Efeito do fator de crescimento insulina-símile-I em promastigota e amastigota intracelular de Leishmania (Viannia) braziliensis de pacientes com  diferentes formas clínicas de leishmaniose tegumentar americana  / Effect of Insulin-like growth factor-I on promastigotes and intracellular amastigotes of Leishmania (Viannia) braziliensis from patients with different clinical forms of American tegumentary leishmaniasis

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

03/10/2012

RESUMO

Leishmaniasis are diseases caused by protozoa of the genus Leishmania that may manifest as cutaneous or visceral disease. In Brazil, American tegumentary leishmaniasis (ATL) is caused mostly by Leishmania (Viannia) braziliensis and cutaneous (CL), mucosal (ML) and disseminated (DL) forms of the disease are known.The diversity of clinical manifestations has been attributed to differences in the host immune response, but recently it has also been related to intraspecific variability of L. (V.) braziliensis. In the present study we evaluated whether there were biological variability in different isolates of L. (V.) braziliensis from patients with CL, ML, and DL, mainly in response to insulin-like growth factor-I (IGF-I). Growth factors of the host have been investigated in the development of leishmaniasis including IGF-I. In previous studies using Leishmania (Leishmania) amazonensis IGF-I was shown to induce proliferation, to increase the activity of arginase, generating polyamines and to decrease the synthesis of nitric oxide. In this study we analyzed the effect of IGF-I in L. (V.) braziliensis, a species prevalent in Brazil. Initially we evaluated the characteristics of individual isolates as promastigote and further as amastigote within human macrophage cell line THP-1 with and without IGF-I stimulation. Our data suggest that there are differences in the basal arginase activity amongst isolates of L. (V.) braziliensis, being higher in those from patients with ML. IGF-I increased the activity of arginase in the isolates of CL and DL, but not of ML. In isolates in the form of amastigotes within THP-1 cells, IGF-I induced the increase of parasitism of isolates from CL and ML, and decrease of those from DL. In isolates of DL the basal arginase activity was lower than in those of CL. Moreover, the production of nitric oxide tended to be higher with isolates of DL upon IGF-I stimulation. The data suggest that differences in the biological characteristics of parasites may contribute to the diversity of clinical presentation of ATL.

ASSUNTO(S)

arginase arginase cutaneous leishmaniasis disseminated leishmaniasis fator de crescimento insulina símile-i insulin like growth factor i leishmania (viannia) braziliensis leishmania (viannia) braziliensis leishmaniose cutânea leishmaniose disseminada leishmaniose mucosa mucosal leishmaniasis

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