Induction of immunity in sheep toFasciola hepaticawith mimotopes of cathepsin L selected from a phage display library

Abstract

An M13 phage random 12-mers peptide library was used to screen cathepsin L mimotopes of Fasciola hepatica and to evaluate their immunogenicity in sheep. Seven clones showed positive reactivity to a rabbit anti-cathepsin L1/L2 antiserum in ELISA, and their amino acid sequences deduced by DNA sequencing were tentatively mapped on the protein. Twenty sheep were randomly allocated into 4 groups of 5 animals each, for immunization with 1x10(14) phage particles of clones 1, 20, a mixture of 7 clones and PBS, without adjuvant at the beginning, and 4 weeks later. All groups were challenged with 300 metacercariae at week 6 and slaughtered 16 weeks later. The mean worm burdens after challenge were reduced by 47.61% and 33.91% in sheep vaccinated with clones 1 and 20, respectively; no effect was observed in animals inoculated with the clone mixture. Also, a significant reduction in worm size and burden was observed for those sheep immunized with clone 1. Animals receiving clone 20, showed a significant reduction in egg output. Immunization induced a reduction of egg viability ranging from 58.92 to 82.11%. Furthermore, vaccinated animals produced clone-specific antibodies which were boosted after challenge with metacercariae of F. hepatica.

Proteases in Blood-Feeding Nematodes and Their Potential as Vaccine Candidates

“…Lambs vaccinated with some individual clones and some mixtures had reduced worm burdens and egg outputs compared to controls indicating that the approach may provide an alternative method for vaccine production. 95 Perhaps the biggest technological shift impacting on helminth protease discovery DQG IXQFWLRQDO GH¿QLWLRQ LV WKH UDSLG DGYDQFH LQ JHQRPH VHTXHQFLQJ WHFKQRORJLHV )RU the blood-feeding nematodes, sequencing initiatives have already revealed numerous, previously uncharacterized proteases. Bioinformatics analyses can be used to predict function and whether or not a protease is likely to be secreted but a key issue, in terms of identifying control targets, is whether the protease is essential for parasite survival.…”

Proteolytic activity inFasciola hepaticais reduced by the administration of cathepsin L mimotopes

“…The phage library was subjected to affinity selection using a rabbit anti-cathepsin L1/L2 antiserum in enzyme-linked immunosorbent assay (ELISA). Phage was amplified and titrated, and DNA sequencing was performed using procedures described previously by Villa-Mancera et al (2008).…”

Triosephosphate isomerase of Taenia solium (TTPI): phage display and antibodies as tools for finding target regions to inhibit catalytic activity

“…The most important feature lies in developing vaccines and efforts to obtain effective therapies for pathogens, such as Plasmodium vivax (Demangel et al 1998), Sc. mansoni (Arnon et al 2000), Cryptococcus neoformans (Fleuridor et al 2001), P. falciparum (Casey et al 2004;Sabo et al 2007), Fasciola hepatica (Villa-Mancera et al 2008, 2011, Streptococcus pneumonia (Smith et al 2009), Toxoplasma gondii (Cunha-Júnior et al 2010), and Helicobacter pylori (Li et al 2010).…”