Previously we demonstrated that the iNOS/arginase balance was biased towards arginase in Trypanosoma cruzi infected macrophages (Mo) pre-incubated with mannose-BSA (man-BSA, mannose receptor (MR) specific ligand). Moreover, intracellular parasite growth was increased. In addition, the study of MAP kinase intracellular signals showed that pre-incubation with man-BSA but not mannan, induced down-regulation of p-JNK and p-p44/p42 and up-regulation of p-p38 MAPK in T. cruzi infected J774 cells. These results are coincident with previous data published by our group in T. cruzi infected Mo pre-incubated with Cruzipain (Cz). These results suggested that man-BSA and Cz might interact with the same receptor (MR). Moreover, we showed that pre-incubation with man-BSA induced MR up-regulation or increased MR recycling on Mo surface. In this work, we study MR behavior in Cz-Mo interaction. J774 cells were treated with Cz during 2h and then incubated with man-BSA-FITC for 20 minutes. Flow cytometry analysis showed that Cz increased the percentage of FITC+ cells. Therefore, Cz might interact with MR in the same way that man-BSA. Then, we studied whether Cz or man-BSA induced MR up-regulation or increased MR recycling. Therefore, J774 cells were incubated for 1, 2 or 3 hs with man-BSA-FITC at