Antisense inhibition of expression of cysteine proteinases does not affect <i>Entamoeba histolytica</i> cytopathic or haemolytic activity but inhibits phagocytosis

Abstract

Inhibition of most of the expression of the cysteine proteinases of Entamoeba histolytica strain HM-1:IMSS was successfully performed by transcription of ehcp5 antisense RNA using the promoter of ehg34, which encodes a L21 ribosomal protein of E. histolytica. We have generated a stable transfectant in which the overall level of cysteine proteinase activity is strongly reduced ( 90%). This transfectant has a normal growth rate in Diamond's TYI-S-33 medium, a cytopathic and haemolytic activity similar to the control HM-1:IMSS pEhAct-Neo transfectant but with a significantly lower phagocytic activity.