Elimination of Leishmania donovani amastigotes by activated macrophages.

AUTOR(ES)

Haidaris, C G

RESUMO

Tissue macrophages are the obligatory host cells for Leishmania donovani, the causative agent of visceral leishmaniasis. In this study we sought to determine whether activated macrophages, as defined by the functional criterion of tumor cell cytotoxicity, were also able to exert a microbicidal effect on ingested L. donovani amastigotes. We found that mouse peritoneal macrophages activated by a variety of means exerted a cytotoxic effect on tumor cell targets but were not able to kill L. donovani amastigotes unless the infected macrophages were exposed continually to an activating stimulus. Corynebacterium parvum, Mycobacterium tuberculosis H37Ra, and lymphokine-activated peritoneal macrophages from C57BL/6J mice were cytotoxic for EMT6 tumor cell targets. However, L. donovani Sudan strain 1S amastigotes were not killed by these macrophages unless the activated state was maintained by daily addition of lymphokine to the infected monolayers for several days postinfection. The killing of amastigotes was dependent on the time of exposure to lymphokine, as well as on the concentration of lymphokine added to the culture.

Documentos Relacionados

• Lipophosphoglycan blocks attachment of Leishmania major amastigotes to macrophages.
• Proteophosphoglycan secreted by Leishmania mexicana amastigotes causes vacuole formation in macrophages.
• Comparison of receptors required for entry of Leishmania major amastigotes into macrophages.
• c-fos and tumor necrosis factor gene expression in Leishmania donovani-infected macrophages.
• pH homeostasis in Leishmania donovani amastigotes and promastigotes.