INVESTIGADORES
SUSPERREGUY Sebastian
congresos y reuniones científicas
Título:
THYROID HORMONE ACTION IN THE INITIATION OF THE IMMUNE RESPONSE: EFFECT OF TRIIODOTHYRONINE ON MICE DENDRITIC FUNCTION
Autor/es:
MASCANFRONI I D; MONTESINOS MM; SUSPERREGUY S; CERVI L; MASINI- REPISO AM; ILARREGUI JM; RABINOVICH GA; PELLIZAS CG
Lugar:
Santiago de Chile, Abril 2007
Reunión:
Congreso; XI Congreso de la Sociedad Latinoamericana de Tiroides (LATS); 2007
Resumen:
A cross-talk between the
endocrine and the immune systems was established. However, the role of thyroid hormones
(TH) in the initiation of the immune response is still lacking. The majority of
TH action is exerted through nuclear TH receptors (TR) although growing
evidence supports the involvement of non-genomic pathways. The main antigen
presenting cells are dendritic cells (DC) that stimulate naive T cells and
initiate and regulate primary immune responses. In vitro, mice DC can be
generated from bone marrow (immature DC: iDC) with a retained capability for
uptaking and processing antigens. The exposure of iDC to pro-inflammatory
stimuli (as lipopolysaccharide, LPS) generates mature DC able to stimulate T cells.
Previously, we presented initial evidence for the presence of TR in DC. The aim
of this study was to further characterize TR from DC, to evaluate the effect of
T3 on DC function and to analyze the signalling pathway involved. Mice DC were
cultured from bone marrow with GM-CSF for 7 days. Afterwards, DC were pulsed
with LPS 10 µg/ml (DCLPS) or T3 500-0.05 nM (DCT3) for
the final 18 h. After cell harvesting, TR were revealed by Western Blot of subcellular
fractions and immunocytochemistry. DC surface phenotype was determined by flow
cytometry and cytokine production by ELISA. The ability of DCT3 to
stimulate T cells was assessed in a mixed lymphocyte reaction (MLR). Cytoplasmic-nuclear
shuttling of nuclear factor kb (NFkb) was assessed by
Western Blot. Results: 1) TR were
expressed in DC mainly in the cytoplasm. 2) T3 induced a significant increase of:
DC surface maturation markers (MHC-II, CD80, CD86 and CD40), IL-12 as well as
INFg production and an
allogenic T lymphocyte proliferative response. 3) The involvement of NFkb pathway was evidenced.
Conclusions and Discussion: These results provide evidence for a positive effect
of physiologic levels of T3 on mice DC activation, assessed by surface phenotype,
cytokine production and functional properties, with the involvement of the NFkb signalling
pathway. In agreement with other cell types reported, TR was mainly localized
in the cytoplasm of DC.