STUDY OF THE NLRP3 INFLAMMASOME IN AN INFECTION MODEL WITH TRYPANOSOMA CRUZI

PAROLI A; ONOFRIO LI; AROCENA ALFREDO; CABALÉN M.E; CRESPO P; CANO ROXANA CAROLINA; GEA S

Córdoba

Congreso; LXI Reunión Anual de la Sociedad Argentina de Inmunología; 2013

Sociedad Argentina de Inmunología

The activation of the citosolic receptor NLRP3 assembles its inflammasome and leads to IL-1β maturation. We have previously reported an increment in the mRNA of nlrp3 and tlr9 at 14 and 21 dpi (days post infection) in the liver of infected mice. At cardiac level, nlrp3 also increased but this was even greater for asc and tlr9 (p<0,001). The aim of this work was to study the dynamics of the NLRP3 inflammasome in different cells and tissues in an infection model with Trypanosoma cruzi. 6-8 weeks C57BL/6 mice were infected with 1000 trypomastigotes (Tulahuen) and samples of serum, spleen, heart and liver were collected at different points post infection. Also, splenocytes and J774 macrophages (MФ) were cultivated under different experimental conditions. IL-1β serum levels increased at 21 dpi (p<0,05) compared with the uninfected controls, whereas TNF-α kept high at 14 (p<0,05) and 21 dpi (p<0,001). On the other hand, nitric oxide reached a peak at 14 dpi (p<0,001) and stayed high at 21 dpi (p<0,01). The ex vivo stimulation with parasite antigens revealed the ability of splenocytes from 14 and 21 dpi mice to significantly secrete IL-1β and TNF-α when compared with the controls. 10:1 (parasite:cell) ex vivo infected splenocytes released IL-1β and TNF-α at 6 (p<0,05) and 24 hs (p<0,001) of stimulation but did not respond to the treatment with cholesterol crystals (CC). Nevertheless, NLRP3 was able to be detected by immunofluorescence within the cytoplasm of MФ treated with ?LPS+ATP?, ?CC? and ?Infected? at 5 hs post-stimulation. Last, 6, 18 and 24 hs tests using MФ showed a synergic increment in the secretion of both cytoquines in the ?T. cruzi+CC? group (5:1 parasite:cell)(p<0,001). The so far presented data of the acute infection with T. cruzi and the ex vivo and in vitro infections allows us to conclude that Trypanosoma cruzi would be able to activate the NLRP3 inflammasome.