Gilson Macedo - Academia.edu (original) (raw)

Papers by Gilson Macedo

The endocannabinoid system (ECS) is composed of endocannabinoid molecules synthesizing and degrad... more The endocannabinoid system (ECS) is composed of endocannabinoid molecules synthesizing and degrading ligands and cannabinoid receptors such as types CB1 and CB2. The ECS is present in various tissues and cell types, such as in central nervous system, immune system, and mesenchymal stem cells. The presence of these receptors in both immune system cells and stem cells shows a common pathway of communication-related to repair and immunomodulation. The aim of the present study was to verify the participation of ECS in the immunomodulatory profile of stem cells from human exfoliated deciduous teeth (SHED), in the presence or absence of TNF-α. SHED was cultured in the presence or absence of the agonist anandamide and the two antagonists AM251 and SR144528 of CB1 and CB2 receptors, under stimulation or not of TNF-α. For immunomodulation analysis, surface molecules linked to immunomodulation: HLA-DR, PD-L1 and PD-L2 were measured by flow cytometry. The results showed that SHED respond to EC...

Parasitology International, 2021

Granulomas are inflammatory tissue responses directed to a set of antigens. Trapped Schistosoma m... more Granulomas are inflammatory tissue responses directed to a set of antigens. Trapped Schistosoma mansoni eggs promote productive granulomas in the tissues, and they are the main damage caused by schistosomiasis. Some S. mansoni antigenic proteins may have a direct involvement in the resolution of the granulomatous response. The ATP diphosphohydrolases isoforms of this parasite are immunogenic, expressed in all phases of the parasite life cycle and secreted by eggs of adult worms. Potato apyrase is a vegetable protein that is cross-reactive with parasite ATP diphosphohydrolases isoforms. In this study, the vegetable protein was purified, before being inoculated in C57BL/6 mice that were later infected with cercariae. Sixty days after infection, adult worms were recovered, antibodies and cytokines were measured, and morphological granuloma alterations evaluated. Immunization of the animals induced significant levels of IgG and IgG1 antibodies and IFN-γ, IL-10 and IL-5 cytokines, but not IL-13, suggesting that potato apyrase is an immunoregulatory protein. Supporting this hypothesis, it was found that liver damage associated with schistosomiasis was mitigated, reducing the size of the areas affected by granuloma to 35% and increasing the presence of multinucleated giant cells in this environment. In conclusion, potato apyrase was found to be effective immunomodulatory antigen for murine schistosomiasis.

The Journal of Immunology, 2008

Brucella abortus is a facultative intracellular bacterium that infects humans and domestic animal... more Brucella abortus is a facultative intracellular bacterium that infects humans and domestic animals. The enhanced susceptibility to virulent B. abortus observed in MyD88 knockout (KO) mice led us to investigate the mechanisms involved in MyD88-dependent immune responses. First, we defined the role of MyD88 in dendritic cell (DC) maturation. In vitro as well as in vivo, B. abortus-exposed MyD88 KO DCs displayed a significant impairment on maturation as observed by expression of CD40, CD86, and MHC class II on CD11c ؉ cells. In addition, IL-12 and TNF-␣ production was totally abrogated in MyD88 KO DCs and macrophages. Furthermore, B. abortus-induced IL-12 production was found to be dependent on TLR2 in DC, but independent on TLR2 and TLR4 in macrophages. Additionally, we investigated the role of exogenous IL-12 and TNF-␣ administration on MyD88 KO control of B. abortus infection. Importantly, IL-12, but not TNF-␣, was able to partially rescue host susceptibility in MyD88 KO-infected animals. Furthermore, we demonstrated the role played by TLR9 during virulent B. abortus infection. TLR9 KO-infected mice showed 1 log Brucella CFU higher than wild-type mice. Macrophages and DC from TLR9 KO mice showed reduced IL-12 and unaltered TNF-␣ production when these cells were stimulated with Brucella. Together, these results suggest that susceptibility of MyD88 KO mice to B. abortus is due to impaired DC maturation and lack of IL-12 synthesis. Additionally, DC activation during Brucella infection plays an important regulatory role by stimulating and programming T cells to produce IFN-␥.

PLoS Neglected Tropical Diseases, 2008

Background: Schistosomiasis continues to be a significant public health problem. This disease aff... more Background: Schistosomiasis continues to be a significant public health problem. This disease affects 200 million people worldwide and almost 800 million people are at risk of acquiring the infection. Although vaccine development against this disease has experienced more failures than successes, encouraging results have recently been obtained using membranespanning protein antigens from the tegument of Schistosoma mansoni. Our group recently identified Sm29, another antigen that is present at the adult worm tegument surface. In this study, we investigated murine cellular immune responses to recombinant (r) Sm29 and tested this protein as a vaccine candidate. Methods and Findings: We first show that Sm29 is located on the surface of adult worms and lung-stage schistosomula through confocal microscopy. Next, immunization of mice with rSm29 engendered 51%, 60% and 50% reduction in adult worm burdens, in intestinal eggs and in liver granuloma counts, respectively (p,0.05). Protective immunity in mice was associated with high titers of specific anti-Sm29 IgG1 and IgG2a and elevated production of IFN-c, TNF-a and IL-12, a typical Th1 response. Gene expression analysis of worms recovered from rSm29 vaccinated mice relative to worms from control mice revealed a significant (q,0.01) down-regulation of 495 genes and up-regulation of only 22 genes. Among downregulated genes, many of them encode surface antigens and proteins associated with immune signals, suggesting that under immune attack schistosomes reduce the expression of critical surface proteins. Conclusion: This study demonstrates that Sm29 surface protein is a new vaccine candidate against schistosomiasis and suggests that Sm29 vaccination associated with other protective critical surface antigens is the next logical strategy for improving protection.

Nanomedicine

Aim: To isolate licochalcone A (LicoA) from licorice, prepare LicoA-loaded solid lipid nanopartic... more Aim: To isolate licochalcone A (LicoA) from licorice, prepare LicoA-loaded solid lipid nanoparticles (L-SLNs) and evaluate the L-SLNs in vitro and in vivo against Schistosoma mansoni. Materials & methods: LicoA was obtained by chromatographic fractionation and encapsulated in SLNs by a modified high shear homogenization method. Results: L-SLNs showed high encapsulation efficiency, with satisfactory particle size, polydispersity index and Zeta potential. Transmission electron microscopy revealed that L-SLNs were rounded and homogenously distributed. Toxicity studies revealed that SLNs decreased the hemolytic and cytotoxic properties of LicoA. Treatment with L-SLNs showed in vivo efficacy against S. mansoni. Conclusion: L-SLNs are efficient in reducing worm burden and SLNs may be a promising delivery system for LicoA to treat S. mansoni infections.

Clinical & Experimental Allergy

Bioorganic & medicinal chemistry, Jan 24, 2018

Resveratrol is a natural polyphenol found mainly on red grapes and in red wine, pointed as an imp... more Resveratrol is a natural polyphenol found mainly on red grapes and in red wine, pointed as an important anti-inflammatory/immunomodulatory molecule. However, its bioavailability problems have limited its use encouraging the search for new alternatives agents. Thus, in this study, we synthetize 12 resveratrol analogues (6 imines, 1 thioimine and 5 hydrazones) and investigated its cytotoxicity, antioxidant activity and in vitro anti-inflammatory/immunomodulatory properties. The most promising compounds were also evaluated in vivo. The results showed that imines presented less cytotoxicity, were more effective than resveratrol on DPPH scavenger and exhibited an anti-inflammatory profile. Among them, the imines with a radical in the para position, on the ring B, not engaged in an intramolecular hydrogen-interaction, showed more prominent anti-inflammatory activity modulating, in vivo, the edema formation, the inflammatory infiltration and cytokine levels. An immunomodulatory activity al...

Chemico-biological interactions, Jan 9, 2018

Leishmaniases are infectious diseases, caused by protozoa of the Leishmania genus. These drugs pr... more Leishmaniases are infectious diseases, caused by protozoa of the Leishmania genus. These drugs present high toxicity, long-term administration, many adverse effects and are expensive, besides the identification of resistant parasites. In this work, the antileishmanial activity of quinoline derivative salts (QDS) was evaluated, as well as the toxicity on mammalian cells and the mechanism of action of the most promising compound. Among the compound tested, only the compound QDS3 showed activity against promastigotes and amastigotes of Leishmania spp., being more active against the intracellular amastigotes of L. amazonensis-GFP (IC of 5.48 μM). This value is very close to the one observed for miltefosine (IC of 4.05 μM), used as control drug. Furthermore, the compound QDS3 exhibited a selective effect, being 40.35 times more toxic to the amastigote form than to the host cell. Additionally, promastigotes of L. amazonensis treated with this compound exhibited characteristics of cells in...

Parasite immunology, Jan 30, 2017

NTPDases are enzymes that hydrolyze di- and tri-phosphate nucleosides, regulating purinergic sign... more NTPDases are enzymes that hydrolyze di- and tri-phosphate nucleosides, regulating purinergic signaling in many organisms. The Schistosoma mansoni NTPDases, SmATPDases 1 and 2 are antigenic proteins and display a significant homology with the isoforms found in mammalian cells. In this work, we investigated whether anti-SmATPDase antibodies from S. mansoni-infected mice sera show cross-reactivity with the NTPDase 1 isoform from macrophages and how this event affect the cell proliferation. By Western blot, anti-SmATPDase antibodies present in serum from infected mice recognized two bands with approximately 53 and 58 kDa, corresponding to NTPDase 1. Additionally, the enzyme was identified in macrophages by immunofluorescence and the anti-SmATPDase antibodies were able to reduce activity enzyme (22%). Macrophages incubated with commercial polyclonal antibodies reactive with NTPDase 1 (anti-CD39) showed a reduction of 40% of the enzyme activity. In proliferation assays, macrophage prolife...

Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry, Jan 8, 2017

In our previous work, we demonstrated the promising in vitro effect of VOSalophen, a vanadium com... more In our previous work, we demonstrated the promising in vitro effect of VOSalophen, a vanadium complex with a stilbene derivative, against Leishmania amazonensis. Its antileishmanial activity has been associated with oxidative stress in L. amazonensis promastigotes and L. amazonensis-infected macrophages. In the present study, the mechanism involved in the death of parasites after treatment with VOSalophen, as well as in vivo effect in the murine model cutaneous leishmaniasis, has been investigated. Promastigotes of L. amazonensis treated with VOSalophen presented apoptotic cells features, such as cell volume decrease, phosphatidylserine externalization, and DNA fragmentation. An increase in autophagic vacuoles formation in treated promastigotes was also observed, showing that autophagy also may be involved in the death of these parasites. In intracellular amastigotes, DNA fragmentation was observed after treatment with VOSalophen, but this effect was not observed in host cells, high...

Pathogens and Global Health, 2017

Parasitic diseases, such as malaria and leishmaniasis, are relevant public health problems worldw... more Parasitic diseases, such as malaria and leishmaniasis, are relevant public health problems worldwide. For both diseases, the alarming number of clinical cases and deaths reported annually has justified the incentives directed to better understanding of host's factors associated with susceptibility to infection or protection. In this context, over recent years, some studies have given special attention to B lymphocytes with a regulator phenotype, known as Breg cells. Essentially important in the maintenance of immunological tolerance, especially in autoimmune disease models such as rheumatoid arthritis and experimentally induced autoimmune encephalomyelitis, the function of these lymphocytes has so far been poorly explored during the course of diseases caused by parasites. As the activation of Breg cells has been proposed as a possible therapeutic or vaccine strategy against several diseases, here we reviewed studies focused on understanding the relation of parasite and Breg cells in malaria and leishmaniasis, and the possible implications of these strategies in the course of both infections.

Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology], Jan 9, 2017

Onychomycosis is a fungal infection of the nail caused by high densities of filamentous fungi and... more Onychomycosis is a fungal infection of the nail caused by high densities of filamentous fungi and yeasts. Treatment for this illness is long-term, and recurrences are frequently detected. This study evaluated in vitro antifungal activities of 12 organic compounds derived from amino alcohols against standard fungal strains, such as Trichophyton rubrum CCT 5507 URM 1666, Trichophyton mentagrophytes ATCC 11481, and Candida albicans ATCC 10231. The antifungal compounds were synthesized from p-hydroxybenzaldehyde (4a-4f) and p-hydroxybenzoic acid (9a-9f). Minimum inhibitory concentrations and minimum fungicidal concentrations were determined according to Clinical and Laboratory Standards Institute protocols M38-A2, M27-A3, and M27-S4. The amine series 4b-4e, mainly 4c and 4e compounds, were effective against filamentous fungi and yeast (MIC from 7.8 to 312μg/mL). On the other hand, the amide series (9a-9f) did not present inhibitory effect against fungi, except amide 9c, which demonstrat...

Planta medica, Jan 20, 2016

Multiple sclerosis is a chronic inflammatory and autoimmune disease of the central nervous system... more Multiple sclerosis is a chronic inflammatory and autoimmune disease of the central nervous system that affects more than 2.5 million people worldwide. Experimental autoimmune encephalomyelitis is a murine autoimmune disease used to study multiple sclerosis. Parthenolide, a natural sesquiterpene lactone found in Tanacetum parthenium L., is known for its strong anti-inflammatory activity. Herein, we have investigated the in vitro immunomodulatory effects of parthenolide on cytokine production and nitric oxide in cultured cells from myelin oligodendrocyte glycoprotein 35-55 amino acid peptide mice. Experimental autoimmune encephalomyelitis was induced in C57BL/6 mice with myelin oligodendrocyte glycoprotein 35-55 amino acid peptide, and parthenolide was isolated from T. parthenium. Splenocytes and peritoneal cells were obtained from experimental autoimmune encephalomyelitis-induced mice and incubated with parthenolide (1, 5, and 20 µM). After in vitro treatment with parthenolide, super...

Genetics and molecular research : GMR, Jan 19, 2014

Cryopreservation injuries involve nuclear DNA damage. A protocol for cryopreserving and isolating... more Cryopreservation injuries involve nuclear DNA damage. A protocol for cryopreserving and isolating adipocyte nuclei is proposed. Adipose tissue samples were directly analyzed (NoCRYO-0h), or stored at -196°C for 7 days without 10% dimethyl sulfoxide (DMSO) (CRYO-WO-DMSO) or with DMSO (CRYO-W-DMSO). To determine the effect of DMSO on cryopreservation treatment, adipose tissue samples were stored at 4°C for 24 h with 10% DMSO (NoCRYO-W-DMSO-24h) and without (NoCRYO-WO-DMSO-24h). Samples were processed in isolation buffer, and nuclear integrity was measured by flow cytometry. The coefficient of variation, forward scatter, side scatter, and number of nuclei analyzed were evaluated. Pea (Pisum sativum) was used to measure the amount of DNA. All groups contained similar amounts of DNA to previously reported values and a satisfactory number of nuclei were analyzed. CRYO-W-DMSO presented a higher coefficient of variation (3.19 ± 0.09) compared to NoCRYO-0h (1.85 ± 0.09) and CRYO-WO-DMSO (2.0...

Microbial cell factories, Jan 23, 2006

Brucella spp. are facultative intracellular pathogens that have the ability to survive and multip... more Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in professional and non-professional phagocytes, and cause abortion in domestic animals and undulant fever in humans. Several species are recognized within the genus Brucella and this classification is mainly based on the difference in pathogenicity and in host preference. Brucella strains may occur as either smooth or rough, expressing smooth LPS (S-LPS) or rough LPS (R-LPS) as major surface antigen. This bacterium possesses an unconventional non-endotoxic lipopolysaccharide that confers resistance to anti-microbial attacks and modulates the host immune response. The strains that are pathogenic for humans (B. abortus, B. suis, B. melitensis) carry a smooth LPS involved in the virulence of these bacteria. The LPS O-chain protects the bacteria from cellular cationic peptides, oxygen metabolites and complement-mediated lysis and it is a key molecule for Brucella survival and replication...

Journal of Immunology Research, 2015

Many immune-based intestinal disorders, such as ulcerative colitis and Crohn’s disease, as well a... more Many immune-based intestinal disorders, such as ulcerative colitis and Crohn’s disease, as well as other illnesses, may have the intestines as an initial cause or aggravator in the development of diseases, even apparently not correlating directly to the intestine. Diabetes, obesity, multiple sclerosis, depression, and anxiety are examples of other illnesses discussed in the literature. In parallel, importance of the gut microbiota in intestinal homeostasis and immunologic conflict between tolerance towards commensal microorganisms and combat of pathogens is well known. Recent researches show that the immune system, when altered by the gut microbiota, influences the state in which these diseases are presented in the patient directly and indirectly. At the present moment, a considerable number of investigations about this subject have been performed and published. However, due to difficulties on correlating information, several speculations and hypotheses are generated. Thus, the pres...

The Open Veterinary Science Journal, 2010

Brucellosis is an important zoonotic disease of nearly worldwide distribution. This pathogen caus... more Brucellosis is an important zoonotic disease of nearly worldwide distribution. This pathogen causes abortion in cattle and undulant fever, arthritis, endocarditis and meningitis in human. The immune response against B. abortus involves innate and adaptive immunity involving antigen-presenting cells, NK cells and CD4 + and CD8 + T cells. IFN-is a crucial immune component that results from Brucella recognition by host immune receptors such as Toll-like receptors (TLRs) that lead to IL-12 production. Although great efforts to elucidate immunity against Brucella have been employed, the subset of cells and factors involved in host immune response remains not completely understood. Our group and others have been working in an attempt to understand the mechanisms involved in innate responses to Brucella. Understanding the requirements for immune protection can help the design of alternative vaccines that would avoid the drawbacks of currently available vaccines to Brucella. This review discusses recent studies in host immunity to Brucella and new approaches for vaccine development.

Lecture Notes in Computer Science, 2012

ABSTRACT The human body is protected against pathogenic invasions by a complex system of cells, t... more ABSTRACT The human body is protected against pathogenic invasions by a complex system of cells, tissues and organs which form the Human Immune System (HIS). Understanding how the HIS works is therefore essential to obtain new insights into its nature and to deal effectively with diseases. Mathematical and computational modeling can be used for this purpose. Unfortunately, these complex mathematical models are very difficult to develop, understand and use by a more general and multidisciplinary team. This paper presents a System Dynamics Metamodeling tool, called JynaCore API, that supports the development of complex models using System Dynamics in a more abstract level. To demonstrate the power and usefulness of the proposed System Dynamics Metamodeling tool, in this work we present the development of a complex two-dimensional tissue model that simulates the dynamics of the immune response.