INVESTIGADORES
CRIBB Pamela
congresos y reuniones científicas
Título:
DECIPHERING THE PUTATIVE ROLE OF HIGH MOBILITY GROUP B PROTEIN FROM Trypanosoma cruzi IN INFLAMMATION
Autor/es:
TAVERNELLI, LUIS; MANARIN, ROMINA; PERDOMO, VIRGINIA; BARRIOS-PAYAN, JORGE; HERNANDEZ PANDO, ROGELIO; SERRA, ESTEBAN; CRIBB, PAMELA
Lugar:
Mar del Plata
Reunión:
Congreso; X Congreso Argentino de Protozoología y Enfermedades Parasiarias; 2014
Institución organizadora:
Sociedad Argentina de Protozoología
Resumen:
High Mobility Group B (HMGB) proteins are evolutionary-conserved ubiquitous proteins
described more than 30 years ago and named for their high mobility in SDS-PAGE. As
abundant components of chromatin, they act as architectural factors and take part of many
nuclear processes like transcriptional regulation, DNA repair and replication. A member of
this family of proteins, HMGB1, has gained a lot of interest in the last decade because,
besides its nuclear functions, it can be secreted by activated macrophages or passively
released by necrotic or injured cells and act as a pro-inflammatory mediator. We
previously demonstrated that the HMGB protein from Trypanosoma cruzi (TcHMGB) is a
nuclear protein expressed in all life cycle stages with architectural functions. We decided
to test if TcHMGB can also act as an immune regulator, as a first approach to study its
putative role in Chagas Disease. We first determined the presence of TcHMGB in the
supernatants of epimastigote cultures and blood trypomastigotes incubated in PBS by
western blot, suggesting the protein can be secreted. Consistent with observations in other
organisms, acetylation may be the signal for TcHMGB secretion, since treatment with
deacetylase-inhibitors enhance the protein signal in western blots. We then stimulated
RAW 264.7 macrophages with the recombinant TcHMGB for different time periods.
Culture supernatants were collected and nitric oxide production was analyzed measuring
nitrite release by Griess reaction. Also, total RNA was purified from treated macrophages
and mRNAs for different cytokines were quantified by qRT-PCR. Recombinant TcHMGB
showed to be able of inducing macrophage activation in vitro. Finally, we tested the
immune activity in vivo, stimulating male BALBc mice with the recombinant protein for
different periods of time. Peritoneal fluid and spleens were collected to test for cytokineproduction.
These preliminary results indicate that TcHMGB may have a role in
inflammation.