Among human and veterinary parasitic diseases the trematodiases (e.g. schistosomiasis, fascioliasis) represent a problem of global importance with vast social, economic and public health impacts, especially in developing countries. Therefore, host-parasite (host-trematode) interactions represent a key topic in many research laboratories, and modern approaches and technologies allow us to study the molecular basis of these interactions. As a consequence, key molecules produced by trematodes in order to ensure parasite invasion and survival within a hosts can be characterized. Trematode peptidases certainly belong to such molecules; as they are indispensable biocatalysts in a number of basal biological processes in trematodes (e.g. tissue invasion/migration, nutrition, immune evasion or other host-parasite interactions). Schistosoma mansoni cercarial elastase (CE) (penetration enzyme), cathepsin B (CB) (mainly nutrition enzyme) and Fasciola hepatica cathepsin L (CL) (nutrition, immune evasion enzyme) are probably the most studied trematode peptidases with well-characterized critical functions. Due to the importance of peptidases in host-parasite interactions they are considered to be promising targets for the development of novel chemotherapeutic drugs and vaccines against a number of trematodiases, including schistosomiasis, fascioliasis, paragonimiasis and opisthorchiasis. The present chapter summarizes the data on the biochemical and molecular features of the major trematode peptidases, and describes their role in trematode biology and host-parasite interactions based on proteolysis (peptidolysis).

Department of Parasitology Faculty of Science Charles University Prague Prague Czech Republic

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Winners vs. losers: Schistosoma mansoni intestinal and liver eggs exhibit striking differences in gene expression and immunogenicity

Blood-feeding adaptations and virome assessment of the poultry red mite Dermanyssus gallinae guided by RNA-seq

Transcriptomic and proteomic profiling of peptidase expression in Fasciola hepatica eggs developing at host's body temperature

Secreted cathepsin L-like peptidases are involved in the degradation of trapped antibodies on the surface of Echinostoma caproni

Molecular evidence for distinct modes of nutrient acquisition between visceral and neurotropic schistosomes of birds

Identification and partial characterization of a novel serpin from Eudiplozoon nipponicum (Monogenea, Polyopisthocotylea)

Cysteine peptidases of Eudiplozoon nipponicum: a broad repertoire of structurally assorted cathepsins L in contrast to the scarcity of cathepsins B in an invasive species of haematophagous monogenean of common carp

Excretion/secretion products from Schistosoma mansoni adults, eggs and schistosomula have unique peptidase specificity profiles

Comparative Transcriptomic Exploration Reveals Unique Molecular Adaptations of Neuropathogenic Trichobilharzia to Invade and Parasitize Its Avian Definitive Host

Trypsin- and Chymotrypsin-like serine proteases in schistosoma mansoni-- 'the undiscovered country'

Cercarial dermatitis, a neglected allergic disease

Secretory glands in cercaria of the neuropathogenic schistosome Trichobilharzia regenti - ultrastructural characterization, 3-D modelling, volume and pH estimations

Cathepsins B1 and B2 in the neuropathogenic schistosome Trichobilharzia regenti: distinct gene expression profiles and presumptive roles throughout the life cycle