, demonstrates that HIV-1-specific T cell responses can be induced or augmented by exposure to HIV-1 without infection.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Anticorpos Anti-HIV/sangue , Infecções por HIV/imunologia , HIV-1/imunologia , Reações Cruzadas , Epitopos de Linfócito T/imunologia , Feminino , Antígenos HLA-DR/imunologia , Humanos , Masculino
11.
Sci Rep ; 12(1): 18366, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36319836

RESUMO

T cell exhaustion develops in human immunodeficiency virus (HIV) infection due to chronic viral antigenic stimulation. This adaptive response primarily affects virus-specific CD8+ T cells, which may remain dysfunctional despite viral load-reducing antiretroviral therapy; however, abnormalities may also be evident in non-HIV-specific populations. Both could limit the efficacy of cell therapies against viral reservoirs. Here, we show that bulk (polyclonal) CD8+ T cells from people living with HIV (PLWH) express proposed markers of dysfunctional HIV-specific T cells at high levels yet form lytic immunological synapses (IS) and eliminate primary resting infected (HIV Gaglo) CD4+ T cells, when redirected by potent bispecific T cell-retargeting molecules, Immune mobilising monoclonal T cell receptors (TCR) Against Virus (ImmTAV). While PLWH CD8+ T cells are functionally impaired when compared to CD8+ T cells from HIV-naïve donors, ImmTAV redirection enables them to eliminate Gaglo CD4+ T cells that are insensitive to autologous HIV-specific cytolytic T cells. ImmTAV molecules may therefore be able to target HIV reservoirs, which represent a major barrier to a cure.


Assuntos
Infecções por HIV , HIV-1 , Humanos , Linfócitos T CD8-Positivos , HIV-1/fisiologia , Sinapses Imunológicas , Linfócitos T CD4-Positivos , Receptores de Antígenos de Linfócitos T
12.
Dose Response ; 20(4): 15593258221138506, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36458282

RESUMO

This review article describes our simplified biophysical model for the response of a group of cells to ionizing radiation. The model, which is a product of 10 years of studies, acts as (a) a comprehensive stochastic approach based on the Monte Carlo simulation with a probability tree and (b) the thereof derived detailed deterministic models describing the selected biophysical and radiobiological phenomena in an analytical manner. Specifically, the presented model describes effects such as the risk of neoplastic transformation of cells relative to the absorbed radiation dose, the dynamics of tumor development, the priming dose effect (also called the Raper-Yonezawa effect) based on the introduced adaptive response approach, and the bystander effect. The model is also modifiable depending on users' potential needs.

13.
bioRxiv ; 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36380764

RESUMO

People living with HIV (PLWH) on suppressive antiretroviral therapy (ART) can have residual immune dysfunction and often display poorer responses to vaccination. We assessed in a cohort of PLWH (n=110) and HIV negative controls (n=64) the humoral and spike-specific B-cell responses following 1, 2 or 3 SARS-CoV-2 vaccine doses. PLWH had significantly lower neutralizing antibody (nAb) titers than HIV-negative controls at all studied timepoints. Moreover, their neutralization breadth was reduced with fewer individuals developing a neutralizing response against the Omicron variant (BA.1) relative to controls. We also observed a delayed development of neutralization in PLWH that was underpinned by a reduced frequency of spike-specific memory B cells (MBCs) and pronounced B cell dysfunction. Improved neutralization breadth was seen after the third vaccine dose in PLWH but lower nAb responses persisted and were associated with global, but not spike-specific, MBC dysfunction. In contrast to the inferior antibody responses, SARS-CoV-2 vaccination induced robust T cell responses that cross-recognized variants in PLWH. Strikingly, a subset of PLWH with low or absent neutralization had detectable functional T cell responses. These individuals had reduced numbers of circulating T follicular helper cells and an enriched population of CXCR3 + CD127 + CD8 + T cells after two doses of SARS-CoV-2 vaccination, which may compensate for sub-optimal serological responses in the event of infection. Therefore, normalisation of B cell homeostasis could improve serological responses to vaccines in PLWH and evaluating T cell immunity could provide a more comprehensive immune status profile in these individuals and others with B cell imbalances.

14.
Oxf Open Immunol ; 2(1): iqab010, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34522886

RESUMO

The rapid design and implementation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines is testament to a successfully coordinated global research effort. While employing a variety of different technologies, some of which have been used for the first time, all approved vaccines demonstrate high levels of efficacy with excellent safety profiles. Despite this, there remains an urgent global demand for coronavirus disease 2019 vaccines that require further candidates to pass phase 3 clinical trials. In the expectation of SARS-CoV-2 becoming endemic, researchers are looking to adjust the vaccine constructs to tackle emerging variants. In this review, we outline different platforms used for approved vaccines and summarize latest research data with regards to immunogenicity, dosing regimens and efficiency against emerging variants.

15.
J Virus Erad ; 7(3): 100056, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34611495

RESUMO

OBJECTIVE: HIV-remission strategies including kick-and-kill could induce viral transcription and immune-activation in the central nervous system, potentially causing neuronal injury. We investigated the impact of kick-and-kill on plasma neurofilament light (NfL), a marker of neuro-axonal injury, in RIVER trial participants commencing antiretroviral treatment (ART) during primary infection and randomly allocated to ART-alone or kick-and-kill (ART + vaccination + vorinostat (ART + V + V)). DESIGN: Sub-study measuring serial plasma NfL concentrations. METHODS: Plasma NfL (using Simoa digital immunoassay), plasma HIV-1 RNA (using single-copy assay) and total HIV-1 DNA (using quantitative polymerase chain reaction in peripheral CD4+ T-cells) were measured at randomisation (following ≥22 weeks ART), week 12 (on final intervention day in ART + V + V) and week 18 post-randomisation. HIV-specific T-cells were quantified by intracellular cytokine staining at randomisation and week 12. Differences in plasma NfL longitudinally and by study arm were analysed using mixed models and Student's t-test. Associations with plasma NfL were assessed using linear regression and rank statistics. RESULTS: At randomisation, 58 male participants had median age 32 years and CD4+ count 696 cells/µL. No significant difference in plasma NfL was seen longitudinally and by study arm, with median plasma NfL (pg/mL) in ART-only vs ART + V + V: 7.4 vs 6.4, p = 0.16 (randomisation), 8.0 vs 6.9, p = 0.22 (week 12) and 7.1 vs 6.8, p = 0.74 (week 18). Plasma NfL did not significantly correlate with plasma HIV-1 RNA and total HIV-1 DNA concentration in peripheral CD4+ T-cells at any timepoint. While higher HIV-specific T-cell responses were seen at week 12 in ART + V + V, there were no significant correlations with plasma NfL. In multivariate analysis, higher plasma NfL was associated with older age, higher CD8+ count and lower body mass index. CONCLUSIONS: Despite evidence of vaccine-induced HIV-specific T-cell responses, we observed no evidence of increased neuro-axonal injury using plasma NfL as a biomarker up to 18 weeks following kick-and-kill, compared with ART-only.

16.
Res Sq ; 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33758833

RESUMO

There is an urgent need to understand the nature of immune responses against SARS-CoV-2, to inform risk-mitigation strategies for people living with HIV (PLWH). We show that the majority of PLWH, controlled on ART, mount a functional adaptive immune response to SARS-CoV-2. Humoral and SARS-CoV-2-specific T cell responses are comparable between HIV-positive and negative subjects and persist 5-7 months following predominately mild COVID-19 disease. T cell responses against Spike, Membrane and Nucleocapsid are the most prominent, with SARS-CoV-2-specific CD4 T cells outnumbering CD8 T cells. We further show that the overall magnitude of SARS-CoV-2-specific T cell responses relates to the size of the naive CD4 T cell pool and the CD4:CD8 ratio in PLWH, in whom disparate antibody and T cell responses are observed. These findings suggest that inadequate immune reconstitution on ART, could hinder immune responses to SARS-CoV-2 with implications for the individual management and vaccine effectiveness in PLWH.

17.
Nat Commun ; 12(1): 5839, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34611163

RESUMO

There is an urgent need to understand the nature of immune responses against SARS-CoV-2, to inform risk-mitigation strategies for people living with HIV (PLWH). Here we show that the majority of PLWH with ART suppressed HIV viral load, mount a detectable adaptive immune response to SARS-CoV-2. Humoral and SARS-CoV-2-specific T cell responses are comparable between HIV-positive and negative subjects and persist 5-7 months following predominately mild COVID-19 disease. T cell responses against Spike, Membrane and Nucleoprotein are the most prominent, with SARS-CoV-2-specific CD4 T cells outnumbering CD8 T cells. We further show that the overall magnitude of SARS-CoV-2-specific T cell responses relates to the size of the naive CD4 T cell pool and the CD4:CD8 ratio in PLWH. These findings suggest that inadequate immune reconstitution on ART, could hinder immune responses to SARS-CoV-2 with implications for the individual management and vaccine effectiveness in PLWH.


Assuntos
Infecções por HIV/imunologia , Infecções por HIV/virologia , Imunidade Humoral , SARS-CoV-2/fisiologia , Linfócitos T/imunologia , Adulto , Idoso , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Antígenos Virais/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , COVID-19/sangue , COVID-19/imunologia , COVID-19/virologia , Estudos de Coortes , Feminino , Genoma Humano , Infecções por HIV/sangue , Humanos , Interferon gama/metabolismo , Masculino , Pessoa de Meia-Idade , Fenótipo , Especificidade da Espécie , Doadores de Tecidos
18.
bioRxiv ; 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33619489

RESUMO

There is an urgent need to understand the nature of immune responses generated against SARS-CoV-2, to better inform risk-mitigation strategies for people living with HIV (PLWH). Although not all PLWH are considered immunosuppressed, residual cellular immune deficiency and ongoing inflammation could influence COVID-19 disease severity, the evolution and durability of protective memory responses. Here, we performed an integrated analysis, characterizing the nature, breadth and magnitude of SARS-CoV-2-specific immune responses in PLWH, controlled on ART, and HIV negative subjects. Both groups were in the convalescent phase of predominately mild COVID-19 disease. The majority of PLWH mounted SARS-CoV-2 Spike- and Nucleoprotein-specific antibodies with neutralizing activity and SARS-CoV-2-specific T cell responses, as measured by ELISpot, at levels comparable to HIV negative subjects. T cell responses against Spike, Membrane and Nucleocapsid were the most prominent, with SARS-CoV-2-specific CD4 T cells outnumbering CD8 T cells. Notably, the overall magnitude of SARS-CoV-2-specific T cell responses related to the size of the naive CD4 T cell pool and the CD4:CD8 ratio in PLWH, in whom disparate antibody and T cell responses were observed. Both humoral and cellular responses to SARS-CoV-2 were detected at 5-7 months post-infection, providing evidence of medium-term durability of responses irrespective of HIV serostatus. Incomplete immune reconstitution on ART and a low CD4:CD8 ratio could, however, hamper the development of immunity to SARS-CoV-2 and serve as a useful tool for risk stratification of PLWH. These findings have implications for the individual management and potential effectiveness of vaccination against SARS-CoV-2 in PLWH.

19.
J Med Virol ; 82(1): 94-103, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19950243

RESUMO

The cytomegalovirus ppUL83 protein contains an immunodominant A*0201 restricted epitope between residues 495 and 503. We investigated the tolerance of this epitope to sequence variation in the context of peptide binding to HLA A*0201 and the ability to induce an Interferon gamma (IFNgamma) response through engagement with the T-cell receptor (TCR). The majority of mutations investigated resulted in a decrease in the production of IFNgamma indicating that if such variants occurred in vivo they would not be recognized by CD8 T-cell clones specific for the wild-type epitope. The mechanistic basis for the majority of the mutant peptides was their failure to bind and stabilize class I HLA cell surface expression. However, one peptide with a mutation at the P5 position (methionine to cysteine) resulted in a significant enhanced binding to HLA A*0201 and also an increase in cell surface expression over the wild-type peptide but was unable to engage with the CD8 TCR and trigger IFNgamma production. This peptide acted as a competitive inhibitor of the wild-type peptide but could not fully inhibit IFNgamma production by the latter. We subsequently investigated whether mutations of the HLA A*0201 epitope were evident in immunocompromized patients experiencing either rapid exponential or persistent cytomegalovirus replication.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/química , Antígenos HLA-A/metabolismo , Epitopos Imunodominantes/química , Mutação , Fosfoproteínas/química , Proteínas da Matriz Viral/química , Sequência de Aminoácidos , Epitopos de Linfócito T/imunologia , Antígeno HLA-A2 , Humanos , Epitopos Imunodominantes/imunologia , Interferon gama/biossíntese , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/imunologia , Fosfoproteínas/genética , Fosfoproteínas/imunologia , Fosfoproteínas/metabolismo , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/metabolismo , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/imunologia , Proteínas da Matriz Viral/metabolismo
20.
Sci Rep ; 9(1): 18713, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31822717

RESUMO

Despite an efficacious prophylactic human papillomavirus (HPV) vaccine there is still a considerable global burden of HPV-related disease. Therapeutic vaccines that could prevent cancers in at-risk women are urgently needed. Most candidate therapeutic vaccines have focused on two high-risk (hr) HPV genotypes, 16 and 18, and two viral targets, E6 and E7, which may limit global coverage and efficacy. We designed the synthetic gene '5GHPV3' by selecting conserved regions from each of the six early proteins and generating consensus sequences to represent five hrHPV genotypes. 5GHPV3 was delivered by plasmid DNA, chimpanzee adenovirus (ChAdOx1) and modified vaccinia Ankara (MVA) vectors in prime-boost regimens to mice. ChAdOx1-5GHPV3 / MVA-5GHPV3 induced higher magnitude and more durable HPV-specific T cell responses than other regimens. Vaccine-induced T cells were polyfunctional and persisted at high frequencies for at least six weeks. Importantly, HPV-specific effector CD8 + T cells were detected in the cervix following systemic administration of ChAdOx1-5GHPV3 / MVA-5GHPV3 and increased in frequency over time, indicating continued trafficking of T cells to the cervix. Finally, T cells specific for 5GHPV3 encoded antigens were detected by IFN-γ Elispot in women with current or past hrHPV infections, confirming the presence of epitopes relevant to natural immune control.


Assuntos
Papillomaviridae/genética , Papillomaviridae/imunologia , Vacinas contra Papillomavirus/imunologia , Adolescente , Adulto , Animais , Linfócitos T CD8-Positivos/imunologia , Feminino , Vetores Genéticos , Genótipo , Humanos , Imunização Secundária , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/metabolismo , Vacinas contra Papillomavirus/genética , Vacinação , Vacinas de DNA/genética , Vacinas de DNA/imunologia
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