Toxoplasma gondii Triggers Release of Human and Mouse Neutrophil Extracellular Traps

Infect Immun. 2011 Nov 21. [Epub ahead of print]

Toxoplasma gondii Triggers Release of Human and Mouse Neutrophil Extracellular Traps.

Abi Abdallah DS, Lin C, Ball CJ, King MR, Duhamel GE, Denkers EY.

SourceDepartment of Microbiology and Immunology.

Abstract
Neutrophils have recently been shown to release DNA-based extracellular traps that contribute to microbicidal killing and have also been implicated in autoimmunity. The role of neutrophil extracellular trap (NET) formation in the host response to nonbacterial pathogens has received much less attention. Here, we show that the protozoan pathogen Toxoplasma gondii elicits production of NETs from human and mouse neutrophils. Tachyzoites of each of the three major parasite strain types were efficiently entrapped within NETs, resulting in decreased parasite viability. We also show that Toxoplasma activates a MEK-ERK pathway in neutrophils and that inhibition of this pathway leads to decreased NET formation. To determine if Toxoplasma induced NET formation in vivo we employed a mouse intranasal infection model. We found that administration of tachyzoites by this route induced rapid tissue recruitment of neutrophils with evidence of extracellular DNA release. Taken together, these data indicate a role for NETs in the host innate response to protozoan infection. We propose that NET formation limits infection by direct microbicidal effects on Toxoplasma as well as by interfering with the ability of the parasite to invade target host cells.

PMID:22104111[PubMed - as supplied by publisher]