Chromoblastomycosis (CBM) is a chronic, subcutaneous, granulomatous
infection caused by traumatic implantation in the skin of several dematiaceous fungi,
usually Fonsecaea pedrosoi. Brazil has second highest disease prevalence in the
world and Para State is the most endemic area. Histologically, CBM is characterized
by the presence of multinucleated giant cells and sclerotic cells can be found
engulfed by macrophages. The objective of this study was to analyze the different
aspects of interaction between peritoneal macrophages from BALB/c or C57/BL6
mice with F. pedrosoi conidia or sclerotic cells, calculating infection, phagocytosis
and cellular fusion rates. The results showed phagocytosis and infection rates with
conidia higher than sclerotic cells to BALB/c (p <0.05), while the rate of cellular fusion
was higher for sclerotic cells interaction, with Langhans giant cells formation, in
comparison to foreign-body giant cells after interaction with conidia. Macrophages
from BALB/c co-cultured with conidia produced more TNF-α than control group after
3 to 72 hours, and more IL-10 after 3h. Macrophages interacting with sclerotic cells
produced more TNF-α than control group after 1h and 3h, and the amount of IL-10
was higher after 72h of interaction. In the co-culture of C57/BL6 macrophages with
conidia, the presence of large vacuoles after 24h was observed, while in the coculture
with sclerotic cells, macrophages were detached from coverslip glasses after
24 h. Our results indicate higher levels of TNF-α after interaction of conidia compared
to controls at 1 and 72 h and increase of IL-10 after 48h. However, after interaction
with sclerotic cells, only IL-10 differed from control, being higher after 1 to 48 hours.
All of these data suggest that macrophage response to fungus is different between
BALB/c and C57/BL6 mice, differing also on the response of the same type
macrophage for each fungal form, sclerotic cells apparently being more immunogenic
than conidia.
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