Antisense inhibition of expression of cysteine proteinases affects Entamoeba histolytica-induced formation of liver abscess in hamsters

Abstract

Trophozoites of virulent Entamoeba histolytica transfected with the antisense gene encoding cysteine proteinase 5 (CP5) have only 10% of the CP activity but retain their cytopathic activity on mammalian monolayers. In the present study we found that the transfected trophozoites with low levels of CP activity were incapable of inducing the formation of liver lesions in hamsters.

FIG. 1

Restriction analysis of plasmid rescued in E. coli XL1-blue from pEhAct-Neo- and pSA8-transfected trophozoites isolated from liver abscess. Plasmid preparations were digested by restriction enzymes (XhoI-SalI) and size fractionated on agarose gels. Lanes: 1, plasmid pEhAct-Neo; 2, plasmid pSA8; 3, plasmid rescued from pEhAct-Neo transfectant isolated from liver abscess; 4, plasmid rescued from pSA8 transfectant isolated from liver abscess; 5, plasmid rescued from pEhAct-Neo transfectant cultivated in TYI-S-33 medium for 2 weeks in the absence of G418; and 6, plasmid rescued from pSA8 transfectant cultivated in TYI-S-33 medium for 2 weeks in the absence of G418.