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1.
Immunol Cell Biol ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38757764

RESUMO

Delta inulin, or Advax, is a polysaccharide vaccine adjuvant that significantly enhances vaccine-mediated immune responses against multiple pathogens and was recently licensed for use in the coronavirus disease 2019 (COVID-19) vaccine SpikoGen. Although Advax has proven effective as an immune adjuvant, its specific binding targets have not been characterized. In this report, we identify a cellular receptor for Advax recognition. In vitro uptake of Advax particles by macrophage cell lines was substantially greater than that of latex beads of comparable size, suggesting an active uptake mechanism by phagocytic cells. Using a lectin array, Advax particles were recognized by lectins specific for various carbohydrate structures including mannosyl, N-acetylgalactosamine and galactose moieties. Expression in nonphagocytic cells of dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN), a C-type lectin receptor, resulted in enhanced uptake of fluorescent Advax particles compared with mock-transfected cells. Advax uptake was reduced with the addition of ethylenediaminetetraacetic acid and mannan to cells, which are known inhibitors of DC-SIGN function. Finally, a specific blockade of DC-SIGN using a neutralizing antibody abrogated Advax uptake in DC-SIGN-expressing cells. Together, these results identify DC-SIGN as a putative receptor for Advax. Given the known immunomodulatory role of DC-SIGN, the findings described here have implications for the use of Advax adjuvants in humans and inform future mechanistic studies.

2.
J Vet Pharmacol Ther ; 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38345094

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect a broad range of animal species and has been associated with severe disease in some taxa. Few studies have evaluated optimal strategies to mitigate the risk to susceptible zoo animals. This study evaluated the safety and immunogenicity of a protein-based veterinary SARS-CoV-2 vaccine (SpikeVet™) in zoo animals. Two to three doses of SpikeVet™ were administered intramuscularly or subcutaneously 3-4 weeks apart to 354 zoo animals representing 38 species. SpikeVet™ was very well tolerated across all species. Minor adverse effects were observed in 1.69% of animals vaccinated, or 1.04% of vaccine doses administered. Preliminary immunogenicity analyses in representative carnivores (meerkats, lions) and an artiodactylid (domestic goat) showed SpikeVet™-immunized animals developed serum antibodies able to neutralize a range of SARS-CoV-2 variants, including the vaccine-homologous Wuhan and Mu variants, as well as vaccine-heterologous Omicron BA.2 and XBB.1 strains. Prior to vaccination, all eight lions were seropositive for Wuhan strain by surrogate viral neutralization testing, suggesting past infection with SARS-CoV-2 or cross-reactive antibodies generated by another closely related coronavirus. These results from a range of zoo species support the ongoing development of SpikeVet™ as a safe and effective veterinary SARS-CoV-2 vaccine.

3.
J Infect Dis ; 2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38157402

RESUMO

BACKGROUND: The aim of this study was to determine the safety and immunogenicity of trivalent inactivated influenza vaccine (TIV) alone or formulated with Advax™ delta inulin adjuvant in those of older age (> 60 years) or with chronic disease. METHODS: Over four consecutive years from 2008-2011, adult participants with chronic disease or over 60 years were recruited into a randomised controlled study to assess the safety, tolerability and immunogenicity of Advax-adjuvanted versus standard TIV. The per protocol (PP) population with at least one post-baseline measurement of influenza antibodies comprised 1297 participants: 447 in the TIV, and 850 in the Advax-adjuvanted TIV, groups. RESULTS: No safety issues were identified. Variables negatively affecting vaccine responses included obesity and diabetes mellitus. Advax adjuvant had a positive impact on anti-influenza IgM responses and on H3N2 and B strain seropositivity as assessed by hemagglutination inhibition. CONCLUSIONS: Advax-adjuvanted TIV was safe and well tolerated in individuals with chronic disease. There is an ongoing need for research into improved influenza vaccines for high-risk populations. Australia New Zealand Clinical Trial Registry: ACTRN 12608000364370.

4.
Immunology ; 170(2): 193-201, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37199229

RESUMO

SpikoGen® vaccine is a subunit COVID-19 vaccine expressed in insect cells comprising recombinant spike protein extracellular domain formulated with Advax-CpG55.2™ adjuvant. A Phase 2 trial was conducted in 400 adult participants randomised 3:1 to receive two intramuscular doses of SpikoGen® vaccine or saline placebo 3 weeks apart. Some Phase 2 trial participants later enrolled in a separate booster study and received a third dose of SpikoGen® vaccine. This stored serum was used to assess the ability of SpikoGen® vaccine to induce cross-neutralising antibodies against SARS-CoV-2 variants of concern. Sera taken at baseline and 2 weeks after the second vaccine dose from baseline seronegative Phase 2 subjects was evaluated using a panel of spike pseudotype lentivirus neutralisation assays for the ability to cross-neutralise a wide range of SARS-CoV-2 variants, including Omicron BA.1, BA.2 and BA.4/5. Stored samples of subjects who participated in both the 2-dose Phase 2 trial and a third dose booster trial 6 months later were also analysed for changes in cross-neutralising antibodies over time and dose. Two weeks after the second dose, sera broadly cross-neutralised most variants of concern, albeit with titres against Omicron variants being ~10-fold lower. While Omicron titres fell to low levels 6 months after the second vaccine dose in most subjects, they showed a ~20-fold rise after the third dose booster, after which there was only a ~2-3-fold difference in neutralisation of Omicron and the ancestral strains. Despite being based on the ancestral Wuhan sequence, after two doses, SpikoGen® vaccine induced broadly cross-neutralising serum antibodies. Titres then reduced over time but were rapidly restored by a third dose booster. This resulted in high neutralisation including against the Omicron variants. This data supports ongoing use of SpikoGen® vaccine for protection against recent SARS-CoV-2 Omicron variants.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Adulto , Humanos , SARS-CoV-2 , Anticorpos Amplamente Neutralizantes , Glicoproteína da Espícula de Coronavírus/genética , COVID-19/prevenção & controle , Adjuvantes Imunológicos , Vacinas Sintéticas/genética , Anticorpos Antivirais , Anticorpos Neutralizantes
5.
Int J Mol Sci ; 24(4)2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36835602

RESUMO

Drugs against novel targets are needed to treat COVID-19 patients, especially as SARS-CoV-2 is capable of rapid mutation. Structure-based de novo drug design and repurposing of drugs and natural products is a rational approach to discovering potentially effective therapies. These in silico simulations can quickly identify existing drugs with known safety profiles that can be repurposed for COVID-19 treatment. Here, we employ the newly identified spike protein free fatty acid binding pocket structure to identify repurposing candidates as potential SARS-CoV-2 therapies. Using a validated docking and molecular dynamics protocol effective at identifying repurposing candidates inhibiting other SARS-CoV-2 molecular targets, this study provides novel insights into the SARS-CoV-2 spike protein and its potential regulation by endogenous hormones and drugs. Some of the predicted repurposing candidates have already been demonstrated experimentally to inhibit SARS-CoV-2 activity, but most of the candidate drugs have yet to be tested for activity against the virus. We also elucidated a rationale for the effects of steroid and sex hormones and some vitamins on SARS-CoV-2 infection and COVID-19 recovery.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Simulação de Dinâmica Molecular , Tratamento Farmacológico da COVID-19 , Simulação de Acoplamento Molecular , Ácidos Graxos , Reposicionamento de Medicamentos/métodos , Antivirais/farmacologia
6.
Immunology ; 167(3): 340-353, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35758850

RESUMO

SpikoGen® is a subunit recombinant spike protein vaccine combined with Advax-CpG55.2™ adjuvant. This COVID-19 vaccine was shown to be safe, immunogenic and efficacious in previous clinical trials. This study aimed to assess the safety and immunogenicity of SpikoGen® vaccine as a homologous and heterologous booster vaccination. This double-blind and randomized placebo-controlled (5:1) trial was performed on 300 already vaccinated participants. SpikoGen® or saline placebo was administered as a booster dose to participants who had received a full two-dose COVID-19 vaccination course. Immunogenicity assessments were done 14 days after the booster dose with the primary immunogenicity outcome seroconversion rate of neutralizing antibodies. Safety outcomes included the incidence of solicited adverse events up to 7 days after the booster dose. SpikoGen® vaccine induced a robust humoral response both as a homologous and heterologous booster, when compared to the placebo. At Day 14, seroconversion of neutralizing antibodies was 76% (95% confidence interval [CI]: 69%-82%) in the SpikoGen® group versus 3% (95% CI: 0%-13%) in the placebo group. The most common local and systemic reported adverse events were injection site pain and fatigue. No serious adverse events were reported. The SpikoGen®-booster induced cross-neutralization of other SARS-CoV-2 variants. Irrespective of the primary vaccine course received, SpikoGen® vaccine showed promising effects as both a homologous and heterologous booster dose. This vaccine also had a good safety profile with no vaccine-associated serious adverse events. On the basis of these results, SpikoGen® vaccine has been approved as a booster dose.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Glicoproteína da Espícula de Coronavírus , Adjuvantes Imunológicos , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Humanos , SARS-CoV-2 , Vacinação/métodos , Vacinas de Subunidades Antigênicas , Vacinas Sintéticas/efeitos adversos
7.
Int J Mol Sci ; 23(14)2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35887049

RESUMO

Repurposing of existing drugs is a rapid way to find potential new treatments for SARS-CoV-2. Here, we applied a virtual screening approach using Autodock Vina and molecular dynamic simulation in tandem to screen and calculate binding energies of repurposed drugs against the SARS-CoV-2 helicase protein (non-structural protein nsp13). Amongst the top hits from our study were antivirals, antihistamines, and antipsychotics, plus a range of other drugs. Approximately 30% of our top 87 hits had published evidence indicating in vivo or in vitro SARS-CoV-2 activity. Top hits not previously reported to have SARS-CoV-2 activity included the antiviral agents, cabotegravir and RSV-604; the NK1 antagonist, aprepitant; the trypanocidal drug, aminoquinuride; the analgesic, antrafenine; the anticancer intercalator, epirubicin; the antihistamine, fexofenadine; and the anticoagulant, dicoumarol. These hits from our in silico SARS-CoV-2 helicase screen warrant further testing as potential COVID-19 treatments.


Assuntos
Produtos Biológicos , Tratamento Farmacológico da COVID-19 , Antivirais/química , Antivirais/farmacologia , Antivirais/uso terapêutico , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Reposicionamento de Medicamentos , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , SARS-CoV-2
8.
Am J Physiol Cell Physiol ; 321(1): C187-C198, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34106786

RESUMO

Ca2+ signaling plays a critical role in the regulation of hepatic metabolism by hormones including insulin. Changes in cytoplasmic Ca2+ regulate synthesis and posttranslational modification of key signaling proteins in the insulin pathways. Emerging evidence suggests that hepatocyte intracellular Ca2+ signaling is altered in lipid-loaded liver cells isolated from obese rodent models. The mechanisms of altered Ca2+-insulin and insulin-Ca2+ signaling pathways in obesity remain poorly understood. Here, we show that the kinetics of insulin-initiated intracellular (initial) Ca2+ release from endoplasmic reticulum is significantly impaired in steatotic hepatocytes from obese Alström syndrome mice. Furthermore, exenatide, a glucagon-like peptide-1 (GLP-1) analog, reversed lipid-induced inhibition of intracellular Ca2+ release kinetics in steatotic hepatocytes, without affecting the total content of intracellular Ca2+ released. Exenatide reversed the lipid-induced inhibition of intracellular Ca2+ release, at least partially, via lipid reduction in hepatocytes, which then restored hormone-regulated cytoplasmic Ca2+ signaling and insulin sensitivity. This data provides additional evidence for the important role of Ca2+ signaling pathways in obesity-associated impaired hepatic lipid homeostasis and insulin signaling. It also highlights a potential advantage of GLP-1 analogs when used to treat type 2 diabetes associated with hepatic steatosis.


Assuntos
Síndrome de Alstrom/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Exenatida/farmacologia , Hipoglicemiantes/farmacologia , Fígado/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Obesidade/tratamento farmacológico , Síndrome de Alstrom/metabolismo , Síndrome de Alstrom/patologia , Animais , Glicemia/metabolismo , Cálcio/metabolismo , Sinalização do Cálcio , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Modelos Animais de Doenças , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Corantes Fluorescentes/metabolismo , Fura-2/metabolismo , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Insulina/metabolismo , Resistência à Insulina , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Transgênicos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Obesidade/metabolismo , Obesidade/patologia , Ácido Palmítico/farmacologia
9.
Mol Pharm ; 18(1): 228-235, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33301675

RESUMO

The nearly insurmountable adversity that accompanies opioid use disorder (OUD) creates life-altering complications for opioid users. To worsen matters, existing small-molecule drugs continue to inadequately address OUD due to their engagement of the opioid receptor, which can leave the user to deal with side effects and financial hardships from their repeated use. An alternative therapeutic approach utilizes endogenously generated antibodies through active vaccination to reduce the effect of opioids without modulating the opioid receptor. Here, we explore different adjuvants and storage conditions to improve opioid vaccine efficacy and shelf life. Our results revealed that inulin-based formulations (Advax) containing a CpG oligodeoxynucleotide (ODN) acted as effective adjuvants when combined with a heroin conjugate: immunized mice showed excellent recovery from heroin-induced antinociception accompanied by high titer, high opioid affinity serum antibodies similar to the immunopotentiating properties of traditional alum-based adjuvants. Moreover, nonhuman primates vaccinated with a heroin/fentanyl combination vaccine demonstrated potent antibody responses against opioids when formulated with both inulin and alum adjuvants. Finally, storing a freeze-dried opioid vaccine formulation maintained efficacy for up 1 year at room temperature. The results from our studies represent an advance toward a clinically feasible opioid vaccine.


Assuntos
Adjuvantes Imunológicos/farmacologia , Adjuvantes Farmacêuticos/farmacologia , Fentanila/imunologia , Heroína/imunologia , Vacinas Conjugadas/imunologia , Analgésicos Opioides/imunologia , Animais , Imunização/métodos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Oligodesoxirribonucleotídeos/imunologia , Transtornos Relacionados ao Uso de Opioides/imunologia , Vacinação/métodos
10.
J Allergy Clin Immunol ; 144(2): 504-513.e16, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31300280

RESUMO

BACKGROUND: Allergic reactions to Hymenoptera insect stings remain a major global clinical problem. Although effective, parenteral desensitization regimens require use of costly venom extracts and require frequent visits over extended periods of time. OBJECTIVE: Adjuvants are commonly used to enhance the efficacy of infectious disease vaccines, and this study asked whether Advax (Vaxine Pty Ltd, Adelaide, Australia), a novel noninflammatory polysaccharide adjuvant, might provide similar benefits for allergy desensitization. METHODS: A randomized, controlled phase 1/2 trial was undertaken in 27 adults with a history of rapid-onset systemic allergic reactions to honeybee stings and positive specific IgE levels to evaluate the safety and efficacy of honeybee venom immunotherapy (HBVIT) combined with Advax adjuvant. Venom immunotherapy (VIT) was administered monthly for 30 months after achievement of maintenance doses. RESULTS: Advax-adjuvanted HBVIT was well tolerated. Around week 14 of VIT, specific IgG4 responses peaked in both groups but increased earlier, peaked higher, and were better maintained through the end of the study in the Advax-adjuvanted arm. Several different patterns of serologic response to VIT were seen; some subjects had a dominant IgG4 response, some had a combined IgG4 and IgG1 response, and some had an exclusively IgG1 response. In some subjects specific IgE levels increased during the induction phase and then decreased, whereas in others specific IgE levels progressively decreased from the start of VIT. CONCLUSION: Advax adjuvant favorably enhanced the immunogenicity of HBVIT, with an early and prolonged switch to specific IgG4 production. The ability of Advax adjuvant to enhance VIT efficacy warrants further study.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Venenos de Abelha/administração & dosagem , Hipersensibilidade , Imunoglobulina E/imunologia , Imunoterapia , Mordeduras e Picadas de Insetos , Inulina/análogos & derivados , Adulto , Idoso , Feminino , Humanos , Hipersensibilidade/imunologia , Hipersensibilidade/patologia , Hipersensibilidade/terapia , Mordeduras e Picadas de Insetos/imunologia , Mordeduras e Picadas de Insetos/patologia , Mordeduras e Picadas de Insetos/terapia , Inulina/administração & dosagem , Masculino , Pessoa de Meia-Idade
11.
BMC Med Genet ; 19(1): 71, 2018 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-29739359

RESUMO

BACKGROUND: Diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) are sight-threatening complications of diabetes mellitus and leading causes of adult-onset blindness worldwide. Genetic risk factors for diabetic retinopathy (DR) have been described previously, but have been difficult to replicate between studies, which have often used composite phenotypes and been conducted in different populations. This study aims to identify genetic risk factors for DME and PDR as separate complications in Australians of European descent with type 2 diabetes. METHODS: Caucasian Australians with type 2 diabetes were evaluated in a genome-wide association study (GWAS) to compare 270 DME cases and 176 PDR cases with 435 non-retinopathy controls. All participants were genotyped by SNP array and after data cleaning, cases were compared to controls using logistic regression adjusting for relevant covariates. RESULTS: The top ranked SNP for DME was rs1990145 (p = 4.10 × 10- 6, OR = 2.02 95%CI [1.50, 2.72]) on chromosome 2. The top-ranked SNP for PDR was rs918519 (p = 3.87 × 10- 6, OR = 0.35 95%CI [0.22, 0.54]) on chromosome 5. A trend towards association was also detected at two SNPs reported in the only other reported GWAS of DR in Caucasians; rs12267418 near MALRD1 (p = 0.008) in the DME cohort and rs16999051 in the diabetes gene PCSK2 (p = 0.007) in the PDR cohort. CONCLUSION: This study has identified loci of interest for DME and PDR, two common ocular complications of diabetes. These findings require replication in other Caucasian cohorts with type 2 diabetes and larger cohorts will be required to identify genetic loci with statistical confidence. There is considerable overlap in the patient cohorts with each retinopathy subtype, complicating the search for genes that contribute to PDR and DME biology.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/genética , Estudo de Associação Genômica Ampla/métodos , Edema Macular/genética , Polimorfismo de Nucleotídeo Único , Idoso , Austrália , Estudos de Casos e Controles , Cromossomos Humanos Par 2/genética , Cromossomos Humanos Par 5/genética , Diabetes Mellitus Tipo 2/genética , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Pró-Proteína Convertase 2/genética , Receptores de LDL/genética , População Branca/genética
12.
Curr Issues Mol Biol ; 22: 17-40, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27648581

RESUMO

Poor immunogenicity remains the single biggest obstacle to human DNA vaccines achieving their potential. Strategies to improve DNA vaccine efficacy include codon optimization, transfection reagents, electroporation, vaccine adjuvants or combination with a protein or vector boost. Increased understanding of molecular events driving innate and adaptive immune responses has assisted development of molecular adjuvants for DNA vaccine use. Such adjuvants comprise plasmid-encoded signalling molecules including cytokines, chemokines, immune costimulatory molecules, toll-like receptor agonists or inhibitors of immune suppressive pathways. New approaches including gene knockdown, epigenetics and systems biology have also contributed to an increased range of molecular adjuvant options. This review explores current and future trends in vaccine design including the latest molecular adjuvants for enhanced DNA vaccine efficacy.


Assuntos
Vacinas de DNA/imunologia , Adjuvantes Imunológicos , Adjuvantes Farmacêuticos , Humanos
13.
J Gen Virol ; 98(8): 2143-2155, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28758637

RESUMO

The partial success of the RV144 trial underscores the importance of envelope-specific antibody responses for an effective HIV-1 vaccine. Oligomeric HIV-1 envelope proteins delivered with a potent adjuvant are expected to elicit strong antibody responses with broad neutralization specificity. To test this hypothesis, two SIV envelope proteins were formulated with delta inulin-based adjuvant (Advax) and used to immunize nonhuman primates. Oligomeric gp140-gp145 from SIVmac251 and SIVsmE660 was purified to homogeneity. Oligomers showed high-affinity interaction with CD4 and were highly immunogenic in rabbits, inducing Tier 2 SIV-neutralizing antibodies. The immunogenicity of an oligomeric Env DNA prime and protein boost together with Advax was evaluated in Chinese rhesus macaques. DNA administration elicited antibodies to both envelopes, and titres were markedly enhanced following homologous protein boosts via intranasal and intramuscular routes. Strong antibody responses were detected against the V1 and V2 domains of gp120. During peak immune responses, a low to moderate level of neutralizing activity was detected against Tier 1A/1B SIV isolates, with a moderate level noted against a Tier 2 isolate. Increased serum antibody affinity to SIVmac251 gp140 and generation of Env-specific memory B cells were observed in the immunized macaques. Animals were subjected to low-dose intravaginal challenge with SIVmac251 one week after the last protein boost. One out of three immunized animals was protected from infection. Although performed with a small number of macaques, this study demonstrates the utility of oligomeric envelopes formulated with Advax in eliciting broad antibody responses with the potential to provide protection against SIV transmission.


Assuntos
Anticorpos Antivirais/imunologia , DNA Viral/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , Vacinas contra a SAIDS/imunologia , Vírus da Imunodeficiência Símia/imunologia , Vacinas contra a AIDS , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Neutralizantes/imunologia , DNA Viral/administração & dosagem , DNA Viral/genética , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/administração & dosagem , Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , HIV-1/genética , HIV-1/imunologia , Humanos , Imunidade Humoral , Imunização Secundária , Inulina/administração & dosagem , Macaca mulatta , Coelhos , Vacinas contra a SAIDS/administração & dosagem , Vacinas contra a SAIDS/genética , Vírus da Imunodeficiência Símia/genética , Vacinação
15.
Biochim Biophys Acta Gen Subj ; 1861(8): 1981-1991, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28499821

RESUMO

Thiazolidinedione (TZD) compounds targeting the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) demonstrate unique benefits for the treatment of insulin resistance and type II diabetes. TZDs include rosiglitazone, pioglitazone and rivoglitazone, with the latter being the most potent. The TZDs are only marginally selective for the therapeutic target PPARγ as they also activate PPARα and PPARδ homologues to varying degrees, causing off-target effects. While crystal structures for TZD compounds in complex with PPARγ are available, minimal structural information is available for TZDs bound to PPARα and PPARδ. This paucity of structural information has hampered the determination of precise structural mechanisms involved in TZD selectivity between PPARs. To help address these questions molecular dynamic simulations were performed of rosiglitazone, pioglitazone and rivoglitazone in complex with PPARα, PPARδ, and PPARγ in order to better understand the mechanisms of PPAR selectivity. The simulations revealed that TZD interactions with residues Tyr314 and Phe318 of PPARα and residues Phe291 and Thr253 of PPARδ as well as the omega loop, are key determinants of TZD receptor selectivity. Notably, in this study, we solve the first X-ray crystal structure of rivoglitazone bound to any PPAR. Rivoglitazone forms a unique hydrogen bond network with the residues of the PPARγ co-activator binding surface (known as AF2) and makes more extensive contacts with helix 3 and the ß-sheet as compared to model TZD compounds such as rosiglitazone.


Assuntos
PPAR delta/química , PPAR gama/química , Tiazolidinedionas/química , Sítios de Ligação , Cristalografia por Raios X , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína
16.
J Virol ; 89(6): 2995-3007, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25520500

RESUMO

UNLABELLED: Although the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) epidemic was controlled by nonvaccine measures, coronaviruses remain a major threat to human health. The design of optimal coronavirus vaccines therefore remains a priority. Such vaccines present major challenges: coronavirus immunity often wanes rapidly, individuals needing to be protected include the elderly, and vaccines may exacerbate rather than prevent coronavirus lung immunopathology. To address these issues, we compared in a murine model a range of recombinant spike protein or inactivated whole-virus vaccine candidates alone or adjuvanted with either alum, CpG, or Advax, a new delta inulin-based polysaccharide adjuvant. While all vaccines protected against lethal infection, addition of adjuvant significantly increased serum neutralizing-antibody titers and reduced lung virus titers on day 3 postchallenge. Whereas unadjuvanted or alum-formulated vaccines were associated with significantly increased lung eosinophilic immunopathology on day 6 postchallenge, this was not seen in mice immunized with vaccines formulated with delta inulin adjuvant. Protection against eosinophilic immunopathology by vaccines containing delta inulin adjuvants correlated better with enhanced T-cell gamma interferon (IFN-γ) recall responses rather than reduced interleukin-4 (IL-4) responses, suggesting that immunopathology predominantly reflects an inadequate vaccine-induced Th1 response. This study highlights the critical importance for development of effective and safe coronavirus vaccines of selection of adjuvants based on the ability to induce durable IFN-γ responses. IMPORTANCE: Coronaviruses such as SARS-CoV and Middle East respiratory syndrome-associated coronavirus (MERS-CoV) cause high case fatality rates and remain major human public health threats, creating a need for effective vaccines. While coronavirus antigens that induce protective neutralizing antibodies have been identified, coronavirus vaccines present a unique problem in that immunized individuals when infected by virus can develop lung eosinophilic pathology, a problem that is further exacerbated by the formulation of SARS-CoV vaccines with alum adjuvants. This study shows that formulation of SARS-CoV spike protein or inactivated whole-virus vaccines with novel delta inulin-based polysaccharide adjuvants enhances neutralizing-antibody titers and protection against clinical disease but at the same time also protects against development of lung eosinophilic immunopathology. It also shows that immunity achieved with delta inulin adjuvants is long-lived, thereby overcoming the natural tendency for rapidly waning coronavirus immunity. Thus, delta inulin adjuvants may offer a unique ability to develop safer and more effective coronavirus vaccines.


Assuntos
Eosinófilos/imunologia , Pulmão/imunologia , Síndrome Respiratória Aguda Grave/imunologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/imunologia , Vacinas Virais/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Feminino , Humanos , Imunização , Interferon gama/imunologia , Interleucina-4/imunologia , Inulina/administração & dosagem , Inulina/análogos & derivados , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genética , Síndrome Respiratória Aguda Grave/patologia , Síndrome Respiratória Aguda Grave/prevenção & controle , Síndrome Respiratória Aguda Grave/virologia , Glicoproteína da Espícula de Coronavírus/administração & dosagem , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Células Th1/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
17.
Diabetologia ; 58(10): 2288-97, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26188370

RESUMO

AIMS/HYPOTHESIS: Diabetic retinopathy is a serious complication of diabetes mellitus and can lead to blindness. A genetic component, in addition to traditional risk factors, has been well described although strong genetic factors have not yet been identified. Here, we aimed to identify novel genetic risk factors for sight-threatening diabetic retinopathy using a genome-wide association study. METHODS: Retinopathy was assessed in white Australians with type 2 diabetes mellitus. Genome-wide association analysis was conducted for comparison of cases of sight-threatening diabetic retinopathy (n = 336) with diabetic controls with no retinopathy (n = 508). Top ranking single nucleotide polymorphisms were typed in a type 2 diabetes replication cohort, a type 1 diabetes cohort and an Indian type 2 cohort. A mouse model of proliferative retinopathy was used to assess differential expression of the nearby candidate gene GRB2 by immunohistochemistry and quantitative western blot. RESULTS: The top ranked variant was rs3805931 with p = 2.66 × 10(-7), but no association was found in the replication cohort. Only rs9896052 (p = 6.55 × 10(-5)) was associated with sight-threatening diabetic retinopathy in both the type 2 (p = 0.035) and the type 1 (p = 0.041) replication cohorts, as well as in the Indian cohort (p = 0.016). The study-wide meta-analysis reached genome-wide significance (p = 4.15 × 10(-8)). The GRB2 gene is located downstream of this variant and a mouse model of retinopathy showed increased GRB2 expression in the retina. CONCLUSIONS/INTERPRETATION: Genetic variation near GRB2 on chromosome 17q25.1 is associated with sight-threatening diabetic retinopathy. Several genes in this region are promising candidates and in particular GRB2 is upregulated during retinal stress and neovascularisation.


Assuntos
Diabetes Mellitus Tipo 2/genética , Retinopatia Diabética/genética , Proteína Adaptadora GRB2/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Animais , Austrália , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , Camundongos
18.
Ophthalmology ; 122(9): 1828-36, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26072347

RESUMO

PURPOSE: To investigate associations between single nucleotide polymorphisms (SNPs) in the VEGFC gene and the development of diabetic retinopathy (DR) in white patients with type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM). DESIGN: Cross-sectional, case control study. PARTICIPANTS: White patients with T1DM or T2DM (n = 2899) were recruited from ophthalmology and endocrine clinics in Australia and the United Kingdom. Patients with T2DM were required to have diabetes mellitus (DM) for at least 5 years and be receiving oral hypoglycemic treatment or insulin. METHODS: Participants were categorized according to their worst-ever DR grading, as having "no DR" (no history of nonproliferative DR [NPDR], proliferative DR [PDR], or diabetic macular edema [DME]) or "any DR" (further subclassified as NPDR or PDR, without or with DME). Clinical characteristics, glycemic control (hemoglobin A1c [HbA1c]), and presence of diabetic complications were determined at recruitment. Genotyping was performed for 13 VEGFC tag SNPs. MAIN OUTCOME MEASURES: Odds ratios (ORs) were determined for associations with DR of VEGFC tag SNPs, individually and within haplotypes. Logistic regression was used to adjust for clinical covariates, including DM type, age, sex, DM duration, hypertension, nephropathy, HbA1c, and smoking. RESULTS: Participants with DM but "no DR" (n = 980) were compared with 1919 participants with DM and "any DR." Three VEGFC SNPs were associated with DR after logistic regression: rs17697419 (P = 0.001; OR, 0.67; confidence interval [CI], 0.52-0.85), rs17697515 (P = 0.001; OR, 0.62; CI, 0.47-0.81), and rs2333526 (P = 0.005; OR, 0.69; CI, 0.54-0.90). rs17697515 Was also specifically associated with DME in those with T2DM (P = 0.004; OR, 0.53; CI, 0.35-0.82). Haplotype analysis revealed 2 significantly associated haplotypes, both protective against DR development. CONCLUSIONS: Significant associations were found between VEGFC tag SNPs (individually and within haplotypes) and the presence of any DR or DME in white participants with T1DM and T2DM.


Assuntos
Retinopatia Diabética/genética , Edema Macular/genética , Polimorfismo de Nucleotídeo Único , Fator C de Crescimento do Endotélio Vascular/genética , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 2/complicações , Feminino , Variação Genética , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Sitios de Sequências Rotuladas , População Branca/genética
19.
Alzheimers Dement ; 11(10): 1246-59, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26192465

RESUMO

Traditional vaccination against infectious diseases relies on generation of cellular and humoral immune responses that act to protect the host from overt disease even though they do not induce sterilizing immunity. More recently, attempts have been made with mixed success to generate therapeutic vaccines against a wide range of noninfectious diseases including neurodegenerative disorders. After the exciting first report of successful vaccine prevention of progression of an Alzheimer's disease (AD) animal model in 1999, various epitope-based vaccines targeting amyloid beta (Aß) have proceeded to human clinical trials, with varied results. More recently, AD vaccines based on tau protein have advanced into clinical testing too. This review seeks to put perspective to the mixed results obtained so far in clinical trials of AD vaccines and discusses the many pitfalls and misconceptions encountered on the path to a successful AD vaccine, including better standardization of immunologic efficacy measures of antibodies, immunogenicity of platform/carrier and adjuvants.


Assuntos
Doença de Alzheimer/prevenção & controle , Vacinas contra Alzheimer/uso terapêutico , Doença de Alzheimer/terapia , Animais , Formação de Anticorpos , Ensaios Clínicos como Assunto , Humanos , Vacinação , Proteínas tau/imunologia
20.
J Virol ; 87(8): 4395-402, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23388724

RESUMO

JE-ADVAX is a new, delta inulin-adjuvanted, Japanese encephalitis (JE) candidate vaccine with a strong safety profile and potent immunogenicity that confers efficient immune protection not only against JE virus but also against related neurotropic flaviviruses such as West Nile virus. In this study, we investigated the immunological mechanism of protection by JE-ADVAX vaccine using knockout mice deficient in B cells or CD8(+) T cells and poor persistence of neutralizing antibody or by adoptive transfer of immune splenocyte subpopulations. We show that memory B cells induced by JE-ADVAX provide long-lived protection against JE even in the absence of detectable pre-exposure serum neutralizing antibodies and without the requirement of CD8(+) T cells. Upon virus encounter, these vaccine-induced memory B cells were rapidly triggered to produce neutralizing antibodies that then protected immunized mice from morbidity and mortality. The findings suggest that the extent of the B-cell memory compartment might be a better immunological correlate for clinical efficacy of JE vaccines than the currently recommended measure of serum neutralizing antibody. This may explain the paradox where JE protection is observed in some subjects even in the absence of detectable serum neutralizing antibody. Our investigation also established the suitability of a novel flavivirus challenge model (ß(2)-microglobulin-knockout mice) for studies of the role of B-cell memory responses in vaccine protection.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Encefalite Japonesa/prevenção & controle , Inulina/análogos & derivados , Vacinas contra Encefalite Japonesa/imunologia , Animais , Linfócitos B/imunologia , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Encefalite Japonesa/imunologia , Inulina/administração & dosagem , Vacinas contra Encefalite Japonesa/administração & dosagem , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
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