Estudo dos fatores determinantes do grau de infectividade de linhagens de Strongyloides venezuelensis e analise de antigenos heterologos no imunodiagnostico da estrongiloidiase humana

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

In this study, we have shown that, in mice, L-2 and L-49 strains of S. venezuelensis induced an increase in the total number of leukocytes, eosinophils (EO) and mononuclear cells in blood, peritoneal cavity (LCP) and in the bronchoalveolar space (LBA), in a similar manner. Both strains stimulated synthesis of TH1 or TH2 type immune response cytokines, with a greater tendency to TH2. L-2 strain was more infective than L-49, inducing earlier synthesis of IL-4, IL-5 and IFN-y, and antibodies. In L-2, there was a direct correlation between greater production of IL-4 and IgG and expulsion of parasites, but no correlation to greater synthesis of IL-5 or proliferation and recruitment of EO and MO. Time and temperature had influence on parasite infectivity. Larvae that remained in the cultures for shorter periods of time had their infectivity affected, inducing a more intense innate immune response in blood and LCP, with rapid elimination of the parasites. Parasites kept in higher temperatures rapidly induced higher eosinophil levels in LCP, while for low temperatures, eosinophils appeared later and in lower numbers. When larvae were cultured for shorter periods of time, they stimulated a cellular immune response capable of quickly expelling female parasites, while those submitted to shorter periods and high temperatures induced a higher synthesis of antibodies, IL-4 and IL-10. Larvae kept in culture for short periods induced greater synthesis of IL-12, while longer periods lead to greater IFN-y production. Neither time nor temperature affected IL-5 synthesis. It was observed that, in strongyloidiasis, leukotrienes participate on the increase of total leukocyte numbers, EO, and MO in blood, LCP and LBA. IL-5 is also involved in the increase of leukocyte numbers in these compartments. 80th IL-12 and IFN-y protect the parasite against host defense. It was also verified, through indirect immunofluorescence, ELISA, and Immunoblot, that eight strains of S. venezuelensis presented similar antigenicity. The antibody anti-S. stercoralis IgG was able to recognize the antigenic fraction with apparent molecular weight of 45 kDa. Therefore, antigens to these strains may be used for the immunodiagnosis of human strongyloidiasis. Key words: S. venezue/ensis, strongyloidiasis, leukocytes, eosinophils, mononuclear cells, cytokines, antibody, leukotrienes, immunodiagnosis, mice

ASSUNTO(S)

leucotrienos imunoglobulinas eosinofilia

ACESSO AO ARTIGO

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