Navegando por Assunto "Leishmaniose cutânea"
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Item Acesso aberto (Open Access) Atividade e expressão da metaloprotease GP63 nas espécies Leishmania (Leishmania) amazonensis e Leishmania (Viannia) brasiliensis(Universidade Federal do Pará, 2021-06) SOARES, Dara da Costa; SILVA, Edilene Oliveira da; http://lattes.cnpq.br/7410116802190343; https://orcid.org/0000-0001-6555-6868The american cutaneous leishmaniasis (ATL) is a neglected tropical disease caused by protozoa of the genus Leishmania sp. In Brazil, Leishmania (L.) amazonensis and Leishmania (V.) braziliensis are the main pathogenic species. The different strains and species, as well as the immune response of the vertebrate host, are key points in the development of the disease and, consequently, in the different clinical manifestations caused by these protozoa such as localized cutaneous leishmaniasis (LCL), diffuse cutaneous leishmaniasis (LCD) and mucocutaneous leishmaniasis (CML). Leishmania parasites have improved mechanisms with the ability to silence the microbicidal response of infected macrophages through the action of virulence factors such as glycoprotein 63 (GP63). This glycoprotein, which has a zinc- dependent catalytic site, is the main surface metalloprotease of Leishmania and is able to modulate the vertebrate host's immune response by cleaving a wide set of cytosolic substrates. However, due to the need to understand the role and involvement of GP63 in infection processes and different clinical manifestations, it is important to analyze how this molecule is present during these processes. In view of this, the hypothesis of this study is whether there is a difference in the expression of the virulence factor GP63 between two ATL-causing species, Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis, which cause different clinical manifestations. Therefore, the objective of this work was to analyze the expression and activity of GP63 in the species Leishmania (L.) amazonensis and Leishmania (V.) braziliensis, which are more relevant to the involvement of ATL. The activity of GP63 was analyzed using promastigote forms in the stationary phase (7 days of culture) and they were submitted to analysis of the proteolytic profile through DQ-gelatin (10μg / ml) in fluorimeter (VICTOR Multilabel Plate Reader X) with wavelength of 480-520 nm and by zymography gel containing 0.1% gelatin as substrate. The expression of GP63 was analyzed by Western blot using anti-GP63 antibody. The immunostaining and quantification of the GP63 protein were analyzed by indirect immunofluorescence. This work showed for the first time that the species Leishmania (L.) amazonensis shows greater expression of the glycoprotein 63 kDa compared to the species Leishmania (V.) braziliensis. The greater expression of this protease was also accompanied by an increase in gelatinolytic activity in the analyzed species. These results allow suggesting a correlation in the involvement of this virulence factor between the clinical manifestations that are caused by these two species analyzed in this work.Item Acesso aberto (Open Access) Avaliação da susceptibilidade de camundongos BALB/c e Swiss, hamster e Proechimys roberti à infecção por Leishmania (Viannia) Naiffi e Leishmania (Viannia) Lindenbergi(Universidade Federal do Pará, 2005) SODRÉ, Roberta Nice Salgado; ISHIKAWA, Edna Aoba Yassui; http://lattes.cnpq.br/3074963539505872Leishmania (Viannia) naiffi and Leishmania (Viannia) lindenbergi are species that cause cutaneous leishmaniasis in Amazonia and present great similarity in its isoenzymatic profile, monoclonals antibodies and production of unapparent infection in hamsters. The fact of not having a highly susceptible experimental model to the infection for L. (V.) naiffi and L. (V.) lindenbergi, the objective of this study was evaluate the susceptibility of BALB/c and Swiss mice, hamsters and Proechimys roberti to the infection for those two species. It was prepared inoculums with salivary glands and without glands for each group of animals, associated to the promastigotes. The experimental animals, of both sexes, were inoculated intradermally in the dorsal surface of back feet and they were observed for 90 days. In the period of 30, 60 and 90 days after inoculation, the animals were sacrificed and different fragments of skin of the inoculation place were used in the culture, microscopic exam and polymerase chain reaction (PCR). It was not possible to observe lesions in the animals inoculated with L. (V.) naiffi and L. (V.) lindenbergi even at the presence or absence of salivary glands. As well as, forms amastigotes during 30, 60 and 90 days after the inoculation. In the culture, all the animals inoculated with L. (V.) lindenbergi haven’t developed promastigotes. For the other hand, BALB/c mice inoculated with L. (V.) naiffi presented positively when sacrificed 30 days after inoculation. PCR presented low sensibility compared to the culture. This way, we concluded that L. (V.) naiffi and L. (V.) lindenbergi is species that present low infectivity and none of the animals used in the study experimental model can be considered highly susceptible to the infection for those two species.Item Acesso aberto (Open Access) Caracterização isoenzimática e por anticorpos monoclonais dos agentes da leismaniose tegumentar americana (LTA) na mesorregião do Baixo Amazonas, estado do Pará, Brasil(Universidade Federal do Pará, 2003) JENNINGS, Yara Lúcia Lins; SILVEIRA, Fernando Tobias; http://lattes.cnpq.br/8106158306299969There are a diversity of Leishmania species in the Amazon region responsible for cutaneous leismnaniasis and although a high occurence of the disease is known in the lower Amazon region, little information exists regarding the etiological agents. For this reason the present study has set out to characterise strains of Leishmania isolated from patients coming from this area by enzyme electroforesis, to confirm the presence of Leishmania species already recorded in other parts of Amazonia and to detect possible intraspecific variation. For identification of 43 isolate obtained, 7 reference-strains of Leishmania species from other regions of Pará were selected for comparison by way of isoenzyme eletrophoresis, using the seven enzymes 6PGDH, PGM, G6PD, MPI, ASAT e ALAT. The isolates had previously been examined by the indirect immunofluorescence teste (IFAT), using the biotin-avidin system and battery of 23 monoclonal antibodies (McAbs). Identifications by the isoenzyme eletrophoresis were as follows: 20(46,50%) strains of L. (V) guyanensis, 11 (25,28%) of L. (V) braziliensis, 6 (13,950/0) of L. (V) lainsoni, 4 (9,300/0) of L. (V) shawi and 2 (4,60%) de L. (L.) amazonensis. Enzyme eletrophoresis, using the above mentioned enzymes proved of high value in identification. For the first time in the lower amazon region, it was possible to detect the occurence of intraspecific variation indicating the presence of 3 different serodemes among the strains of L. (V) braziliensis. Arnong the strains of L. (V) guyanensis there were observed two variants: one which showing reation against McAb B19, considered to be specific for this parasite, but with variation for the enzymes 6PGDH and PGM, and another with no reaction against McAb B19 but showed enzymatic profiles similar to the reference strain of that parasite, especially 6PGDH (but with 3 bands) and PGM, which are considered to be the best enzyme markers. The presence of all 5 dermotropic Leishmania spp. Already know to variably exist in other parts of north Brazil suggests sympatric transmission within the lower Amazon region of the present study.Item Acesso aberto (Open Access) Efeito in vitro e in vivo do 5-hidroxi-2-hidroximetil-gama-pirona durante a infecção por Leishmania (Leishmania) amazonensis(Universidade Federal do Pará, 2013-05-27) RODRIGUES, Ana Paula Drummond; SILVA, Edilene Oliveira da; http://lattes.cnpq.br/7410116802190343Leishmaniasis includes a group of infectious diseases with worldwide distribution. Chemotherapy is one of the most effective treatments for this disease; although a number of anti-leishmanial drugs are available, these drugs are in general toxic, expensive and require long-term treatment. Kojic acid, or 5-hydroxy-2-hydroxymethyl-γ-pyrone (HMP), is well known for effectively inhibiting the tyrosinase enzyme in the process of melanin biosynthesis and is extensively used in cosmetics and as a topical treatment for melasm with no cytotoxicity observed in humans; however its potential as anti-leishmanial agent are unknown. The present study was designed to determine the effect of this bioproduct on L. amazonensis, following in vitro and in vivo infections. HMP (50μg/mL) was found to decrease the growth by 62% (IC50 34 μg/mL) and 79% (IC50 27.84 μg/mL) of promastigotes and amastigotes in vitro, respectively. Ultrastructural analysis of both evolutive forms showed that HMP increasing the presence of vesicles bodies into the flagellar pocket, and inducing an intense intracellular vacuolization and swelling of the mitochondrion. In vitro study also demonstrated that HMP is able to reverse ROS inhibitory mechanism promoted by L. amazonensis observed by nitroblue tetrazolium reaction. Histopathologycal analysis of in vivo topical treatment with HMP ointment showed healing process and suppressed ulcer dissemination in animal model. In addition, collagen fibers stained by picrosirus red, were found at the infection site of HMP-treated animals and an absence or low-level cellular infiltrate was observed, as well as a decrease in parasite burden. In view of the in vitro selective action of HMP on leishmania parasites, the activation of host cells and in vivo decrease in parasite burden, observed using HMP ointment, as well as the fact that HMP is widely and safely applied as an antimelasm agent in humans, this compound could be useful for the selective treatment of cutaneous leishmaniasis and may hold great potential as an anti-leishmanial agent.