R. Felleisen et B. Gottstein, ECHINOCOCCUS-MULTILOCULARIS - MOLECULAR AND IMMUNOCHEMICAL CHARACTERIZATION OF DIAGNOSTIC ANTIGEN II 3-10/, Parasitology, 107, 1993, pp. 335-342
A recombinant Echinococcus multilocularis antigen (II/3-10), which had
previously been shown to exhibit immunodiagnostic characteristics hig
hly specific for human alveolar echinococcosis, and the corresponding
native parasite antigen, were further characterized with immunochemica
l and molecular biological methods. Immunoblot analysis using a polycl
onal antiserum raised in rabbits against the recombinant protein, and
subsequent Northern hybridization analysis, revealed that the native a
ntigen was expressed by E. multilocularis at the adult as well as at t
he metacestode stage. In metacestodes, the antigen was shown by using
indirect immunofluorescence and the same antiserum to be localized wit
hin the germinal layer and membrane structures of developing protoscol
ices. Electrophoretic analyses revealed remarkable differences in the
apparent molecular weight of the antigen under reducing and non-reduci
ng conditions. In further immunoblot analyses, anti-II/3-10 antibodies
identified the corresponding epitopes on bands with identical M(r) in
all E. multilocularis isolates investigated (European, Asian and Nort
h American). By Southern hybridization analyses of the respective gene
, phylogenetically related sequences were shown to be present in other
helminth species such as E. granulosus and several Taenia spp. In the
same respect, immunoblotting revealed that anti-II/3-10 antibodies re
acted with antigens of different Mr from various E. granulosus isolate
s and some other cestode species, indicating the presence of shared an
d thus potentially cross-reacting epitopes. The relevance of these fin
dings for the immunodiagnostic performance of the recombinant antigen
is discussed.