Mosaic Qbeta coats as a new presentation model.

The new protein carrier was developed on the basis of recombinant RNA phage Qbeta capsid. C-terminal UGA extension of the short form of Qbeta coat, so-called A1 extension, served as a target for presentation of foreign peptides on the outer surface of mosaic Qbeta particles. In conditions of enhanced UGA suppression, the proportion of A1-extended to short coats in mosaic particles dropped from 48% to 14%, with an increase of the length of A1 extension. A model insertion, short preS1 epitope 31-DPAFR-35 of hepatitis B surface antigen, demonstrated superficial location on the mosaic Qbeta particles and ensured specific antigenicity and immunogenicity.