1Wahby A. F., 1El-Hakim A. M. and 2Saad A. H.
1Department of Molecular Biology National Research
Center, Cairo Egypt, 2Department of Zoology Faculty of Science Cairo
University.
The
immunological relationship and cross reactivity of the venoms from Naja
haje, Pseudocerastes fieldi, Echis coloratus, Cerastes cerastes and the
antisera raised against these venoms, were investigated using different assays.
All the venoms contain highly antigenic and immunogenic proteins, which are
quite different with respect to the number of bands and molecular weights. The
immobilized venoms binds all the antivenom antibodies from the corresponding
antisera and different proportions (20% to 76.7%) of antibodies from the
heterologous antivenoms. Each of the venoms contained characteristic
antigen(s), and others of shared identity with the non-homologous venoms. The
antigenicity of venoms was greatly altered by reduction, indicating that both
continuous and discontinuous epitopes were involved in the cross-reactions. The
results demonstrated a high degree of immunological relationship among the
venom components of the different species, and the presence of species specific
antigens. The in vitro hemolytic activity of venoms was inhibited
by the heterologous antivenoms, suggesting that the venom hemolytic factor(s)
have shared epitopes. Also, a new mode for graphic representation of the
neutralization data was used to compare the antigenicity of the hemolytic
factor(s). The derived quantitative data revealed that the hemolytic factor(s)
share most of their antigenicity. The data explored the importance of the
non-shared factors as immunogens.