Bacterial lipopeptides constitute efficient novel immunogens and adjuvants in parenteral and oral immunization.

Synthetic lipopeptide analogues derived from the N-terminus of bacterial lipoprotein constitute potent B-lymphocyte and macrophage/monocyte activators in vitro. In vivo they act as immunoadjuvants in parenteral and oral immunization when administered in combination with antigens. When added to bacterial or viral vaccines, lipopeptides markedly enhance the vaccine effect. After the coupling of lipopeptides to haptens or non immunogenic low molecular mass antigens, a specific antibody response is induced often after only one application of the conjugate. The response can be further enhanced by introducing haplotype specific T helper cell epitopes into the conjugate. Lipopeptide antigen conjugates can also be applied as synthetic vaccines that give protection e.g. against foot-and-mouth-disease. The novel chemically well defined lipopeptides described here can be synthesized in gram amounts with high purity and reproducibility; they are non-toxic and can be stored for long time even at room temperature. For veterinary application, by replacing Freund's adjuvant, side reactions and inflammatory processes are avoided.