FIG 4.

In vivo virulence and stability of the rLCMV(IGR/Ssyn-L) constructs. (A) Six-week-old C57BL/6J mice (4 mice/group) were infected (10³ FFU i.c.) with the rLCMV WT or an rLCMV(IGR/Ssyn-L) construct or left uninfected (naive). At 28 days p.i. (broken line), mice that survived were subjected to a lethal challenge with the rLCMV WT (10³ FFU i.c.). (B) Stability of the rLCMV(IGR/Ssyn-L) constructs. BHK-21 cells were infected with the rLCMV WT or an rLCMV(IGR/Ssyn-L) construct (MOI = 0.01). At 72 h p.i., the TCS was collected and the virus titers in the TCS were determined by an immunofocus assay. Fresh BHK-21 cell monolayers were infected with the TCS (MOI = 0.01); this process was serially repeated throughout P2 to P10. (Panel B includes data republished from reference 21.)