Developmental expression of cathepsin D aspartic protease in Schistosoma japonicum

Boudicca , a Retrovirus-Like Long Terminal Repeat Retrotransposon from the Genome of the Human Blood Fluke Schistosoma mansoni

“…Negative control reactions were carried out with DNase-treated RNA as the template. Genomic DNA from adult S. mansoni was used as the positive control (64).…”

Cellular responses to Schistosoma japonicum cathepsin D aspartic protease

“…SWA and SEA were prepared from homogenized, ultracentrifuged S. japonicum (Philippine strain) worms and eggs, respectively, as previously described (9). Two recombinant forms of S. japonicum cathepsin D aspartic protease, bacterially expressed r Sj ASP1 (9) and baculovirus‐expressed r Sj ASP2 (6), were used as antigens for immunization, and in order to retain consistency, the immunization regime used in our previous vaccination experiments (8) was reproduced. Female CBA mice (6–8 weeks old, four mice per group) were immunized s.c. in the abdomen on days 0, 14 and 56 with 15 µg of r Sj ASP1 in phosphate‐buffered saline (PBS) (group 1), 15 µg of r Sj ASP2 in PBS (group 2) or PBS (group 3), all containing 15 µg of the adjuvant Quil A (Superfos Biosector a/s, Vedbaek, Denmark).…”

“…In the present study, we examined aspects of the cell‐mediated immune responses in mice vaccinated (but not subsequently challenged) with two recombinant forms of the S. japonicum cathepsin D aspartic protease, r Sj ASP1, an enzymatically inactive form produced in Escherichia coli (9) and r Sj ASP2, an enzymatically active form secreted by insect cells, involving a baculovirus expression system (6). Splenocytes from vaccinated mice were tested for their ability to proliferate and release cytokines in response to r Sj ASP1 and r Sj ASP2, and comparisons were made to soluble schistosome worm antigen (SWA) and egg antigen (SEA).…”

Genomic organization of the Schistosoma mansoni aspartic protease gene, a platyhelminth orthologue of mammalian lysosomal cathepsin D

“…While the presence of cathepsin D transcripts noted in other developmental stages indicates additional roles for this enzyme in the physiology of the schistosome (Verity et al, 1999;Hu et al, 2003), overexpression within the gut tissue of adult female schistosomes demonstrates that a primary function of this enzyme is in hemoglobin digestion (BrindFig. 4.…”