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1.
Planta Med ; 79(3-4): 253-8, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23408270

RESUMO

Blood fluke of the genus Schistosoma are the etiological agents of human schistosomiasis, an important neglected tropical disease that afflicts over 200 million people worldwide. The treatment for this disease relies heavily on a single drug, praziquantel. Recent reports of praziquantel resistance raise concerns about future control of the disease and show the importance of developing new antischistosomal drugs. Currently, natural products have been a good source for drug development. (+)-Limonene epoxide is a mixture of cis and trans isomers found in many plants. Here, we report the in vitro effect of this natural compound on the survival time of Schistosoma mansoni adult worms. In addition, we examined alterations on the tegumental surface of adult schistosomes by means of confocal laser scanning microscopy. The effects of (+)-limonene epoxide at 25 µg/mL on S. mansoni adult worms were similar to those of the positive control (praziquantel), with reduction in motility and death of all worms after 120 h. Confocal laser scanning microscopy revealed that (+)-limonene epoxide-mediated worm killing was associated with tegumental destruction. Our results, along with the low toxicity of the (+)-limonene epoxide, suggest that this natural compound might be promising for the development of new schistosomicidal agents.


Assuntos
Anti-Helmínticos/farmacologia , Cicloexenos/farmacologia , Compostos de Epóxi/farmacologia , Monoterpenos/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Terpenos/farmacologia , Animais , Cricetinae , Monoterpenos Cicloexânicos , Cicloexenos/química , Relação Dose-Resposta a Droga , Feminino , Limoneno , Masculino , Microscopia Confocal , Monoterpenos/química , Praziquantel/farmacologia , Schistosoma mansoni/fisiologia , Esquistossomicidas/farmacologia , Terpenos/química
2.
Int J Mol Sci ; 14(3): 4969-81, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23455467

RESUMO

The present study describes the development of a green synthesis of silver nanoparticles reduced and stabilized by exuded gum from Anacardium occidentale L. and evaluates in vitro their antibacterial and cytotoxic activities. Characterization of cashew gum-based silver nanoparticles (AgNPs) was carried out based on UV-Vis spectroscopy, transmission electron microscopy and dynamic light scattering analysis which revealed that the synthesized silver nanoparticles were spherical in shape, measuring about 4 nm in size with a uniform dispersal. AgNPs presented antibacterial activity, especially against Gram-negative bacteria, in concentrations where no significant cytotoxicity was observed.

3.
FEBS Open Bio ; 11(9): 2541-2559, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34254458

RESUMO

Infectious diseases are among the major causes of death in the human population. A wide variety of organisms produce antimicrobial peptides (AMPs) as part of their first line of defense. A peptide from Acanthoscurria rondoniae plasma, rondonin-with antifungal activity, a molecular mass of 1236 Da and primary sequence IIIQYEGHKH-was previously studied (UniProt accession number B3EWP8). It showed identity with the C terminus of subunit 'D' of the hemocyanin of the Aphonopelma hentzi spider. This result led us to propose a new pathway of the immune system of arachnids that suggests a new function to hemocyanin: production of antimicrobial peptides. Rondonin does not interact with model membranes and was able to bind to yeast nucleic acids but not bacteria. It was not cytotoxic against mammalian cells. The antifungal activity of rondonin is pH-dependent and peaks at pH ˜ 4-5. The peptide presents synergism with gomesin (spider hemocyte antimicrobial peptide-UniProtKB-P82358) against human yeast pathogens, suggesting a new potential alternative treatment option. Antiviral activity was detected against RNA viruses, measles, H1N1, and encephalomyocarditis. This is the first report of an arthropod hemocyanin fragment with activity against human viruses. Currently, it is vital to invest in the search for natural and synthetic antimicrobial compounds that, above all, present alternative mechanisms of action to first-choice antimicrobials.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Peptídeos Antimicrobianos/química , Peptídeos Antimicrobianos/farmacologia , Animais , Antifúngicos/química , Antifúngicos/farmacologia , Antivirais/química , Antivirais/farmacologia , Candida/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana
4.
Biomed Pharmacother ; 88: 488-499, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28126674

RESUMO

Schistosomiasis is a world health problem, and praziquantel is the only drug currently used for the treatment. There is some evidence that extensive monotherapy of praziquantel may be leading to drug resistance in the parasite. In order to find alternative treatments, the effects of the combination of epiisopiloturine (EPI), piplartine (PPT) and praziquantel (PZQ) were evaluated. Similarity analysis of these compounds was performed using optimized molecular structures to compare the shape and the charge modeling of combinations between PZQ and EPI or PPT. Supported by this data, in vitro association of PZQ-PPT, PZQ-EPI, and EPI-PPT was carried out, and the activity of these combinations against Schistosoma mansoni was assessed. The results showed synergistic activity with a combination index (CI) of 0.42 for the treatment with PZQ-PPT. Both PZQ-EPI and EPI-PPT combinations also showed synergistic effects, with CI values of 0.86 and 0.61, respectively. Surface alterations in the tegument of adult schistosomes after the treatments were observed using laser confocal microscopy and scanning electron microscopy. Additionally, the association of EPI-PPT decreased the cytotoxicity when compared with both isolated compounds in three different lines of mammalian cells. Thus, synergistic combinations of PZQ-PPT, PZQ-EPI, and EPI-PPT create the possibility of reduced doses to be used against Schistosoma mansoni.


Assuntos
4-Butirolactona/análogos & derivados , Imidazóis/farmacologia , Piperidonas/farmacologia , Praziquantel/farmacologia , Schistosoma mansoni/efeitos dos fármacos , 4-Butirolactona/química , 4-Butirolactona/farmacologia , Animais , Antiprotozoários/farmacologia , Forma Celular/efeitos dos fármacos , Chlorocebus aethiops , Cricetinae , Cães , Sinergismo Farmacológico , Quimioterapia Combinada , Imidazóis/química , Células Madin Darby de Rim Canino , Masculino , Camundongos , Microscopia Confocal , Piperidonas/química , Praziquantel/química , Schistosoma mansoni/ultraestrutura , Células Vero
5.
Chem Biol Interact ; 244: 129-39, 2016 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-26697994

RESUMO

The use of natural products has a long tradition in medicine, and they have proven to be an important source of lead compounds in the development of new drugs. Among the natural compounds, terpenoids present broad-spectrum activity against infective agents such as viruses, bacteria, fungi, protozoan and helminth parasites. In this study, we report a biological screening of 38 chemically characterized terpenes from different classes, which have a hydroxyl group connected by hydrophobic chain or an acceptor site, against the blood fluke Schistosoma mansoni, the parasite responsible for schistosomiasis mansoni. In vitro bioassays revealed that 3,7-dimethyl-1-octanol (dihydrocitronellol) (10) was the most active terpene (IC50 values of 13-52 µM) and, thus, we investigated its antischistosomal activity in greater detail. Confocal laser scanning microscopy revealed that compound 10 induced severe tegumental damage in adult schistosomes and a correlation between viability and tegumental changes was observed. Furthermore, we compared all the inactive compounds with dihydrocitronellol structurally by using shape and charge modeling. Lipophilicity (miLogP) and other molecular properties (e.g. molecular polar surface area, molecular electrostatic potential) were also calculated. From the 38 terpenes studied, compound 10 is the one with the greatest flexibility, with a sufficient apolar region by which it may interact in a hydrophobic active site. In conclusion, the integration of biological and chemical analysis indicates the potential of the terpene dihydrocitronellol as an antiparasitic agent.


Assuntos
Anti-Helmínticos/química , Anti-Helmínticos/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Terpenos/química , Terpenos/farmacologia , Animais , Cricetinae , Relação Dose-Resposta a Droga , Estrutura Molecular , Testes de Sensibilidade Parasitária , Relação Estrutura-Atividade
6.
Biotechnol Prog ; 21(1): 99-105, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15903246

RESUMO

Previously it was reported that supplementation of insect cell culture with Lonomia obliqua hemolymph could extend culture longevity (Maranga et al. Biotechnol. Prog. 2003, 19, 58-63). In this work the anti-apoptotic properties of this hemolymph in Spodoptera frugiperda (Sf-9) cell culture were investigated. The presence or absence of apoptotic cells was characterized by light microscopy, flow cytometry, and agarose gel electrophoresis. Hemolymph was fractionated by several ion exchange and gel filtration chromatographic steps for identification of the compounds responsible for this effect. Fractions exhibiting a potent anti-apoptotic effect were isolated and tested in cell culture. A protein of about 51 kDa was identified, isolated, and tested for apoptosis inhibition. Addition of this purified protein to Sf-9 cultures was able to prevent apoptosis induced by nutrient depletion as well as by potent apoptosis chemical inducers such as Actinomycin D. This work confirms that the enhanced culture longevity obtained by supplementation with L. obliqua hemolymph is due to the presence of potent anti-apoptotic factors.


Assuntos
Apoptose/efeitos dos fármacos , Hemolinfa/química , Mariposas/química , Proteínas , Animais , Apoptose/fisiologia , Técnicas de Cultura de Células/métodos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Cromatografia em Gel/métodos , Cromatografia por Troca Iônica/métodos , Meios de Cultura/farmacologia , DNA/química , Dactinomicina/farmacologia , Proteínas/química , Proteínas/isolamento & purificação , Proteínas/farmacologia , Spodoptera/citologia , Spodoptera/metabolismo , Fatores de Tempo
7.
Cytotechnology ; 67(2): 331-42, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24969017

RESUMO

The baculovirus Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV), a member of the family Baculoviridae, has been widely applied as a biopesticide for the control of the velvetbean caterpillar, a pest of soybean crop field. Baculoviruses are considered safe and efficient agents for this purpose, because they do not infect vertebrates, being safe for the health of humans and animals, as well as to the environment. The objective of this work was to identify proteins obtained from Lonomia obliqua hemolymph with potential application in the optimization of baculovirus AgMNPV replication in Sf9 insect cell culture. In this work the improvement of the cell culture and viral replication of the AgMNPV baculovirus was observed when Grace medium was supplemented with 10 % (v/v) Fetal Bovine Serum (FBS), 1 % (v/v) hemolymph extract, or 3 % (v/v) of hemolymph fractions or hemolymph sub-fractions obtained by purifying hemolymph through High Performance Liquid Chromatography. Hemolymph presented a positive effect on the synthesis of polyhedra and enhanced baculovirus replication in Spodoptera frugiperda (Sf9) cells (TCID50/mL), and led to Sf9 cell culture improvement. Grace medium supplemented with 10 % (v/v) FBS and 1 % (v/v) hemolymph provided an increase of baculovirus replication, when the cells were infected with multiplicity of infection of 1. In this case, the baculovirus replication was 6,443.91 times greater than that obtained with the control: Grace medium supplemented with 10 % (v/v) FBS. In addition, this work suggests that hemolymph from L. obliqua could have an interesting application in biotechnology, due to an increase in the viability of the cells and virus replication.

8.
Toxicol In Vitro ; 29(4): 681-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25553916

RESUMO

Garcinielliptone FC (GFC) is a natural prenylated benzophenone found in the seeds of Platonia insignis Mart. (Clusiaceae), a native Brazilian plant. It has been chemically characterized and it is known that GFC has several biological activities such as antioxidant and vasorelaxant properties. In this study, we report the in vitro effect of GFC against the blood fluke Schistosoma mansoni, the parasite responsible for schistosomiasis mansoni. The anti-S. mansoni activity and cytotoxicity toward mammalian cells were determined for the compound. GFC⩾6.25 µM showed antischistosomal activity and confocal laser scanning microscopy analysis demonstrated several morphological alterations on the tegument of worms, and a correlation between viability and tegumental damage was observed. In addition, at sub-lethal concentrations of GFC (⩽3.125 µM), the number of S. mansoni eggs was reduced. More importantly, GFC exhibited no activity toward mammalian cells and, therefore, there is an appreciable selectivity of this compound against the helminths. In conclusion, these findings indicate the potential of GFC as an antiparasitic agent.


Assuntos
Antiparasitários/farmacologia , Triterpenos/farmacologia , Animais , Antiparasitários/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Chlorocebus aethiops , Clusiaceae/química , Feminino , Masculino , Modelos Moleculares , Atividade Motora/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Schistosoma mansoni/efeitos dos fármacos , Esquistossomicidas/toxicidade , Sementes/química , Triterpenos/isolamento & purificação , Triterpenos/toxicidade , Células Vero
9.
J Biotechnol ; 97(1): 13-22, 2002 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-12052679

RESUMO

The control of cell death occurring in high density cultures performed in bioreactors is an important factor in production processes. In this work, medium nutrient removal or feeding was used to determine at which extension apoptosis could be, respectively, involved or prevented in VERO cell cultures on microcarriers. Glutamine and galactose present in the VERO cell culture medium was consumed after, respectively, 6 and 12 days of culture. Kinetics studies showed that fresh medium replacement and, to some extent, galactose or glutamine depleted-fresh medium replacement provided a nutritional environment, allowing the VERO cell cultures to attain high densities. Galactose was shown to be a more critical nutrient when cultures reached a high density. In agreement with that, VERO cell cultures supplemented with galactose and/or glutamine were shown to confirm previous findings and, again at high densities, galactose was shown to be a critical nutrient for VERO cell growth. These observations also indicated that in VERO cell cultures, for feeding purposes, the glutamine could be replaced by galactose. The inverse was not true and led, at high densities, to a decrease of cell viability. In the absence of glutamine and galactose, apoptosis was observed in VERO cell cultures by cytofluorometry, Acridine orange staining or light and electron microscopy, reaching high levels when compared to cultures performed with complete medium. VERO cells apoptosis process could be prevented by the galactose and/or glutamine feeding and, at high densities, galactose was more efficient in protecting the cultures. These cultures, prevented from apoptosis, were shown to synthesize high levels of measles virus following infection. Our data show that apoptosis prevention by glutamine/galactose feeding, led to high productive and metabolic active VERO cell cultures, as indicated by the high cell density obtained and the virus multiplication leading to higher virus titers.


Assuntos
Apoptose/efeitos dos fármacos , Reatores Biológicos , Galactose/farmacologia , Glutamina/farmacologia , Células Vero/metabolismo , Animais , Antígenos Virais/biossíntese , Divisão Celular/efeitos dos fármacos , Chlorocebus aethiops , Meios de Cultura/farmacologia , Citometria de Fluxo , Vírus do Sarampo/crescimento & desenvolvimento , Necrose , Células Vero/citologia , Células Vero/virologia , Replicação Viral
10.
Toxicon ; 42(2): 143-53, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12906885

RESUMO

This paper presents the antiviral activity found in a snake with Crotalus durissus terrificus venom (Cdt), studied by use of microplate inhibition assay, using measles virus (MV). Cdt at concentrations below 100 microg/ml showed no cytotoxicity for Vero cells. This study shows the optimal conditions for cell treatment and infection. Two factors that affect virus binding and infection efficiency were studied: the use of an adsorption step, where infection volume was varied; and the concentration of fetal bovine serum (FBS). The adsorption step, with or without FBS, increased the bound virus percentage, whereas it increased bound virus at equilibrium only in FBS-free until 2.5% FBS. In contrast, the addition of 10% FBS decreased the bound virus percentage. The inhibition of MV replication in Vero cells was observed when Cdt was added either before or during cell infection with virus. Its inhibitory concentration against MV replication was 0.1 until 100 microg/ml, respectively. The anti-MV effect of the Cdt was gradually decreased when it was added before or during infection, and little inhibition was observed when Cdt was added 1 h after infection, suggesting that the MV infection was inhibited at the time of the initial events such as at the moment of adsorption and penetration of the viral cycle. In conclusion, Cdt contains anti-MV effects that may be of potential clinical interest.


Assuntos
Venenos de Crotalídeos/farmacologia , Crotalus , Vírus do Sarampo/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Animais , Ligação Competitiva , Chlorocebus aethiops , Venenos de Crotalídeos/toxicidade , Vírus do Sarampo/crescimento & desenvolvimento , Camundongos , Células Vero , Inativação de Vírus/efeitos dos fármacos
11.
Biotechnol Prog ; 19(1): 58-63, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12573007

RESUMO

The benefits of insect cell culture medium supplementation with hemolymph of Lonomia obliqua were investigated. The addition of hemolymph to the medium induced high levels of cell growth, and the viability was maintained for longer periods. The maximum cell yield increased almost 3-fold after hemolymph supplementation. Cultures in their stationary phase were rescued through hemolymph supplementation, also reaching high cell concentrations. These actions were much dependent on the concentration of hemolymph; low hemolymph concentration had a positive effect in cell growth, whereas high hemolymph concentration showed a deleterious effect. Fractionation of hemolymph by gel filtration chromatography showed the presence of three factors with different activity in insect cell culture: an potential anti-apoptotic factor, a growth-promoting factor, and an enzyme that hydrolyzes sucrose. Addition of hemolymph to the medium induced high levels of glucose production. The sucrose to glucose conversion was also linearly dependent upon the hemolymph concentration. Therefore, we conclude that cell growth and longevity can be increased by supplementation of the culture medium with hemolymph.


Assuntos
Meios de Cultivo Condicionados/farmacologia , Hemolinfa/metabolismo , Spodoptera/efeitos dos fármacos , Spodoptera/crescimento & desenvolvimento , Animais , Baculoviridae/patogenicidade , Contagem de Células , Técnicas de Cultura de Células/métodos , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Glucose/metabolismo , Lepidópteros/efeitos dos fármacos , Lepidópteros/metabolismo , Spodoptera/citologia , Spodoptera/virologia
12.
Zootaxa ; 3860(4): 361-70, 2014 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-25283212

RESUMO

The species Ixodes aragaoi Fonseca was described as Ixodes ricinus aragaoi, and later placed in synonymy with Ixodes affinis. However, this synonymy was rejected and the subspecies was elevated to species, and named as I. aragaoi. Some researchers did not consider the validity of I. aragaoi and maintained the synonymy proposed until 1998 when I. aragaoi was revalidated, and it was suggested that Ixodes pararicinus could be a synonym. The aim of this study was to confirm the taxonomic validity of I. aragaoi by means of redescription of adults and molecular analysis. Morphological studies were performed by optical and scanning electron microscopy; types of I. aragaoi were compared with those of I. pararicinus from Argentina, and also with material of I. pararicinus from Uruguay and I. affinis from the United States. Mitochondrial 16S rDNA sequences were obtained for determining phylogenetic relationships based on maximum parsimony. Morphological and molecular differences between I. aragaoi, I. pararicinus from Argentina, and I. affinis confirm the validity of the first each of these species. The morphological similarities of I. pararicinus from Uruguay with I. aragaoi, and the small distance of nucleotide sequences between them, confirm that the Uruguayan ticks are in fact I. aragaoi and expand the geographical distribution of this species. Based on the specimens of Ixodes examined in the present study, from the same locality of the types of I. ricinus rochensis in Uruguay, we agree with the synonymy of this subspecies with I. aragaoi as previously reported. Finally, our analyses indicate that both I. aragaoi and Ixodes fuscipes, another South American tick species, belong to the I. ricinus complex, currently composed of 19 species. 


Assuntos
Ixodes/classificação , Ixodes/genética , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Feminino , Ixodes/anatomia & histologia , Ixodes/crescimento & desenvolvimento , Masculino , Dados de Sequência Molecular , Tamanho do Órgão , Filogenia
13.
Appl Biochem Biotechnol ; 163(1): 1-13, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21161610

RESUMO

An animal protein-free medium composed of IPL-41 containing 6 g L(-1) yeastolate ultrafiltrate, 10 g L(-1) glucose, 2 g L(-1) lactose, 5 g L(-1) glutamine, 1% lipid emulsion, and 0.1% Pluronic F-68 was used for producing recombinant proteins in batch mode employing two cell lines, S2AcRVGP2k expressing the G glycoprotein from rabies virus (RVGP) and S2AcHBsAgHy-9C expressing the surface antigen of hepatitis B virus (HBsAg), both obtained from Drosophila melanogaster S2 cells. Growth of wild-type S2 cells was also evaluated in the same medium. Cell behavior in the tested medium was compared to that verified in Sf900 II®. The results show that in shake flasks, S2AcRVGP2k and S2AcHBsAgHy-9C cells reached around 2 × 10(7) cells mL(-1) in both media. In supplemented IPL-41 and Sf900 II® media, S2AcRVGP2k cells produced 367 ng RVGP mL(-1) and 638 ng RVGP mL(-1), respectively, while S2AcHBsAgHy-9C cells correspondently produced 573 ng HBsAg mL(-1) and 322 ng HBsAg mL(-1) in the mentioned media. In stirred tanks, S2AcRVGP2k cells reached 3 × 10(7) cells mL(-1) and produced up to 758 ng RVGP mL(-1). In general, glucose was consumed by cells, while lactate and ammonia were produced.


Assuntos
Técnicas de Cultura de Células , Meios de Cultura Livres de Soro/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/crescimento & desenvolvimento , Transfecção , Animais , Linhagem Celular , Drosophila melanogaster/metabolismo , Expressão Gênica , Vírus da Hepatite B/genética , Vírus da Hepatite B/metabolismo , Vírus da Raiva/genética , Vírus da Raiva/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo
14.
Cytotechnology ; 62(6): 547-55, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20936342

RESUMO

Apoptosis is a major problem in animal cell culture during production of biopharmaceuticals, such as recombinant proteins or viral particles. In the present work baculovirus-insect cell expression system (BEVS/IC) is used as model to produce rotavirus like-particles, composed by three layers of three different viral proteins (VP2, VP6 and VP7). In this model baculovirus infection also induces host cell death. Herein a new strategy to enhance cell life span and to increase recombinant rotavirus protein production of BEVS/IC system was developed. This strategy relies on hemolymph from Lonomia oblique (total extracts or a semi-purified fraction) medium supplementation. The total extract and a purified fraction from hemolymph of Lonomia obliqua were able to protect Sf-9 cell culture against apoptosis triggered by oxidative stress (using the pro-oxidant agents tert butylhydroperoxide and hydrogen peroxide) and by baculovirus infection. Furthermore, hemolymph enhance final recombinant protein production, as it was observed by the increased amounts of VP6 and VP7, which were measured by the semi-quantitative western blot method. In conclusion, hemolymph medium supplementation can be a promising strategy to improve cell viability and productivity of recombinant protein in BEVS/IC system.

15.
Antiviral Res ; 84(1): 84-90, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19665487

RESUMO

Potent antiviral activity against measles, influenza and polio viruses was observed in the hemolymph of Lonomia obliqua. The antiviral protein responsible for this activity was isolated, purified by gel filtration chromatography using a gel filtration column system (Superdex 75) and further fractionated using a Resource-Q ion exchange column system. Experiments with the purified protein led to a 157-fold reduction (from 3.3+/-1.25 x 10(7) to 2.1+/-1.5 x 10(5) TCID(50)mL(-1)) in measles virus production and a 61-fold reduction (from 2.8+/-1.08 x 10(9) to 4.58+/-1.42 x 10(7)mL(-1)) in polio virus production. Heating and freezing seem to have no influence over its antiviral activity. Also, the protein does not display virucidal activity and does not act on receptors on the cell membrane. The observations suggest an intracellular mechanism of action and that the protein may act as a constitutive agent that affects the innate antiviral immune response.


Assuntos
Hemolinfa/imunologia , Proteínas de Insetos/imunologia , Mariposas/química , Mariposas/imunologia , Animais , Linhagem Celular , Chlorocebus aethiops , Cães , Hemolinfa/química , Proteínas de Insetos/isolamento & purificação , Estabilidade Proteica , Células Vero , Replicação Viral/efeitos dos fármacos , Vírus/efeitos dos fármacos
16.
Cytotechnology ; 60(1-3): 143-51, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19842054

RESUMO

Gene expression in insect cells is an advantageous system for recombinant protein production, mainly because of its capacity to produce complex proteins with correct post-translational modifications. Recently, we identified and purified a protein from Lonomia obliqua hemolymph able to increase the production of rabies virus glycoprotein, expressed in Drosophila melanogaster cells, by about 60%. In this work, the kinetic parameters for cell growth and recombinant rabies virus glycoprotein production were determined in cultures of transfected Drosophila melanogaster Schneider 2 (S2) cells expressing recombinant rabies virus glycoprotein (rRVGP), enriched and non-enriched with the hemolymph of Lonomia obliqua (Hb). The highest concentration of rRVGP was achieved at the beginning of the culture enriched with Hb, indicating that the cells produce greater amounts of rRVGP per cell (specific rRVGP concentration) at the early exponential growth phase. After day 8, a decrease in the concentration of rRVGP (ng/mL) was observed, probably due to protein decomposition. The average specific rRVGP production rate (mu(rRVGP)) was 30 ng rRVGP/10(7)cell.day, higher than that observed in the non-enriched culture.

17.
Cytotechnology ; 57(1): 11-22, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-19003168

RESUMO

An animal protein-free medium was developed for Drosophila melanogaster S2 (S2AcGPV2) cells genetically modified to produce the rabies virus G glycoprotein (GPV). IPL-41, used as a basal medium, was supplemented with yeastolate, carbohydrates, amino acids and lipids aiming initially to reduce and further to eliminate the need of fetal bovine serum. The S2AcGPV2 cells were fully capable of growing in serum-free supplemented IPL-41 medium containing 6 g L(-1) yeastolate ultrafiltrate, 10 g L(-1) glucose, 3.5 g L(-1) glutamine, 0.5 g L(-1) fructose, 2 g L(-1) lactose, 0.6 g L(-1) tyrosine, 1.48 g L(-1) methionine and 1% (v/v) lipid emulsion, reaching 19 x 10(6) cells mL(-1). Maximum specific growth rate and cell productivity were 0.025 h(-1) and 0.57 x 10(5) cells mL(-1) h(-1), respectively. Glucose and lactose were consumed during cell culture, but not fructose. Lactate concentration generally decreased during cell culture, while ammonium concentration reached 167 mg L(-1), however, without noticeable deleterious effects on cell growth. GPV concentration values achieved were, however, modest in the proposed medium formulation.

18.
Cytotechnology ; 57(1): 83-91, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-19003176

RESUMO

Gene expression in animal cells allows large scale production of proteins used for either structure and function studies or therapeutic purposes. Maximizing recombinant protein production is necessary to optimize cell growth and protein expression. Some studies have demonstrated the presence of pharmacologically active substances in insect hemolymph. In this work, we have identified and purified a protein from Lonomia obliqua hemolymph able to increase the production of the rabies virus glycoprotein, expressed in Drosophila melanogaster S2 cells, by about 59%.

19.
J Immunol ; 177(5): 3193-200, 2006 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-16920958

RESUMO

The participation of type I IFNs (IFN-I) in NO production and resistance to Trypanosoma cruzi infection was investigated. Adherent cells obtained from the peritoneal cavity of mice infected by the i.p. route produced NO and IFN-I. Synthesis of NO by these cells was partially inhibited by treatment with anti-IFN-alphabeta or anti-TNF-alpha Abs. Compared with susceptible BALB/c mice, peritoneal cells from parasite-infected resistant C57BL/6 mice produced more NO (2-fold), IFN-I (10-fold), and TNF-alpha (3.5-fold). Later in the infection, IFN-I levels measured in spleen cell (SC) cultures from 8-day infected mice were greater in C57BL/6 than in infected BALB/c mice, and treatment of the cultures with anti-IFN-alphabeta Ab reduced NO production. IFN-gamma or IL-10 production by SCs was not different between the two mouse strains; IL-4 was not detectable. Treatment of C57BL/6 mice with IFN-I reduced parasitemia levels in the acute phase of infection. Mice deprived of the IFN-alphabetaR gene developed 3-fold higher parasitemia levels in the acute phase in comparison with control 129Sv mice. Production of NO by peritoneal macrophages and SCs was reduced in mice that lacked signaling by IFN-alphabeta, whereas parasitism of macrophages was heavier than in control wild-type mice. We conclude that IFN-I costimulate NO synthesis early in T. cruzi infection, which contributes to a better control of the parasitemia in resistant mice.


Assuntos
Doença de Chagas/metabolismo , Doença de Chagas/prevenção & controle , Interferon-alfa/biossíntese , Interferon beta/biossíntese , Óxido Nítrico/biossíntese , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/fisiologia , Animais , Células Cultivadas , Doença de Chagas/parasitologia , Feminino , Interferon gama/biossíntese , Interleucina-10/biossíntese , Macrófagos/metabolismo , Macrófagos/parasitologia , Camundongos , Camundongos Knockout , Receptores de Interferon/deficiência , Receptores de Interferon/genética , Receptores de Interferon/metabolismo , Baço/metabolismo , Baço/parasitologia , Fator de Necrose Tumoral alfa/biossíntese
20.
Mediators Inflamm ; 2005(6): 349-59, 2005 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-16489255

RESUMO

Crotalus durissus terrificus venom (Cdt) is toxic for a variety of eukaryotic cells, especially at high concentrations. However its effects on host immune cells are not well known. The purpose of this study was to determine the effect of Cdt on functional status and the mediators production in peritoneal macrophages. The effects of Cdt were analyzed in vitro and were detected using functional status of macrophages as determined by the H(2)O(2) release, spreading percentage, phagocytic index, vacuole formation, and mediators production. Several functional bioassays were employed: cytotoxicity was determined by taking the lyses percentage and the presence of hydrogen peroxide (H(2)O(2)) in macrophages, using the horseradish peroxidase-dependent oxidation of phenol red and nitric oxide (NO) in the supernatants of macrophages by the Griess reaction. The tumor necrosis factor (TNF) activity was detected by measuring its cytotoxic activity on L929 cells, and the production the level of other cytokines was assayed using enzyme-linked immunosorbent assay. In vitro studies revealed that Cdt produced (a) a discrete increase in the release of H(2)O(2) and vacuole formation; (b) a decrease in spreading percentage and in the phagocytic index; and (c) an increment in the mediators production. More pronounced increments of IL-6 and TNF were observed after 24 and 48 hours, respectively. Maximum levels of IFN-gamma and NO were observed after 96 hours. Interestingly, levels of all mediators presented a discreet decrease, as the amount of Cdt was increased. In contrast, the IL-10 levels observed for all doses studied here did not alter. The IL-6/IL-10 ratio may possibly reflect the balance of pro- and anti-inflammatory cytokines in macrophages, which may be manifested in the inflammatory status during the envenoming processes. Taken together, these data indicate that Cdt have a differential effect on macrophage activation and that this venom is a potent inhibitor of anti-inflammatory response.


Assuntos
Forma Celular/efeitos dos fármacos , Venenos de Crotalídeos/farmacologia , Crotalus , Macrófagos Peritoneais , Animais , Citocinas/metabolismo , Feminino , Peróxido de Hidrogênio/metabolismo , Ativação de Macrófagos , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Oxidantes/metabolismo , Fagocitose/fisiologia , Vacúolos/metabolismo
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