Artículo especial: Induccion de arginasa: un nuevo mecanismo de evasion de parasitos

CINTHIA STEMPIN, FABIO CERBAN

MEDICINA (BUENOS AIRES)

Fundación Revista Medicina (Manuscrito en Revision).

Lugar: Buenos Aires; Año: 2006

0025-7680

Abstract Although there are several immunological mechanisms to eliminate the intracellular pathogens, they have elaborated a variety of strategies to escape of the immune response and to make possible their survival and replication in the host. Some parasites modulate the production of several toxic molecules synthesized by the immune system. Several parasites are highly sensible to nitric oxide (ON) and their derivatives. ON is produced in macrophages (Mf) after stimulation with microbial products or cytokines. In the past, Mf were defined as inflammatory cells (classically activated Mf), able to produce inflammatory mediators, to act like antigens presenting cells and to kill intracellular pathogens. Nevertheless, in the present activated Mf involve a more heterogeneous group of cells with different biological markers that can carry out different immunological functions. Alternatively activated Mf ƒnfail to produce ON due to the arginase induction and consequently they have diminished its capacity to kill intracellular pathogens. It has been reported the induction of arginase by different parasites; therefore this mechanism could favor its survival in the host. In our group, we studied the participation of arginase in a model of Trypanosoma cruzi infection and the intracellular signals involved in the replication of this parasite in Mf. The data obtained from our works would allow the understanding of some mechanisms by which cells can be programmed to favor the establishment of chronic parasitic infections.