Together, our data suggest that alterations in DC maturation and cytokine production upon infection with L. mexicana promastigotes involve activation of PTPs that can dephosphorylate important MAP kinases and inhibit nuclear translocation of AP-1 and NF-κB, resulting in DCs with a suppressed activation phenotype, characterized by decreased expression of MHC and costimulatory molecules, decreased IL-12 production and increased production of IL-10. This evidence concerns the gene IL10 and infection.