<it>Toxoplasma gondii </it>peroxiredoxin promotes altered macrophage function, caspase-1-dependent IL-1β secretion enhances parasite replication

• Main Authors: Marshall Edward S, Elshekiha Hany M, Hakimi Mohamed-Ali, Flynn Robin J
• Format: Article
• Language: English
• Published: BMC 2011-06-01
• Series: Veterinary Research
• Online Access: http://www.veterinaryresearch.org/content/42/1/80
• ISSN: 0928-4249; 1297-9716

<p>Abstract</p> <p>Alternatively activated macrophages (AAM) are a key feature Th2 immunity and have been associated with a variety of roles during helminth infection. The role this cell subset plays in protzoan infection remain relatively unexplored, herein we describe the effects of a redox enzyme (rTgPrx) derived from <it>Toxoplasma gondii </it>on murine macrophage phenotype in vitro. RTgPrx has been previously associated with the maintainence of parasite oxidative balance. Here our experiments show that rTgPrx promotes AAM as indicated by high arginase-1 (arg-1), YM1 and FIZZ expression via both signal transducer and activator of transcription (STAT)6-dependent and -independent mechanisms. Additionally rTgPrx treatment reduced caspase-1 activity and IL-1β secretion, while simultaneously increasing IL-10 release. Furthermore the in vitro replication of <it>T. gondii </it>(RH strain) was enhanced when macrophages were treated with rTgPrx. This is in contrast with the previously described effects of a <it>Plasmodium berghei </it>ANKA 2-cys-peroxiredoxin that promotes pro-inflammatory cytokine production. These results highlight the role of <it>T. gondii </it>derived redox enzymes as important immune modulators and potentially indicate a role for AAM in modulating immunopathology and promoting parasite replication during <it>T. gondii </it>infection.</p>