Mosaic Qβ coats as a new presentation model

The new protein carrier was developed on the basis of recombinant RNA phage Qβ capsid. C-terminal UGA extension of the short form of Qβ coat, so-called A1 extension, served as a target for presentation of foreign peptides on the outer surface of mosaic Qβ 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 Qβ particles and ensured specific antigenicity and immunogenicity.