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1.
J Gen Virol ; 101(12): 1229-1241, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32975505

RESUMO

Non-human primates form an important animal model for the evaluation of immunogenicity and efficacy of novel 'universal' vaccine candidates against influenza virus. However, in most studies a combination of intra-tracheal or intra-bronchial, oral and nasal virus inoculation is used with a standard virus dose of between 1 and 10 million tissue culture infective doses, which differs from typical modes of virus exposure in humans. This paper studies the systemic and local inflammatory and immune effects of aerosolized versus combined-route exposure to pandemic H1N1 influenza virus. In agreement with a previous study, both combined-route and aerosol exposure resulted in similar levels of virus replication in nose, throat and lung lavages. However, the acute release of pro-inflammatory cytokines and chemokines, acute monocyte activation in peripheral blood as well as increased cytokine production and T-cell proliferation in the lungs were only observed after combined-route infection and not after aerosol exposure. Longitudinal evaluation by computed tomography demonstrated persistence of lung lesions after resolution of the infection and a tendency for more lesions in the lower lung lobes after combined-route exposure versus upper and middle lung lobes after aerosol exposure. Computed tomography scores were observed to correlate with fever. In conclusion, influenza virus infection by aerosol exposure is accompanied by less immune-activation and inflammation in comparison with direct virus installation, despite similar levels of virus replication and development of lesions in the lungs.


Assuntos
Modelos Animais de Doenças , Vírus da Influenza A Subtipo H1N1 , Pulmão/imunologia , Macaca fascicularis , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Animais , Brônquios/virologia , Líquido da Lavagem Broncoalveolar/imunologia , Líquido da Lavagem Broncoalveolar/virologia , Citocinas/sangue , Citocinas/metabolismo , Humanos , Imunidade Celular , Imunidade Humoral , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/fisiologia , Influenza Humana/imunologia , Influenza Humana/virologia , Pulmão/virologia , Linfopenia , Masculino , Boca/virologia , Nariz/virologia , Infecções por Orthomyxoviridae/patologia , Replicação Viral , Eliminação de Partículas Virais
2.
J Gen Virol ; 100(5): 738-751, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30920368

RESUMO

Antibodies directed against the conserved regions within the influenza A haemagglutinin (HA) protein are detected at low frequency in humans. These antibodies display a broad reactivity against divergent influenza virus strains and could potentially offer broad protection. The in vivo protective effect of these antibodies is mainly mediated through Fc receptor effector functions. While antibody-dependent phagocytosis (ADP) of anti-HA antibodies has been demonstrated in human sera and sera from influenza virus-infected macaques, it is not known whether ADP can also be induced by vaccination and what the relative strength of ADP responses is in comparison to other antibody functions. Using a cohort of influenza virus-infected and immunized macaques, we demonstrate that infection as well as immunization with DNA-encoding HA induces high-titre ADP responses against HA, which are of potency 100-1000 times higher than virus inhibitory functions including antibody-dependent cell-mediated cytotoxicity (ADCC), virus neutralization (VN) and haemagglutinin inhibition (HAI). ADP activity was equally high against HA of heterologous influenza strains of the same subtype, in contrast to virus inhibitory functions, which were all greatly diminished. ADP titres against H5, representing a hetero-subtypic virus, were much lower. ADP was measured in THP-1 cells but was also observed in primary peripheral blood monocytes and neutrophils. Furthermore, at high serum dilution enhanced infection of both monocytes and myeloid dendritic cells (mDC) was observed. Hence, influenza virus infection as well as DNA-immunization against HA can induce high-titre ADP responses that can potentially enhance influenza virus infection of primary phagocytic and dendritic cells.


Assuntos
Anticorpos Antivirais/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vacinas contra Influenza/imunologia , Monócitos/imunologia , Orthomyxoviridae/imunologia , Fagocitose , Vacinas de DNA/imunologia , Animais , Células Cultivadas , Células Dendríticas/imunologia , Modelos Animais de Doenças , Humanos , Vacinas contra Influenza/administração & dosagem , Macaca , Neutrófilos/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Vacinas de DNA/administração & dosagem
3.
J Virol ; 91(19)2017 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-28701402

RESUMO

Strategies are needed to improve the immunogenicity of HIV-1 envelope (Env) antigens (Ag) for more long-lived, efficacious HIV-1 vaccine-induced B-cell responses. HIV-1 Env gp140 (native or uncleaved molecules) or gp120 monomeric proteins elicit relatively poor B-cell responses which are short-lived. We hypothesized that Env engagement of the CD4 receptor on T-helper cells results in anergic effects on T-cell recruitment and consequently a lack of strong, robust, and durable B-memory responses. To test this hypothesis, we occluded the CD4 binding site (CD4bs) of gp140 by stable cross-linking with a 3-kDa CD4 miniprotein mimetic, serving to block ligation of gp140 on CD4+ T cells while preserving CD4-inducible (CDi) neutralizing epitopes targeted by antibody-dependent cellular cytotoxicity (ADCC) effector responses. Importantly, immunization of rhesus macaques consistently gave superior B-cell (P < 0.001) response kinetics and superior ADCC (P < 0.014) in a group receiving the CD4bs-occluded vaccine compared to those of animals immunized with gp140. Of the cytokines examined, Ag-specific interleukin-4 (IL-4) T-helper enzyme-linked immunosorbent spot (ELISpot) assays of the CD4bs-occluded group increased earlier (P = 0.025) during the inductive phase. Importantly, CD4bs-occluded gp140 antigen induced superior B-cell and ADCC responses, and the elevated B-cell responses proved to be remarkably durable, lasting more than 60 weeks postimmunization.IMPORTANCE Attempts to develop HIV vaccines capable of inducing potent and durable B-cell responses have been unsuccessful until now. Antigen-specific B-cell development and affinity maturation occurs in germinal centers in lymphoid follicles through a critical interaction between B cells and T follicular helper cells. The HIV envelope binds the CD4 receptor on T cells as soluble shed antigen or as antigen-antibody complexes, causing impairment in the activation of these specialized CD4-positive T cells. We proposed that CD4-binding impairment is partly responsible for the relatively poor B-cell responses to HIV envelope-based vaccines. To test this hypothesis, we blocked the CD4 binding site of the envelope antigen and compared it to currently used unblocked envelope protein. We found superior and durable B-cell responses in macaques vaccinated with an occluded CD4 binding site on the HIV envelope antigen, demonstrating a potentially important new direction in future design of new HIV vaccines.


Assuntos
Anticorpos Neutralizantes/imunologia , Linfócitos B/imunologia , Antígenos CD4/imunologia , Anticorpos Anti-HIV/imunologia , Macaca mulatta/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Vacinas contra a AIDS/imunologia , Animais , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Sítios de Ligação de Anticorpos/imunologia , HIV-1/imunologia , Macaca mulatta/virologia , Vacinação
4.
J Virol ; 90(2): 1023-33, 2016 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-26537681

RESUMO

UNLABELLED: Influenza virus infection of nonhuman primates is a well-established animal model for studying pathogenesis and for evaluating prophylactic and therapeutic intervention strategies. However, usually a standard dose is used for the infection, and there is no information on the relation between challenge dose and virus replication or the induction of immune responses. Such information is also very scarce for humans and largely confined to evaluation of attenuated virus strains. Here, we have compared the effect of a commonly used dose (4 × 10(6) 50% tissue culture infective doses) versus a 100-fold-higher dose, administered by intrabronchial installation, to two groups of 6 cynomolgus macaques. Animals infected with the high virus dose showed more fever and had higher peak levels of gamma interferon in the blood. However, virus replication in the trachea was not significantly different between the groups, although in 2 out of 6 animals from the high-dose group it was present at higher levels and for a longer duration. The virus-specific antibody response was not significantly different between the groups. However, antibody enzyme-linked immunosorbent assay, virus neutralization, and hemagglutination inhibition antibody titers correlated with cumulative virus production in the trachea. In conclusion, using influenza virus infection in cynomolgus macaques as a model, we demonstrated a relationship between the level of virus production upon infection and induction of functional antibody responses against the virus. IMPORTANCE: There is only very limited information on the effect of virus inoculation dose on the level of virus production and the induction of adaptive immune responses in humans or nonhuman primates. We found only a marginal and variable effect of virus dose on virus production in the trachea but a significant effect on body temperature. The induction of functional antibody responses, including virus neutralization titer, hemagglutination inhibition titer, and antibody-dependent cell-mediated cytotoxicity, correlated with the level of virus replication measured in the trachea. The study reveals a relationship between virus production and functional antibody formation, which could be relevant in defining appropriate criteria for new influenza virus vaccine candidates.


Assuntos
Anticorpos Antivirais/sangue , Formação de Anticorpos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/fisiologia , Replicação Viral , Animais , Anticorpos Neutralizantes/sangue , Relação Dose-Resposta Imunológica , Ensaio de Imunoadsorção Enzimática , Testes de Inibição da Hemaglutinação , Macaca fascicularis , Masculino , Testes de Neutralização , Traqueia/virologia , Carga Viral
5.
J Gen Virol ; 96(Pt 6): 1478-1483, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25667320

RESUMO

The Thai trial (RV144) indicates that a prime-boost vaccine combination that induces both T-cell and antibody responses may be desirable for an effective HIV vaccine. We have previously shown that immunization with synthetic long peptides (SLP), covering the conserved parts of SIV, induced strong CD4 T-cell and antibody responses, but only modest CD8 T-cell responses. To generate a more balanced CD4/CD8 T-cell and antibody response, this study evaluated a pox-vector prime/SLP boost strategy in rhesus macaques. Priming with a replication-competent NYVAC, encoding HIV-1 clade C gag, pol and nef, induced modest IFNγ T-cell immune responses, predominantly directed against HIV-1 Gag. Booster immunization with SLP, covering the conserved parts of HIV-1 Gag, Pol and Env, resulted in a more than 10-fold increase in IFNγ ELISpot responses in four of six animals, which were predominantly HIV-1 Pol-specific. The animals showed a balanced polyfunctional CD4 and CD8 T-cell response and high Ab titres.


Assuntos
Vacinas contra a AIDS/imunologia , Formação de Anticorpos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Anticorpos Anti-HIV/sangue , HIV-1/imunologia , Imunização Secundária/métodos , Vacinas contra a AIDS/administração & dosagem , Animais , Macaca mulatta , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
6.
Sci Rep ; 13(1): 5074, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36977691

RESUMO

Influenza virosomes serve as antigen delivery vehicles and pre-existing immunity toward influenza improves the immune responses toward antigens. Here, vaccine efficacy was evaluated in non-human primates with a COVID-19 virosome-based vaccine containing a low dose of RBD protein (15 µg) and the adjuvant 3M-052 (1 µg), displayed together on virosomes. Vaccinated animals (n = 6) received two intramuscular administrations at week 0 and 4 and challenged with SARS-CoV-2 at week 8, together with unvaccinated control animals (n = 4). The vaccine was safe and well tolerated and serum RBD IgG antibodies were induced in all animals and in the nasal washes and bronchoalveolar lavages in the three youngest animals. All control animals became strongly sgRNA positive in BAL, while all vaccinated animals were protected, although the oldest vaccinated animal (V1) was transiently weakly positive. The three youngest animals had also no detectable sgRNA in nasal wash and throat. Cross-strain serum neutralizing antibodies toward Wuhan-like, Alpha, Beta, and Delta viruses were observed in animals with the highest serum titers. Pro-inflammatory cytokines IL-8, CXCL-10 and IL-6 were increased in BALs of infected control animals but not in vaccinated animals. Virosomes-RBD/3M-052 prevented severe SARS-CoV-2, as shown by a lower total lung inflammatory pathology score than control animals.


Assuntos
COVID-19 , Vacinas contra Influenza , Influenza Humana , Animais , Humanos , Macaca mulatta , Virossomos , SARS-CoV-2 , Receptor 7 Toll-Like , COVID-19/prevenção & controle , Adjuvantes Imunológicos , Anticorpos Amplamente Neutralizantes , Vacinas contra COVID-19 , Anticorpos Antivirais , Anticorpos Neutralizantes
7.
Front Immunol ; 13: 1026951, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36405682

RESUMO

Several studies have shown that the first encounter with influenza virus shapes the immune response to future infections or vaccinations. However, a detailed analysis of the primary antibody response is lacking as this is difficult to study in humans. It is therefore not known what the frequency and dynamics of the strain-specific hemagglutinin (HA) head- and stem-directed antibody responses are directly after primary influenza virus infection. Here, sera of twelve H1N1pdm2009 influenza virus-infected cynomolgus macaques were evaluated for HA-head and HA-stem domain antibody responses. We observed an early induction of HA-stem antibody responses, which was already decreased by day 56. In contrast, responses against the HA-head domain were low early after infection and increased at later timepoint. The HA-specific B cell repertoires in each animal showed diverse VH-gene usage with preferred VH-gene and JH-gene family usage for HA-head or HA-stem B cells but a highly diverse allelic variation within the VH-usage. HA-head B cells had shorter CDRH3s and higher VH-gene somatic hyper mutation levels relative to HA-stem B cells. In conclusion, our data suggest that HA-stem antibodies are the first to react to the infection while HA-head antibodies show a delayed response, but a greater propensity to enter the germinal center and undergo affinity maturation.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Infecções por Orthomyxoviridae , Humanos , Animais , Formação de Anticorpos , Hemaglutininas , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Anticorpos Antivirais
8.
Front Immunol ; 13: 857440, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35479095

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic. Here, we present non-human primate immunogenicity and protective efficacy data generated with the capsid virus-like particle (cVLP)-based vaccine ABNCoV2 that has previously demonstrated immunogenicity in mice. In rhesus macaques, a single vaccination with either 15 or 100 µg ABNCoV2 induced binding and neutralizing antibodies in a dose-dependent manner, at levels comparable to those measured in human convalescents. A second vaccine administration led to a >50-fold increase in neutralizing antibodies, with 2-log higher mean levels in the 100-µg ABNCoV2 group compared with convalescent samples. Upon SARS-CoV-2 challenge, a significant reduction in viral load was observed for both vaccine groups relative to the challenge control group, with no evidence of enhanced disease. Remarkably, neutralizing antibody titers against an original SARS-CoV-2 isolate and against variants of concern were comparable, indicating a potential for broad protection afforded by ABNCoV2, which is currently in clinical testing.


Assuntos
COVID-19 , Vacinas Virais , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Capsídeo , Proteínas do Capsídeo , Humanos , Macaca mulatta , SARS-CoV-2
9.
Front Immunol ; 13: 845887, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35371043

RESUMO

Novel safe, immunogenic, and effective vaccines are needed to control the COVID-19 pandemic, caused by SARS-CoV-2. Here, we describe the safety, robust immunogenicity, and potent efficacy elicited in rhesus macaques by a modified vaccinia virus Ankara (MVA) vector expressing a full-length SARS-CoV-2 spike (S) protein (MVA-S). MVA-S vaccination was well tolerated and induced S and receptor-binding domain (RBD)-binding IgG antibodies and neutralizing antibodies against SARS-CoV-2 and several variants of concern. S-specific IFNγ, but not IL-4, -producing cells were also elicited. After SARS-CoV-2 challenge, vaccinated animals showed a significant strong reduction of virus loads in bronchoalveolar lavages (BAL) and decreased levels in throat and nasal mucosa. Remarkably, MVA-S also protected macaques from fever and infection-induced cytokine storm. Computed tomography and histological examination of the lungs showed reduced lung pathology in MVA-S-vaccinated animals. These findings favor the use of MVA-S as a potential vaccine for SARS-CoV-2 in clinical trials.


Assuntos
COVID-19 , Vaccinia virus , Animais , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Macaca mulatta , Pandemias , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus , Vaccinia virus/genética
10.
J Med Virol ; 83(11): 1938-50, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21915869

RESUMO

Herpesvirus saimiri (HVS) causes acute lymphoma and leukemia upon experimental infection of various monkey species. HVS strain C488 is also capable of transforming human T-lymphocytes to stable growth in culture. The most susceptible species for oncogenesis are New World primates, in particular the cottontop tamarin (Saguinus oedipus). However, Old World monkeys such as macaques are the most used animal model for the close-to-human situation. The limited data on HVS infection in Old World monkeys prompted us to investigate susceptibility to infection and disease induction by HVS in macaques. After having established that rhesus macaques can be infected productively, and that rhesus T-cells can be transformed in vivo by HVS, we observed induction of lymphoma in all inoculated animals. Pre-existing humoral immunity in part of the rhesus colony capable of blocking HVS infection could be overcome by preselecting rhesus macaques for lack of this immunity of unknown origin. HVS infection of rhesus macaques as compared to that of New World monkeys has the advantages that disease progression is more prolonged, and larger blood volumes can be collected, which allows more extended analyses. Also, rhesus monkeys are the best immunologically and immunogenetically characterized primate species next to humans. This model could be useful for the evaluation of candidate tumor vaccines and to test novel approaches for cancer immunotherapy. In addition, HVS infection of macaques could eventually be useful as a surrogate model to address certain questions in rhadinovirus-induced human cancer such as effusion lymphoma or Kaposi's sarcoma.


Assuntos
Transformação Celular Viral , Modelos Animais de Doenças , Infecções por Herpesviridae/patologia , Herpesvirus Saimiriíneo 2/patogenicidade , Linfoma/patologia , Linfócitos T/virologia , Infecções Tumorais por Vírus/patologia , Animais , Feminino , Linfoma/virologia , Macaca mulatta , Masculino , Rhadinovirus/patogenicidade
11.
Viruses ; 13(2)2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33671829

RESUMO

Infection with highly pathogenic avian H5N1 influenza virus in humans often leads to severe respiratory disease with high mortality. Experimental infection in non-human primates can provide additional insight into disease pathogenesis. However, such a model should recapitulate the disease symptoms observed in humans, such as pneumonia and inflammatory cytokine response. While previous studies in macaques have demonstrated the occurrence of typical lesions in the lungs early after infection and a high level of immune activation, progression to severe disease and lethality were rarely observed. Here, we evaluated a routinely used combined route of infection via intra-bronchial, oral, and intra-nasal virus inoculation with aerosolized H5N1 exposure, with or without the regular collection of bronchoalveolar lavages early after infection. Both combined route and aerosol exposure resulted in similar levels of virus replication in nose and throat and similar levels of immune activation, cytokine, and chemokine release in the blood. However, while animals exposed to H5N1 by combined-route inoculation developed severe disease with high lethality, aerosolized exposure resulted in less lesions, as measured by consecutive computed tomography and less fever and lethal disease. In conclusion, not virus levels or immune activation, but route of infection determines fatal outcome for highly pathogenic avian H5N1 influenza infection.


Assuntos
Aerossóis/análise , Brônquios/virologia , Virus da Influenza A Subtipo H5N1/fisiologia , Influenza Humana/virologia , Macaca fascicularis/virologia , Boca/virologia , Nariz/virologia , Microbiologia do Ar , Animais , Citocinas/genética , Citocinas/imunologia , Modelos Animais de Doenças , Exposição Ambiental , Humanos , Virus da Influenza A Subtipo H5N1/genética , Influenza Humana/genética , Influenza Humana/imunologia , Masculino
12.
J Exp Med ; 218(7)2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-33909009

RESUMO

Safe and effective coronavirus disease-19 (COVID-19) vaccines are urgently needed to control the ongoing pandemic. While single-dose vaccine regimens would provide multiple advantages, two doses may improve the magnitude and durability of immunity and protective efficacy. We assessed one- and two-dose regimens of the Ad26.COV2.S vaccine candidate in adult and aged nonhuman primates (NHPs). A two-dose Ad26.COV2.S regimen induced higher peak binding and neutralizing antibody responses compared with a single dose. In one-dose regimens, neutralizing antibody responses were stable for at least 14 wk, providing an early indication of durability. Ad26.COV2.S induced humoral immunity and T helper cell (Th cell) 1-skewed cellular responses in aged NHPs that were comparable to those in adult animals. Aged Ad26.COV2.S-vaccinated animals challenged 3 mo after dose 1 with a SARS-CoV-2 spike G614 variant showed near complete lower and substantial upper respiratory tract protection for both regimens. Neutralization of variants of concern by NHP sera was reduced for B.1.351 lineages while maintained for the B.1.1.7 lineage independent of Ad26.COV2.S vaccine regimen.


Assuntos
Adenoviridae/imunologia , Envelhecimento/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Temperatura Corporal , Lavagem Broncoalveolar , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Relação Dose-Resposta Imunológica , Feminino , Imunidade Humoral , Cinética , Pulmão/patologia , Pulmão/virologia , Macaca mulatta , Masculino , Glicoproteína da Espícula de Coronavírus/metabolismo , Resultado do Tratamento , Vacinação , Carga Viral
13.
J Gen Virol ; 91(Pt 12): 2974-84, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20826621

RESUMO

Recent advances in human immunodeficiency virus (HIV) vaccine design have resulted in induction of strong CD4 T-cell proliferative and polyfunctional cytokine responses, which are also characteristic for long-term non-progressing (LTNP) HIV-infected individuals. However, limited information is available on the persistence of these responses after infection. Results from studies in non-human primates indicate that vaccine-induced immune responses are partially maintained upon viral infection and differ from the responses seen in non-vaccinated animals that typically progress to disease. However, it is unclear how these partially preserved responses compare to immune responses that are acquired naturally by LTNP animals. In this study, immune-response profiles were compared between vaccinated animals that, upon SHIV89.6 challenge, became infected but were able to control virus replication, and a group of animals having spontaneous control of this viral infection. Both groups were found to develop very similar immune responses with regard to induction of CD4 and CD8 T-cell polyfunctional cytokine responses, proliferative capacity and cytotoxic capacity, as measured by a standard 51Cr release assay and more direct ex vivo and in vivo CTL assays. Hence, vaccinated animals that become infected, but control infection, appear to establish immune responses that are similar to those elicited by long-term non-progressors.


Assuntos
Produtos do Gene env/imunologia , Produtos do Gene gag/imunologia , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Proliferação de Células , Radioisótopos de Cromo/metabolismo , Citocinas/metabolismo , Citotoxicidade Imunológica , Humanos , Macaca mulatta , Replicação Viral
14.
NPJ Vaccines ; 3: 25, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29977611

RESUMO

Seasonal vaccines are currently the most effective countermeasure against influenza. However, seasonal vaccines are only effective against strains closely related to the influenza strains contained in the vaccine. Recently a new hemagglutinin (HA) stem-based antigen, the so-called "mini-HA", has been shown to induce a cross-protective immune response in influenza-naive mice and non-human primates (NHP). However, prior exposure to influenza can have a profound effect on the immune response to subsequent influenza infection and the protective efficacy of vaccination. Here we show that mini-HA, compared to a trivalent influenza vaccine (TIV), elicits a broadened influenza-specific humoral immune response in NHP previously exposed to influenza. Serum transfer experiments showed that antibodies induced by both mini-HA and seasonal vaccine protected mice against lethal challenge with a H1N1 influenza strain heterologous to the H1 HA included in the TIV. However, antibodies elicited by mini-HA showed an additional benefit of protecting mice against lethal heterosubtypic H5N1 influenza challenge, associated with H5 HA-specific functional antibodies.

15.
PLoS One ; 10(5): e0126132, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25946071

RESUMO

The close immunological and physiological resemblance with humans makes non-human primates a valuable model for studying influenza virus pathogenesis and immunity and vaccine efficacy against infection. Although both cynomolgus and rhesus macaques are frequently used in influenza virus research, a direct comparison of susceptibility to infection and disease has not yet been performed. In the current study a head-to-head comparison was made between these species, by using a recently described swine-origin pandemic H1N1 strain, A/Mexico/InDRE4487/2009. In comparison to rhesus macaques, cynomolgus macaques developed significantly higher levels of virus replication in the upper airways and in the lungs, involving both peak level and duration of virus production, as well as higher increases in body temperature. In contrast, clinical symptoms, including respiratory distress, were more easily observed in rhesus macaques. Expression of sialyl-α-2,6-Gal saccharides, the main receptor for human influenza A viruses, was 50 to 73 times more abundant in trachea and bronchus of cynomolgus macaques relative to rhesus macaques. The study also shows that common marmosets, a New World non-human primate species, are susceptible to infection with pandemic H1N1. The study results favor the cynomolgus macaque as model for pandemic H1N1 influenza virus research because of the more uniform and high levels of virus replication, as well as temperature increases, which may be due to a more abundant expression of the main human influenza virus receptor in the trachea and bronchi.


Assuntos
Callithrix/virologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/fisiologia , Macaca fascicularis/imunologia , Macaca fascicularis/virologia , Macaca mulatta/imunologia , Macaca mulatta/virologia , Animais , Quimiocinas/sangue , Citocinas/sangue , Modelos Animais de Doenças , Febre/etiologia , Especificidade de Hospedeiro , Interações Hospedeiro-Patógeno/imunologia , Humanos , Mediadores da Inflamação/sangue , Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Influenza Humana/virologia , Pulmão/patologia , Masculino , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/patologia , Infecções por Orthomyxoviridae/virologia , Pandemias , Receptores Virais/metabolismo , Suínos/virologia , Carga Viral , Virulência/imunologia , Replicação Viral
16.
AIDS ; 18(1): 25-36, 2004 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-15090826

RESUMO

OBJECTIVE: To develop a novel SIV-CCR5 receptor vaccine strategy that will protect macaques from SHIV infection by the vaginal mucosal route. DESIGN: The rationale for this strategy is that humans who express the homozygous delta32 CCR5 mutation and the associated upregulation of CC chemokines, the down-modulation of cell-surface expression of CCR5 and antibodies to CCR5 are protected against HIV infection. METHODS: A vaccine was prepared consisting of three extracellular peptides of CCR5, an N-terminal HIV gp120 fragment generated in transgenic plants and recombinant SIV p27. These were linked to the 70 000 Mr microbial heat shock protein (HSP70) carrier. The vaccine was administered (x3) either by the vaginal mucosal route or by targeting the proximity of the draining iliac lymph nodes. RESULTS: Serum and vaginal fluid IgG and IgA antibodies, IL-2 and IFN-gamma-producing cells, and macrophage-inflammatory protein (MIP) 1beta and MIP-1alpha (CCL4 and CCL3) were significantly raised in immunized macaques (P = 0.01-0.05). Vaginal challenge with SHIV(89.6P) infected all macaques, but sequential analysis over 24 weeks showed a significant variation in viral loads between the animals (P = 0.05). Whereas SHIV(89.6P) persisted in the four unimmunized macaques, in five of the eight immunized macaques the virus was cleared or became undetectable by reverse transcriptase-polymerase chain reaction. The CD4 cell counts in the immunized macaques were significantly higher than those in unimmunized animals (P < 0.05). CONCLUSION: An immunization strategy that targets both the virus and its CCR5 receptor has significantly inhibited SHIV(89.6P) infection and may serve as a novel strategy in the prevention of HIV transmission.


Assuntos
Vacinas contra a AIDS/uso terapêutico , Receptores CCR5/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Animais , Anticorpos Antivirais/análise , Biomarcadores/análise , Contagem de Linfócito CD4 , Quimiocina CCL5/análise , Feminino , Infecções por HIV/imunologia , Imunoglobulina G/análise , Imunoglobulina M/análise , Interferon gama/análise , Interleucina-2/análise , Linfonodos/imunologia , Macaca mulatta , Proteínas Inflamatórias de Macrófagos/análise , Mucosa/imunologia , Receptores CCR5/análise , Linfócitos T/imunologia , Vagina/imunologia , Carga Viral
17.
PLoS One ; 8(8): e72702, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23977339

RESUMO

BACKGROUND: Passive transfer of antibodies can be protective in the simian human immunodeficiency virus (SHIV)--rhesus macaque challenge model. The human monoclonal antibody IgG1 b12 neutralizes human immunodeficiency type 1 (HIV-1) in vitro and protects against challenge by SHIV. Our hypothesis is that neutralizing antibodies can only completely inactivate a relatively small number of infectious virus. METHODS AND FINDINGS: We have used GHOST cell assays to quantify individual infectious events with HIV-1SF162 and its SHIV derivatives: the relatively neutralization sensitive SHIV(SF162P4) isolate and the more resistant SHIV(SF162P3). A plot of the number of fluorescent GHOST cells with increasing HIV-1SF162 dose is not linear. It is likely that with high-dose inocula, infection with multiple virus produces additive fluorescence in individual cells. In studies of the neutralization kinetics of IgG1 b12 against these isolates, events during the absorption phase of the assay, as well as the incubation phase, determine the level of neutralization. It is possible that complete inactivation of a virus is limited to the time it is exposed on the cell surface. Assays can be modified so that neutralization of these very low doses of virus can be quantified. A higher concentration of antibody is required to neutralize the same dose of resistant SHIV(SF162P3) than the sensitive SHIV(SF162P4). In the absence of selection during passage, the density of the CCR5 co-receptor on the GHOST cell surface is reduced. Changes in the CD4 : CCR5 density ratio influence neutralization. CONCLUSIONS: Low concentrations of IgG1 b12 completely inactivate small doses of the neutralization resistant SHIV(SF162P3). Assays need to be modified to quantify this effect. Results from modified assays may predict protection following repeated low-dose shiv challenges in rhesus macaques. It should be possible to induce this level of antibody by vaccination so that modified assays could predict the outcome of human trials.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Macaca mulatta/imunologia , Testes de Neutralização , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Absorção Fisiológica , Animais , Contagem de Células , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Relação Dose-Resposta Imunológica , Citometria de Fluxo , Fluorescência , HIV-1/imunologia , Humanos , Modelos Lineares , Macaca mulatta/virologia , Receptores CCR5/metabolismo , Inoculações Seriadas , Síndrome de Imunodeficiência Adquirida dos Símios/virologia
18.
AIDS ; 27(18): 2841-51, 2013 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-24105029

RESUMO

OBJECTIVES: We recently developed a HIVconsv vaccine strategy, consisting of combined conserved regions of HIV-1, to adequately cover viral diversity. To evaluate efficacy in nonhuman primates, an equivalent SIV-derived immunogen SIVconsv was designed and delivered as plasmid DNA or synthetic long peptides. DESIGN: Rhesus macaques lacking protective MHC class I alleles Mamu-A*001 : 01, B*008 : 01, B*017 : 01 were immunized with either SIVconsv synthetic long peptides (S) alone or in combination with plasmid DNA encoding the same conserved regions (D) using SSS or DDSS regimens. METHODS: The SIVconsv synthetic long peptide vaccine consisted of 46 approximately 30-amino acid-long peptides emulsified in Montanide ISA-720 and adjuvanted with pegylated type I interferon and imiquimod. RESULTS: Both SSS and DDSS regimens generated high frequencies of SIV-specific IFN-γ-producing cells comparable with reported adenoviral vector systems. Strong polyfunctional CD4⁺ T-cell and modest CD8⁺ T-cell responses were generated, which were of central memory T-cell phenotype. Furthermore, SIVconsv-specific antibody responses were induced capable of recognizing the Env glycoprotein. Eight weeks after the last immunization, control and SIVconsv-vaccinated animals were challenged intrarectally with 10 MID50 of pathogenic SIVmac251. Two out of six animals in the DDSS group were protected against infection, while all 14 animals in the SSS and two control groups were infected. Vaccine induced SIV-specific IgG responses in mucosal washes prechallenge were highest in the two protected animals. CONCLUSION: This study demonstrates that vaccine-elicited responses towards conserved regions can afford partial protection against a high-dose intrarectal SIVmac251 challenge.


Assuntos
Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vacinação/métodos , Vacinas de DNA/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Macaca mulatta , Vacinas contra a SAIDS/administração & dosagem , Vacinas contra a SAIDS/genética , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vacinas de DNA/administração & dosagem , Vacinas de DNA/genética , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/genética , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
19.
PLoS One ; 6(12): e28974, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22216149

RESUMO

BACKGROUND: A vaccine is needed to control the spread of human immunodeficiency virus type 1 (HIV-1). An in vitro assay that can predict the protection induced by a vaccine would facilitate the development of such a vaccine. A potential candidate would be an assay to quantify neutralization of HIV-1. METHODS AND FINDINGS: We have used sera from rhesus macaques that have been immunized with HIV candidate vaccines and subsequently challenged with simian human immunodeficiency virus (SHIV). We compared neutralization assays with different formats. In experiments with the standardized and validated TZMbl assay, neutralizing antibody titers against homologous SHIV(SF162P4) pseudovirus gave a variable correlation with reductions in plasma viremia levels. The target cells used in the assays are not just passive indicators of virus infection but are actively involved in the neutralization process. When replicating virus was used with GHOST cell assays, events during the absorption phase, as well as the incubation phase, determine the level of neutralization. Sera that are associated with protection have properties that are closest to the traditional concept of neutralization: the concentration of antibody present during the absorption phase has no effect on the inactivation rate. In GHOST assays, events during the absorption phase may inactivate a fixed number, rather than a proportion, of virus so that while complete neutralization can be obtained, it can only be found at low doses particularly with isolates that are relatively resistant to neutralization. CONCLUSIONS: Two scenarios have the potential to predict protection by neutralizing antibodies at concentrations that can be induced by vaccination: antibodies that have properties close to the traditional concept of neutralization may protect against a range of challenge doses of neutralization sensitive HIV isolates; a window of opportunity also exists for protection against isolates that are more resistant to neutralization but only at low challenge doses.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , HIV-1/imunologia , Animais , Cinética , Macaca mulatta
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