Unique antigenic gene expression at different developmental stages of Trichinella pseudospiralis
Résumé
Parasite-induced and parasite-regulated larval capsule formation and host immunosuppression
are two major characteristics that are unique in Trichinella spp. infections, but
the molecule(s) and mechanism(s) that mediate these processes remain largely unknown.
Trichinella pseudospiralis and Trichinella spiralis, are obviously different with respect to these
two characteristics. A comparative study of these two species, in particular their antigen
expression profiles at different developmental stages (the main molecules involved in the
cross-talk or interaction between each parasite and its host), may help us better understand
the parasite molecules and mechanisms involved. Here, we constructed cDNA libraries
from T. pseudospiralis adults (Ad), newborn larvae (NBL) and muscle larvae (ML) mRNA
and screened them with pig anti-T. pseudospiralis serum collected 26, 32 and 60 days postinfection
(p.i.). The most abundant antigens were found to vary among life-cycle stages.
Pyroglutamy peptidase 1-like and 6-phosphogluconolactonase-like genes predominated
in the Ad stage and a serine protease (SS2-1-like gene) predominated in NBL similar to that
observed in T. spiralis. Muscle larvae expressed proteasome activator complex subunit 3-
like and 21 kDa excretory/secretory protein-like genes. This study indicated that parasites
of two species may utilise different molecules and mechanisms for larvae capsule formation
and host immunosuppression during their infections. Proteins of antigenic genes identified
in this study may be also good candidates for diagnosis, treatment or vaccination for T.
pseudospiralis infection, and also for the differential diagnosis of two species’ infections.