Immunolocalization of the fatty acid-binding protein Sj-FABPc within adult Schistosoma japonicum

This paper describes the first localization study of the 14.7 kDa fatty acid-binding protein in Schistosoma japonicum (Sj-FABPc) using transmission electron microscopy. A polyclonal antibody raised against recombinant Sj- FABPc was used in combination with a colloidal gold marker to determine the distribution of the protein within adult parasites. Sj-FABPc was localized within lipid droplets below the subtegumental region of the male parasite. Additionally, Sj-FABPc was present in the vitelline droplets of the vitelline glands of female parasites. There were no detectable levels of Sj-FABPc on the surface or within the tegument of male or female parasites. Possible functions of Sj-FABPc within S. japonicum and the relevance of these immunolocalization findings in light of the recent reports that the homologue Sm-FABPc is an important anti-S. mansoni vaccine target molecule are also discussed.