POTENT IMMUNOGENIC SHORT LINEAR PEPTIDE CONSTRUCTS COMPOSED OF B-CELLEPITOPES AND PAN DR T-HELPER EPITOPES (PADRE) FOR ANTIBODY-RESPONSES IN-VIVO

Induction of humoral immune responses against protein antigen requires that two independent signals be delivered to B cells. It is currently assumed that simple monovalent synthetic peptides would not be effect ive immunogens for antibody responses because they would not be antici pated to effectively generate the necessary signals unless conjugated to a complex carrier system. In this study, the immunogenicity;of shor t linear peptide constructs comprising Plasmodium vivax B cell epitope s (PVB) and non-natural Pan-DR T helper cell epitopes (PADRE) was asse ssed in mice and compared to other types of antigen constructs. The 33 -residue PADRE-PVB linear constructs were highly immunogenic and induc ed responses comparable to those obtained with the multiple antigen pe ptides (MAP) constructs, both in terms of absolute titers and quality of antibody responses. The anti-PVB antibody responses were of long du ration, composed mostly of IgG and reactive with intact sporozoites. T he PADRE-PVB constructs were immunogenic when formulated in adjuvants such as Alum and Montanide ISA 51 underlining the relevance of these f indings for vaccine development. (C) 1997 Elsevier Science Ltd.