The antiviral potential of Mx2 protein remains unknown, because the Mx2 gen
e in commonly used strains of laboratory mice is nonfunctional. Our previou
s study showed that functional Mx2 protein in some feral-origin strains was
induced upon interferon treatment, was localized in the cytoplasm, and inh
ibited vesicular stomatitis virus replication. In the present study, we hav
e demonstrated chat the embryonic fibroblastic cells from a feral-origin st
rain (SPR) expressed 74 kDa Mx2 protein, which prevented the accumulation o
f viral transcripts and proteins of hantaviruses when the Mx2 gene was cons
titutively expressed in transfected Vero cells. Furthermore, the cells show
ed significantly lower titers of the virus than control cells. In contrast,
influenza virus replication was not affected by the expression of Mx2 prot
ein in the Vero cells.