Immunomodulating activity of 1,2-difattyacyl-3-mercaptoglycerol adducts

Adducts of 1,2-diacyl-(2RS)-3-mercaptoglycerol to 3-maleimidopropionic acid and to 3-maleimidopropionyl-L-alanyl-D-isoglutamine as well as a new lipophilic MTP derivative have been analysed for their immunomodulating activity in comparison to the well known adjuvants CFA and IFA using a suboptimal concentration of BSA as antigen. A concentration-dependent immunostimulating activity was established for these lipophilic molecules when applied in water/oil (IFA) emulsions. The results clearly indicate that the new series of compounds behave as competent adjuvants, a fact which is further supported by the immunoadjuvant effect triggered by two of these diacylthioglyceryl adducts as examples, even when applied in aqueous systems. In the light of these findings it seems promising to use these thiol-functionalized molecules to build in immunoadjuvancy via the maleimide-thiol reaction principle. Attachment of such "sticky fingers" to peptides might enhance interaction of haptens and immunogens with cell membranes and thus, may represent a useful tool for inducing or increasing immunological responses to synthetic antigen presenting systems.