Abstract

Fasciola gigantica cathepsin B belongs to a family of cysteine proteases which is involved in invasion of host tissues. In this study, the recombinant cathepsin B2 (rFgCatB2), synthesized in Pichia pastoris, showed enzymatic activity on a fluorometric substrate Z-Phe-Arg-AMC and gelatin. Furthermore, this recombinant enzyme could degrade IgG and type I collagen. Mouse antiserum against rFgCatB2 reacted with the native FgCatB2 in whole body (WB) extracts of metacercariae (MET), newly excysted juveniles (NEJ) and 2week-old juveniles, but not in 3, 4 week-old juveniles and adult flukes. Immunolocalization showed the presence of cathepsin B2 only in the caecal epithelium of MET, NEJ and 2 week-old juveniles. Co-localization of FgCatB2 and a prominent antigen of NEJ, FgCatB3, revealed that these proteins were expressed at the same regions in the caecal epithelium. Anti-rFgCatB2 showed no cross reaction with the other parasites' antigens by Western blotting. These findings suggest that CatB2 is expressed only in early stages of the parasite and may be involved in digestion of host connective tissues and evasion of the host immune system during their penetration and migration. Thus, CatB2 could be considered as an immunodiagnostic and vaccine candidate for fasciolosis.

Links

Publisher Full Text

Authors

Chantree P, Wanichanon C, Phatsara M, Meemon K, Sobhon P

Institution

Department of Anatomy, Mahidol University, Bangkok 10400, Thailand.

Source

Experimental parasitology 132:2 2012 Oct pg 249-56

MeSH

Animals
Antigens, Helminth
Blotting, Western
Cathepsin B
Cattle
Cecum
Cricetinae
Cross Reactions
Electrophoresis, Polyacrylamide Gel
Fasciola
Fluorescent Antibody Technique
Gene Expression Regulation, Enzymologic
Lymnaea
Mesocricetus
Metacercariae
Mice
Mice, Inbred ICR
Microscopy, Confocal
Pichia
Recombinant Proteins

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22885402