28 research outputs found
Tissue distribution of DNA-Hsp65/TDM-loaded PLGA microspheres and uptake by phagocytic cells
This study aimed to demonstrate that microspheres, used as delivery vehicle of DNA-Hsp65/TDM [plasmid DNA encoding heat shock protein 65 (Hsp65) coencapsulated with trehalose dimycolate (TDM) into PLGA microspheres], are widely spread among several organs after intramuscular administration in BALB/c mice. In general, we showed that these particles were phagocytosed by antigen presenting cells, such as macrophages and dendritic cells. Besides, it was demonstrated herein that draining lymph node cells presented a significant increase in the number of cells expressing costimulatory molecules (CD80 and CD86) and MHC class II, and also that the administration of the DNA-Hsp65/TDM and vector/TDM formulations resulted in the up-regulation of CD80, CD86 and MHC class II expression when compared to control formulations (vector/TDM and empty). Regarding the intracellular trafficking we observed that following phagocytosis, the microspheres were not found in the late endosomes and/or lysosomes, until 15 days after internalization, and we suggest that these constructions were hydrolysed in early compartments. Overall, these data expand our knowledge on PLGA [poly (lactic-co- glycolic acid)] microspheres as gene carriers in vaccination strategies, as well as open perspectives for their potential use in clinical practice
Serum Amyloid P Therapeutically Attenuates Murine Bleomycin-Induced Pulmonary Fibrosis via Its Effects on Macrophages
Macrophages promote tissue remodeling but few mechanisms exist to modulate their activity during tissue fibrosis. Serum amyloid P (SAP), a member of the pentraxin family of proteins, signals through Fcγ receptors which are known to affect macrophage activation. We determined that IPF/UIP patients have increased protein levels of several alternatively activated pro-fibrotic (M2) macrophage-associated proteins in the lung and monocytes from these patients show skewing towards an M2 macrophage phenotype. SAP therapeutically inhibits established bleomycin-induced pulmonary fibrosis, when administered systemically or locally to the lungs. The reduction in aberrant collagen deposition was associated with a reduction in M2 macrophages in the lung and increased IP10/CXCL10. These data highlight the role of macrophages in fibrotic lung disease, and demonstrate a therapeutic action of SAP on macrophages which may extend to many fibrotic indications caused by over-exuberant pro-fibrotic macrophage responses
Effectiveness, against tuberculosis, of pseudo-ternary complexes: Peptide-DNA-cationic liposome
We report the effects of a synthetic peptide designed to act as a nuclear localization signal on the treatment of tuberculosis. The peptide contains 21 amino acid residues with the following specific domains: nuclear localization signal from SV 40T, cationic shuttle sequence, and cysteamide group at the C-terminus. The peptide was complexed with the plasmid DNAhsp65 and incorporated into cationic liposomes, forming a pseudo-ternary complex. The same cationic liposomes, composed of egg chicken L-alpha-phosphatidylcholine, 1,2-dioleoyl-3-trimethylammonium-propane, and 1,2-dioleoyl-3-trimethylammonium-propane (2:1:1 M), were previously evaluated as a gene carrier for tuberculosis immunization protocols with DNAhsp65. The pseudo-ternary complex presented a controlled size (250 nm), spherical-like shape, and various lamellae in liposomes as evaluated by transmission electron microscopy. An assay of fluorescence probe accessibility confirmed insertion of the peptide/DNA into the liposome structure. Peptide addition conferred no cytotoxicity in vitro, and similar therapeutic effects against tuberculosis were seen with four times less DNA compared with naked DNA treatment. Taken together, the results indicate that the pseudo-ternary complex is a promising gene vaccine for tuberculosis treatment. This work contributes to the development of multifunctional nanostructures in the search for strategies for in vivo DNA delivery373102109FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO – FAPESPsem informaçã
Effectiveness, against tuberculosis, of pseudo-ternary complexes: Peptide-DNA-cationic liposome
We report the effects of a synthetic peptide designed to act as a nuclear localization signal on the treatment of tuberculosis. The peptide contains 21 amino acid residues with the following specific domains: nuclear localization signal from SV 40T, cationic shuttle sequence, and cysteamide group at the C-terminus. The peptide was complexed with the plasmid DNAhsp65 and incorporated into cationic liposomes, forming a pseudo-ternary complex. The same cationic liposomes, composed of egg chicken L-alpha-phosphatidylcholine, 1,2-dioleoyl-3-trimethylammonium-propane, and 1,2-dioleoyl-3-trimethylammonium-propane (2:1:1 M), were previously evaluated as a gene carrier for tuberculosis immunization protocols with DNAhsp65. The pseudo-ternary complex presented a controlled size (250 nm), spherical-like shape, and various lamellae in liposomes as evaluated by transmission electron microscopy. An assay of fluorescence probe accessibility confirmed insertion of the peptide/DNA into the liposome structure. Peptide addition conferred no cytotoxicity in vitro, and similar therapeutic effects against tuberculosis were seen with four times less DNA compared with naked DNA treatment. Taken together, the results indicate that the pseudo-ternary complex is a promising gene vaccine for tuberculosis treatment. This work contributes to the development of multifunctional nanostructures in the search for strategies for in vivo DNA delivery. (C) 2011 Elsevier Inc. All rights reserved.Fundacao de Amparo Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo Pesquisa do Estado de Sao Paulo (FAPESP
Effects of extrusion, lipid concentration and purity on physico-chemical and biological properties of cationic liposomes for gene vaccine applications
We developed cationic liposomes containing DNA through a conventional process involving steps of (i) preformation of liposomes, (ii) extrusion, (iii) drying and rehydration and (iv) DNA complexation. Owing to its high prophylactic potentiality against tuberculosis, which had already been demonstrated in preclinical assays, we introduced modifications into the conventional process towards getting a simpler and more economical process for further scale-up. Elimination of the extrusion step, increasing the lipid concentration (from 16 to 64 mM) of the preformed liposomes and using good manufacturing practice bulk lipids (96-98% purity) instead of analytical grade purity lipids (99.9-100%) were the modifications studied. The differences in the physico-chemical properties, such as average diameter, zeta potential, melting point and morphology of the liposomes prepared through the modified process, were not as significant for the biological properties, such as DNA loading on the cationic liposomes, and effective immune response in mice after immunisation as the control liposomes prepared through the conventional process. Beneficially, the modified process increased productivity by 22% and reduced the cost of raw material by 75%.Fundacao de Auxilio a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Auxilio a Pesquisa do Estado de Sao Paulo (FAPESP
Functional Liposomal Configuration And Method For Obtaining Said Functional Liposomal Configuration
CONFIGURAÇÃO LIPOSSOMAL FUNCIONAL E PROCESSO DE OBTENÇÃO DE CONFIGURAÇÃO LIPOSSOMAL FUNCIONAL. A invenção apresenta um produto para terapia e vacinação, constituído de uma configuração lipossomal funcional contendo polinucleotídeos complexados preferencialmente na superfície externa de lipossomas do tipo DRVs, e o seu processo de produção. Essa configuração lipossomal funcional contendo polinucleotídeos possui propriedades de mucoadesão que permite a administração através de vias não invasivas como a via nasal, e é capaz de carrear eficientemente os polinucleotídeos até o interior das células, liberando-os no citoplasma. Essas propriedades potencializam maior eficiência de ação in vivo dos polinucleotídeos carreados, redução da concentração e frequência de doses, e, no caso da vacinação produz proteção contra a doença específica.BRPI0705630 (A2); BRPI0705630 (E2)A61K9/127C12N15/64BR2007PI05630A61K9/127C12N15/6
Functional Liposomal Configuration And Method For Obtaining Said Functional Liposomal Configuration
This invention provides a product for therapy and vaccination, constituted by a functional liposomal configuration containing complexes polynucleotides preferably on the outer surface of dehydrated-rehydrated liposomes (DRV), and the production process thereof. This functional liposomal configuration containing polynucleotides has mucoadhesion properties which allow administration by non-invasive routes, such as the nasal route, and is able to efficiently carry the polynucleotides to the interior of cells, releasing them in the cytoplasm. These properties allows for higher in vivo action efficiency of the carried polynucleotides, reduced concentration and dose frequency, and, in the case of vaccination, give protection against the specific disease. The present technology also develops a liposomal configuration carrying polynucleotides, which encode the protein HSP65, for prevention and treatment of tuberculosis.WO2009073941 (A2); WO2009073941 (A3)A61K9/127A61K9/50A61K9/51A61K31/7088WO2008BR00387A61K9/127A61K9/50A61K9/51A61K31/7088US6110745 (A)US2004043954 (A1)WO2006086330 (A2
Experimental tuberculosis: Designing a better model to test vaccines against tuberculosis
Experimental models of infection are good tools for establishing immunological parameters that have an effect on the host-pathogen relationship and also for designing new vaccines and immune therapies. In this work, we evaluated the evolution of experimental tuberculosis in mice infected with increasing bacterial doses or via distinct routes. We showed that mice infected with low bacterial doses by the intratracheal route were able to develop a progressive infection that was proportional to the inoculum size. In the initial phase of disease, mice developed a specific Th1-driven immune response independent of inoculum concentration. However, in the late phase, mice infected with higher concentrations exhibited a mixed Th1/Th2 response, while mice infected with lower concentrations sustained the Th1 pattern. Significant IL-10 concentrations and a more preeminent T regulatory cell recruitment were also detected at 70 days post-infection with high bacterial doses. These results suggest that mice infected with higher concentrations of bacilli developed an immune response similar to the pattern described for human tuberculosis wherein patients with progressive tuberculosis exhibit a down modulation of IFN-gamma production accompanied by increased levels of IL-4. Thus, these data indicate that the experimental model is important in evaluating the protective efficacy of new vaccines and therapies against tuberculosis. (C) 2010 Elsevier Ltd. All rights reserved.FAPESP: Foundation for the Support of Research in the State of Sao Paulo[03/11303-2]FAPESP: Foundation for the Support of Research in the State of Sao Paulo[05/01995-0]CNPq, Council for Scientific and Technological DevelopmentRede-TB, Brazilian Tuberculosis Research Networ
The synergy between structural stability and DNA-binding controls the antibody production in EPC/DOTAP/DOPE liposomes and DOTAP/DOPE lipoplexes
We present a comparative study of the physico-chemical properties, in vitro cytotoxicity and in vivo antibody production of surface-complexed DNA in EPC/DOTAP/DOPE (50/25/25% molar) liposomes and DOTAP/DOPE (50/50% molar) lipoplexes. The study aims to correlate the biological behavior and structural properties of the lipid carriers. We used DNA-hsp65, whose naked action as a gene vaccine against tuberculosis has already been demonstrated. Additionally, surface-complexed DNA-hsp65 in EPC/DOTAP/DOPE (50/25/25% molar) liposomes was effective as a single-dose tuberculosis vaccine. The results obtained showed that the EPC inclusion stabilized the DOTAP/DOPE structure, producing higher melting temperature and lower zeta potential despite a close mean hydrodynamic diameter. Resemblances in morphologies were identified in both structures, although a higher fraction of loaded DNA was not electrostatically bound in EPC/DOTAP/DOPE. EPC also induced a striking reduction in cytotoxicity, similar to naked DNA-hsp65. The proper immune response lead to a polarized antibody production of the IgG2a isotype, even for the cytotoxic DOTAP/DOPE. However, the antibody production was detected at 15 and 30 days for DOTAP/DOPE and EPC/DOTAP/DOPE, respectively. Therefore, the in vivo antibody production neither correlates with the in vitro cytotoxicity, nor with the structural stability alone. The synergistic effect of the structural stability and DNA electrostatic binding upon the surface of structures account for the immunological effects. By adjusting the composition to generate proper packing and cationic lipid/DNA interaction, we allow for the optimization of liposome formulations for required immunization or gene therapy. In a specific manner, our results contribute to studies on the tuberculosis therapy and vaccination. (C) 2009 Elsevier B.V. All rights reserved.Fundacao de Auxilio a Pesquisa de Sao Paulo (FAPESP