RESUMO
Previously, chronic-phase protection against SHIV(89.6P) challenge was significantly greater in macaques primed with replicating adenovirus type 5 host range mutant (Ad5hr) recombinants encoding HIVtat and env and boosted with Tat and Env protein compared with macaques primed with multigenic adenovirus recombinants (HIVtat, HIVenv, SIVgag, SIVnef) and boosted with Tat, Env, and Nef proteins. The greater protection was correlated with Tat- and Env-binding Abs. Because the macaques lacked SHIV(89.6P)-neutralizing activity prechallenge, we investigated whether Ab-dependent cellular cytotoxicity (ADCC) and Ab-dependent cell-mediated viral inhibition (ADCVI) might exert a protective effect. We clearly show that Tat can serve as an ADCC target, although the Tat-specific activity elicited did not correlate with better protection. However, Env-specific ADCC activity was consistently higher in the Tat/Env group, with sustained cell killing postchallenge exhibited at higher levels (p < 0.00001) for a longer duration (p = 0.0002) compared with the multigenic group. ADCVI was similarly higher in the Tat/Env group and significantly correlated with reduced acute-phase viremia at wk 2 and 4 postchallenge (p = 0.046 and 0.011, respectively). Viral-specific IgG and IgA Abs in mucosal secretions were elicited but did not influence the outcome of the i.v. SHIV(89.6P) challenge. The higher ADCC and ADCVI activities seen in the Tat/Env group provide a plausible mechanism responsible for the greater chronic-phase protection. Because Tat is known to enhance cell-mediated immunity to coadministered Ags, further studies should explore its impact on Ab induction so that it may be optimally incorporated into HIV vaccine regimens.
Assuntos
Anticorpos Antivirais/biossíntese , Vacinas contra a SAIDS/administração & dosagem , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Produtos do Gene env do Vírus da Imunodeficiência Humana/administração & dosagem , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene tat do Vírus da Imunodeficiência Humana/administração & dosagem , Produtos do Gene tat do Vírus da Imunodeficiência Humana/imunologia , Adenoviridae/genética , Adenoviridae/imunologia , Animais , Anticorpos Antivirais/fisiologia , Citotoxicidade Celular Dependente de Anticorpos/genética , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antivirais/administração & dosagem , Antivirais/imunologia , Sítios de Ligação de Anticorpos/genética , Linhagem Celular Transformada , Células Cultivadas , Feminino , Humanos , Macaca mulatta , Masculino , Testes de Neutralização , Vacinas contra a SAIDS/genética , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vacinas de DNA/administração & dosagem , Vacinas de DNA/genética , Vacinas de DNA/imunologia , Vaccinia virus/genética , Vaccinia virus/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene tat do Vírus da Imunodeficiência Humana/genéticaRESUMO
We demonstrate that the FATAL cytolysis assay can be adapted into a rapid and fluorometric antibody-dependent cellular cytotoxicity assay (RFADCC). The RFADCC relies on double-staining target cells with a membrane dye (PKH-26) and a viability dye (CFSE) prior to the addition of antibody and effector cells. We used the RFADCC to assess dose-dependent and envelope-specific anti-human immunodeficiency virus (HIV) ADCC responses mediated by monoclonal antibody-2G12 and human sera. Using the assay, we also detected early anti-simian immunodeficiency virus (SIV) ADCC responses in rhesus macaques infected with pathogenic SIV(mac251). Importantly, the RFADCC was further useful in monitoring anti-HIV and anti-SIV ADCC responses elicited by immunizing chimpanzees and rhesus macaques with replicating adenovirus-based AIDS vaccine candidates. In comparison to the standard chromium release assay, the RFADCC provides a higher cell killing readout and is advantageous in allowing use of viably frozen as well as fresh effector cells, thus facilitating assay standardization. The RFADCC is therefore a simple, reliable, and highly sensitive method that can be applied to assess the ADCC activity of monoclonal antibodies as well as ADCC responses elicited by HIV or SIV infection or by AIDS vaccine candidates.
Assuntos
Citotoxicidade Celular Dependente de Anticorpos , Testes Imunológicos de Citotoxicidade , Fluorometria/métodos , Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Monoclonais , Anticorpos Antivirais/sangue , Cromo , Fluoresceínas , Corantes Fluorescentes , Infecções por HIV/imunologia , Humanos , Técnicas In Vitro , Macaca mulatta , Compostos Orgânicos , Pan troglodytes , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , SuccinimidasRESUMO
Possible inhibitory effects of hepatitis C virus (HCV) proteins on cellular protein synthesis were analyzed using transient expression system. The core protein, the nonstructural protein 4A (NS4A) and NS4B, but not NS3, NS5A or NS5B, inhibited p21/Waf1 expression post-transcriptionally. Further analysis revealed that the inhibition by NS4A and NS4B was mediated at least partly, if not entirely, at the translation level. NS4A-mediated translational inhibition was counteracted to some extent by NS3 co-expressed either in trans or cis. Co-expression of NS4A and NS4B exerted an additive effect on the translational inhibition. The N-terminal two-thirds of NS4A (amino acids 1-40) was shown to be involved in the translational inhibition. We also tested possible inhibitory effects of NS4A and NS4B on synthesis of other cellular proteins in parallel with p21/Waf1. NS4A and NS4B inhibited p21/Waf1 most strongly, followed by RNase L, p53, a C-terminally truncated form of CREB-RP and 2'-5' oligoadenylate synthetase. p21/Waf1, RNase L and p53 are known to have the PEST (proline-glutamic acid-serine-threonine) motif with relatively high scores in their sequences and considered to be sensitive to intracellular degradation. Taken together, our results suggest that NS4A and NS4B each mediate translational inhibition and, probably, increased degradation of certain cellular proteins.
Assuntos
Ciclinas/antagonistas & inibidores , Ciclinas/metabolismo , Hepacivirus/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas não Estruturais Virais/farmacologia , Células 3T3 , Sequência de Aminoácidos , Animais , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/química , Hepacivirus/genética , Humanos , Camundongos , Dados de Sequência Molecular , Células Tumorais Cultivadas , Proteínas não Estruturais Virais/metabolismo , Proteínas Virais/antagonistas & inibidores , Proteínas Virais/química , Proteínas Virais/metabolismoRESUMO
OBJECTIVE: To characterize the correlates of protection from systemic infection in a vaccinated rhesus macaque, RAt-9, which had been challenged sequentially with two related clade C simian/human immunodeficiency viruses (SHIV-Cs) yet remained aviremic for more than 5 years despite indirect evidence of cryptic infection. DESIGN: To measure long-term anti-SHIV-C immunity, host genetics and gene-expression patterns for protective correlates. METHODS: Long-term immune reactivity was evaluated and identification of virus in RAt-9 was attempted by RT-PCR analysis of concentrated plasma and blood transfer to CD8(+) cell-depleted infant macaques. Full MHC genotyping of RAt-9, TRIM5α and KIR3DL allelic expression analysis of PBMC, and microarray gene expression analysis were performed. RESULTS: All attempts to detect/isolate virus, including blood transfer to CD8(+) cell-depleted infant rhesus macaques, were negative, and the animal maintained normal levels of memory CD4(+) T cells in both peripheral blood and gut tissues. However, RAt-9 maintained high levels of anti-SHIV-C humoral and cellular immunity, including reactivity to nonvaccine neoantigens (Nef and Rev), up to 63 months postinitial challenge, suggesting chronic sub-threshold infection. RAt-9 expressed the Mamu A*001 allele negative for B*008 and B*017, had a B13 serotype, and had increased expression of killer-cell immunoglobulin-like receptors (KIRs) previously linked to favorable outcomes of lentiviral infection. Elements of the gene expression profiling coincided with genotyping results. RAt-9 also displayed CD8 cell noncytotoxic antiviral response (CNAR) activity. CONCLUSION: Monkey RAt-9 is the first example of a virus-exposed, persistently aviremic animal that has maintained long-term, high-level cellular and humoral antiviral immunity in the absence of an identifiable cryptic reservoir.
Assuntos
Vacinas contra a AIDS/farmacologia , Regulação Viral da Expressão Gênica/imunologia , HIV-1/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Viremia/imunologia , Viremia/prevenção & controle , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Antivirais/sangue , DNA Viral/sangue , Regulação Viral da Expressão Gênica/genética , HIV-1/genética , Macaca mulatta , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Síndrome de Imunodeficiência Adquirida dos Símios/sangue , Síndrome de Imunodeficiência Adquirida dos Símios/genética , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/genética , Viremia/genéticaRESUMO
The role of antibodies directed against the hyper variable envelope region V1 of human immunodeficiency virus type 1 (HIV-1), has not been thoroughly studied. We show that a vaccine able to elicit strain-specific non-neutralizing antibodies to this region of gp120 is associated with control of highly pathogenic chimeric SHIV(89.6P) replication in rhesus macaques. The vaccinated animal that had the highest titers of antibodies to the amino terminus portion of V1, prior to challenge, had secondary antibody responses that mediated cell killing by antibody-dependent cellular cytotoxicity (ADCC), as early as 2 weeks after infection and inhibited viral replication by antibody-dependent cell-mediated virus inhibition (ADCVI), by 4 weeks after infection. There was a significant inverse correlation between virus level and binding antibody titers to the envelope protein, (R=-0.83, p=0.015), and ADCVI (R=-0.84 p=0.044). Genotyping of plasma virus demonstrated in vivo selection of three SHIV(89.6P) variants with changes in potential N-linked glycosylation sites in V1. We found a significant inverse correlation between virus levels and titers of antibodies that mediated ADCVI against all the identified V1 virus variants. A significant inverse correlation was also found between neutralizing antibody titers to SHIV(89.6) and virus levels (R=-0.72 p=0.0050). However, passive inoculation of purified immunoglobulin from animal M316, the macaque that best controlled virus, to a naïve macaque, resulted in a low serum neutralizing antibodies and low ADCVI activity that failed to protect from SHIV(89.6P) challenge. Collectively, while our data suggest that anti-envelope antibodies with neutralizing and non-neutralizing Fc(R-dependent activities may be important in the control of SHIV replication, they also demonstrate that low levels of these antibodies alone are not sufficient to protect from infection.
Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Anti-HIV/sangue , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , HIV-1/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vacinas contra a AIDS/administração & dosagem , Animais , Citotoxicidade Celular Dependente de Anticorpos , Humanos , Macaca mulatta , Carga ViralRESUMO
Previously, replicating adenovirus type 5 host range (Ad5hr)-HIV/SIV recombinant priming in combination with SIV envelope boosting, resulted in significant, durable protection in 39% of rhesus macaques after SIVmac251 challenge. Both Env-specific antibody mediating ADCC, and cellular immunity correlated with protection. Here we evaluate the relative immunogenicities of novel HIV proteins and their contribution to protection in a SHIV89.6P model. All groups were primed with Ad-HIVenv89.6P, SIVgag239, and SIVnef239 recombinants. One group was not boosted, one received HIV89.6Pgp140DeltaCFI protein, and one a novel HIV-1 poly-peptide "peptomer". The HIV89.6Pgp140DeltaCFI protein in adjuvant strongly boosted Env-specific antibody and memory T cell responses in blood and tissue, resulting in significant reductions in acute and set point viremia. Macaques not boosted, showed a significant reduction in set point viremia, a full 32 weeks after the last Ad priming immunization. The HIV peptomer-boosted group showed a trend toward chronic viremia reduction, but was not protected.
Assuntos
Adenoviridae/fisiologia , Vetores Genéticos , HIV-1/imunologia , Vírus da Imunodeficiência Símia/imunologia , Viremia/prevenção & controle , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/imunologia , Adenoviridae/genética , Animais , Anticorpos Anti-HIV/sangue , Infecções por HIV/prevenção & controle , HIV-1/genética , HIV-1/patogenicidade , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Imunização , Imunização Secundária , Macaca mulatta , Masculino , Recombinação Genética , Vacinas contra a SAIDS/administração & dosagem , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/patogenicidade , Vírus da Imunodeficiência Símia/efeitos da radiação , Linfócitos T/imunologia , Replicação Viral , Produtos do Gene env do Vírus da Imunodeficiência Humana/administração & dosagemRESUMO
Protection afforded by HIV Tat-based vaccines has differed in Indian rhesus and Mauritian cynomolgus macaques. We evaluated native Tat and Ad-HIVtat priming/Tat-boosting regimens in both species. Both vaccines were immunogenic. Only the Ad-tat regimen modestly reduced acute viremia in rhesus macaques after SHIV(89.6P) challenge. Confounding variables uncovered in Mauritian macaques included significant associations of susceptibility to infection with MHC class IB and class II H2 and H5 haplotypes, and resistance to infection with class IB haplotypes H3 and H6. Although protection here was limited, Tat-based vaccines incorporating other HIV components have shown greater efficacy. Combination strategies should be further explored.
Assuntos
Vacinas contra a AIDS/imunologia , Suscetibilidade a Doenças , Haplótipos , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Produtos do Gene tat do Vírus da Imunodeficiência Humana/imunologia , Animais , Macaca fascicularis , Macaca mulatta , Carga Viral , ViremiaRESUMO
We previously demonstrated that replication-competent adenovirus (Ad)-simian immunodeficiency virus (SIV) recombinant prime/protein boost regimens elicit potent immunogenicity and strong, durable protection of rhesus macaques against SIV(mac251). Additionally, native Tat vaccines have conferred strong protection against simian/human immunodeficiency virus SHIV(89.6P) challenge of cynomolgus monkeys, while native, inactivated, or vectored Tat vaccines have failed to elicit similar protective efficacy in rhesus macaques. Here we asked if priming rhesus macaques with replicating Ad-human immunodeficiency virus (HIV) tat and boosting with the Tat protein would elicit protection against SHIV(89.6P). We also evaluated a Tat/Env regimen, adding an Ad-HIV env recombinant and envelope protein boost to test whether envelope antibodies would augment acute-phase protection. Further, expecting cellular immunity to enhance chronic viremia control, we tested a multigenic group: Ad-HIV tat, -HIV env, -SIV gag, and -SIV nef recombinants and Tat, Env, and Nef proteins. All regimens were immunogenic. A hierarchy was observed in enzyme-linked immunospot responses (with the strongest response for Env, followed by Gag, followed by Nef, followed by Tat) and antibody titers (with the highest titer for Env, followed by Tat, followed by Nef, followed by Gag). Following intravenous SHIV(89.6P) challenge, all macaques became infected. Compared to controls, no protection was seen in the Tat-only group, confirming previous reports for rhesus macaques. However, the multigenic group blunted acute viremia by approximately 1 log (P = 0.017), and both the multigenic and Tat/Env groups reduced chronic viremia by 3 and 4 logs, respectively, compared to controls (multigenic, P = 0.0003; Tat/Env, P < 0.0001). The strikingly greater reduction in the Tat/Env group than in the multigenic group (P = 0.014) was correlated with Tat and Env binding antibodies. Since prechallenge anti-Env antibodies lacked SHIV(89.6P)-neutralizing activity, other functional anti-Env and anti-Tat activities are under investigation, as is a possible synergy between the Tat and Env immunogens.
Assuntos
Adenoviridae/genética , Produtos do Gene env/metabolismo , Produtos do Gene tat/metabolismo , HIV/imunologia , HIV/metabolismo , Vírus da Imunodeficiência Símia/fisiologia , Replicação Viral , Animais , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/farmacologia , Produtos do Gene env/genética , Produtos do Gene env/imunologia , Produtos do Gene tat/genética , Produtos do Gene tat/imunologia , HIV/genética , Memória Imunológica/imunologia , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Macaca mulatta , Produtos do Gene tat do Vírus da Imunodeficiência HumanaRESUMO
Although HIV subtype B predominates in North America and Western Europe, most HIV infections worldwide are non-subtype B. Globally effective AIDS vaccines need to elicit broad immunity against multiple HIV strains. In this study, 10 chimpanzees were intranasally primed sequentially with adenovirus type 5 (Ad5)- and Ad7-HIVMNenv/rev recombinants and boosted twice intramuscularly with heterologous oligomeric HIVSF162 gp140DeltaV2 protein in MF59 adjuvant. Sera were evaluated for binding, neutralizing, and antibody-dependent cellular cytotoxicity (ADCC) against HIV clades A, B, C, and CRF01_AE. The vaccine regimen elicited high-titered HIV subtype A, B, C and CRF01_AE gp120-binding antibodies. Sera from 7 of 10 vaccinated chimpanzees cross-neutralized the heterologous South African subtype C primary HIVTV-1 isolate. Significant cross-clade neutralization against other subtype A, C and E isolates was not observed. Sera from all animals mediated ADCC of cells coated with gp120 from HIV subtypes A and B. Nine of 10 animals also exhibited ADCC activity against HIV subtype C and CRF01_AE gp120-coated targets. This subtype B Ad-HIV recombinant prime/envelope protein boost regimen is a promising approach for eliciting broad ADCC activity against diverse HIV clades. Incorporating additional non-subtype B envelope genes and protein boosts in a multivalent strategy may be required to elicit broader neutralizing antibodies against non-subtype B HIV strains.
Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Imunização Secundária , Vacinas contra a AIDS/administração & dosagem , Adenoviridae/genética , Animais , Reações Cruzadas , Avaliação Pré-Clínica de Medicamentos , Vetores Genéticos/imunologia , Anticorpos Anti-HIV/sangue , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1/classificação , HIV-1/genética , Testes de Neutralização , Pan troglodytes , Proteínas Recombinantes/imunologia , Vacinas Sintéticas/imunologia , Vacinas Virais/administração & dosagemRESUMO
Previously, priming with replication-competent adenovirus-SIV multigenic vaccines and boosting with envelope subunits strongly protected 39% of rhesus macaques against rectal SIV(mac251) challenge. To evaluate protection durability, eleven of the protected and two SIV-infected unimmunized macaques that controlled viremia were re-challenged rectally with SIV(mac251). Strong protection was observed in 8/11 vaccinees, including two exhibiting <50 SIV RNA copies. Decreased viremia compared to naïve controls was observed in the other three. The SIV-infected unimmunized macaques modestly controlled viremia but exhibited CD4 counts < or =200, unlike the protected macaques. Durable protection was associated with significantly increased SIV-specific ELISPOT responses and lymphoproliferative responses to p27 at re-challenge. After CD8 depletion, 2 of 8 re-challenged, protected vaccinees maintained <50 SIV RNA copies; SIV RNA emerged in 6. Re-appearance of CD8 cells and restoration of SIV-specific cellular immunity coincided with viremia suppression. Overall, cellular immunity induced by vaccination and/or low-level, inapparent viremia post-first SIV(mac251) challenge, was associated with durable protection against re-challenge.
Assuntos
Adenoviridae/genética , Linfócitos T CD8-Positivos/imunologia , Vacinas contra a SAIDS/administração & dosagem , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Adenoviridae/imunologia , Administração Retal , Animais , Imunidade Celular , Imunização Secundária , Macaca mulatta , RNA Viral/análise , Proteínas Recombinantes de Fusão/imunologia , Vacinas contra a SAIDS/genética , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/isolamento & purificação , Fatores de Tempo , Vacinação , Vacinas Sintéticas/administração & dosagem , Viremia , Replicação ViralRESUMO
Previously, Ab-dependent cellular cytotoxicity (ADCC) was significantly correlated with reduced acute viremia upon intrarectal SIVmac251 challenge of immunized rhesus macaques. To directly assess ADCC protective efficacy, six neonatal macaques were infused s.c. with immune IgG (220 mg/kg) purified from the immunized animals and positive for ADCC and Ab-dependent cell-mediated viral inhibition (ADCVI) activities. Six neonates received control IgG. The neonates were challenged twice orally with 10(5) 50% inhibiting tissue culture-infective dose of SIVmac251 2 days post-IgG infusion. At challenge, plasma of neonates that received immune IgG did not neutralize SIVmac251 but had geometric mean ADCC titers of 48,130 and 232,850 against SIVmac251 -infected and gp120-coated targets, respectively. Peak ADCVI activity varied from 62 to 81%. ADCC activity declined with the 2-wk IgG half-life but was boosted at wk 4, together with de novo ADCC-mediating Abs in controls, by postchallenge viremia. ADCVI activity was similarly induced. No protection, assessed by viral burdens, CD4 counts, and time to euthanasia was observed. Possible factors contributing to the discrepancy between the previous correlation and lack of protection here include: the high oral challenge dose compared with the 400-fold lower intrarectal dose; the challenge route with regard to viral dissemination and distribution of infused IgG; insufficient NK effector activity and/or poor functionality in newborns; insufficient immune IgG; and the possibility that the previous correlation of ADCC with protection was augmented by cellular immune responses also present at challenge. Future studies should explore additional challenge routes in juvenile macaques using higher amounts of potent IgG preparations.