Fv4

Mice expressing the Fv-4 gene are resistant to infection by ecotropic murine leukemia viruses (MuLVs). TheFv-4 gene encodes an envelope (Env) protein whose putative receptor-binding domain resembles that of ecotropic MuLV Env protein. Resistance to ecotropic MuLVs appears to result from viral interference involving binding of the endogenously expressed Fv-4 env-encoded protein to the ecotropic receptor, although the immune system also plays a role in resistance.