Rotavirus particles function as immunological carriers for the delivery of peptides from infectious agents and...

A major problem in the development of useful animal subunit vaccines has been the generation of immune responses to weakly immunogenic molecules. For this purpose a new and effective delivery system has been devised. This system is based upon the inner capsid of bovine rotavirus. Under the appropriate conditions, the inner capsid protein, designated BP6, can be made to self-assemble in vitro and form spherical particles. These particles possess an inherent capacity to target to cells of the immune system. Exploitation of these properties has led to the development of technology to couple antigens to the VP6 particles such that the sphere acts as a novel immunological carrier. This is based on a "binding peptide" derived from another rotavirus peptide, VP4, as well as on more traditional techniques of chemical coupling. We have coupled peptides or proteins to this carrier via the binding peptide and have shown that every epitope tested to date gave excellent immune responses. Furthermore, using this carrier, immunity has been developed without the use of adjuvants. This has far-reaching implications for animal and human immunization.