Leporipoviruses and Suipoxviruses

Members of the genera Leporipoxvirus and Suipoxvirus are poxviruses that infect a relatively narrow range of vertebrate host species, namely leporids and swine, respectively. All cause benign, self-limiting dermal infections in their native host species, except for myxoma virus, which causes a lethal disease called myxomatosis in the European rabbit. The replication of these large DNA viruses occurs in the cytoplasm of infected cells, similar to that of other poxviruses. All of these viruses express approximately 150 viral proteins, a substantial fraction of which mediate host tropism, pathogenesis, and immunomodulation. Myxoma virus virulence factors have been studied extensively, and have been shown to inhibit a variety of host immune molecules, such as tumor necrosis factor and interferon. Secreted anti-immune proteins from myxoma virus have shown efficacy as novel biotherapeutics to treat inflammatory diseases. The extreme pathogenicity of myxoma virus in European rabbits and its narrow host range were major factors in the decision to deliberately release myxoma virus in the attempt to control feral rabbit populations in Australia in the 1950s. Myxoma virus can also infect and kill human cancer cells and is under preclinical analysis as a novel oncolytic therapy to treat cancer.