FIG 7.

In vivo virulence and stability of rLCMV(IGR/S-Ssyn2) and rLCMV(IGR/S-Sggv). (A) Six-week-old C57BL/6J mice (4 mice/group) were infected (10³ FFU i.c.) with the rLCMV WT, rLCMV(IGR/S-Ssyn2), or rLCMV(IGR/S-Sggv) or left uninfected (naive). At 30 days p.i. (broken line), mice that survived were subjected to a lethal challenge with the rLCMV WT (10³ FFU i.c.). (B) Immunization with rLCMV(IGR/S-Ssyn2) or rLCMV(IGR/S-Sggv) induces protection against a lethal LCMV challenge. Six-week-old C57BL/6J mice (4 mice/group) were infected (10⁵ FFU i.p.) with the rLCMV WT, rLCMV(IGR/S-Ssyn2), or rLCMV(IGR/S-Sggv) or left uninfected (naive). At 28 days p.i. (broken line), mice were subjected to a lethal LCMV challenge (10³ FFU i.c.). (C) Stability of rLCMV(IGR/S-Ssyn2) and rLCMV(IGR/S-Sggv) in cultured cells. BHK-21 cells were infected with the rLCMV WT, rLCMV(IGR/S-Ssyn2), or rLCMV(IGR/S-Sggv) (MOI = 0.01). At 72 h p.i., the TCS was collected and virus titers 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.