Lipid-specific antibodies elicited with synthetic lipid conjugates

Abstract

Antibodies with specificity towards two groups of naturally occurring lipids, namely, cytolipin H and sphingomyelins, respectively, have been elicited by immunization of rabbits with synthetically prepared antigens. The corresponding antigens were conjugates consisting of copolymers of amino acids used as carriers, onto which synthetic lipid compounds were attached. Lactosyl sphingosine was the hapten used for eliciting anticytolipin H response, whereas either sphingosylphosphorylcholine (SPC) or ceramidephosphorylethanolamine (CPL) were used for provoking antisphingomyelin antobodies. The specificity of the antibodies was established, using several immunological techniques, by the cross-reactions with heterologous antigens containing similar haptenic groups, and by inhibition of the homologous antigen-antibody reactions by means of related lipid compounds. The contribution of both the sugar part and other parts of the lipid molecule to the immunological specificity were thus established. The resulting antibodies are capable of reacting with the corresponding lipid moiety present in biological membranes.