Homologous cysteine proteinases of pathogenic and nonpathogenic Entamoeba histolytica. Differences in structure and expression.

Adherence and Cytotoxicity of Entamoeba histolytica or How Lectins Let Parasites Stick Around

“…Proteolytic activities of E. histolytica are believed to be involved in damage of cells and the extracellular matrix of the host. Secreted amebic cysteine proteases cause a cytopathic (as opposed to cytotoxic) effect manifested by cells being released from monolayers in vitro without cell death (24,45,57). Expression of a secreted amebic 56-kDa cysteine proteinase has been correlated with the potential of clinical isolates of E. histolytica to produce invasive disease, because the cysteine proteinase was identified by gelatin substrate gel electrophoresis in 10 of 10 isolates from patients with colitis or amebic liver abscesses but in only I of 10 isolates from asymptomatic patients (44).…”