BIOLOGICAL STUDIES OF LIPOPHILIC MDP-DERIVATIVES INCORPORATED IN LIPOSOMES

Adjuvant activities of fatty acid derivatives of N-acetyl-muramyl-L-alanyl-D-isoglutamine (MDP) in saline, emulsified in Incomplete Freund Adjuvant (IFA) or incorporated in liposomes were compared. All derivatives were active when given in saline. The potency of MDP-L-Ala-glycerol mycolate was highly enhanced by administration in IFA or after incorporation in liposomes. These procedures had no effect on the activity of MDP-α-methyl-α-n-butyl ester and MDP-α-methyl-α-n-decyl ester although the presence of MDP could be demonstrated at the surface of the liposomes by anti-MDP antibodies.