MAPPING OF LINEAR B-CELL EPITOPES ON THE 14-KDA FATTY-ACID-BINDING PROTEIN OF CHINESE SCHISTOSOMA-JAPONICUM

The 14-kDa fatty-acid binding protein (FABP) of schistosomes is of rec ognised importance as a potential vaccine and/or drug target against s chistosomiasis, but little is known of its antigenicity. In this study we have identified and compared linear B-cell epitopes present on the FABP of Chinese strain Schistosoma japonicum, using sera obtained fro m experimentally infected mice, or from mice immunised with the functi onally active recombinant antigen (rSjFABP). Sera from three strains o f mice, CBA, C57BL/6 and BALB/c, representing different genetic backgr ounds, were reacted with a series of overlapping peptides in epitope-s canning studies. Sera from experimentally infected mice reacted predom inantly with peptides 9-12, encoding amino acids 91-132, in the C-term inal region of the molecule. This was in contrast to sera from mice im munised with rSjFABP, which reacted predominantly with peptides 4-9, e ncoding amino acids 41-101, in the central portion of the molecule. Th e results presented here describing the epitope mapping of this molecu le may prove important in research aimed at further defining immune re sponses to schistosomal antigens. They indicate that epitopes recognis ed during vaccination with functionally active rSjFABP, at least in th e murine model, differ from those recognised during natural infection. (C) 1998 Australian Society for Parasitology. Published by Elsevier S cience Ltd.