RESUMO
We investigated the impact of monocytes, NK cells, and CD8+ T-cells in primary HTLV-1 infection by depleting cell subsets and exposing macaques to either HTLV-1 wild type (HTLV-1WT) or to the HTLV-1p12KO mutant unable to infect replete animals due to a single point mutation in orf-I that inhibits its expression. The orf-I encoded p8/p12 proteins counteract cytotoxic NK and CD8+ T-cells and favor viral DNA persistence in monocytes. Double NK and CD8+ T-cells or CD8 depletion alone accelerated seroconversion in all animals exposed to HTLV-1WT. In contrast, HTLV-1p12KO infectivity was fully restored only when NK cells were also depleted, demonstrating a critical role of NK cells in primary infection. Monocyte/macrophage depletion resulted in accelerated seroconversion in all animals exposed to HTLV-1WT, but antibody titers to the virus were low and not sustained. Seroconversion did not occur in most animals exposed to HTLV-1p12KO. In vitro experiments in human primary monocytes or THP-1 cells comparing HTLV-1WT and HTLV-1p12KO demonstrated that orf-I expression is associated with inhibition of inflammasome activation in primary cells, with increased CD47 "don't-eat-me" signal surface expression in virus infected cells and decreased monocyte engulfment of infected cells. Collectively, our data demonstrate a critical role for innate NK cells in primary infection and suggest a dual role of monocytes in primary infection. On one hand, orf-I expression increases the chances of viral transmission by sparing infected cells from efferocytosis, and on the other may protect the engulfed infected cells by modulating inflammasome activation. These data also suggest that, once infection is established, the stoichiometry of orf-I expression may contribute to the chronic inflammation observed in HTLV-1 infection by modulating monocyte efferocytosis.
Assuntos
Infecções por HTLV-I , Vírus Linfotrópico T Tipo 1 Humano , Animais , Inflamassomos/metabolismo , Células Matadoras Naturais , MonócitosRESUMO
[This corrects the article DOI: 10.1371/journal.ppat.1008121.].
RESUMO
The recombinant Canarypox ALVAC-HIV/gp120/alum vaccine regimen was the first to significantly decrease the risk of HIV acquisition in humans, with equal effectiveness in both males and females. Similarly, an equivalent SIV-based ALVAC vaccine regimen decreased the risk of virus acquisition in Indian rhesus macaques of both sexes following intrarectal exposure to low doses of SIVmac251. Here, we demonstrate that the ALVAC-SIV/gp120/alum vaccine is also efficacious in female Chinese rhesus macaques following intravaginal exposure to low doses of SIVmac251 and we confirm that CD14+ classical monocytes are a strong correlate of decreased risk of virus acquisition. Furthermore, we demonstrate that the frequency of CD14+ cells and/or their gene expression correlates with blood Type 1 CD4+ T helper cells, α4ß7+ plasmablasts, and vaginal cytocidal NKG2A+ cells. To better understand the correlate of protection, we contrasted the ALVAC-SIV vaccine with a NYVAC-based SIV/gp120 regimen that used the identical immunogen. We found that NYVAC-SIV induced higher immune activation via CD4+Ki67+CD38+ and CD4+Ki67+α4ß7+ T cells, higher SIV envelope-specific IFN-γ producing cells, equivalent ADCC, and did not decrease the risk of SIVmac251 acquisition. Using the systems biology approach, we demonstrate that specific expression profiles of plasmablasts, NKG2A+ cells, and monocytes elicited by the ALVAC-based regimen correlated with decreased risk of virus acquisition.
Assuntos
Células Matadoras Naturais/imunologia , Monócitos/imunologia , Vacinas contra a SAIDS/imunologia , Vírus da Imunodeficiência Símia/imunologia , Células Th1/imunologia , Vacinação , Vagina/imunologia , Vacinas Virais/imunologia , Animais , Feminino , Células Matadoras Naturais/patologia , Macaca mulatta , Monócitos/patologia , Células Th1/patologiaRESUMO
Immunization with recombinant ALVAC/gp120 alum vaccine provided modest protection from human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) acquisition in humans and macaques. Vaccine-mediated protection was associated with the elicitation of IgG against the envelope V2 loop and of envelope-specific CD4+ T cell responses. We hypothesized that the simultaneous expression of the costimulatory molecule CD40L (CD154) by the ALVAC-HIV vector could increase both protective humoral and cellular responses. We engineered an ALVAC-SIV coexpressing CD40L with SIVmac251 (ALVAC-SIV/CD40L) gag, pol, and env genes. We compared its immunogenicity in macaques with that of a canonical ALVAC-SIV, with both given as a vector-prime/gp120 in alum boost strategy. The ALVAC-SIV/CD40L was superior to the ALVAC-SIV regimen in inducing binding and tier 1 neutralizing antibodies against the gp120. The increase in humoral responses was associated with the expression of the membrane-bound form of the CD40L by CD4+ T cells in lymph nodes. Unexpectedly, the ALVAC-SIV/CD40L vector had a blunting effect on CD4+ Th1 helper responses and instead favored the induction of myeloid-derived suppressor cells, the immune-suppressive interleukin-10 (IL-10) cytokine, and the down-modulatory tryptophan catabolism. Ultimately, this strategy failed to protect macaques from SIV acquisition. Taken together, these results underlie the importance of balanced vaccine-induced activating versus suppressive immune responses in affording protection from HIV.IMPORTANCE CD40-CD40 ligand (CD40L) interaction is crucial for inducing effective cytotoxic and humoral responses against pathogens. Because of its immunomodulatory function, CD40L has been used to enhance immune responses to vaccines, including candidate vaccines for HIV. The only successful vaccine ever tested in humans utilized a strategy combining canarypox virus-based vector (ALVAC) together with an envelope protein (gp120) adjuvanted in alum. This strategy showed limited efficacy in preventing HIV-1/SIV acquisition in humans and macaques. In both species, protection was associated with vaccine-induced antibodies against the HIV envelope and CD4+ T cell responses, including type 1 antiviral responses. In this study, we tested whether augmenting CD40L expression by coexpressing it with the ALVAC vector could increase the protective immune responses. Although coexpression of CD40L did increase humoral responses, it blunted type 1 CD4+ T cell responses against the SIV envelope protein and failed to protect macaques from viral infection.
Assuntos
Vacinas contra a AIDS , Ligante de CD40 , Expressão Gênica , Vetores Genéticos , Proteína gp120 do Envelope de HIV , Imunogenicidade da Vacina , Vírus da Imunodeficiência Símia , Vacinas Virais , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Animais , Ligante de CD40/genética , Ligante de CD40/imunologia , Vetores Genéticos/genética , Vetores Genéticos/imunologia , Células HEK293 , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Humanos , Macaca mulatta , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/imunologia , Vacinas Virais/genética , Vacinas Virais/imunologiaRESUMO
The ALVAC-HIV clade B/AE and equivalent SIV-based/gp120 + Alum vaccines successfully decreased the risk of virus acquisition in humans and macaques. Here, we tested the efficacy of HIV clade B/C ALVAC/gp120 vaccine candidates + MF59 or different doses of Aluminum hydroxide (Alum) against SHIV-Cs of varying neutralization sensitivity in macaques. Low doses of Alum induced higher mucosal V2-specific IgA that increased the risk of Tier 2 SHIV-C acquisition. High Alum dosage, in contrast, elicited serum IgG to V2 that correlated with a decreased risk of Tier 1 SHIV-C acquisition. MF59 induced negligible mucosal antibodies to V2 and an inflammatory profile with blood C-reactive Protein (CRP) levels correlating with neutralizing antibody titers. MF59 decreased the risk of Tier 1 SHIV-C acquisition. The relationship between vaccine efficacy and the neutralization profile of the challenge virus appear to be linked to the different immunological spaces created by MF59 and Alum via CXCL10 and IL-1ß, respectively.
Assuntos
Adjuvantes Imunológicos/farmacologia , Compostos de Alúmen/farmacologia , Anticorpos Neutralizantes/imunologia , Vacinas contra a SAIDS/química , Vacinas contra a SAIDS/imunologia , Vacinas contra a AIDS/química , Vacinas contra a AIDS/imunologia , Animais , Anticorpos Antivirais/imunologia , Feminino , Infecções por HIV , Macaca mulatta , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Vacinas Virais/química , Vacinas Virais/imunologiaRESUMO
The recombinant ALVAC vaccine coupled with the monomeric gp120/alum protein have decreased the risk of HIV and SIV acquisition. Ab responses to the V1/V2 regions have correlated with a decreased risk of virus acquisition in both humans and macaques. We hypothesized that the breadth and functional profile of Abs induced by an ALVAC/envelope protein regimen could be improved by substituting the monomeric gp120 boost, with the full-length single-chain (FLSC) protein. FLSC is a CD4-gp120 fusion immunogen that exposes cryptic gp120 epitopes to the immune system. We compared the immunogenicity and relative efficiency of an ALVAC-SIV vaccine boosted either with bivalent FLSC proteins or with monomeric gp120 in alum. FLSC was superior to monomeric gp120 in directing Abs to the C3 α2 helix, the V5 loop, and the V3 region that contains the putative CCR5 binding site. In addition, FLSC boosting elicited significantly higher binding Abs to V2 and increased both the Ab-dependent cellular cytotoxicity activity and the breadth of neutralizing Abs. However, the FLSC vaccine regimen demonstrated only a trend in vaccine efficacy, whereas the monomeric gp120 regimen significantly decreased the risk of SIVmac251 acquisition. In both vaccine regimens, anti-V2 Abs correlated with a decreased risk of virus acquisition but differed with regard to systemic or mucosal origin. In the FLSC regimen, serum Abs to V2 correlated, whereas in the monomeric gp120 regimen, V2 Abs in rectal secretions, the site of viral challenge, were associated with efficacy.
Assuntos
Anticorpos Antivirais/imunologia , Antígenos CD4/imunologia , Produtos do Gene env/imunologia , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vacinas Virais/imunologia , Animais , Antígenos CD4/química , Linhagem Celular , Produtos do Gene env/química , Macaca mulatta , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controleRESUMO
The human papillomavirus pseudovirions (HPV-PsVs) approach is an effective gene-delivery system that can prime or boost an immune response in the vaginal tract of nonhuman primates and mice. Intravaginal vaccination with HPV-PsVs expressing SIV genes, combined with an i.m. gp120 protein injection, induced humoral and cellular SIV-specific responses in macaques. Priming systemic immune responses with i.m. immunization with ALVAC-SIV vaccines, followed by intravaginal HPV-PsV-SIV/gp120 boosting, expanded and/or recruited T cells in the female genital tract. Using a stringent repeated low-dose intravaginal challenge with the highly pathogenic SIVmac251, we show that although these regimens did not demonstrate significant protection from virus acquisition, they provided control of viremia in a number of animals. High-avidity Ab responses to the envelope gp120 V1/V2 region correlated with delayed SIVmac251 acquisition, whereas virus levels in mucosal tissues were inversely correlated with antienvelope CD4(+) T cell responses. CD8(+) T cell depletion in animals with controlled viremia caused an increase in tissue virus load in some animals, suggesting a role for CD8(+) T cells in virus control. This study highlights the importance of CD8(+) cells and antienvelope CD4(+) T cells in curtailing virus replication and antienvelope V1/V2 Abs in preventing SIVmac251 acquisition.
Assuntos
Anticorpos Antivirais/imunologia , Fragmentos de Peptídeos/imunologia , Vírus da Imunodeficiência Símia/imunologia , Subpopulações de Linfócitos T/imunologia , Vagina/imunologia , Proteínas do Envelope Viral/imunologia , Viremia/imunologia , Alphapapillomavirus/genética , Animais , Especificidade de Anticorpos/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Feminino , Vetores Genéticos/genética , Depleção Linfocítica , Macaca mulatta , Dados de Sequência Molecular , Mucosa/imunologia , Mucosa/virologia , Vacinas contra a SAIDS/genética , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Subpopulações de Linfócitos T/virologia , Vacinação , Vacinas de DNA/genética , Vacinas de DNA/imunologia , Vagina/virologia , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Viremia/prevenção & controle , Viremia/virologiaRESUMO
Vaccine-induced protection against infection by HIV or highly pathogenic and virulent SIV strains has been limited. In a proof-of-concept study, we show that a novel vaccine approach significantly protects rhesus macaques from mucosal infection by the highly pathogenic strain SIVmac251. We vaccinated three cohorts of 12 macaques each with live, irradiated vaccine cells secreting the modified endoplasmic reticulum chaperone gp96-Ig. Cohort 1 was vaccinated with cells secreting gp96(SIV)Ig carrying SIV peptides. In addition, Cohort 2 received recombinant envelope protein SIV-gp120. Cohort 3 was injected with cells secreting gp96-Ig (no SIV Ags) vaccines. Cohort 2 was protected from infection. After seven rectal challenges with highly pathogenic SIVmac251, the hazard ratio was 0.27, corresponding to a highly significant, 73% reduced risk for viral acquisition. The apparent success of the novel vaccine modality recommends further study.
Assuntos
Mucosa Intestinal/imunologia , Glicoproteínas de Membrana/administração & dosagem , Glicoproteínas de Membrana/uso terapêutico , Vacinas contra a SAIDS/administração & dosagem , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antivirais/biossíntese , Estudos de Coortes , Feminino , Células HEK293 , Humanos , Injeções Intraperitoneais , Mucosa Intestinal/patologia , Mucosa Intestinal/virologia , Macaca mulatta , Masculino , Mucosa/imunologia , Mucosa/virologia , Doenças Retais/imunologia , Doenças Retais/prevenção & controle , Doenças Retais/virologia , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Vírus da Imunodeficiência Símia/patogenicidade , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/patologia , Linfócitos T Citotóxicos/virologiaRESUMO
We used the simian immunodeficiency virus mac251 (SIV(mac251)) macaque model to study the effect of the dose of mucosal exposure on vaccine efficacy. We immunized macaques with a DNA prime followed by SIV gp120 protein immunization with ALVAC-SIV and gp120 in alum, and we challenged them with SIV(mac251) at either a single high dose or at two repeated low-dose exposures to a 10-fold-lower dose. Infection was neither prevented nor modified following a single high-dose challenge of the immunized macaques. However, two exposures to a 10-fold-lower dose resulted in protection from SIV(mac251) acquisition in 3 out of 12 macaques. The remaining animals that were infected had a modulated pathogenesis, significant downregulation of interferon responsive genes, and upregulation of genes involved in B- and T-cell responses. Thus, the choice of the experimental model greatly influences the vaccine efficacy of vaccines for human immunodeficiency virus (HIV).
Assuntos
Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vírus da Imunodeficiência Símia/imunologia , Vírus da Imunodeficiência Símia/patogenicidade , Animais , Produtos do Gene env/genética , Macaca , Dados de Sequência Molecular , Vacinas contra a SAIDS/administração & dosagem , Análise de Sequência de DNA , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologiaRESUMO
Human immunodeficiency virus (HIV) infection is associated with immune activation, CD4âº-T-cell loss, and a progressive decline of immune functions. Antiretroviral therapy (ART) only partially reverses HIV-associated immune dysfunction, suggesting that approaches that target immune activation and improve virus-specific immune responses may be needed. We performed a preclinical study in rhesus macaques infected with the pathogenic simian immunodeficiency virus SIV(mac251) and treated with ART. We tested whether vaccination administered together with cytotoxic-T-lymphocyte-associated antigen 4 (CTLA-4) blockade and treatment with the indoleamine 2,3-dioxygenase (IDO) inhibitor 1-methyl-D-tryptophan (D-1mT), decreased immune activation and improved vaccine efficacy. The treatment did not augment vaccine immunogenicity; rather, it dramatically increased ART-related toxicity, causing all treated animals to succumb to acute pancreatitis and hyperglycemic coma. The onset of fulminant diabetes was associated with severe lymphocyte infiltration of the pancreas and complete loss of the islets of Langerhans. Thus, caution should be used when considering approaches aimed at targeting immune activation during ART.
Assuntos
Fármacos Anti-HIV/efeitos adversos , Didanosina/efeitos adversos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Pancreatite/etiologia , Vírus da Imunodeficiência Símia/fisiologia , Estavudina/efeitos adversos , Vacinas contra a AIDS/administração & dosagem , Vacinas contra a AIDS/imunologia , Animais , Fármacos Anti-HIV/uso terapêutico , Antígeno CTLA-4/antagonistas & inibidores , Didanosina/uso terapêutico , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Quimioterapia Combinada/efeitos adversos , Infecções por HIV/complicações , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/imunologia , HIV-1/fisiologia , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Macaca mulatta , Pancreatite/imunologia , Pancreatite/mortalidade , Vírus da Imunodeficiência Símia/efeitos dos fármacos , Vírus da Imunodeficiência Símia/imunologia , Estavudina/uso terapêutico , Triptofano/efeitos adversos , Triptofano/análogos & derivados , Triptofano/uso terapêuticoRESUMO
At the heart of the DNA/ALVAC/gp120/alum vaccine's efficacy in the absence of neutralizing antibodies is a delicate balance of pro- and anti-inflammatory immune responses that effectively decreases the risk of SIVmac251 acquisition in macaques. Vaccine efficacy is linked to antibodies recognizing the V2 helical conformation, DC-10 tolerogenic dendritic cells eliciting the clearance of apoptotic cells via efferocytosis, and CCR5 downregulation on vaccine-induced gut homing CD4+ cells. RAS activation is also linked to vaccine efficacy, which prompted the testing of IGF-1, a potent inducer of RAS activation with vaccination. We found that IGF-1 changed the hierarchy of V1/V2 epitope recognition and decreased both ADCC specific for helical V2 and efferocytosis. Remarkably, IGF-1 also reduced the expression of CCR5 on vaccine-induced CD4+ gut-homing T-cells, compensating for its negative effect on ADCC and efferocytosis and resulting in equivalent vaccine efficacy (71% with IGF-1 and 69% without).
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The human immunodeficiency virus epidemic continues in sub-Saharan Africa, and particularly affects adolescent girls and women who have limited access to antiretroviral therapy. Here we report that the risk of vaginal simian immunodeficiency virus (SIV)mac251 acquisition is reduced by more than 90% using a combination of a vaccine comprising V1-deleted (V2 enhanced) SIV envelope immunogens with topical treatment of the zinc-finger inhibitor SAMT-247. Following 14 weekly intravaginal exposures to the highly pathogenic SIVmac251, 80% of a cohort of 20 macaques vaccinated and treated with SAMT-247 remained uninfected. In an arm of 18 vaccinated-only animals without microbicide, 40% of macaques remained uninfected. The combined SAMT-247/vaccine regimen was significantly more effective than vaccination alone. By analysing immune correlates of protection, we show that, by increasing zinc availability, SAMT-247 increases natural killer cytotoxicity and monocyte efferocytosis, and decreases T-cell activation to augment vaccine-induced protection.
Assuntos
Anti-Infecciosos , Vacinas contra a SAIDS , Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Vacinas , Animais , Humanos , Feminino , Adolescente , Macaca mulattaRESUMO
The development of an effective vaccine to protect against HIV acquisition will be greatly bolstered by in-depth understanding of the innate and adaptive responses to vaccination. We report here that the efficacy of DNA/ALVAC/gp120/alum vaccines, based on V2-specific antibodies mediating apoptosis of infected cells (V2-ADCC), is complemented by efferocytosis, a cyclic AMP (cAMP)-dependent antiphlogistic engulfment of apoptotic cells by CD14+ monocytes. Central to vaccine efficacy is the engagement of the CCL2/CCR2 axis and tolerogenic dendritic cells producing IL-10 (DC-10). Epigenetic reprogramming in CD14+ cells of the cyclic AMP/CREB pathway and increased systemic levels of miRNA-139-5p, a negative regulator of expression of the cAMP-specific phosphodiesterase PDE4D, correlated with vaccine efficacy. These data posit that efferocytosis, through the prompt and effective removal of apoptotic infected cells, contributes to vaccine efficacy by decreasing inflammation and maintaining tissue homeostasis.
Assuntos
Vacinas contra a AIDS , Infecções por HIV , Feminino , Animais , Eficácia de Vacinas , Macaca mulatta , Vacinação , Citotoxicidade Celular Dependente de Anticorpos , Anticorpos Anti-HIV , Infecções por HIV/prevenção & controle , Proteína gp120 do Envelope de HIV/genéticaRESUMO
Human T cell leukemia virus type 1 (HTLV-1) persists in the host despite a vigorous immune response that includes cytotoxic T cells (CTL) and natural killer (NK) cells, suggesting the virus has developed effective mechanisms to counteract host immune surveillance. We recently showed that in vitro treatment of HTLV-1-infected cells with the drug pomalidomide (Pom) increases surface expression of MHC-I, ICAM-1, and B7-2, and significantly increases the susceptibility of HTLV-1-infected cells to NK and CTL killing, which is dependent on viral orf-I expression. We reasoned that by restoring cell surface expression of these molecules, Pom treatment has the potential to reduce virus burden by rendering infected cells susceptible to NK and CTL killing. We used the rhesus macaque model to determine if Pom treatment of infected individuals activates the host immune system and allows recognition and clearance of HTLV-1-infected cells. We administered Pom (0.2 mg/kg) orally to four HTLV-1-infected macaques over a 24 day period and collected blood, urine, and bone marrow samples throughout the study. Pom treatment caused immune activation in all four animals and a marked increase in proliferating CD4+, CD8+, and NK cells as measured by Ki-67+ cells. Activation markers HLA-DR, CD11b, and CD69 also increased during treatment. While we detected an increased frequency of cells with a memory CD8+ phenotype, we also found an increased frequency of cells with a Treg-like phenotype. Concomitant with immune activation, the frequency of detection of viral DNA and the HTLV-1-specific humoral response increased as well. In 3 of 4 animals, Pom treatment resulted in increased antibodies to HTLV-1 antigens as measured by western blot and p24Gag ELISA. Consistent with Pom inducing immune and HTLV-1 activation, we measured elevated leukotrienes LTB4 and LTE4 in the urine of all animals. Despite an increase in plasma LTB4, no significant changes in plasma cytokine/chemokine levels were detected. In all cases, however, cellular populations, LTB4, and LTE4 decreased to baseline or lower levels 2 weeks after cessation of treatment. These results indicated that Pom treatment induces a transient HTLV-1-specific immune activation in infected individuals, but also suggest Pom may not be effective as a single-agent therapeutic.
RESUMO
The efficacy of ALVAC-based HIV and SIV vaccines in humans and macaques correlates with antibodies to envelope variable region 2 (V2). We show here that vaccine-induced antibodies to SIV variable region 1 (V1) inhibit anti-V2 antibody-mediated cytotoxicity and reverse their ability to block V2 peptide interaction with the α4ß7 integrin. SIV vaccines engineered to delete V1 and favor an α helix, rather than a ß sheet V2 conformation, induced V2-specific ADCC correlating with decreased risk of SIV acquisition. Removal of V1 from the HIV-1 clade A/E A244 envelope resulted in decreased binding to antibodies recognizing V2 in the ß sheet conformation. Thus, deletion of V1 in HIV envelope immunogens may improve antibody responses to V2 virus vulnerability sites and increase the efficacy of HIV vaccine candidates.
RESUMO
Vaccination with DNA-SIV + ALVAC-SIV + gp120 alum results in inflammasome activation, high levels of IL-1ß production, emergency myelopoiesis, and the egress of CXCR4+ CD14+ pre-monocytes from bone marrow. Previously we have shown that this vaccine-induced innate monocyte memory is associated with decreased risk of SIVmac251 acquisition. Because IL-1ß also promotes the propagation of monocyte-derived suppressor (M-MDSC)-like cells, here we extended our analysis to this negative regulator subset, characterizing its levels and functions in macaques. Interestingly, we found that DNA prime engages M-MDSC-like cells and their levels are positively associated with the frequency of CD14+ classical monocytes, and negatively with the levels of CD16+ monocytes, correlates of decreased and increased risk of SIV acquisition, respectively. Accordingly, M-MDSC frequency, arginase activity, and NO were all associated with decrease of CD8 T cells responses and worse vaccination outcome. DNA vaccination thus induces innate immunity by engaging three subsets of myeloid cells, M-MDSCs, CD14+ innate monocyte memory, and CD16+ monocytes all playing different role in protection. The full characterization of the immunological space created by myeloid cell crosstalk will likely provide clues to improve the efficacy of HIV vaccine candidates.
Assuntos
Proteína gp120 do Envelope de HIV/imunologia , Células Supressoras Mieloides/fisiologia , Vacinas contra a SAIDS/imunologia , Vacinas de DNA/imunologia , Vacinas Virais/imunologia , Animais , Arginase/sangue , Arginase/fisiologia , Linfócitos B/imunologia , Comunicação Celular , Antígenos HLA-DR/análise , Macaca mulatta , Óxido Nítrico/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Linfócitos T/imunologiaRESUMO
Qualitative differences in the innate and adaptive responses elicited by different HIV vaccine candidates have not been thoroughly investigated. We tested the ability of the Aventis Pasteur live recombinant canarypox vector (ALVAC)-SIV, DNA-SIV and Ad26-SIV vaccine prime modalities together with two ALVAC-SIV + gp120 protein boosts to reduce the risk of SIVmac251 acquisition in rhesus macaques. We found that the DNA and ALVAC prime regimens were effective, but the Ad26 prime was not. The activation of hypoxia and the inflammasome in CD14+CD16- monocytes, gut-homing CCR5-negative CD4+ T helper 2 (TH2) cells and antibodies to variable region 2 correlated with a decreased risk of SIVmac251 acquisition. By contrast, signal transducer and activator of transcription 3 activation in CD16+ monocytes was associated with an increased risk of virus acquisition. The Ad26 prime regimen induced the accumulation of CX3CR1+CD163+ macrophages in lymph nodes and of long-lasting CD4+ TH17 cells in the gut and lungs. Our data indicate that the selective engagement of monocyte subsets following a vaccine prime influences long-term immunity, uncovering an unexpected association of CD14+ innate monocytes with a reduced risk of SIVmac251 acquisition.
Assuntos
Vacinas contra a AIDS/imunologia , Hipóxia/imunologia , Inflamassomos/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Monócitos/patologia , Vírus da Imunodeficiência Símia/fisiologia , Animais , Formação de Anticorpos/imunologia , Biomarcadores/metabolismo , Linfócitos T CD4-Positivos/imunologia , Inflamação/patologia , Células Matadoras Naturais/imunologia , Macaca mulatta , Receptores CCR5/metabolismo , Fatores de Risco , Linfócitos T Auxiliares-Indutores/imunologia , Vacinas de DNA/imunologiaRESUMO
A recombinant vaccine containing Aventis Pasteur's canarypox vector (ALVAC)-HIV and gp120 alum decreased the risk of HIV acquisition in the RV144 vaccine trial. The substitution of alum with the more immunogenic MF59 adjuvant is under consideration for the next efficacy human trial. We found here that an ALVAC-simian immunodeficiency virus (SIV) and gp120 alum (ALVAC-SIV + gp120) equivalent vaccine, but not an ALVAC-SIV + gp120 MF59 vaccine, was efficacious in delaying the onset of SIVmac251 in rhesus macaques, despite the higher immunogenicity of the latter adjuvant. Vaccine efficacy was associated with alum-induced, but not with MF59-induced, envelope (Env)-dependent mucosal innate lymphoid cells (ILCs) that produce interleukin (IL)-17, as well as with mucosal IgG to the gp120 variable region 2 (V2) and the expression of 12 genes, ten of which are part of the RAS pathway. The association between RAS activation and vaccine efficacy was also observed in an independent efficacious SIV-vaccine approach. Whether RAS activation, mucosal ILCs and antibodies to V2 are also important hallmarks of HIV-vaccine efficacy in humans will require further studies.
Assuntos
Adjuvantes Imunológicos/uso terapêutico , Compostos de Alúmen/uso terapêutico , Vacinas contra a SAIDS/uso terapêutico , Síndrome de Imunodeficiência Adquirida dos Símios/prevenção & controle , Vacinas Virais/uso terapêutico , Imunidade Adaptativa/imunologia , Animais , Imunidade Inata/imunologia , Imunidade nas Mucosas , Imunogenicidade da Vacina , Imunoglobulina G/imunologia , Interleucina-17/imunologia , Linfócitos , Macaca mulatta , Glicoproteínas de Membrana/imunologia , Distribuição Aleatória , Transdução de Sinais , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Transcriptoma , Proteínas do Envelope Viral/imunologia , Proteínas ras/imunologiaRESUMO
Subsets of CD16-positive monocytes produce proinflammatory cytokines and expand during chronic infection with the human immunodeficiency virus type 1 (HIV). HIV-infected macrophage in tissues may be long lived and contribute to the establishment and maintenance of the HIV reservoir. We found that the (intermediate) CD14(++)CD16(+) and (nonclassical) CD14(+)CD16(++) monocyte subsets are significantly expanded during infection of Rhesus macaques with pathogenic SIV(mac251) but not during infection of sooty mangabeys with the nonpathogenic isolate SIVSM. In vitro glucocorticoid (GC) treatment of peripheral blood mononuclear cells (PBMCs) from uninfected or SIV(mac251)-infected Rhesus macaques and HIV-infected patients treated or not with antiretroviral therapy (ART) resulted in a significant decrease in the frequency of both CD16-positive monocyte subsets. Short-term in vivo treatment with high doses of GC of chronically SIV(mac251)-infected macaques resulted in a significant decrease in the CD14(+)CD16(++) population and, to a lesser extent, in the CD14(++)CD16(+) monocytes, as well as a significant decrease in the number of macrophages in tissues. Surprisingly, treatment of SIV(mac251)-infected macaques with ART significantly increased the CD14(++)CD16(+) population and the addition of GC resulted in a significant decrease in only the CD14(+)CD16(++) subset. No difference in SIV DNA levels in blood, lymph nodes, gut, and spleen was found between the groups treated with ART or ART plus GC. Thus, it appears that high doses of GC treatment in the absence of ART could affect both CD16-positive populations in vivo. Whether the efficacy of this treatment at higher doses to decrease virus levels outweighs its risks remains to be determined.