Comparative neurovirulence of selected vesicular stomatitis virus temperature-sensitive mutants of complementation groups II and III.

Weanling mice were inoculated intracerebrally with selected vesicular stomatitis virus (VSV) complementation group II and III temperature-sensitive (ts) mutants. Of the VSV ts mutants studied, only ts G32, a group III complementation mutant, appeared neurovirulent. Interestingly, neither the capacity to replicate in central nervous system tissue nor the ability to replicate in certain neurally derived continuous cell lines at semipermissive or nonpermissive temperatures appeared different among the VSV ts mutants employed. Finally, the pathological alterations in central nervous system tissue produced by VSV ts G32 were entirely different than those produced by G31 VSV ts in the group III mutant. These studies support the hypothesis that both the virological and neuropathological features produced by different VSV ts mutants are dependent upon the unique characteristics of each mutant, rather than upon a common biochemical defect shared by all members of a complementation group.