Toll-like receptor-2 and interleukin-6 mediate cardiomyocyte protection from apoptosis during Trypanosoma cruzi murine infection

PONCE NE; CANO RC; CARRERA SILVA EA; LIMA AP; GEA S; AOKI MP

SPRINGER

Año: 2011

ocal innate immunity plays a key role in initiating and coordinating homeostatic and defense responses in the heart. We have previously reported that the cardiotropic parasite Trypanosoma cruzi, the etiological agent of Chagas disease, protects cardiomyocytes against growth factor deprivation-induced apoptosis. In this study, we investigated cardiomyocyte innate immune response to T. cruzi infection and its role in cellular protection from apoptosis. We found that Toll-like receptor (TLR) 2-expressing cells were strongly increased by the parasite in BALB/c neonatal mouse cardiomyocyte cultures. Using a dominant-negative system, we showed that TLR2 mediated cardiomyocyte survival and the secretion of interleukin (IL) 6,which acted as an essential antiapoptotic factor. Moreover, IL6 released by infected cells, as well as the recombinant bioactive cytokine, induced the phosphorylation of the signal transducers and activators of transcription-3 (STAT3) in cultured cardiomy