Transfer of Anti-Rotavirus Antibodies during Pregnancy and in Milk Following Maternal Vaccination with a Herpes Simplex Virus Type-1 Amplicon Vector

Meier, Anita F.; Suter, Mark; Schraner, Elisabeth M.; Humbel, Bruno M.; Tobler, Kurt; Ackermann, Mathias; Laimbacher, Andrea S.

The mature infectious RV particles are non-enveloped, triple-layered capsids composed of the structural proteins VP2, forming the inner most shell, VP6 assembling as the middle layer and VP7 as third and most outer layer that forms a net-like structure adhering to VP6 [1] . For the attachment to the host cell, the capsids also contain VP4 spikes that protrude through VP7 pores and attach to the VP6 layer. To produce VLPs of RV, many expression vectors exist and several vaccine candidates have been proven to be effective against RV induced diarrhea or virus shedding in small animal models. Triple-layered VLPs containing VP2, VP6 and VP7 [9, 10] or double-layered VLPs consisting of VP2 and VP6 are examples of this approach [11] . Moreover, subunit vaccines produced of VP6 in eukaryotic cells [12, 13] or VP2 and VP6 expressed as soluble proteins in Escherichia coli and assembled into VLPs [14] showed protection against RV induced disease. However, the assembly of RV structural proteins into rotavirus like particles (RVLPs) requires the simultaneous expression of several recombinant RV genes in a single cell followed by multiple purification steps of these RVLPs. These are challenging steps in the production of a stable, mass-produced vaccine.