Vaccinia, cowpox, and camelpox viruses encode soluble gamma interferon receptors with novel broad species specificity.


Soluble receptors for gamma interferon (IFN-gamma) are secreted from cells infected by 17 orthopoxviruses, including vaccinia, cowpox, rabbitpox, buffalopox, elephantpox, and camelpox viruses, representing three species (vaccinia, cowpox, and campelpox viruses). The B8R open reading frame of vaccinia virus strain Western Reserve, which has sequence similarity to the extracellular binding domain of cellular IFN-gamma receptors (IFN-gamma Rs), is shown to encode an IFN-gamma binding activity by expression in recombinant baculovirus. The soluble virus IFN-gamma Rs bind IFN-gamma and, by preventing its interaction with the cellular receptor, interfere with the antiviral effects induced by this cytokine. Interestingly, in contrast to cellular IFN-gamma Rs, which are highly species specific, the vaccinia, cowpox, and camelpox virus IFN-gamma Rs bind and inhibit the biological activity of human, bovine, and rat IFN-gamma but not mouse IFN-gamma. This unique broad species specificity of the IFN-gamma R would aid virus replication in different species and suggests that vaccinia, cowpox, and camelpox viruses may have evolved in several species, possibly including humans but excluding mice. Last, the conservation of an IFN-gamma R in orthopoxviruses emphasizes the importance of IFN-gamma in defense against poxvirus infections.

6 Figures and Tables

Citations per Year

1,693 Citations

Semantic Scholar estimates that this publication has 1,693 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Alcam1995VacciniaCA, title={Vaccinia, cowpox, and camelpox viruses encode soluble gamma interferon receptors with novel broad species specificity.}, author={Antonio Alcam{\'i} and Geoffrey L Smith}, journal={Journal of virology}, year={1995}, volume={69 8}, pages={4633-9} }