Atividade e expressão da metaloprotease GP63 nas espécies Leishmania (Leishmania) amazonensis e Leishmania (Viannia) brasiliensis

Abstract

The 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.