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 sequence for the construction of the synthetic transgene cassettes of sWa[VP2/6/7] and sWa[VP2/6/7_V5] was derived from the human RV strain Wa (Dhaka isolate) and codon-optimized to human gene codon preference-verified by Genescript (Piscataway, NJ, USA) and synthesized by Biomatik (Cambridge, Ontario, Canada)-and predicted splice sites were removed [44] . The codon adaption index [45] was calculated using The European Molecular Biology Open Software Suite (EMBOSS) [46] . Herpes simplex virus type-1 amplicon plasmids were cloned using Gateway technology (Thermo Fisher Scientific, Waltham, MA, USA). The attB flanked synthetic gene expression cassettes (sWaRV) encoding the RV proteins VP2, VP6 and VP7, separated by internal ribosome entry sites (IRES) either with or without stop codon at the 5 end were generated by Biomatik. The Gateway B/P recombination between the attB flanked sWaRV cassette and the attP containing donor vector pDONR221 led to two entry plasmids containing the sWaRV gene expression cassette flanked by attL sites either with (pE_sWaRV_STOP) or without stop codon (pE_sWaRV). The amplicon plasmid used to produce sWa[VP2/6/7] vector stocks was generated by the Gateway L/R recombination between the attL sites containing entry vector pE_sWaRV_STOP and the attR sites containing destination vector pHSV-EYFP-RfC_C.1. For production of sWa[VP2/6/7_V5] amplicon vector stocks, pE_sWaRV was recombined with the destination vector pHSV-V5/His. The amplicon expression plasmids pHSV-EYFP-RfC_C.1 and pHSV-V5/His contain a transcription unit consisting of the HSV-1 immediate early (IE) 4/5 promoter and the SV40 polyadenylation signal as well the HSV-1 origin of replication (oriS) and the HSV-1 packaging/cleavage signal (pac) necessary for packaging into helper virus-free HSV-1 amplicon particles. The HSV-1 amplicon vectors encoding single structural RV proteins have been generated as follows: The single RV genes were amplified using the synthetic gene expression cassettes (sWaRV) as the template. The resulting PCR product was inserted into pHSV S [47] .