MTOR INHIBITION IN TRYPANOSOMA CRUZI INFECTED MACROPHAGES PRODUCES INFLAMMATORY MEDIATORS THAT REGULATE ITS SURVIVAL.

ROJAS MARQUEZ, JORGE D.; ANA, YAMILE; STEMPIN, CINTHIA C.; CERBAN, FABIO M.

Mar del Plata, Buenos Aires

Congreso; LXIV Reunión anual de la Sociedad Argentina de Inmunología.; 2017

Sociedad Argentina de Inmunología

We have previously shown that Trypanosoma cruziinfection in macrophages (Mo) activates mTOR and itsinhibition decreased parasite replication. Besides, in rapamycin(Rap) pre-treated and infected Mo we observedreduced arginase activity and expression comparedto control cells. Surprisingly, we also found reducediNOS activity and expression. Therefore, the aim ofthis work was to determine alternative mechanismsinvolved in controlling parasite replication in Rap pretreatedand infected Mo. In this context, we evaluatedROS production. We did not found differences in ROSproduction after 24h post infection (pi) between Rap orDMSO pre-treated and infected Mo. Also, we evaluatedwhether indoleamine 2,3-dioxygenase (IDO) enzymewas involved. To do that, we inhibit IDO activity by using1MT (1-methyl-tryptophan) and we study parasite replicationby immunofluorescence (IF). We did not founddifferences compared to control cells without 1MT andthen IDO activity is either not involved in decreasingparasite replication in Rap pre-treated and infected Mo.Consequently, to study possible mediators involved inparasite killing in BMDM from different KO mice (TLR2,TLR4, IFNa-R, Caspase-1, IL-6, TNFa-R and NLRP3),parasite load was evaluated 72h pi by IF. We observeda significant increase in parasite load in Rap pre-treatedand infected BMDM from IL-6-KO, TNFa-R-KO andNLRP3-KO mice compared to WT pre-treated and infectedcontrol cells for each strain. However, parasitenumber stands out in BMDM from NLRP3 KO (p<0.05).Taking into account that NLRP3 is one of the main componentsof the inflammasome our current studies arefocused on demonstrating its activation during infectionand mTOR inhibition. We found that Rap pre-treatedand infected WT BMDM showed a significant increasein NLRP3 expression at 6h pi (p<0.05). These resultswould indicate that NLRP3 activation may be one of themechanisms involved in reducing parasite replication inRap pre-treated and infected Mo.