L. Quijada et al., DURING CANINE VISCERO-CUTANEOUS LEISHMANIASIS THE ANTI-HSP70 ANTIBODIES ARE SPECIFICALLY ELICITED BY THE PARASITE PROTEIN, Parasitology, 112, 1996, pp. 277-284
A Leishmania infantum cDNA library was screened with sera from dogs wi
th viscero-cutaneous leishmaniasis. Sequence analysis of a positive cl
one isolated from the library revealed that it coded for the carboxyl-
terminal region of a member of the 50-kDa heat-shock protein family. T
he full-length sequence of the L. infantum hsp70 gene was determined a
fter isolation of genomic clones. This protein shows a high degree of
sequence conservation with the homologous protein from other organisms
. To test its antigenicity a recombinant Hsp70 protein fused to the ma
ltose-binding protein was produced in Escherichia coli using the expre
ssion vector pMAL-cRI. By FAST-ELISA assays it was observed that while
the complete recombinant protein was recognized by 100% of the sera,
the 20 carboxyl-terminal amino acids of the protein were only recogniz
ed by 30% of those sera. Thus, although a B-cell epitope must be prese
nt within the carboxyl terminal end of the protein other antigenic det
erminant(s) must reside out of this region. The analysis of the cross-
reactivity with mouse Hsp70 by Western blotting strongly suggests that
the anti-Hsp70 antibodies generated by infection with L. infantum are
directed at specific determinants of the L. infantum Hsp70. Thus, our
results indicate that anti-Hsp70 autoantibodies are not induced durin
g Leishmania infection.