A study was undertaken to search for DNA recombinant
Schistosoma mansoni
proteins responsible for eliciting an antibody response from the host at
a very early phase after infection. A
S. mansoni
adult worm cDNA expression library was screened using pooled sera from baboons
with four weeks of infection. Based on their specific reactivity with the
S. mansoni
infected sera and no reactivity when tested against the pre-infection sera
from the same baboons, four clones were selected for further studies. Sequence
analysis revealed that they were homologous to the
S. mansoni
heat shock protein 70 (hsp70). The insert sizes of the four selected clones
varied from 1150 to 2006 bp. The preliminary characterization for antibody
reactivity against a panel of baboon sera showed that the longest clone
was the most reactive, eight out of eight acute and three out of four chronic
sera reacting positively to this clone. The shortest clone was the least
reactive. Our results suggest that the
S. mansoni
hsp70 elicits an early and strong antibody response in baboons and that
antibodies to this protein can be detected in chronically infected animals.
Therefore
S. mansoni
hsp70 may be a valid target for immunodiagnosis. However further studies
are needed to identify the portion of the hsp70 that best fits the requirements
for a valuable diagnostic antigen.
