Modulation of the Immunogenic Characters of Protective Epitopes in Synthetic Vaccines

Abstract

Protective antigenic determinants can be mimicked by chemical synthesis. To become part of efficient vaccines B and T epitopes must be inserted in appropriate structures so as to elicit a strong, long lasting protective immune response. To achieve this goal synthetic peptides can be either linked to a carrier or, preferably associated within totally synthetic constructions. Adjuvants such as synthetic muramyl dipeptides can afford tools not only to enhance the level of the immune response but also to modulate its characters. These points will be illustrated using synthetic malarial vaccine models and a totally synthetic polyvalent vaccine containing B and T epitopes. Finally, a model of prevention against experimental allergic encephalomyelitis will be discussed to illustrate how the immunogenic characters of a synthetic antigen can be modulated by association with adjuvants or by suitable coupling.