Cysteine peptidases in pathogenesis

Abstract

Entamoeba histolytica is characterized by its extraordinary capacity to invade and destroy human tissues. The main lytic activity has been attributed to cysteine peptidases, and a number of studies have shown that cysteine peptidases constitute major pathogenicity factors in E. histolytica. Interestingly, although most of the classes of peptidases are present in E. histolytica, only cysteine peptidases, and on a lesser scale, metallo-peptidases and serine peptidases, have been adequately studied. In this chapter, the peptidase families of E. histolytica are introduced, and their involvement in colonic invasion and in liver abscess formation are discussed.