Resumen:
(245) CATHEPSIN L3 FROM FASCIOLA HEPATICA INDUCES IL-6 AND IL-10 PRODUCTION IN MURINE DENDRITIC CELLS THROUGH THE TOLL-LIKE RECEPTOR
4 SIGNALING
Celias, Daiana Pamela1; Corvo, Ileana2; Tort, José2; Silvane, Leonardo1; Motrán, Cristina1; Cervi, Laura1
Facultad de Ciencias Químicas. Centro de Investigaciones
en Bioquímica Clínica e Inmunología (CIBICI) CONICETUNC1. Depto. de Genética, Facultad de Medicina. Universidad de la República, Uruguay2
During its migration through host tissue, the helminth parasite
F. hepatica, excrete-secrete a number of products among which
are cathepsins. These enzymes belong to the family of cysteineproteases that are essential for survival and colonization of the
parasite. While Cathepsin L1 is mainly secreted by adult parasites,
Cathepsin L3 (CL3) is released by juvenile worms. Recently, it
has been described a collagenolytic activity of this enzyme, which
may be relevant in the parasite?s ability to cross the intestinal wall,
thus continuing with its life cycle in the host. However, there is no
information about the interaction of this protein with immune cells
system. Playing dendritic cells (DC) a key role for sensing antigens
and inducing different adaptive responses, the aim of this work was
to investigate the ability of CL3 to modulate the murine DC maturation and its interaction with TLR receptors. Bone marrow-derived
DC from mice C57BL/6 mice were differentiated with GM-CSF
factor and cultured for 18 h with recombinant CL3, produced in
Hansenula polymorpha. After this time, CL3 didn?t show cytotoxic
activity on DC compared to untreated DC (Student?s test p =
NS), by cell viability assay with MTT 3 (4,5-di-methyl-thiazol-2-yl)
-2,5-di-phenyl tetrazoliumbromide. We also demonstrated that CL3
increases the levels of IL-6 and IL-10 (Student test, p<0,05) and
in lower levels of IL-12p70 production, compared to untreated DC
determined by ELISA test. Using DC from TLR4 defiient mice,
we observed that IL-6 and IL-10 production induced by CL3 was
completely abrogated, while IL12p70 production didn?t change
compared to DC from wild type mice. This effect was not found
with DC fromTLR2 defiient mice. These results are the fist report
showing the ability of CL3, a highly expressed protein in excretorysecretory products of juvenile F. hepatica larva, to interact with
TLR4 in DC, increasing IL-6 and IL-10 production, which could
inflence the development of the adaptive immune response