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Archaeosomes were manufactured from natural archaeal lipids by a microfluidics-assisted single-step production method utilizing a mixture of di- and tetraether lipids extracted from Sulfolobus acidocaldarius. The primary aim of this study was to investigate the exceptional stability of archaeosomes as potential carriers for oral drug delivery, with a focus on powdered formulations. The archaeosomes were negatively charged with a size of approximately 100 nm and a low polydispersity index. To assess their suitability for oral delivery, the archaeosomes were loaded with two model drugs: calcein, a fluorescent compound, and insulin, a peptide hormone. The archaeosomes demonstrated high stability in simulated intestinal fluids, with only 5% of the encapsulated compounds being released after 24 h, regardless of the presence of degrading enzymes or extremely acidic pH values such as those found in the stomach. In a co-culture cell model system mimicking the intestinal barrier, the archaeosomes showed strong adhesion to the cell membranes, facilitating a slow release of contents. The archaeosomes were loaded with insulin in a single-step procedure achieving an encapsulation efficiency of approximately 35%. These particles have been exposed to extreme manufacturing temperatures during freeze-drying and spray-drying processes, demonstrating remarkable resilience under these harsh conditions. The fabrication of stable dry powder formulations of archaeosomes represents a promising advancement toward the development of solid dosage forms for oral delivery of biological drugs.
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With the continued transmission of SARS-CoV-2 across widely vaccinated populations, it remains important to develop new vaccines and vaccination strategies capable of providing protective immunity and limiting the spread of disease. Heterologous prime-boost vaccination based on the selection of different vaccine formulations and administration routes for priming and booster doses presents a promising strategy for inducing broader immune responses in key systemic and respiratory mucosal compartments. Intranasal vaccination can induce mucosal immune responses at the site of SARS-CoV-2 infection; however, the lack of clinically approved mucosal adjuvants makes it difficult to induce robust immune responses with protein subunit vaccines. Herein, we evaluated the immunogenicity of heterologous prime-boost regimens in mice and hamsters based on a parenteral vaccination of the antigen in combination with sulfated lactosylarchaeol (SLA) archaeosomes, a liposome adjuvant comprised of a single semisynthetic archaeal lipid, followed by an intranasally administered unadjuvanted SARS-CoV-2 spike antigen. Intranasal administration of unadjuvanted spike to mice and hamsters increased serum spike-specific IgG titers and spike-neutralizing activity compared with nonboosted animals. Spike-specific IgA responses were also detected in the bronchoalveolar lavage fluid in the lungs of mice that received an intranasal boost. In hamsters, the intranasal boost showed high efficacy against SARS-CoV-2 infection by protecting from body weight loss and reducing viral titers in the lungs and nasal turbinate. Overall, our heterologous intramuscular prime-intranasal boost with SLA-adjuvanted and unadjuvanted spike, respectively, demonstrated the potential of protein subunit formulations to promote antigen-specific systemic and mucosal immune responses.
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Administração Intranasal , Anticorpos Antivirais , Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Vacinas de Subunidades Antigênicas , Animais , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/administração & dosagem , Camundongos , SARS-CoV-2/imunologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Cricetinae , COVID-19/prevenção & controle , COVID-19/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Feminino , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Imunização Secundária , Adjuvantes Imunológicos/administração & dosagem , Camundongos Endogâmicos BALB C , Imunidade nas Mucosas/imunologia , Humanos , Vacinação/métodosRESUMO
Neutral and positively charged archaeal ether lipids (AEL) have been studied for their utilization as novel delivery systems for pDNA, showing efficient immune response with a strong memory effect while lacking noticeable toxicity. Recent technological advances placed mRNA lipid nanoparticles (LNPs) at the forefront of next-generation delivery systems; however, no study has examined AELs in mRNA delivery yet. In this study, we investigated either a crude lipid extract or the purified tetraether lipid caldarchaeol from Sulfolobus acidocaldarius as potential novel excipients for mRNA LNPs. Depending on their molar share in the respective LNP, particle uptake, and mRNA expression levels could be increased by up to 10-fold in in vitro transfection experiments using both primary cell sources (HSMM) and established cell lines (Caco-2, C2C12) compared to a well-known reference formulation. This increased efficiency might be linked to a substantial effect on endosomal escape, indicating fusogenic and lyotropic features of AELs. This study shows the high value of archaeal ether lipids for mRNA delivery and provides a solid foundation for future in vivo experiments and further research.
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Lipídeos , Nanopartículas , Humanos , Éter , Archaea , RNA Mensageiro/genética , Células CACO-2 , Lipossomos , Transfecção , Éteres , Etil-Éteres , RNA Interferente PequenoRESUMO
Cannabidiol (CBD) has received great scientific interest due to its numerous therapeutic applications. Degradation in the gastrointestinal (GI) tract, first-pass metabolism, and low water solubility restrain bioavailability of CBD to only 6% in current oral administration. Lipid-based nanocarriers are delivery systems that may enhance accessibility and solubility of hydrophobic payloads, such as CBD. Conventional lecithin-derived liposomes, however, have limitations regarding stability in the GI tract and long-term storage. Ether lipid-based archaeosomes may have the potential to overcome these problems due to chemical and structural uniqueness. In this study, we compared lecithin-derived liposomes with archaeosomes in their applicability as an oral delivery system of CBD. We evaluated drug load, storage stability, stability in a simulated GI tract, and in vitro particle uptake in Caco-2 cells. Loading capacity was 6-fold higher in archaeosomes than conventional liposomes while providing a stable formulation over six months after lyophilization. In a simulated GI tract, CBD recovery in archaeosomes was 57 ± 3% compared to only 34 ± 1% in conventional liposomes and particle uptake in Caco-2 cells was enhanced up to 6-fold. Our results demonstrate that archaeosomes present an interesting solution to tackle current issues of oral CBD formulations due to improved stability and endocytosis.
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Canabidiol , Lipossomos , Humanos , Lipossomos/química , Células CACO-2 , Lecitinas , Administração Oral , Sistemas de Liberação de MedicamentosRESUMO
Archaea are microorganisms more closely related to eukaryotes than bacteria. Almost 50 years after being defined as a new domain of life on earth, new species continue to be discovered and their phylogeny organized. The study of the relationship between their genetics and metabolism and some of their extreme habitats has even positioned them as a model of extraterrestrial life forms. Archaea, however, are deeply connected to the life of our planet: they can be found in arid, acidic, warm areas; on most of the earth's surface, which is cold (below 5 °C), playing a prominent role in the cycles of organic materials on a global scale and they are even part of our microbiota. The constituent materials of these microorganisms differ radically from those produced by eukaryotes and bacteria, and the nanoparticles that can be manufactured using their ether lipids as building blocks exhibit unique properties that are of interest in nanomedicine. Here, we present for the first time a complete overview of the pre-clinical applications of nanomedicines based on ether archaea lipids, focused on drug delivery and adjuvancy over the last 25 years, along with a discussion on their pros, cons and their future industrial implementation.
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Éter , Lipossomos , Archaea , Bactérias , Éteres , Etil-Éteres , Lipídeos , VacinaçãoRESUMO
Liposomes and planar membranes made of archaea or archaea-like lipids exhibit many unusual physical properties compared to model membranes composed of conventional diester lipids. Here, we review several recent findings in this research area, which include (1) thermosensitive archaeosomes with the capability to drastically change the membrane surface charge, (2) MthK channel's capability to insert into tightly packed tetraether black lipid membranes and exhibit channel activity with surprisingly high calcium sensitivity, and (3) the intercalation of apolar squalane into the midplane space of diether bilayers to impede proton permeation. We also review the usage of tetraether archaeosomes as nanocarriers of therapeutics and vaccine adjuvants, as well as the biomedical applications of planar archaea lipid membranes. The discussion on archaeosomal therapeutics is focused on partially purified tetraether lipid fractions such as the polar lipid fraction E (PLFE) and glyceryl caldityl tetraether (GCTE), which are the main components of PLFE with the sugar and phosphate removed.
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Archaea , Lipossomos , Lipídeos , Membranas , PrótonsRESUMO
Archaea are prokaryotic organisms that were classified as a new domain in 1990. Archaeal cellular components and metabolites have found various applications in the pharmaceutical industry. Some archaeal lipids can be used to produce archaeosomes, a new family of liposomes that exhibit high stability to temperatures, pH and oxidative conditions. Additionally, archaeosomes can be efficient antigen carriers and adjuvants promoting humoral and cellular immune responses. Some archaea produce gas vesicles, which are nanoparticles released by the archaea that increase the buoyancy of the cells and facilitate an upward flotation in water columns. Purified gas vesicles display a great potential for bioengineering, due to their high stability, immunostimulatory properties and uptake across cell membranes. Both archaeosomes and archaeal gas vesicles are attractive tools for the development of novel drug and vaccine carriers to control various diseases. In this review we discuss the current knowledge on production, preparation methods and potential applications of archaeosomes and gas vesicles as carriers for vaccines. We give an overview of the traditional structures of these carriers and their modifications. A comparative analysis of both vaccine delivery systems, including their advantages and limitations of their use, is provided. Gas vesicle- and archaeosome-based vaccines may be powerful next-generation tools for the prevention and treatment of a wide variety of infectious and non-infectious diseases.
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Archaea , Vesículas Citoplasmáticas , Portadores de Fármacos , Lipossomos , Desenvolvimento de Vacinas/métodos , Adjuvantes Imunológicos , Animais , Humanos , NanopartículasRESUMO
The number of approved macromolecular drugs such as peptides, proteins and antibodies steadily increases. Since drugs with high molecular weight are commonly not suitable for oral delivery, research on carrier strategies enabling oral administration is of vital interest. In past decades, nanocarriers, in particular liposomes, have been exhaustively investigated as oral drug-delivery platform. Despite their successful application as parenteral delivery vehicles, liposomes have up to date not succeeded for oral administration. However, a plenitude of approaches aiming to increase the oral bioavailability of macromolecular drugs administered by liposomal formulations has been published. Here, we summarize the strategies published in the last 10 years (vaccine strategies excluded) with a main focus on strategies proven efficient in animal models.
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Produtos Biológicos , Lipossomos , Administração Oral , Animais , Disponibilidade Biológica , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , HumanosRESUMO
Archaeosomes, composed of sulphated lactosyl archaeol (SLA) glycolipids, have been proven to be an effective vaccine adjuvant in multiple preclinical models of infectious disease or cancer. In addition to efficacy, the stability of vaccine components including the adjuvant is an important parameter to consider when developing novel vaccine formulations. To properly evaluate the potential of SLA glycolipids to be used as vaccine adjuvants in a clinical setting, a comprehensive evaluation of their stability is required. Herein, we evaluated the long term stability of preformed empty SLA archaeosomes prior to admixing with antigen at 4 °C or 37 °C for up to 6 months. In addition, the stability of adjuvant and antigen was evaluated for up to 1 month following admixing. Multiple analytical parameters evaluating the molecular integrity of SLA and the liposomal profile were assessed. Following incubation at 4 °C or 37 °C, the SLA glycolipid did not show any pattern of degradation as determined by mass spectroscopy, nuclear magnetic resonance (NMR) and thin layer chromatography (TLC). In addition, SLA archaeosome vesicle characteristics, such as size, zeta potential, membrane fluidity and vesicular morphology, were largely consistent throughout the course of the study. Importantly, following storage for 6 months at both 4 °C and 37 °C, the adjuvant properties of empty SLA archaeosomes were unchanged, and following admixing with antigen, the immunogenicity of the vaccine formulations was also unchanged when stored at both 4 °C and 37 °C for up to 1 month. Overall this indicates that SLA archaeosomes are highly stable adjuvants that retain their activity over an extended period of time even when stored at high temperatures.
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Lipossomos , Vacinas , Antígenos Arqueais , Imunidade Celular , LipídeosRESUMO
Schistosomiasis threatens 800 million people worldwide. Chronic pathology manifests as hepatosplenomegaly, and intestinal schistosomiasis caused by Schistosoma mansoni can lead to liver fibrosis, cirrhosis, and blood in the stool. To assist the only FDA-approved drug, praziquantel, in parasite elimination, the development of a vaccine would be of high value. S. mansoni Cathepsin B (SmCB) is a well-documented vaccine target for intestinal schistosomiasis. Herein, we test the increased efficacy and immunogenicity of SmCB when combined with sulfated lactosyl archaeol (SLA) archaeosomes or AddaVax™ (a squalene based oil-in-water emulsion). Both vaccine formulations resulted in robust humoral and cell mediated immune responses. Impressively, both formulations were able to reduce parasite burden greater than 40% (WHO standard), with AddaVax™ reaching 86.8%. Additionally, SmCB with both adjuvants were able to reduce granuloma size and the amount of larval parasite hatched from feces, which would reduce transmission. Our data support SmCB as a target for S. mansoni vaccination; especially when used in an adjuvanted formulation.
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Adjuvantes Imunológicos/farmacologia , Antígenos Arqueais/farmacologia , Catepsina B/farmacologia , Proteínas de Helminto/farmacologia , Lipídeos/farmacologia , Polissorbatos/farmacologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/prevenção & controle , Esqualeno/farmacologia , Vacinas Sintéticas/farmacologia , Animais , Anticorpos/sangue , Catepsina B/imunologia , Células Cultivadas , Citocinas/metabolismo , Composição de Medicamentos , Feminino , Proteínas de Helminto/imunologia , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Imunização , Imunogenicidade da Vacina , Camundongos Endogâmicos C57BL , Contagem de Ovos de Parasitas , Schistosoma mansoni/enzimologia , Esquistossomose mansoni/imunologia , Esquistossomose mansoni/parasitologia , Caramujos , Vacinas Sintéticas/imunologiaRESUMO
Archaeosomes have drawn increasing attention in recent years as novel nano-carriers for therapeutics. The main obstacle of using archaeosomes for therapeutics delivery has been the lack of an efficient method to trigger the release of entrapped content from the otherwise extremely stable structure. Our present study tackles this long-standing problem. We made hybrid archaeosomes composed of tetraether lipids, called the polar lipid fraction E (PLFE) isolated from the thermoacidophilic archaeon Sulfolobus acidocaldarius, and the synthetic diester lipid dipalmitoylphosphatidylcholine (DPPC). Differential polarized phase-modulation and steady-state fluorometry, confocal fluorescence microscopy, zeta potential (ZP) measurements, and biochemical assays were employed to characterize the physical properties and drug behaviors in PLFE/DPPC hybrid archaeosomes in the presence and absence of live cells. We found that PLFE lipids have an ordering effect on fluid DPPC liposomal membranes, which can slow down the release of entrapped drugs, while PLFE provides high negative charges on the outer surface of liposomes, which can increase vesicle stability against coalescence among liposomes or with cells. Furthermore, we found that the zeta potential in hybrid archaeosomes with 30 mol% PLFE and 70 mol% DPPC (designated as PLFE/DPPC(3:7) archaeosomes) undergoes an abrupt increase from -48 mV at 37 °C to -16 mV at 44 °C (termed the ZP transition), which we hypothesize results from DPPC domain melting and PLFE lipid 'flip-flop'. The anticancer drug doxorubicin (DXO) can be readily incorporated into PLFE/DPPC(3:7) archaeosomes. The rate constant of DXO release from PLFE/DPPC(3:7) archaeosomes into Tris buffer exhibited a sharp increase (~2.5 times), when the temperature was raised from 37 to 42 °C, which is believed to result from the liposomal structural changes associated with the ZP transition. This thermo-induced sharp increase in drug release was not affected by serum proteins as a similar temperature dependence of drug release kinetics was observed in human blood serum. A 15-min pre-incubation of PLFE/DPPC(3:7) archaeosomal DXO with MCF-7 breast cancer cells at 42 °C caused a significant increase in the amount of DXO entering into the nuclei and a considerable increase in the cell's cytotoxicity under the 37 °C growth temperature. Taken together, our data suggests that PLFE/DPPC(3:7) archaeosomes are stable yet potentially useful thermo-sensitive liposomes wherein the temperature range (from 37 to 42-44 °C) clinically used for mild hyperthermia treatment of tumors can be used to trigger drug release for medical interventions.
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1,2-Dipalmitoilfosfatidilcolina/química , Preparações de Ação Retardada/química , Portadores de Fármacos/química , Lipídeos/química , Nanopartículas/química , Sulfolobus acidocaldarius/química , Linhagem Celular Tumoral , Doxorrubicina/química , Humanos , Cinética , Lipossomos/química , Células MCF-7 , TemperaturaRESUMO
Archaeosomes are liposomes composed of natural or synthetic archaeal lipids that when used as adjuvants induce strong long-lasting humoral and cell-mediated immune responses against entrapped antigens. However, traditional entrapped archaeosome formulations have only low entrapment efficiency, therefore we have developed a novel admixed formulation which offers many advantages, including reduced loss of antigen, consistency of batch-to-batch production as well as providing the option to formulate the vaccine immediately before use, which is beneficial for next generation cancer therapy platforms that include patient specific neo-antigens or for use with antigens that are less stable. Herein, we demonstrate that, when used in combination with anti-CTLA-4 and anti-PD-1 checkpoint therapy, this novel admixed archaeosome formulation, comprised of preformed sulfated lactosyl archaeol (SLA) archaeosomes admixed with OVA antigen (SLA-OVA (adm)), was as effective at inducing strong CD8+ T cell responses and protection from a B16-OVA melanoma tumor challenge as the traditionally formulated archaeosomes with encapsulated OVA protein. Furthermore, archaeosome vaccine formulations combined with anti-CTLA-4 and anti-PD-1 therapy, induced OVA-CD8+ T cells within the tumor and immunohistochemical analysis revealed the presence of CD8+ T cells associated with dying or dead tumor cells as well as within or around tumor blood vessels. Overall, archaeosomes constitute an attractive option for use with combinatorial checkpoint inhibitor cancer therapy platforms.
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Induction of strong antigen-specific cell-mediated and humoral responses are critical to developing a successful therapeutic vaccine. Herein, using HER2 as a model antigen, we aim to evaluate a therapeutic vaccine protocol that elicits anti-tumor antibody and cytotoxic T cells to HER2/neu antigen. Replication-competent (ΔPS AdV) and non-replicating recombinant adenoviral vectors (AdV) expressing a rat HER2/neu (ErbB2) oncogene, were generated and compared for four different doses and over four time points for their ability to induce antigen-specific T and B cell responses in mice. Although ΔPS AdV:Her2 vector was shown to induce more durable antigen-specific CD8+ T cell responses, overall, the AdV:Her2 vector induced broader T and B cell responses. Hence the AdV:Her2 vector was used to evaluate a heterologous prime-boost vaccination regimen using rat HER2 protein encapsulated in archaeosomes composed of a semi-synthetic glycolipid (sulfated S-lactosylarchaeol, SLA; and lactosylarchaeol, LA) (SLA/LA:HER2enc) or admixed with archaeosomes composed of SLA alone (SLA:HER2adm). We first tested AdV:Her2 using a prime-boost approach with SLA/LA:HER2enc, and thereafter evaluated a sub-optimal AdV:Her2 dose in a heterologous prime-boost approach with SLA:HER2adm. A single administration of AdV:Her2 alone induced strong cell-mediated immune responses, whereas SLA/LA:HER2enc alone induced strong antigen-specific IgG titers. In mice primed with a suboptimal dose of AdV:Her2, strong CD8+ T-cell responses were observed after a single dose which were not further augmented by protein boost. AdV:Her2 induced CD4+ specific T-cell responses were augmented by SLA:HER2adm. Homologous vaccination using SLA:HER2adm induced strong antigen-specific antibody responses. However, the overall magnitude of the responses was similar with three doses of SLA:HER2adm or Ad:HER2 prime followed by two doses of SLA:HER2adm. We demonstrate that AdV:Her2 is capable of inducing strong antigen-specific CD8+ T cell responses, even at a low dose, and that these responses can be broadened to include antigen-specific antibody responses by boosting with SLA adjuvanted proteins without compromising CD8 T cell responses elicited by AdV priming.
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Adenoviridae/imunologia , Adjuvantes Imunológicos/administração & dosagem , Vetores Genéticos/imunologia , Receptor ErbB-2/imunologia , Animais , Linfócitos B/imunologia , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular , Feminino , Imunidade Celular/imunologia , Imunização Secundária/métodos , Camundongos , Camundongos Endogâmicos BALB C , Ratos , Vacinação/métodos , Vacinas de DNA/imunologia , Vacinas Virais/imunologiaRESUMO
Archaeosomes are vesicles made of lipids from archaea. They possess many unique features in comparison to other lipid systems, with their high stability being the most prominent one, making them a promising system for biotechnological applications. Here, we report a preparation protocol of large unilamellar vesicles, giant unilamellar vesicles (GUVs), and nanodiscs from archaeal lipids with incorporated cholesterol. Incorporation of cholesterol led to additional increase in thermal stability of vesicles. Surface plasmon resonance, sedimentation assays, intrinsic tryptophan fluorescence measurements, calcein release experiments, and GUVs experiments showed that members of cholesterol-dependent cytolysins, listeriolysin O (LLO), and perfringolysin O (PFO), bind to cholesterol-rich archaeosomes and thereby retain their pore-forming activity. Interestingly, we observed specific binding of LLO, but not PFO, to archaeosomes even in the absence of cholesterol. This suggests a new capacity of LLO to bind to carbohydrate headgroups of archaeal lipids. Furthermore, we were able to express LLO inside GUVs by cell-free expression. GUVs made from archaeal lipids were highly stable, which could be beneficial for synthetic biology applications. In summary, our results describe novel model membrane systems for studying membrane interactions of proteins and their potential use in biotechnology.
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Archaea/metabolismo , Colesterol/química , Citotoxinas/química , Lipossomas Unilamelares/química , Colesterol/metabolismo , Citotoxinas/metabolismo , Lipossomas Unilamelares/metabolismoRESUMO
Archaeosomes are liposomes comprised of ether lipids derived from various archaea. Unlike conventional ester-linked liposomes, archaeosomes exhibit high pH and thermal stability. As adjuvants, archaeosomes can induce robust, long-lasting humoral and cell-mediated immune responses and enhance protection in murine models of infectious disease and cancer. Archaeosomes constituted with total polar lipids (TPL) of various archaea are relatively complex, comprising >10 different lipid compounds. Archaeosomes can be constituted with semi-synthetic glycerolipids built on ether-linked isoprenoid phytanyl cores with varied synthetic glycol- and amino-head groups. However, such semi-synthetic archaeosomes involve many synthetic steps to arrive at the final desired glycolipid composition. We have developed a novel archaeosome formulation comprising a sulfated saccharide group covalently linked to the free sn-1 hydroxyl backbone of an archaeal core lipid (sulfated S-lactosylarchaeol, SLA) mixed with uncharged glycolipid (lactosylarchaeol, LA). This new class of adjuvants can be easily synthesized and retains strong immunostimulatory activity for induction of cell-mediated immunity following systemic immunization. Herein, we demonstrate the safety of SLA/LA archaeosomes following intramuscular injection to mice and evaluate the immunogenicity, in vivo distribution and cellular uptake of antigen (ovalbumin) encapsulated into SLA/LA archaeosomes. Overall, we have found that semi-synthetic sulfated glycolipid archaeosomes are a safe and effective novel class of adjuvants capable of inducing strong antigen-specific immune responses in mice and protection against subsequent B16 melanoma tumor challenge. A key step in their mechanism of action appears to be the recruitment of immune cells to the injection site and the subsequent trafficking of antigen to local draining lymph nodes.
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Adjuvantes Imunológicos/farmacocinética , Archaea/química , Vacinas Anticâncer/imunologia , Glicolipídeos/farmacocinética , Lipossomos/farmacocinética , Animais , Imunidade Celular , Injeções Intramusculares , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Ovalbumina/administração & dosagem , Ovalbumina/imunologia , Distribuição Tecidual , Vacinação/métodosRESUMO
Three decades after the discovery, hepatitis C virus (HCV) is still the leading cause of liver transplantation and poses a major threat to global health. In spite of recent advances in the development of direct acting antivirals, there is still a need for a prophylactic vaccine to limit the virus spread and protect at-risk populations, especially in developing countries, where the cost of the new treatments may severely limit access. The use of recombinant HCV glycoproteins E1E2 (rE1E2) in combination with the MF59, an oil-in-water emulsion-based adjuvant, has previously been shown to reduce the rate of chronicity in chimpanzees and to induce production of cross-neutralizing antibodies and cellular immune responses in human volunteers. To further improve neutralizing antibody responses in recipients along with robust T cell responses, we have explored the immunogenicity of different adjuvants when formulated with the HCV rE1E2 vaccine in mice. Our data show that cyclic di-adenosine monophosphate (c-di-AMP) and archaeosomes elicit strong neutralizing antibodies similar to those elicited using aluminum hydroxide/monophosphoryl lipid A (Alum/monophos. /MPLA) and MF59. However, both c-di-AMP and archaeosomes induced a more robust cellular immune response, which was confirmed by the detection of vaccine-specific poly-functional CD4+ T cells. We conclude that these adjuvants may substantially boost the immunogenicity of our E1E2 vaccine. In addition, our data also indicates that use of a partial or exclusive intranasal immunization regimen may also be feasible using c-di-AMP as adjuvant.
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Adjuvantes Imunológicos/administração & dosagem , Archaea/imunologia , Linfócitos T CD4-Positivos/imunologia , Fosfatos de Dinucleosídeos/administração & dosagem , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/sangue , Proteínas do Envelope Viral/imunologia , Vacinas Virais/imunologia , Administração Intranasal , Anticorpos Neutralizantes/sangue , Humanos , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Proteínas do Envelope Viral/administração & dosagem , Proteínas do Envelope Viral/genética , Vacinas Virais/administração & dosagem , Vacinas Virais/genéticaRESUMO
INTRODUCTION: Liposomal vesicles (archaeosomes) composed of total polar lipids (TPL) or semi-synthetic glycerolipids, unique to the domain Archaea, constitute potent vaccine adjuvant and delivery systems. The characteristics of this adjuvant offer a novel prospect for the development of effective vaccines for emerging infections and cancers, which is reviewed in this article. Areas covered: The areas covered in this review include the chemical composition and physical characteristics, various in-vitro and in-vivo pre-clinical immunogenicity and efficacy studies for systemic immunization, induction of mucosal immunity upon modification of the formulation with cations, and the mechanism of adjuvant action following uptake by antigen presenting cells. Expert commentary: The unique features of archaeal lipids confer archaeosomes with many desirable features. With the use of semi-synthetic archaeosomes, highly defined lipids that are safe and robust for induction of cell-mediated immunity may be chosen. These adjuvants function as Toll-like receptor-independent innate immune stimulants.
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Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/isolamento & purificação , Archaea/química , Imunidade Celular , Lipossomos/administração & dosagem , Lipossomos/isolamento & purificação , Animais , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/isolamento & purificação , HumanosRESUMO
Archaeosomes as liposomes made with one or more ether lipids that are unique to the domain of Archaeobacteria, found in Archaea constitute a novel family of liposome. Achaean-type lipids consist of archaeol (diether) and/or caldarchaeol (tetraether) core structures. Archaeosomes can be produced using standard procedures (hydrated film submitted to sonication, extrusion and detergent dialysis) at any temperature in the physiological range or lower, therefore making it possible to encapsulate thermally stable compounds. Various physiological as well as environmental factors affect its stability. Archaeosomes are widely used as drug delivery systems for cancer vaccines, Chagas disease, proteins and peptides, gene delivery, antigen delivery and delivery of natural antioxidant compounds. In this review article, our major aim was to explore the applications of this new carrier system in pharmaceutical field.
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Adjuvantes Imunológicos/química , Archaea/química , Portadores de Fármacos , Sistemas de Liberação de Medicamentos/métodos , Éteres de Glicerila/administração & dosagem , Lipossomos/química , Peptídeos/administração & dosagem , Peptídeos/metabolismo , Estabilidade de Medicamentos , Técnicas de Transferência de Genes , Éteres de Glicerila/química , Éteres de Glicerila/metabolismo , Éteres de Glicerila/farmacologia , Humanos , Peptídeos/químicaRESUMO
Chagas disease is a neglected parasitic infection caused by the protozoan Trypanosoma cruzi. After a mostly clinically silent acute phase, the disease becomes a lifelong chronic condition that can lead to chronic heart failure and thromboembolic phenomena followed by sudden death. Antichagasic treatment is only effective in the acute phase but fails to eradicate the intracellular form of parasites and causes severe toxicity in adults. Although conventional oral benznidazol is not a safe and efficient drug to cure chronic adult patients, current preclinical data is insufficient to envisage if conventional antichagasic treatment could be realistically improved by a nanomedical approach. This review will discuss how nanomedicines could help to improve the performance of therapeutics, vaccines and diagnosis of Chagas disease.