Tesis Doctorado
Calreticulina de echinococcus granulosus: caracterización molecular y localización en quistes hidatídicos
Autor
Cabezón-Barra, Carolina Andrea
Institución
Resumen
Hydatidosis is one of the most important world-wide zoonosis, representing a parasitism
caused by the flatworm Echinococcus granulosus (E. granulosus). In intermediate hosis, man and
domestic animais, the parasite forms hydatid cysts, presenting an interna] cellular layer. the
germinal layer. From this structure protoscoleces. infective forms of the parasite for the definitive
host (usually canine) are generated. Two types of cysts are described: fertile (producing
protoscoleces) and infertile (which do not produce protoscoleces and therefore. are not able lo
continue the biological cycle of the parasite).
Calreticulin (CRT) is a calcium-binding protein. highly conserved and multifurictionaL it
is preseni in ah celis of higher organisms, except erythrocytes. In this thesis. two DNA clones
containing a partial coding sequence of E. granulosus CRT (EgCRT) were isolated and
characterized. In addition we studied EgCRT in hydatid cysts germinal la yer and in protoscoleces
at the transcripcional and translational leveis. EgCRT was identified using an antibody prepared
against recombinant CRT from Taenia solium (T solium), which presents 90% identity with the
deduced amino acid sequence of EgCRT. Finall y, we analyzed the EgCRT location in hydatid
cyst tissues by immunofluoresce, and its topologic relation with host IgGs.
Our results indicate that mRNA levels were similar in protoscoleces. fertile and infertile
germinal layers. EgCRT was found iii two forrns one of -50-kDa and another of-8O-kDa. l'he
latter may correspond to post-trascriptional processing. or to a dimeric forrn of CRT. EgCRT is
located in protoscoleces, and in the fertile and infertile germinal layers. mainly in cytoplasmic
and perinuchear zones. In addition to EgCRT. host's IgGs were found in ihe germinal ¡ayer of
hydatid cysts.
This is the first report on the presence and characterization of CRT iii E. granulosus.
providing information relevant for the study of the role of EgCRT in E. granu/osus physiology
and in host-parasite interactions. PFCHA-Becas Doctor en Ciencias Silvoagropecuarias y Veterinarias 80 p. PFCHA-Becas TERMINADA