Identification of the immunogenic epitopes of the whole venom component of the Hemiscorpius lepturus scorpion using the phage display peptide library.

The venom of the Hemiscorpius lepturus scorpion contains mixtures of bioactive compounds that disturb biochemical and physiological functions of the victims. Hemiscorpius lepturus envenomation is recognized as a serious health concern in tropical regions. So far, there is no preventive procedure, and the main focus is on treatment of victims with an antiserum purified from hyper-immunized horses. Although antisera can neutralize the venom, they, in some cases, lead to anaphylactic shock and even death. Selection of peptides mimicking antigenic and immunogenic epitopes of toxins from random peptide libraries is a novel approach for the development of recombinant toxins and poly-epitopic vaccine. To achieve this aim, a phage display peptide library and three rounds of biopanning were performed on immobilized antibodies (IgGs) purified from the sera of hyper-immunized horses. The results show that the highest binding of the phage to immobilized horse antibodies occurred in the third round of biopanning. Over 125 individual clones carrying mimotopes of Hemiscorpius lepturus toxins were selected and subjected for sequencing. The sequencing results identified unique peptides mimicking the antigenic and immunogenic epitopes of Hemiscorpius lepturus toxins. The results of this study provide a basis for further studies and the development of a putative epitopic vaccine and a recombinant toxin.