Papers by Marcelo Bispo de Jesus
Journal of Agricultural and Food Chemistry, 2019
Atrazine is one of the most used herbicides and has been associated with persistent surface and g... more Atrazine is one of the most used herbicides and has been associated with persistent surface and groundwater contamination, and novel formulations derived from nanotechnology can be a potential solution. We used poly(ε-caprolactone) nanoencapsulation of atrazine (NC+ATZ) to develop a highly effective herbicidal formulation. Detailed structural study of interaction between the formulation and Brassica juncea plants was carried out with evaluation of the foliar uptake of nanoatrazine and structural alterations induced in the leaves. Following postemergent treatment, NC+ATZ adhered to the leaf and penetrated mesophyll tissue mainly through the hydathode regions. NC+ATZ was transported directly through the vascular tissue of the leaves and into the cells where it degraded the chloroplasts resulting in herbicidal activity. Nanocarrier systems, such as the one used in this study, have great potential for agricultural applications in terms of maintenance of herbicidal activity at low concentrations and a substantial increase in the herbicidal efficacy.
Cell Reports, 2019
Antibiotic-induced dysbiosis is a key factor predis- posing intestinal infection by Clostridium d... more Antibiotic-induced dysbiosis is a key factor predis- posing intestinal infection by Clostridium difficile. Here, we show that interventions that restore butyrate intestinal levels mitigate clinical and path- ological features of C. difficile-induced colitis. Butyrate has no effect on C. difficile colonization or toxin production. However, it attenuates intesti- nal inflammation and improves intestinal barrier function in infected mice, as shown by reduced in- testinal epithelial permeability and bacterial trans- location, effects associated with the increased expression of components of intestinal epithelial cell tight junctions. Activation of the transcription factor HIF-1 in intestinal epithelial cells exerts a protective effect in C. difficile-induced colitis, and it is required for butyrate effects. We conclude that butyrate protects intestinal epithelial cells from damage caused by C. difficile toxins via the stabilization of HIF-1, mitigating local inflam- matory response and systemic consequences of the infection.
Journal of Applied Spectroscopy, 2016
Recently, we demonstrated that reduced graphene oxide (rGO) induces transient opening of the bloo... more Recently, we demonstrated that reduced graphene oxide (rGO) induces transient opening of the blood-brain barrier. When rGO was injected systemically in rats, we observed downregulation in the expression of hippocampal proteins responsible for maintaining paracellular tightness, which suggested weakening of the blood-brain barrier. In addition, analysis of the spatial distribution of rGO by matrix-assisted laser desorption/ionization mass spectrometry imaging and the determination of anatomical, cellular, and molecular parameters suggested that rGO had gained access to the brain. However, it remained unclear whether these events could result in alterations to the molecular homeostasis of the brain. To address this issue, in this study we used Raman spectroscopy and the same rat model and experimental design of the previous study to investigate rGO-provoked molecular changes in the hippocampus. Systemically injected rGO caused a time-dependent reduction in the relative intensity of the Raman bands related to protein and lipid content. Transmission electron microscopy showed alterations in neuronal nuclear membranes and chromatin patterns that could be explained by the Raman spectral alterations. All alterations were reversible and were no longer prominent seven days after rGO administration. We conclude that Raman spectroscopy can be an important complementary technique for monitoring the molecular effects induced by nanomaterials. Introduction. Graphene oxide (GO) is a highly oxidized form of chemically modifi ed graphite. The reduced form of graphene oxide (rGO) is obtained by decreasing the oxygen content of GO under chemical or thermal reducing conditions [1]. The unique chemical, physical, and electronic properties of graphene-based nanomaterials make them suitable for a broad variety of biological applications, such as drug/gene delivery, biosensors, photothermal therapy, stem cell engineering, bioimaging, and neuroscience research [2-4]. We have previously shown that the injection of an aqueous suspension of rGO into rats via a tail vein (i.v.) induced transient disruption of the paracellular tightness of the blood-brain barrier (BBB) in the hippocampus. This was demonstrated by the diffusion of peripheral infused Evans blue dye into the brain and by the infi ltration of the extracellular tracer lanthanum nitrate into the interendothelial cleft accompanied by downregulation of the expression of occludin, β-catenin, and laminin proteins that constitute the matrix/tight-adhesion junction complex in the BBB. The hypothesis that rGO had crossed the BBB was supported by the detection of rGO in the hippocampus and thalamus, as attested by matrix-assisted laser desorption/ionization (MALDI), mass spectrometry imaging (MSI), and determination of the surface morphology and structural parameters of these organs. Most importantly, the changes observed were mild and transitory, i.e., rGO-treated rats showed no signs of neurotoxicity or clinical evidence of discomfort, despite BBB disruption [5]. However, it remained unclear whether the weakening of BBB tightness and the entry of rGO into the brain resulted in alterations to the molecular homeostasis of the BBB.
ACS applied materials & interfaces, 2018
A new nanohydrogel drug delivery platform based on Laponite nanodiscs, polyacrylate, and sodium p... more A new nanohydrogel drug delivery platform based on Laponite nanodiscs, polyacrylate, and sodium phosphate salts is described. The hybrid nanohydrogel is tailored to obtain soft and flexible nanohydrogels with G′ around 3 kPa, which has been proposed as the ideal stiffness for drug delivery applications. In vitro studies demonstrate that the new nanohydrogels are biocompatible, biodegradable, nonswellable, pH-responsive, and noncytotoxic and are able to deliver antineoplastic drugs into cancer cells. The IC 50 of nanohydrogels containing cisplatin, 4-fluorouracil, and cyclo-phosphamide is significantly lower than the IC 50 of the free drugs. In vivo experiments suggest that the new nanomaterials are biocompatible and do not accumulate in crucial organs. The simple formulation procedure enables encapsulation of virtually any water-soluble molecule, without the need for chemical modification of the guests. These nanohydrogels are a versatile platform that enables the simultaneous encapsulation of several cancer drugs, yielding an efficient drug cocktail delivery system, which for instance presents a positive synergistic effect against MCF-7 cells.
Nanotoxicology, 2018
The increasing use of silver nanoparticles (AgNPs) in consumer products raises the risk of human ... more The increasing use of silver nanoparticles (AgNPs) in consumer products raises the risk of human toxicity. Currently, there are no therapeutic options or established treatment protocols in cases of AgNPs intoxication. We demonstrated previously that thiol antioxidants compounds can reverse the cytotoxicity induced by AgNPs in Huh-7 hepatocarcinoma cells. Here, we investigated the use of N-acetylcysteine (NAC) against the systemic toxic effects of AgNPs (79.3 nm) in rats. Biochemical, histopathological, hematological, and oxidative parameters showed that a single intravenous injection of AgNPs (5 mg/kg b.w.) induced deleterious effects such as hepatotox-icity, potentially as a result of AgNPs accumulation in the liver. Treatment with a single intraperitoneal injection of NAC (1 g/kg b.w.) one hour after AgNPs exposure significantly attenuated all toxic effects evaluated and altered the bioaccumulation and release patterns of AgNPs in rats. The findings show that NAC may be a promising candidate for clinical management of AgNPs intoxication. ARTICLE HISTORY
Current Pharmaceutical Design, 2017
Background: Topical drug administration offers an attractive route with minimal invasiveness. It ... more Background: Topical drug administration offers an attractive route with minimal invasiveness. It also avoids limitations of intravenous administration such as the first pass metabolism and presystemic elimination within the gastrointestinal tract. Furthermore, topical drug administration is safe, have few side effects, is easy to apply, and offers a fast onset of action. However, the development of effective topical formulations still represents a challenge for the desired effect to be reached, locally or systemically. Solid lipid nanoparticles and nanos-tructured lipid carriers are particular candidates to overcome the problem of topical drug administration. The nanometric particle size of lipid nanoparticles favors the physical adhesion to the skin or mucosal, what can also be attained with the formation of hybrid (nanoparticles/polymer) systems. Methods: In this review, we discuss the major challenges for lipid nanoparticles formulations for topical application to oral mucosa, skin, and eye, highlighting the strategies to improve the performance of lipid nanoparticles for topical applications. Next, we critically analyzed the in vitro and in vivo approaches used to evaluate lipid nanoparticles performance and toxicity. Conclusion: We addressed some major drawbacks related to lipid nanoparticle topical formulations and concluded the key points that have to be overcome to help them to reach the market in topical formulations to oral mucosa, skin, and eye.
Journal of Infection, 2018
Objectives: To investigate the involvement of NLRP3 in the effector functions of human dendritic ... more Objectives: To investigate the involvement of NLRP3 in the effector functions of human dendritic cells (DCs) in response to Paracoccidioides brasiliensis yeast cells (Pb) and to evaluate its role in the modulation of the adaptive immune response.
Methods: DCs were differentiated from purified peripheral blood monocytes and analyzed in relation to the participation of TLR-2, dectin-1, and Syk in Pb recognition, as well as, the indirect mechanisms (Reac- tive Oxygen Species production, endosome acidification, or K+ efflux) involved in NLRP3 inflammasome activation after the stimulus with Pb. Additionally, we analyzed the role of NLRP3 in the activation of T cells.
Results: Our results demonstrated that the NLRP3 inflammasome activation and cytokines production by DCs are dependent on ROS generation, endosome acidification, and K+ efflux and involve the Pb recog- nition by dectin-1 and Syk phosphorylation. Our data also demonstrate that the NLRP3 inflammasome is essential for the activation/expansion of Th1/Th17 cells and its inhibition leads to an increased frequency of Th2 and Treg cells.
Conclusion: Altogether our data indicated that activation of NLRP3 presents an important role in both the induction of the initial inflammatory response and in the development of the acquired immune response associated with resistance to infection.
Frontiers in Environmental Science, 2018
Recent advances in nanotechnology have shown numerous societal benefits through the development o... more Recent advances in nanotechnology have shown numerous societal benefits through the development or improvement of smart materials. Several engineered nanomaterials (ENMs) have been produced during the last years that may be found in related sectors like health, food, home, automotive, electronics, and computers (Hansen et al., 2016). The estimated output of ENMs produced was up to 270,000 metric tons/year and in this case considering only SiO2, TiO2, FeOx, AlOx, ZnO, and CeO2 nanoparticles (Medina-Velo et al., 2017).
Nanotechnology, 2018
Nanotechnology can produce materials with unique features compared to their bulk counterparts, wh... more Nanotechnology can produce materials with unique features compared to their bulk counterparts, which can be useful for medical applications (i.e. nanomedicine). Among the therapeutic agents used in nanomedicine, small molecules or biomacromolecules, such as proteins or genetic materials, can be designed for disease diagnostics and treatment. To transport these biomacromolecules to the target cells, nanomedicine requires nanocarriers. Solid lipid nanoparticles (SLNs) are among the promising nanocarriers available, because they can be made from biocompatible materials and present high stability (over one year). In addition, upon the binding genetic material, SLNs form SLNplexes. However, little is yet known about how cells process these SLNplexes-in particular, how internalization and endosome acidification affects the transfection mediated by SLNplexes. Therefore, we aim to investigate how these processes affect SLNplex transfection in HEK293T cells. We find that the SLNplex is mainly internalized by clathrin-mediated endocytosis, which is a fast and reliable pathway to transfection, leading to approximately 60% transfection efficiency. Interestingly, upon acidification (below pH 5.0), the SLN seems to release its DNA content, which can be an essential step for SLNplex transfection. The underlying mechanisms described in this work may help improve SLNplex formulations and transfection efficiency. Moreover, these advances can improve the field of nanomedical research and bring new ways to cure diseases. Supplementary material for this article is available online
Frontiers in Environmental Science, 2017
Over the last decade, engineered nanomaterials (NMs) brought a revolutionary development in many ... more Over the last decade, engineered nanomaterials (NMs) brought a revolutionary development in many sectors of human life including electronics, paints, textiles, food, agriculture, and health care. However, the exponential growth in the number of NMs applications resulted in uncertainties regarding their environmental impacts. Currently, the common approach for assessing the toxicity of NMs such as, carbon-(fullerenes, single-and multi-walled carbon nanotubes), mineral-(gold and silver nanoparticles, cerium and zinc oxide, silicon and titanium dioxide), and organic-based NMs (dendrimers) includes standard guidelines applied to all chemical compounds. Nevertheless, NMs differ from traditional materials as their physicochemical and surface properties influence the toxic rather than their composition alone. Considering such NMs specificities, adaptations in some methods are necessary to ensure that environmental and human health risks are accurately investigated. In this context, the focus of this mini-review is to summarize the current knowledge in nanotoxicology regarding relevant organisms and experimental assays for assessing the terrestrial toxicity of NMs.
Biochemistry and Molecular Biology Education, 2017
Metabolism involves numerous reactions and organic compounds that the student must master to unde... more Metabolism involves numerous reactions and organic compounds that the student must master to understand adequately the processes involved. Part of biochemical learning should include some knowledge of the structure of biomolecules, although the acquisition of such knowledge can be time-consuming and may require significant effort from the student. In this report, we describe the "polygonal model" as a new means of graphically representing biomolecules. This model is based on the use of geometric figures such as open triangles, squares, and circles to represent hydroxyl, carbonyl, and carboxyl groups, respectively. The usefulness of the polygonal model was assessed by undergraduate students in a classroom activity that consisted of "transforming" molecules from Fischer models to polygonal models and vice and versa. The survey was applied to 135 undergraduate Biology and Nursing students. Students found the model easy to use and we noted that it allowed identification of students' misconceptions in basic concepts of organic chemistry, such as in stereochemistry and organic groups that could then be corrected. The students considered the polygonal model easier and faster for representing molecules than Fischer representations, without loss of information. These findings indicate that the polygonal model can facilitate the teaching of metabolism when the structures of biomolecules are discussed. Overall, the polygonal model promoted contact with chemical structures, e.g. through drawing activities, and encouraged student-student dialog, thereby facilitating biochemical learning. V C 2017 by The International Union of Biochemistry and Molecular Biology, 46(1):66-75, 2018.
Journal of Pharmaceutical and Biomedical Analysis, 2006
Praziquantel (PZQ) is a broadly effective anthelminthic drug available for human and veterinary u... more Praziquantel (PZQ) is a broadly effective anthelminthic drug available for human and veterinary use, being the drug of choice for the treatment of all forms of schistosomiasis. Nevertheless, large doses are required in order to achieve adequate concentrations at the target site due to the poor solubility of PZQ and its significant first pass metabolism. To improve it, avoiding efficiency loss, we have designed a controlled-release system, in which PZQ was encapsulated in -cyclodextrin (-CD). The inclusion complexes between PZQ/-CD were studied at two different stoichiometries 1:1 and 1:2, through experimental and theoretical analysis. Molecular modeling calculations were used to foresee the better stoichiometry of the complex formed as well as the possible orientations of PZQ inside the -CD cavity. The complexes prepared were analyzed through 1 H two-dimensional nuclear magnetic resonance ( 1 H 2D-NMR) experiments, which provide (evidences) for the 1:1 complexation of PZQ/-CD. 1 H 2D-NMR also revealed details of PZQ/-CD molecular interaction, in which the isoquinoline ring of praziquantel is located inside the -CD cavity. Finally, phase-solubility diagrams revealed a five-fold increase in praziquantel water solubility upon addition of increasing -CD concentrations up to 16 mM, corresponding to the solubility of -CD itself. The solubilization profile is consistent with 1:1 stoichiometry of the PZQ/-CD complex while the solubilization effect will certainly increase the pharmacological activity of praziquantel.
Silver nanoparticles are well known potent antimicrobial agents. Although significant progresses ... more Silver nanoparticles are well known potent antimicrobial agents. Although significant progresses have been achieved on the elucidation of antimicrobial mechanism of silver nanoparticles, the exact mechanism of action is still not completely known. This overview incorporates a retrospective of previous reviews published and recent original contributions on the progress of research on antimicrobial mechanisms of silver nanoparticles. The main topics discussed include release of silver nanoparticles and silver ions, cell membrane damage, DNA interaction, free radical generation, bacterial resistance and the relationship of resistance to silver ions versus resistance to silver nanoparticles. The focus of the overview is to summarize the current knowledge in the field of antibacterial activity of silver nanoparticles. The possibility that pathogenic microbes may develop resistance to silver nanoparticles is also discussed.
Microfluidics offers unique characteristics to control the mixing of liquids under laminar flow. ... more Microfluidics offers unique characteristics to control the mixing of liquids under laminar flow. Its use for the assembly of lipoplexes represents an attractive alternative for the translation of gene delivery studies into clinical trials on a sufficient throughput scale. Here, it was shown that the microfluidic assembly of pDNA/cationic liposome (CL) lipoplexes allows the formation of nanocarriers with enhanced transfection efficiencies compared with the conventional bulk-mixing (BM) process under high pDNA loading conditions. Lipoplexes generated by microfluidic devices exhibit smaller and more homogeneous structures at a molar charge ratio (R ±) of 1.5, representing the ratio of lipid to pDNA content. Using an optimized model to fit small-angle X-ray scattering (SAXS) curves, it was observed that large amounts of pDNA induces the formation of aggregates with a higher number of stacked bilayers (N ∼ 5) when the BM process was used, whereas microfluidic lipoplexes presented smaller structures with a lower number of stacked bilayers (N ∼ 2.5). In vitro studies further confirmed that microfluidic lipoplexes achieved higher in vitro transfection efficiencies in prostate cancer cells at R ± 1.5, employing a reduced amount of cationic lipid. The correlation of mesoscopic characteristics with in vitro performance provides insights for the elucidation of the colloidal arrangement and biological behavior of pDNA/CL lipoplexes obtained by different processes, highlighting the feasibility of applying microfluidics to gene delivery.
Journal of Pharmaceutical and Biomedical Analysis, 2006
Praziquantel (PZQ) is a broadly effective anthelminthic drug available for human and veterinary u... more Praziquantel (PZQ) is a broadly effective anthelminthic drug available for human and veterinary use, being the drug of choice for the treatment of all forms of schistosomiasis. Nevertheless, large doses are required in order to achieve adequate concentrations at the target site due to the poor solubility of PZQ and its significant first pass metabolism. To improve it, avoiding efficiency loss, we have designed a controlled-release system, in which PZQ was encapsulated in -cyclodextrin (-CD). The inclusion complexes between PZQ/-CD were studied at two different stoichiometries 1:1 and 1:2, through experimental and theoretical analysis. Molecular modeling calculations were used to foresee the better stoichiometry of the complex formed as well as the possible orientations of PZQ inside the -CD cavity. The complexes prepared were analyzed through 1 H two-dimensional nuclear magnetic resonance ( 1 H 2D-NMR) experiments, which provide (evidences) for the 1:1 complexation of PZQ/-CD. 1 H 2D-NMR also revealed details of PZQ/-CD molecular interaction, in which the isoquinoline ring of praziquantel is located inside the -CD cavity. Finally, phase-solubility diagrams revealed a five-fold increase in praziquantel water solubility upon addition of increasing -CD concentrations up to 16 mM, corresponding to the solubility of -CD itself. The solubilization profile is consistent with 1:1 stoichiometry of the PZQ/-CD complex while the solubilization effect will certainly increase the pharmacological activity of praziquantel.
Drug Discovery Today, 2010
we studied the optimal conditions for attachment and proliferation of the astrocytes and hBECs. F... more we studied the optimal conditions for attachment and proliferation of the astrocytes and hBECs. Furthermore, we monitored the effect of hBEC growing directly on the surface of an adherent astrocytic monolayer. The tight junctions between the brain endothelial cells forms a diffusion barrier that is responsible for the high paracellular resistance which is a crucial characteristic for any B3-model. In order to test the integrity of this barrier in the B3-model and simultaneously measure the transcellular transport we combined fluorescent compounds and dye labelled large molecules to test the permeability across the barrier. This strategy allows for the discrimination between transcellular and paracellular transport.
Journal of Controlled Release, 2010
. Transfection activity of MENS compared to those of P/DNA, P/DNA/M and naked DNA.
Different techniques have been employed to produce chitosan nanoparticles; thus, suitable alterna... more Different techniques have been employed to produce chitosan nanoparticles; thus, suitable alternatives and easy-handling production methods are highly desired. We used a tank reactor with baffles and mechanical stirring with Cowles impellers that can feasibly be up-scaled and allows for the production of homogenous chitosan nanoparticles. First, we explored the effects of temperature on the produc- tion of chitosan (CHI)/pentasodium tripolyphosphate (TPP) nanoparticles. We compared the effect of gradual temperature decrease between 40 to 55◦C with the effect of isothermal processes (25, 45 and 55◦C). CHI/TPP nanoparticles produced by the gradual temperature decrease technique had polydis- persity indices (PDIs) that were significantly smaller than the nanoparticles produced by isothermal processes. To further control the production process, we employed an experimental design to determine the effects of CHI and TPP concentrations and CHI/TPP mass ratios in the gradual temperature decrease technique. Under all conditions, the sizes of the CHI/TPP nanoparticles were on the nanoscale. Gene deliv- ery capacities of the nanoparticles were evaluated; the plasmid pEGFP-N1 was incorporated (10 and 40% of the chitosan weight) into the nanoparticles and incubated with 293A cells. The in vitro transfection efficiencies were evaluated over 120 h and indicated sustained gene delivery at 10% pDNA. The poly- plexes demonstrated some cytotoxicity after 120 h. These findings will contribute to the development of processes for generating CHI/TPP nanoparticles for gene delivery applications.
Schistosomiasis is still an endemic disease in many regions, with 250 million people infected wit... more Schistosomiasis is still an endemic disease in many regions, with 250 million people infected with Schis- tosoma and about 500,000 deaths per year. Praziquantel (PZQ) is the drug of choice for schistosomiasis treatment, however it is classified as Class II in the Biopharmaceutics Classification System, as its low solubility hinders its per- formance in biological systems. The use of cyclodextrins is a useful tool to increase the solubility and bioavailability of drugs. The aim of this work was to prepare an inclusion compound of PZQ and methyl-b-cyclodextrin (MeCD), perform its physico-chemical characterization, and explore its in vitro cytotoxicity. SEM showed a change of the mor- phological characteristics of PZQ:MeCD crystals, and IR data supported this finding, with changes after interaction with MeCD including effects on the C–H of the aromatic ring, observed at 758 cm-1. Differential scanning calorim- etry measurements revealed that complexation occurred in a 1:1 molar ratio, as evidenced by the lack of a PZQ transition temperature after inclusion into the MeCD cavity. In solution, the PZQ UV spectrum profile in the presence of MeCD was comparable to the PZQ spectrum in a hydro- phobic solvent. Phase solubility diagrams showed that there was a 5.5-fold increase in PZQ solubility, and were indica- tive of a type AL isotherm, that was used to determine an association constant (Ka) of 140.8 M-1. No cytotoxicity of the PZQ:MeCD inclusion compound was observed in tests using 3T3 cells. The results suggest that the association of PZQ with MeCD could be a good alternative for the treat- ment of schistosomiasis.
Several scientific hurdles still have to be overcome before gene therapy becomes a reality. One o... more Several scientific hurdles still have to be overcome before gene therapy becomes a reality. One of them is the development of safe and efficient gene delivery system. Here, we have employed factorial design to optimize the production of solid lipid nanoparticles (SLN) for gene delivery. A 2×3 full-factorial experimental design was used for the optimization of SLNs formulations. The variables were defined by the components of the formulation: concentration of stearic acid, DOTAP, and Pluronic F68 at two levels (−1, 1) and 3 central points (0). Different SNL formulations were prepared by varying the amount of components and several properties were tested, including their capacity to accommodate DNA and protection against DNase degradation, colloidal stability, in vitro cytotoxicity, and transfection efficiency in prostate cancer cells. Finally, response Surface Methodology was used to select the most effective formulation for gene delivery to prostate cancer cells in vitro. In conclusion, this study revealed that stearic acid and Pluronic F68 were determinant to SLN size and stability, respectively, while small amounts of DOTAP are essential for a successful transfection.
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Papers by Marcelo Bispo de Jesus
Methods: DCs were differentiated from purified peripheral blood monocytes and analyzed in relation to the participation of TLR-2, dectin-1, and Syk in Pb recognition, as well as, the indirect mechanisms (Reac- tive Oxygen Species production, endosome acidification, or K+ efflux) involved in NLRP3 inflammasome activation after the stimulus with Pb. Additionally, we analyzed the role of NLRP3 in the activation of T cells.
Results: Our results demonstrated that the NLRP3 inflammasome activation and cytokines production by DCs are dependent on ROS generation, endosome acidification, and K+ efflux and involve the Pb recog- nition by dectin-1 and Syk phosphorylation. Our data also demonstrate that the NLRP3 inflammasome is essential for the activation/expansion of Th1/Th17 cells and its inhibition leads to an increased frequency of Th2 and Treg cells.
Conclusion: Altogether our data indicated that activation of NLRP3 presents an important role in both the induction of the initial inflammatory response and in the development of the acquired immune response associated with resistance to infection.
Methods: DCs were differentiated from purified peripheral blood monocytes and analyzed in relation to the participation of TLR-2, dectin-1, and Syk in Pb recognition, as well as, the indirect mechanisms (Reac- tive Oxygen Species production, endosome acidification, or K+ efflux) involved in NLRP3 inflammasome activation after the stimulus with Pb. Additionally, we analyzed the role of NLRP3 in the activation of T cells.
Results: Our results demonstrated that the NLRP3 inflammasome activation and cytokines production by DCs are dependent on ROS generation, endosome acidification, and K+ efflux and involve the Pb recog- nition by dectin-1 and Syk phosphorylation. Our data also demonstrate that the NLRP3 inflammasome is essential for the activation/expansion of Th1/Th17 cells and its inhibition leads to an increased frequency of Th2 and Treg cells.
Conclusion: Altogether our data indicated that activation of NLRP3 presents an important role in both the induction of the initial inflammatory response and in the development of the acquired immune response associated with resistance to infection.