MODULATION OF METABOLIC PATHWAYS SIGNALING IN MACROPHAGES INFECTED WITH T. CRUZI INDUCE M1-LIKE PHENOTYPES THAT CONTROLS PARASITE SURVIVAL.

BRUGO MARIA BELEN; ROJAS MÁRQUEZ, JORGE DAVID; ANA, YAMILE; CINTHIA STEMPIN; CERBAN F

Congreso; REUNIÓN DE LA SOCIEDAD ARGENTINA DE INMUNOLOGÍA; 2018

Macrophages (Mo) play a key role in the control of intracellular T. cruzi growth. However, parasite subverts Mo polarization through modulation of several signaling pathways to favor its survival. In this study, we focused in metabolic pathways (mTOR and AMPK) and its role during T. cruzi infection in Mo. We have previously shown that mTOR pathway is activated by T. cruzi, and that its inhibition decreased parasite replication in Mo. We observed that, Rapamycin (Rap) (an mTOR inhibitor) pretreated and T. cruzi infected Mo showed reduced nitric oxide (NO) production and iNOS expression. However, those macrophages could control parasite replication through activation of different inflammatory mechanism. Indeed, those Mo showed a significant increase in NLRP3 inflammasome receptor and IL-1β production. Given that inflammasome could employ the mitochondria as platform of assembly, we found a significantly increase in mitochondrial ROS (mtROS) production (3 and 6h pi). To evaluate the relevance of mtROS and inflammasome activation, Bone Marrow Derived Macrophages (BMDM) were treated with DPI (NADPH oxidase inhibitor), or mitoTEMPO (superoxide species [mtROS] scavenger) or CA-074 (cathepsin B inhibitor) and then infected with T. cruzi. We observed that mtROS and cathepsin B (an inflammasome activator) inhibition induce significantly higher parasite load (p<0.05). On the other hand, we found that pretreatment with Metformin (Met) (an AMPK activator) in infected Mo showed a decreased in parasite replication (p<0.05). To determinate Mo activation, we evaluate Arginase and iNOS balance in Met pretreated and infected Mo. We found decreased Arginase activity and expression and increased NO production and INOS expression, respect to control Mo. This may indicate that Met induces a M1-like phenotype, capable to control parasite replication. Taking together, these results suggest that T. cruzi replication could be controlled through modulation of metabolic pathways such as mTOR and AMPK, those allows macrophages polarize M1-like phenotypes.