ISSN:
1365-3083
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
To study the role of Natural Killer (NK) cells in Leishmania infection, peritoneal macrophages from BALB/c mice were infected with Leishmania (Leishmania) amazonensis promastigotes and incubated with interleukin-2 (IL-2)-activated NK (A-NK) cells at different ratios of A-NK cells to infected macrophages (5:1, 1:1, 0.2:1). The A-NK cells were added either together with the parasites (0-h group) or 24 h later (24-h group). Morphological studies of the cultures revealed predominance of parasitic debris within macrophages that were in close contact with A-NK cells and the decrease in parasite recovery was directly proportional to the A-NK cell concentration used. Interferon-γ (IFN-γ) and IL-12 were detected in the supernatant at levels proportional to the A-NK cell concentration used. No significant difference was observed between the groups with respect to NO levels in the culture supernatant. When A-NK cells were added directly to the L. (L.) amazonensis promastigote cultures, the parasite recovery decreased proportional to the number of A-NK cells added. In vivo studies demonstrated smaller lesion sizes in animals inoculated with both parasites and A-NK cells compared with parasites alone. Histopathology of the skin lesions from animals receiving A-NK cells together with the parasites showed moderate parasitism and a nodular inflammatory infiltrate formed by mononuclear cells and a few vacuolized macrophages. In contrast, animals inoculated only with the parasites showed a highly parasitized dermis with infiltration of intensely vacuolized macrophages. These results demonstrate the role of A-NK cells in parasite lysis and in resistance of macrophages to L. (L.) amazonensis in the early phase of infection.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3083.2005.01681.x
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