Modulation of early ?-defensin-2 production as a mechanism developed by type I Toxoplasma gondii to evade human intestinal immunity.

ABSTRACT: We investigated the early innate immune responses induced in human intestinal epithelial cells (IEC) by the three defined Toxoplasma gondii genotype strains. Transcriptome analysis revealed that among differentially expressed genes, ?-defensins distinguished the most IEC infected by fast- or slow-replicating T. gondii genotypes. Although ?-defensin 1 and 3 genes were not expressed in host cells at early time points postinfection, the slow-replicating type II and III parasites induced high levels of ?-defensin 2 gene expression. Notably, no ?-defensin 2 gene expression occurred early after infection with the fast-replicating type I parasite. However, activation of this gene in IEC by poly(I:C) treatment prior to infection substantially decreased parasite viability, and pretreatment of parasites with synthetic ?-defensin 2 significantly reduced their infectivity of IEC. These findings strongly support the modulation of early ?-defensin 2 expression as a mechanism used by type I T. gondii parasites to mediate immune evasion.

SUBMITTER: Morampudi V 

PROVIDER: S-EPMC3088155 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature