Using differential gene expression to study Entamoeba histolytica pathogenesis

Abstract

The release of the Entamoeba histolytica genome has facilitated the development of techniques to survey rapidly and to relate gene expression with biology. The association and potential contribution of differential gene expression to the life cycle and the virulence of this protozoan parasite of humans are reviewed here.

Figure 1

Pathogenesis of amebiasis. The clinical manifestations of amebiasis are the result of interactions of the parasite, host and environment. These include, for example, parasite genotypes that differ in virulence, human leukocyte antigen system Dr/Dq alleles that are associated with resistance to infection and environmental exposure to the parasite. Topics that are covered in this review are shown in black (Figure 1b).

Figure 2

Comparison of mRNA-expression data from two Entamoeba histolytica isolates. The Rahman strain was isolated from an individual who was colonized and HM1:IMSS was cultured from the rectal biopsy of a patient with amebic colitis. Differences in transcripts encoding proteins involved in oxygen detoxification and virulence were observed.

Figure 3

Comparison of in vivo and in vitro mRNA-expression data for Entamoeba histolytica. Experimental models of amebic liver abscess and colitis have facilitated the identification of transcripts expressed in E. histolytica during colonization and invasion.

Figure 4

Comparison of Entamoeba histolytica mRNA expression in trophozoites and cysts. Measurements of changes in gene expression as the parasite transforms from a trophozoite to a cyst have identified several cyst-specific genes.

Figure 5

Impact of epigenetic regulation of gene expression on virulence. Still unknown is the role of the histone code, DNA methylation and other epigenetic mechanisms in control of virulence.