Abstracts (complete list) - Wissenschaft Online

Wibke Bayer, Simone Schimmer, Dennis Hoffmann, Ulf Dittmer, Oliver Wildner
Heterologous Prime-Boost Vaccination with Ad5 and Fiber
Chimeric Adenoviral Vectors Enhances Immune Protection
against Friend Virus
In a vaccination study against the Friend virus we evaluated an Ad5-based vector and a
fiber chimera expressing the fiber protein of Ad35 (Ad5F35). The Friend virus is an
immunosuppressive retroviral complex of spleen focus forming virus and Friend murine
leukemia virus (F-MuLV) that causes lethal erythroleukemia and splenomegaly in
susceptible adult mice. The FV is regarded as a useful model to elucidate basic
requirements for immune protection against retroviral infections.
We vaccinated C57BL/6 and the highly susceptible CB6F1 hybrid mice with Ad5 or
Ad5F35 vectors expressing F-MuLV env and gag proteins or with a prime-boost
combination of the two. After challenge infection, viral load in the spleens of C57BL/6
mice was reduced ~250-fold and was below the detection threshold in more than 50%
of the mice. In CB6F1 mice, on day 10 p.i. all vaccinated animals showed significantly
reduced viremia compared to unvaccinated control mice and the onset of disease was
significantly delayed. The prime-boost combination of the two Ad vectors resulted in
improved immune protection with significantly lower viremia compared to vaccination
with the individual vectors.