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Arginase and polyamine synthesis are key factors in the regulation of experimental leishmaniasis in vivo
Author(s) -
Kropf Pascale,
Fuentes José M.,
Fähnrich Eva,
Arpa Luis,
Herath Shanthi,
Weber Verena,
Soler German,
Celada Antonio,
Modolell Manuel,
Müller Ingrid
Publication year - 2005
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.04-3416fje
Subject(s) - arginase , ornithine , in vivo , polyamine , leishmania , catabolism , arginine , downregulation and upregulation , biology , microbiology and biotechnology , enzyme , immunology , chemistry , biochemistry , parasite hosting , amino acid , world wide web , computer science , gene
Arginase 1, an enzyme induced by Th2 cytokines, is a hallmark of alternatively activated macrophages and is responsible for the hydrolysis of l ‐arginine into ornithine, the building block for the production of polyamines. Upregulation of arginase 1 has been observed in a variety of diseases, but the mechanisms by which arginase contributes to pathology are not well understood. We reveal here a unique role for arginase 1 in the pathogenesis of nonhealing leishmaniasis, a prototype Th2 disease, and demonstrate that the activity of this enzyme promotes pathology and uncontrolled growth of Leishmania parasites in vivo. Inhibition of arginase activity during the course of infection has a clear therapeutic effect, as evidenced by markedly reduced pathology and efficient control of parasite replication. Despite the clear amelioration of the disease, this treatment does not alter the Th2 response. To address the underlying mechanisms, the arginase‐induced l ‐arginine catabolism was investigated and the results demonstrate that arginase regulates parasite growth directly by affecting the polyamine synthesis in macrophages.