Author(s):
Cruz, Maria Teresa 
; Duarte, Carlos B. ; Gonçalo, Margarida ; Figueiredo, Américo ; Carvalho, Arsélio P. ; Lopes, Maria Celeste
Date: 2003
Persistent ID: http://hdl.handle.net/10316/11811
Origin: Estudo Geral - Universidade de Coimbra
Subject(s): Apoptosis; Caspase-3; Cell Death; DCNB; Dendritic Cells; DNFB
Description
In this work, a dendritic cell line derived from mouse skin
(FSDC) was used, as an in vitro experimental model, to evaluate
the cytotoxic effect of two chemical sensitizers, a strong sensitizer
(2,4-dinitrofluorobenzene, DNFB) and a weak sensitizer (2,4-
dichloronitrobenzene, DCNB). The results indicated that DNFB
reduces the cellular metabolism of FSDC, as evaluated by the reduction
of the tetrazolium salt, 3-(4,5-Dimethylthiazol-2-yl)-2,5-
diphenyl tetrazolium bromide (MTT). All the DNFB concentrations
tested, ranging from 5.2 ¹M to 26¹M, significantly inhibited
the MTT reduction after 1 hour of cell exposure to the sensitizer. In
contrast, incubation of FSDC with the weak sensitizer DCNB had
no significant effect on the MTT reduction assay. When the cells
were incubated withDNFB(13¹M), for 3 and 6 hours, morphological
changes characteristics of cell death by apoptosis were observed,
as assessed by propidium iodide (PI) DNA staining and annexin-V
externalization analysis. These results correlate well with an increase
of caspase-3–like activity after FSDC exposure to DNFB
(13 ¹M) for 6 hours. Together, these results indicate that apoptotic
death of skin dendritic cells occurs after exposure to the sensitizer
DNFB, although necrotic cell death was also observed when the
cells were incubated with high concentrations of DNFB (26 ¹M),
or after long periods of cell exposure to the chemicalDNFB(13¹M,
for 6 hours).
