Bacterial cell wall components as immunomodulators--I. Lipopeptides as adjuvants for parenteral and oral immunization.

We investigated the immunostimulatory properties of synthetically prepared lipopeptides derived from the cell wall of Gram negative bacteria. These compounds constitute potent macrophage activators and polyclonal B-lymphocyte stimulators. They are also immunoadjuvants in parenteral or oral immunization. By coupling the lipopeptides to haptens or low molecular weight antigens which are not immunogenic per se, highly immunogenic conjugates can be prepared. Lipopeptide antigen conjugates as synthetic vaccines give protection by enhancing the antibody-mediated immune response, and they stimulate the cellular immune response in vivo by priming of cytotoxic T-cells.