Detoxome Capacity of the Adult Rumen Fluke Calicophoron daubneyi Extends into Its Secreted Extracellular Vesicles

TL;DR

The study explores the detoxification enzymes in the rumen fluke Calicophoron daubneyi, including those in its extracellular vesicles, to better understand its resistance to drugs.

Contribution

This is the first study to characterize the detoxome of Calicophoron daubneyi, including extracellular vesicle enzyme profiles.

Findings

Transcriptome analysis identified Phase I and II xenobiotic metabolizing enzymes in C. daubneyi.

Six GST isoforms were identified in adult rumen fluke, with additional variants found through global proteomics.

Extracellular vesicles of C. daubneyi contain a similar GST profile but lack some isoforms and include a sulfotransferase.

Abstract

Helminth parasites
have long adapted to survive hostile host environments
and can likely adapt against the chemical anthelmintic challenge.
One proposed adaptation route is via Phase I and II xenobiotic metabolizing
enzymes (XMEs). For successful Helminth pharmacotherapy discovery
programs, a working understanding of Helminth-derived chemical detoxification,
the Helminth detoxome, is a must. At present, the detoxome of a newly
emerging Helminth parasite, the rumen fluke Calicophoron
daubneyi, remains unexplored. Thus, a combined bioinformatics,
sub-, and global-proteomic approach has been employed to examine the
detoxome of adult C. daubneyi. Transcriptome
analysis revealed a complement of Phase I (cytochrome P450s and monoamine
oxygenases) and Phase II (glutathione transferases [GSTs] and sulfotransferases)
XMEs. Affinity-led subproteomic exploration of the GSTs revealed six
GST isoforms in adult rumen fluke (CdGST-Mu1-2, S1, and S3–5),
with global approaches identifying additional GSTs (CdGST-O1-2, Z1,
and S2) and a unique egg-specific variant (CdGST-S6). Examination
of C. daubneyi extracellular vesicles
revealed a GST profile replicating that of the adult with the absence
of two isoforms (CdGST-S2 and S4), with an additional identification
of a sulfotransferase. These data represent the first exploration
into the complete rumen fluke detoxification capacity and will provide
direction for future anthelmintic discovery programs.

Figures